ALBERT

Beschreibung: Severe winter windstorms have become an increasingly common occurrence over recent decades in northwestern Europe. Although there exists considerable uncertainty, storminess is projected to increase in the future. On centennial to millennial time scales in particular, the mechanisms forcing storminess remain unsettled. We contribute to available palaeostorm records by reconstructing changes over the last 6670 years using a coastal peat sequence retrieved from the ombrotrophic Laphroaig bog on Islay, southwestern Scotland. We use a combination of ash content, grain size and elemental chemistry to identify periods of greater storminess, which are dated to 6605, 6290–6225, 5315–5085, 4505, 3900–3635, 3310–3130, 2920–2380, 2275–2190, 2005–1860, 1305–1090, 805–435 and 275 cal. a BP. Storm signals in the first half of the record up to ~3000 cal. a BP are mainly apparent in the grain‐size changes. Samples from this time period also have a different elemental signature than those later in the record. We speculate that this is due to receding sea levels and the consequent establishment of a new sand source in the form of dunes, which are still present today. The most significant events and strongest winds are found during the Iron Ages Cold Epoch (2645 cal. a BP), the transition into, and in the middle of, the Roman Ages Warm Period (2235 and 1965 cal. a BP) and early in the Little Ice Age (545 cal. a BP). The Laphroaig record generally agrees with regionally relevant peat palaeostorm records from Wales and the Outer Hebrides, although the relative importance of the different storm periods is not the same. In general, stormier periods are coeval with cold periods in the region as evidenced by parallels with increased ice‐rafted debris in the North Atlantic, highlighting that sea‐ice conditions could impact future storminess and storm track position.

Beschreibung: Holocene sedimentation patterns and environmental development in Aarhus Bay, Denmark, were reconstructed based on proxy analyses of two sediment cores (M1 and M5). Together, the two cores offer an opportunity to examine the history of the area during the past c. 10 000 years. The investigation consisted of acoustic mapping and multi‐proxy analyses of the sediment cores including macrofossils, sediment physical properties, sediment accumulation rates, grain size, and X‐ray fluorescence elemental counts. Radiocarbon dating of the two sediment successions revealed that they cover the periods c. 10 000–3700 cal. a BP (M1) and c. 4400 cal. a BP to the present (M5). The data from the M1 site indicate the presence of a near‐shore lake environment between c. 10 000 and 9000 cal. a BP. The first intrusion of marine water into the area is dated to c. 9000 cal. a BP. In the following c. 1300 years, brackish‐water conditions prevailed in the area characterized by a mixture of taxa from marine, limnic and terrestrial habitats, reflecting a shallow estuarine environment. Around 7700 cal. a BP full marine conditions were established, accompanied by a marked increase in sedimentation rates. The changes to full marine conditions and higher sedimentation rates are probably due to a significant sea‐level rise leading to flooding of former land areas and intensified erosion. A subsequent distinct decrease in sedimentation rates around 6350 cal. a BP is presumably linked to a previously documented sea‐level drop about this time. Continuous sedimentation ceased around 3700 cal. a BP in the central part of the bay, most probably due to a major sea‐level lowering involving widespread erosion. In the eastern and deeper part of the bay, sedimentation continued until today. Fully marine conditions prevailed there for at least the last 4400 years.

Beschreibung: 〈b〉Impacts of Horizontal Resolution and Air–Sea Flux Parameterization on the Intensity and Structure of simulated Typhoon Haiyan (2013)〈/b〉〈br〉 Mien-Tze Kueh, Wen-Mei Chen, Yang-Fan Sheng, Simon C. Lin, Tso-Ren Wu, Eric Yen, Yu-Lin Tsai, and Chuan-Yao Lin〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-333,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 In this study, we show that both the model horizontal resolution and air-sea flux parameterization can exert large influence on tropical cyclone intensity simulation but with different impacts on wind structures. We highlight the intensification and contraction of TC eyewall in response to the reduction of grid spacing. We also suggest that a well-developed eyewall is more conducive to the positive effect of flux formulas on TC development.

Beschreibung: Quaternary fluvial succession of the Jászság Basin (Hungary) was investigated, challenging the stratigraphical potential of ‘early postglacial fluvial magnetic susceptibility episodes' recognized earlier in the Körös Basin. Low field magnetic susceptibility (MS) was measured in four boreholes from the basin centre and margins, representing channel and flood‐plain environments. Statistical distributions of MS data contain significant sets of outliers, regardless of facies conditions. The downhole distribution of these outliers produces magnetic susceptibility cycles. Supported by magnetic susceptibility cycles, high‐resolution facies correlations were performed reflecting a steady palaeohydrographical situation in the area, with a trunk river to the southeast and tributaries to the northwest. SEM‐EDX data revealed that ferromagnetic grains are responsible for the outlying MS values. The heterogeneous association of magnetite indicates a catchment area with volcanic and metamorphic rocks, while the group of small (〈5 μm) magnetite octahedrons originated from nearby rhyolitic tuff formations. Magnetic grains were transported along channel belts, while small (〈2 μm) magnetic particles were floated onto flood‐plains attached to clays. Climatic control is indicated by peaks at ~100 ka frequency in spectra of MS records and was also detected in palaeosol development and in flood frequency using the spectra of measured colour (~100 ka) and logged resistivity (~100 ka, ~41 ka), respectively. The climate‐dependent MS signal traceable far into the basin in both channel and flood‐plain environments can be summoned when the Quaternary fluvial succession of the Pannonian Basin is investigated, assuming some sources of magnetite in the catchment areas. According to the concept of ‘fluvial magnetic susceptibility episodes’, the early postglacial escape and spreading of the magnetite fraction control the MS signal that can support mapping of the unconformable Quaternary base and building of high‐resolution models of aquifers.

Beschreibung: Nares Strait, a major connection between the Arctic Ocean and Baffin Bay, was blocked by coalescent Innuitian and Greenland ice sheets during the last glaciation. This paper focuses on the events and processes leading to the opening of the strait and the environmental response to establishment of the Arctic‐Atlantic throughflow. The study is based on sedimentological, mineralogical and foraminiferal analyses of radiocarbon‐dated cores 2001LSSL‐0014PC and TC from northern Baffin Bay. Radiocarbon dates on benthic foraminifera were calibrated with ΔR = 220±20 years. Basal compact pebbly mud is interpreted as a subglacial deposit formed by glacial overriding of unconsolidated marine sediments. It is overlain by ice‐proximal (red/grey laminated, ice‐proximal glaciomarine unit barren of foraminifera and containing 〉2 mm clasts interpreted as ice‐rafted debris) to ice‐distal (calcareous, grey pebbly mud with foraminifera indicative of a stratified water column with chilled Atlantic Water fauna and species associated with perennial and then seasonal sea ice cover) glacial marine sediment units. The age model indicates ice retreat into Smith Sound as early as c. 11.7 and as late as c. 11.2 cal. ka BP followed by progressively more distal glaciomarine conditions as the ice margin retreated toward the Kennedy Channel. We hypothesize that a distinct IRD layer deposited between 9.3 and 9 (9.4–8.9 1σ) cal. ka BP marks the break‐up of ice in Kennedy Channel resulting in the opening of Nares Strait as an Arctic‐Atlantic throughflow. Overlying foraminiferal assemblages indicate enhanced marine productivity consistent with entry of nutrient‐rich Arctic Surface Water. A pronounced rise in agglutinated foraminifers and sand‐sized diatoms, and loss of detrital calcite characterize the uppermost bioturbated mud, which was deposited after 4.8 (3.67–5.55 1σ) cal. ka BP. The timing of the transition is poorly resolved as it coincides with the slow sedimentation rates that ensued after the ice margins retreated onto land.

Beschreibung: Only a few chronological constraints on Lateglacial and Early Holocene glacier variability in the westernmost Alps have hitherto been obtained. In this paper, moraines of two palaeoglaciers in the southern Écrins massif were mapped. The chronology of the stabilization of selected moraines was established through the use of 10Be cosmic ray exposure (CRE) dating. The equilibrium line altitude (ELA) during moraine deposition was reconstructed assuming an accumulation area ratio (AAR) of 0.67. Ten pre‐Little Ice Age (LIA) ice‐marginal positions of the Rougnoux palaeoglacier were identified and seven of these have been dated. The 10Be CRE age of a boulder on the lowermost sampled moraine indicates that the landform may have been first formed during a period of stable glaciers at around 16.2±1.7 ka (kiloyears before AD 2017) or that the sampled boulder experienced pre‐exposure to secondary cosmic radiation. The moraine was re‐occupied or, alternatively, shaped somewhat before 12.2±0.6 ka when the ELA was lowered by 230 m relative to the LIA ELA. At least six periods of stable ice margins occurred thereafter when the ELA was 220–160 m lower than during the LIA. The innermost dated moraine stabilized at or before 10.9±0.7 ka. Three 10Be CRE ages from a moraine of the Prelles palaeoglacier indicate a period of stationary ice margins at or before 10.9±0.6 ka when the ELA was lowered by 160 m with respect to the end of the LIA. The presented 10Be CRE ages are in good agreement with those of moraines that have been attributed to the Egesen stadial. Assuming unchanged precipitation, summer temperature in the southern Écrins massif at ~12 ka must have been at least 2 °C lower relative to the LIA.

Beschreibung: Glacial lake outburst floods occurred frequently during the last deglaciation of the Laurentide Ice Sheet. Within the Interior Plains, these floods carved large spillway systems; however, due to a lack of abundant sediment, deposits within prairie spillways are rarely preserved. Here, we present geomorphic and sedimentary evidence and hydraulic modelling of the eastern Beaver River Spillway, formed by the catastrophic drainage of the ice‐dammed glacial Lake Algar, in north central Alberta. During this flood, coarse‐grained sediment eroded from local till formed large pendant bars. Within the first ~50 km of the spillway (Reach 1), pendant bars contain downstream orientated foresets overlain by horizontally bedded coarser gravels. The remaining pendant bars (Reach 2), present downflow of a moraine barrier, differ, comprising massive, matrix‐supported, inversely graded gravels capped by a boulder layer. We use a HEC‐GeoRAS/HEC‐RAS system in conjunction with palaeostage indicators to estimate the steady‐state water surface elevation. Modelling results show that peak discharge within Reach 1 of the eastern Beaver River Spillway was approximately 14 000–21 000 m3 s−1. For Reach 2, 30 km downstream, the peak discharge was estimated at 23 000–40 000 m3 s−1 (nbulked 18 000–26 000 m3 s−1). The downstream discharge increase, consistent with the sedimentary change in pendant bar deposits, is attributed to sediment bulking of the flood flow. This provides the opportunity to observe a range of flow conditions, and associated sedimentology, from a single flood event. The reconstructed flow conditions, coupled with lake volume estimates from the ponding above the moraine barrier suggest a minimum flow duration of 3–5 days.

Beschreibung: The azimuth of imbrication of minimum magnetic susceptibility axes in the youngest loess from Ukraine defines prevailing wind directions during aeolian sedimentation. It changes along the studied sections. These changes can be directly correlated with the fluctuations of the Fennoscandian Ice Sheet. The northern and northeastern winds noted in the loess succession separated by a period when southwestern to southeastern winds were predominant may be correlated with two main phases of ice‐sheet advance during the Last Glacial Maximum. The ice‐sheet advances towards the areas of loess deposition generated katabatic winds that influenced aeolian sedimentation in the periglacial zone. A period of relatively stable wind directions during a younger phase of the Last Glacial Maximum was interrupted by periods with more chaotic wind regime most probably caused by fluctuations of the Fennoscandian Ice Sheet during its retreat from the peri‐Baltic part of Europe. These intervals occur where initial soils developed. The distribution of anisotropy of magnetic susceptibility axes defined along the periglacial loess sections from central and eastern Europe can serve to constrain fluctuations of the Fennoscandian Ice Sheet.

Beschreibung: Understanding resource utilization and economic diversification amongst Holocene hunter‐gatherers in southern Brazil requires in‐depth taphonomic analysis of faunal assemblages. Three Early to Late Holocene archaeological sites (Garivaldino, Pilger and Sangão) in Rio Grande do Sul State, southern Brazil, revealed large assemblages of small mammal (˂1 kg) remains, composed mainly of rodents. To appreciate depositional processes of fauna in relation to human consumption, taphonomic attributes and processes were evaluated. The results indicated that the remains accumulated through different antemortem taphonomic pathways, apparently linked to the size and natural history of the species represented. The small‐ and medium‐sized (〈150 g) cricetid rodents (e.g. Pseudoryzomys simplex and Sooretamys angouya) were represented by a low proportion of teeth with lightly digestive corrosion suggesting that they were derived from the predatory activity of owls, possibly Tyto alba. In contrast, large‐sized cricetids (〉150 g; Kunsia tomentosus, Gyldenstolpia sp. and Holochilus sp.), and several caviomorph rodents with aggregated spatial distributions (Echimyidae (†Dicolpomys fossor, Phyllomys sp., †Clyomys riograndensis and †Euryzygomatomys mordax), Caviidae (Cavia sp.) and Ctenomyidae (Ctenomys sp.)) showed evidence of thermoalteration patterns and cut marks on bones, suggesting human exploitation. A postmortem depositional environment was deduced from dendritic and branched patterns of rootlet etching, apparent mostly at Garivaldino and Pilger. Polished areas and holes on bone surfaces, and impregnation of manganese showed moderate (Sangão) or low (Garivaldino and Pilger) incidence, pointing to water transport under moderate (Pilger) and low (Garivaldino and Sangão) energy over short distances. The results obtained here provide the first clear evidence of early human exploitation of small mammals in southern Brazil, suggesting a diversification of economies. In addition, as several of the recorded rodents are today regionally or biologically extinct, a preliminary discussion about the potential impact of humans on this process is provided.

Beschreibung: The Göschenertal (Göschenen valley) is the type locality of the so‐called Göschenen Cold Phases I (~3–2.3 ka) and II (~1.8–1.1 ka). According to earlier studies, these Late Holocene climatic cooling periods were characterized by changes in vegetation and pronounced glacier advances. As a peculiarity, the Göschenen Cold Phase I was thought to be connected to a local surge‐type advance of the Chelengletscher (Chelen glacier) – an exceptional event of unparalleled dimension in the European Alps. Based on cosmogenic 10Be exposure ages from moraine boulders, we investigated the local glacier chronology. In contrast to former research, moraines at different positions within the Göschenen valley (central Swiss Alps) have been dated to the Younger Dryas and the Early Holocene. This questions the applicability of palaeo‐Equilibrium Line Altitude (ELA) calculations for stadial attributions without additional numerical age constraints. Furthermore, we have found compelling evidence that the proposed non‐climatic glacier advance attributed to the Göschenen Cold Phase I did not occur. The present results, along with a reappraisal of the original study, question the scientific reliability and the glaciological definition of the Göschenen Cold Phases as glacier advances that clearly exceeded the Little Ice Age positions. While our data do not exclude potential changes in climate and vegetation, we nonetheless show that the Göschenen Cold Phases are not suitable as reference stadials in the system of Alpine Holocene glacier fluctuations.

Beschreibung: Pronounced climatic warming associated with the Late Weichselian Pleniglacial‐to‐Lateglacial transition caused considerable environmental changes throughout the former periglacial zones (in Europe ~53°–46°N). During permafrost degradation and subsequent ground subsidence (i.e. thermokarst processes), the landscape changed rapidly. In this study we investigated a flat mid‐altitude area in south Bohemia, Czech Republic, lying close to the southern limit of the Weichselian permafrost. We discovered palaeo‐lake basins with sedimentary infillings up to 11 m in depth. According to radiocarbon and palynostratigraphical dating, these basins were formed at the onset of the Late Pleniglacial‐to‐Lateglacial transition, whereas the smaller depressions were formed later. We suggest that the basins resulted from thermal and fluvio‐thermal erosion of the former permafrost and represent remnants of discontinuous gullies and possibly collapsed frost mounds (pingo/lithalsa scars). The formation of this a fossil thermokarst landscape was climatically driven and multiple phased, with the major phase during the climatic warming and wetting at the onset of GI‐1e (Bølling) and the minor phase during GI‐1c (Allerød). This study enhances knowledge of the palaeogeography of the former European periglacial zone by showing that Late Pleistocene thermokarst activity could have had a significant impact on the evolution of the landscape of at least some regions of central Europe along the southern limit of the continuous permafrost zone. The research also points to a similar history for the physical transformation of the landscape of the former European periglacial zone and current thermokarst landscapes and could be a valuable source of information with respect to the future transformation of the Arctic under conditions of ongoing global warming.

Beschreibung: Recent LiDAR surveys have revealed that on postglacially uplifting coasts of Estonia rhythmic coastal landforms (beach ridge sequences and foredune plains) occur to a considerable extent. We studied four of them to reveal age and periodicity in these multiple ridge systems and discussed their genesis in the Subatlantic (semi‐continental) conditions of the Baltic Sea area. Using recent models of Fennoscandian uplift due to glacial isostatic adjustment (GIA), we constructed Holocene apparent sea level curves for the study sites at Õngu, Mänspe, Haldi and Keibu; converted distance–height shore profiles into time series (including corrections on shore profile non‐linearity and variations in GIA‐eustasy balance); and analysed the patterns using spectral analysis. It was suggested that due to non‐tidal conditions, relatively low‐energy hydrodynamic forcing and small aeolian contribution, the ridges mark ancient shorelines. They are relatively modest in height (mostly 0.2–1 m), form regular and extensive (up to 150 ridges) patterns, and date back to ~9000 years before present. We studied 〈5‐ka‐old sections. The mean ridge spacing varied, depending also on coastal slope, between 21 and 39 m. Both simple counting and spectral analysis involved some specific limitations, yet the estimates for typical spacing were alike, at 32 (±5) years. The regular nature of the low‐ridge patterns originated from relative sea level lowering and gradual sediment accretion/erosion. However, the progradation was rather uplift‐ than accretion‐driven and the stepwise process in ridge formation was probably not autocyclic. It was governed or modulated by quasi‐periodic 25–40 year cyclicity in local wave forcing, relative sea level variations and wind conditions. Being most likely connected to the North Atlantic Oscillation, the quasi‐regular, decadal‐scale, similarly phased variations may magnify each other's effect on the westerly exposed coasts of Estonia. Additionally, some other (e.g. event‐driven) mechanisms may also be present.

Beschreibung: The aim of this contribution is to describe a femur (MCRS 199) assigned to Nothrotheriops sp. from the Late Pleistocene of Santa Fe Province (Argentina), and discuss the implications of this find in the context of the dispersal of ground sloths during the Great American Biotic Interchange. The specimen MCRS 199 is smaller than the femora referred to the North American species Nothrotheriops texanus and Nothrotheriops shastensis but shares several features with these species: (i) shape and position of the greater trochanter, (ii) development of the lesser trochanter, (iii) presence of connection between the third trochanter and the ectepicondyle, (iv) distal third of the femur wider, with ML/DW index of 1.93, and (v) location and relationship of the distal condyles. These similarities allow us to assign MCRS 199 to Nothrotheriops sp. The record of Nothrotheriops sp. from Santa Fe Province chronologically coincides with the earliest records of Nothrotheriops shastensis suggesting a broad geographical distribution of Nothrotheriops during the Late Pleistocene, ranging from 33–36°N (e.g. states of California and Arizona, USA) to 31°S (northern Salado River, Santa Fe Province, Argentina). Thus, Nothrotheriops have dispersed from North America (where Nothrotheriops has early records, Calabrian–Middle Pleistocene) to South America where localities bearing Nothrotheriops are Late Pleistocene in age. In addition, once in South America and probably during the Middle Pleistocene, Nothrotheriops probably gave rise to its sister taxon, Nothrotherium, with records from the Middle Pleistocene (e.g. 223 ka BP, northeastern Brazil) to the Late Pleistocene (e.g. 15 ka BP).

Beschreibung: Prehistoric settlements are usually perceived as being in opposition to the natural development of the landscape. Indeed, for woodland snail assemblages in anthropogenic landscapes in central Europe, considerable impoverishment is typical. However, it remains unclear whether this has been caused by humans only or also by climate effects. From an archaeological point of view, the Moravian Karst is one of the classic prehistorical locations in central Europe, but with a more humid climate than the previously studied anthropogenic areas. To learn more about coexistence of humans and natural forests during the Lateglacial and Holocene, we analysed 11 mollusc successions covering this entire area, a unique data set for such a relatively small area. These mollusc successions show several specific features compared to the standard development known from other mid‐European areas. One is that although the Moravian Karst is not far from the Western Carpathians, Carpathian species appeared relatively late, only during the second half of the Holocene climatic optimum. Similarly, some western European and Alpine elements appeared later than expected. In contrast to this, however, a number of forest species with central European range appeared relatively early during the Lateglacial or Early Holocene. Two even survived the Last Glacial Maximum in the Moravian Karst. This would suggest an early occurrence of forest patches in a mosaic landscape. Humans have apparently inhabited this area since the Lateglacial amongst islands of forests, which later changed during the Boreal and then the climatic optimum into humid canopy forests. Thus, a mosaic of anthropogenic and natural habitats persisting in close vicinity was possible in rugged and humid landscapes practically until the Industrial Revolution.

Beschreibung: Boreas, Volume 48, Issue 2, Page i-iv, April 2019.

Beschreibung: Regional‐scale, high‐resolution terrain data permit the study of landforms across south‐central Ontario, where the bed of the former Laurentide Ice Sheet is well exposed and passes downflow from irregular topography on Precambrian Shield highlands to flat‐lying Palaeozoic carbonate bedrock, and thick (50 to 〉200 m) unconsolidated sediment substrates. Rock drumlins and megagrooves are eroded into bedrock and mega‐scale glacial lineations (MSGL) occur on patchy streamlined till residuals in the Algonquin Highlands. Downflow, MSGL pass into juxtaposed rock and drift drumlins on Palaeozoic bedrock and predominantly till‐cored drumlins in areas of thick drift. The Lake Simcoe Moraines, now traceable for more than 80 km across the Peterborough drumlin field (PDF), form a distinct morphological boundary: downflow of the moraine system, drumlins are larger, broader and show no indication of subsequent reworking by the ice, whereas upflow of the moraines, a higher degree of complexity in bedform pattern and morphology is distinguished. Discrete radial and/or cross‐cutting flowset terminate at subtle till‐cored moraine ridges downflow of local topographic lows, indicating multiple phases of late‐stage ice flow with strong local topographic steering. More regional‐scale flow switching is evident as NW‐orientated bedforms modify drumlins south of the Oak Ridges Moraine, and radial flowset emanate from areas within the St. Lawrence and Ottawa River valleys. Most of the drumlins in the PDF formed during an early, regional drumlinization phase of NE–SW flow that followed the deposition of a thick regional till sheet. These were subsequently modified by local‐scale, topographically controlled flows that terminate at till‐cored moraines, providing evidence that the superimposed bedforms record dynamic ice (re)advances throughout the deglaciation of south‐central Ontario. The patterns and relationships of glacial landform distribution and characteristics in south‐central Ontario hold significance for many modern and palaeo‐ice sheets, where similar downflow changes in bed topography and substrate lithology are observed.

Beschreibung: Ten monitoring sites were established in 1986 near the Scottbreen and Renardbreen glaciers (Bellsund, Spitsbergen) in order to determine the rates of gelifluction on raised marine terraces and on talus cones, accumulation on talus cones, and movement of the protalus rampart. The measurements were performed in 1987, 2007 and 2016. The results obtained revealed a very slow rate of changes on the surface of the analysed area. During 30 years, only one out of 84 points where the gelifluction rate was measured was displaced by 15 cm down‐slope. The maximal annual and average gelifluction rates were calculated at 0.5 cm and 0.18 cm a−1, respectively. Several measurement points did not change their position over the observation period. As shown by the observations, the gelifluction rate largely does not depend on slope inclination. Studies of talus cones allowed the level of cone increment to be determined as 314.3 kg of scree per square metre. Analysis of factors influencing the rate of mass movement allowed for correlation of the small‐scale gelifluction movement at the analysed sites with the general trends of climate warming. In this part of the Arctic, these trends are manifested by soil desiccation. It appears that slope processes depend on very local topoclimatic factors. Analysis of the obtained data with regard to palaeogeographical and climatic investigations suggests that the ice segregation forms on raised marine terraces developed during the last Holocene cooling, i.e. the Little Ice Age.

Beschreibung: Boreas, Volume 48, Issue 2, Page 269-272, April 2019.

Beschreibung: Here we investigate, for the first time, the use of optically stimulated luminescence (OSL) for dating cobbles from the body of successive beach ridges and compare cobble surface‐derived ages to standard quartz OSL ages from sand. Between four and eight cobbles and sand samples (age control) were dated with the luminescence method, taken from the modern beach and from beach ridges on the south and north extremes of a prograding spit on the westernmost coast of Lolland, Denmark. Luminescence‐depth profiles perpendicular to the surfaces of the cobbles show that the feldspar infrared signals stimulated at 50 °C were fully reset to various depths into the cobbles prior to final deposition; as a result, the equivalent doses determined from close to the surface of such cobbles can be used to calculate burial ages. Beach‐ridge burial ages given by the average of ages of individual cobbles taken from the same site are consistent, within errors, with the ages derived from the sand samples. Cobble‐ and sand‐derived ages show that the southernmost beach ridge at Albuen was formed around 2 ka ago, indicating that this sandy spit is younger than other coastal systems in Denmark. The agreement between ages derived from clasts and from standard quartz OSL in this study confirms that, even in the absence of sandy sediments, we can reliably date sites using OSL by targeting larger clasts. In addition, the record of prior light exposure contained in the shape of the cobbles’ luminescence‐depth profile removes one of the major uncertainties (i.e. the degree of signal reset prior to burial) in the luminescence dating of high latitude sites.

Beschreibung: This article reports on an Early Saalian proglacial lake formed between the Scandinavian Ice Sheet and the front of the Sudeten Mountains, Poland. Sediments investigated at Mysłów point to a transition from glacifluvial to glaciolacustrine environments. The bulk of the sediments was deposited in deep‐water Gilbert‐type deltas (A–E complexes). A delta plain (topset) gradually passes into a subaerial plateau and then a clastic shoreline and the subaquatic slope of a prograding delta (foreset). The glaciolacustrine lithofacies represent a number of lake‐basin environments, from marginal subaqueous slopes to distal parts of a subaqueous fan. Glaciolacustrine and glaciodeltaic deposits locally reach ˜50–70 m in thickness. Analyses of A–E complexes indicate that the lake existed for more than 130 years and that its origin and evolution were closely connected with the ice front. This case study records lake sedimentation at an ice‐sheet margin with cohesionless gravity flows, turbidity currents, debris‐avalanching and, to a much lesser degree, parapelagic suspension fall‐out and ice‐raft dumping. In the initial stage, the lake extended more than 10 km to the south, and the deposition was relatively slow. In the second stage, recession of the ice sheet caused rapid growth of a delta. The third and ultimate stage coincided with the final glacial recession, with rapid deposition occurring only on the lake bottom. The model of the glaciolacustrine environment presented here may also be applicable to many other proglacial lakes in mountain areas.

Beschreibung: In earlier studies, the topography and melting dynamics of ice‐cored ridges within marginal zones of the Pleistocene ice sheets were routinely reconstructed based only on conceptual and qualitative models supported by geomorphological, sedimentological and palaeogeographical studies. Here, a novel approach based on detailed structural analysis of two collapse structures affecting Pleistocene kame deposits is presented. The high regularity of the geometry of synclines and related strain fields as well as the patterns of subsidence of the folded strata are all interpreted as evidence of topography of ice‐cored ridges and their melting dynamics. The topography is described in terms of elongation, orientation and cross‐sectional shape of ice‐cored ridges. In turn, the melting dynamics are assessed based on a semi‐quantitative model of different relative rates of backwasting and downwasting. The topography of ice‐cored ridges, derived independently from the morphology of the related supraglacial landforms, is interpreted as an effect of ablation controlled by debris bands within parent ice. The reconstructed ice‐cored ridges are considered to represent the second‐order topographic features within a wide ice‐cored depression. The sedimentary evolution of collapse structures expressed as migration of their hinges/depocentres provides new semi‐quantitative insight into melting dynamics of ice showing the predominance of backwasting over downwasting. This evolution concerns the final stage of de‐icing, which was probably preceded by lowering of the ice‐cored topography and progressive formation of the ice‐cored ridges.

Beschreibung: This article presents a new comprehensive assessment of the Holocene hydrological variability of Lake Ladoga, northwest Russia. The reconstruction is based on oxygen isotopes of lacustrine diatom silica (δ18Odiatom) preserved in sediment core Co 1309, and is complemented by a diatom assemblage analysis and a survey of modern isotope hydrology. The data indicate that Lake Ladoga has existed as a freshwater reservoir since at least 10.8 cal. ka BP. The δ18Odiatom values range from +29.8 to +35.0‰, and relatively higher δ18Odiatom values around +34.7‰ between c. 7.1 and 5.7 cal. ka BP are considered to reflect the Holocene Thermal Maximum. A continuous depletion in δ18Odiatom since c. 6.1 cal. ka BP accelerates after c. 4 cal. ka BP, indicating Middle to Late Holocene cooling that culminates during the interval 0.8–0.2 cal. ka BP, corresponding to the Little Ice Age. Lake‐level rises result in lower δ18Odiatom values, whereas lower lake levels cause higher δ18Odiatom values. The diatom isotope record gives an indication for a rather early opening of the Neva River outflow at c. 4.4–4.0 cal. ka BP. Generally, overall high δ18Odiatom values around +33.5‰ characterize a persistent evaporative lake system throughout the Holocene. As the Lake Ladoga δ18Odiatom record is roughly in line with the 60°N summer insolation, a linkage to broader‐scale climate change is likely.

Beschreibung: Seismostratigraphical studies of the 11.8‐km2‐large and ~140‐m‐deep Lake Bolshoye Shchuchye, Polar Ural Mountains, reveal up to 160‐m‐thick acoustically laminated sediments in the lake basin. Using a dense grid of seismic lines, the spatial and temporal distributions of the sedimentary history have been reconstructed. Three regional seismic horizons have been identified and correlated with the well‐dated 24‐m‐long sediment core retrieved from the lake. Isopach maps constructed from the seismic data show four phases of sedimentation. A contour map of the deepest regional seismic reflector represents the earliest hemipelagic sedimentation in the lake. Three contour maps represent time intervals covering the last 23 cal. ka based on the well‐dated core stratigraphy from the lake. The detailed time constraints on the upper stratigraphical units in the lake allow calculation of the lake's development in terms of sediment fluxes and the denudation rates from the Last Glacial Maximum (LGM) to the present. The sedimentation in Lake Bolshoye Shchuchye has been dominated by hemipelagic processes during at least the last 24 cal. ka BP only locally interrupted by delta progradation and slope processes. A major shift in the sediment accumulation at c. 18.7 cal. ka BP is interpreted to mark the end of the local glacial maximum, greatly reduced denudation and the onset of the deglaciation period; this also demonstrates how fast the glaciers melted and possibly disappeared at the end of the LGM. The denudation rate during the Holocene is only a fifth of the LGM rate. The age of the oldest stratified sediments in Lake Bolshoye Shchuchye is not well constrained, but estimated as c. 50–60 ka.

Beschreibung: To assess the reliability of arboreal phytoliths for differentiating vegetation types in temperate forest regions, we systematically analysed arboreal leaf phytoliths from 72 arboreal plants and 49 modern soils from three forest types in northeast China. The arboreal leaf phytolith production and morphotypes were highly variable between species. The arboreal leaf phytolith assemblages could clearly distinguish between broadleaf and coniferous species, but they were much less successful in differentiating broadleaved trees into subtaxa. Coniferous leaf morphotypes were successfully used to differentiate coniferous trees into families and subtaxa, especially in the Pinaceae. Two diagnostic broadleaved and six coniferous phytolith morphotypes were recognized within the modern soil beneath forest ecosystems. These arboreal phytoliths comprised up to 10–15% of the total soil phytoliths, and were dominated by coniferous types. Arboreal phytolith concentrations and phytolith assemblages in the soils fluctuated substantially amongst the three forest types. Soil arboreal phytolith assemblages were successfully used to differentiate samples from Larix mixed forest, broadleaf forest and Pinus koraiensis mixed forest. In addition, the arboreal index quantitatively distinguished the three forest types, with B/BE values 〈0.4 for Larix mixed forest samples, values from 0.4 to 0.6 for broadleaf forest samples, and values from 0.6 to 0.9 for P. koraiensis mixed forest. Thus, our surface soil arboreal phytolith assemblages and arboreal index are a useful reference for differentiating forest ecotypes, and they also provide reliable analogues for arboreal phytoliths from palaeoecological contexts in temperate forest regions.

Beschreibung: A multi‐channel, high‐resolution seismic reflection survey using a Micro‐GI airgun was carried out in the framework of the Russian‐German project PLOT (Paleolimnological Transect) on Lake Levinson‐Lessing, Taymyr Peninsula, in 2016. In total, ~70 km of seismic reflection profiles revealed in unprecedented detail the glacial and postglacial sedimentary infill of the lake basin. Five main seismic units have been recognized and interpreted as glacial (Unit V), subglacial and proglacial (Unit IV), marine (Unit III), fluvial‐lacustrine (Unit II) and lacustrine (Unit I) sediments. Of particular significance are imbricated, south‐orientated structures present in the southernmost part of the lake basin within Unit V and a large topographic ridge recognized in front of those structures. We interpret these structures as push moraines and an end moraine, respectively, left by the glacier after its retreat. The depositional pattern of the units above the moraines documents past lake‐level fluctuations. We interpret Unit IV, Unit III and Unit I as highstand deposits, and Unit II as lowstand deposits. Gas‐charged sediments dominate the northern part of the lake basin, whilst they occur only sporadically and in limited spatial extent in the central and southern parts of the lake. In the latter areas, the seismic and echo‐sounder data suggest recent tectonic activity. Our study contributes to the reconstruction of environmental conditions in the Taymyr Peninsula directly following the Early Weichselian deglaciation and shows that deep tectonic lake basins affected by several glaciations can preserve important palaeoenvironmental records, which contributes significantly to our understanding of palaeoenvironmental changes in the Taymyr Peninsula and the central Russian Arctic.

Beschreibung: Calcareous root tubes (CRTs) contain abundant information about palaeoenvironmental conditions and have been used for palaeoenvironmental studies in the desert hinterlands of arid regions. However, as subclasses of CRTs, calcareous sheaths and rhizocretions are formed by different processes, and it remains unclear whether these differences produce variations in the chemical element composition. Furthermore, it remains uncertain whether variations in chemical element concentrations amongst different subclasses of the CRTs can affect palaeoenvironmental reconstructions. In this study, we collected 54 CRT samples from the Tengger Desert of northwestern China. All samples were dated by accelerator mass spectrometry (AMS) 14C dating, and the chemical element composition and concentration differences of the two CRT subclasses were determined using X‐ray fluorescence spectrometry. The CRT samples were dated to the Holocene. The calcareous sheath and rhizocretion samples contained varying concentrations of the same chemical elements. The rhizocretions had high concentrations of mobile elements (Ca, Mg and Sr) and P, whereas the calcareous sheaths had high concentrations of stable elements, including Al, Si, Ti, Zr, Rb and Ba. These differences were due to the different formation processes of the two subclasses of CRTs. Moreover, the Sr/Ca and Mg/Ca ratios in the calcareous sheaths were higher than those in the rhizocretions from the same period, but these ratio differences had little effect on palaeo‐effective moisture reconstructions at the millennial scale during the Holocene. The reconstructions were not influenced by the various CRT subclasses. The Holocene millennial‐scale moisture changes in the Tengger Desert revealed by the Sr/Ca and Mg/Ca ratios showed that there was an arid period during the Early Holocene, a humid period during the Middle Holocene and a humid to arid period during the Late Holocene.

Beschreibung: Cave bears (Ursus spelaeus) are an iconic component of the European late Quaternary Ice Age megafauna. Recent demographic analyses based on cave bear mtDNA sequences and refined radiocarbon dating indicate that cave bear population size and genetic diversity started to decline some 50 kilo years ago (kya). Hence, neither the coldest phase of the last glaciation (started some 24 kya), nor the colonization of Europe by Palaeolithic hunters (started some 45 kya) coincides with the beginning of population decline. Here, we reconstructed cave bear climatic niche evolution through time. Then, we performed spatially explicit population viability analyses to assess cave bear demographics through time in response to climatic changes, human effects on bear survival and their combination. We found that climate change was responsible for a 10‐fold decrease in cave bear population size after 40 kya. However, climate change on its own could not explain U. spelaeus extinction at 24 kya. Additional negative effects consistent with human population expansion are required to explain both U. spelaeus' retreat from eastern Europe since 40 kya and its final extinction.

Beschreibung: The study presents the first description and analysis of ostracod records from three sites cored in different parts of the Baltic Sea during the IODP Expedition 347, Baltic Sea Paleoenvironment. Our data present the first high‐resolution ostracod records from the Late Weichselian and Holocene sediments collected across the Baltic Sea Basin. Using published data on modern ostracod species ecology of the Baltic Sea, we were able to provide ostracod‐based palaeoreconstructions of the history of the region. The stratigraphical framework for the sites is based on radiocarbon‐based age models. The three studied sites reveal different ostracod assemblage successions that reflect environmental changes in the study area. Site M0060, located in the Kattegat area, contains the oldest ostracod assemblages that document a marine environment with very high sedimentation rates during the most recent deglaciation. Between ~13 000 and 7500 cal. a BP a modern‐like near‐shore environment developed. Site M0059 in the southwestern Baltic Sea, Little Belt area, contains assemblages reflecting the transition from a freshwater lake to the brackish Littorina Sea between ~7500 and 7300 cal. a BP. Site M0063 is the deepest location in the central Baltic, Landsort Deep, and yielded very limited ostracod data, but comparison with our organic carbon data allowed us to distinguish the Yoldia Sea, Ancylus Lake and Littorina Sea intervals. The ostracod record correlates well with the organic carbon record with alternation between periods of hypoxia and periods of low oxygen that still supported ostracods.

Beschreibung: Rock‐Eval pyrolysis provides a quick, relatively inexpensive means of characterizing organic‐rich strata, and has been used for decades to understand global petroleum systems. Although designed to characterize ancient kerogens, pyrolysis is increasingly being used to understand Holocene systems as well. The ability of this technique to distinguish between types of preserved organic matter is useful in characterizing climatic evolution, particularly in systems sensitive to climatic fluctuation such as isolated fens and bogs. Cores collected from the Tokewanna and Garden Basin Cattail fens in central/eastern Utah exhibit variability of organic source, with the mixture of terrestrial and algal sources varying through time, as shown through the hydrogen index (HI) and oxygen index pyrolysis parameters. A sediment core was collected at each fen, and 176 samples were taken from the cores at 6‐cm intervals. Total organic carbon (TOC) for all samples ranges from 1.3 to 44.2%, with an average of 18.2% TOC. Samples range from 84 to 687 HI, equivalent to Type I (lacustrine algal) to Type III (terrestrial) organic material (OM). Variability in HI response represents mixing of the two OM sources, and the relative amount of aqueous organic input can be estimated through time based on age‐calibrated HI curves at the two sites. The balance of organic input serves as an accurate, high‐resolution proxy for climate, and calibration with palynological data near both sites confirms patterns shown by pyrolysis, showing the utility of this method in quickly, affordably and accurately characterizing Holocene sediments for use in understanding palaeoclimate.

Beschreibung: The new pollen record from the upper 12.75 m of a sediment core obtained in Lake Ladoga documents regional vegetation and climate changes in northwestern Russia over the last 13.9 cal. ka. The Lateglacial chronostratigraphy is based on varve chronology, while the Holocene stratigraphy is based on AMS 14C and OSL dates, supported by comparison with regional pollen records. During the Lateglacial (c. 13.9–11.2 cal. ka BP), the Lake Ladoga region experienced several climatic fluctuations as reflected in vegetation changes. Shrub and grass communities dominated between c. 13.9 and 13.2 cal. ka BP. The increase in Picea pollen at c. 13.2 cal. ka BP probably reflects the appearance of spruce in the southern Ladoga region at the beginning of the Allerød interstadial. After c. 12.6 cal. ka BP, the Younger Dryas cooling caused a significant decrease in spruce and increase in Artemisia with other herbs, indicative of tundra‐ and steppe‐like vegetation. A sharp transition from tundra‐steppe habitats to sparse birch forests characterizes the onset of Holocene warming c. 11.2 cal. ka BP. Pine forests dominated in the region from c. 9.0 to 8.1 cal. ka BP. The most favourable climatic conditions for deciduous broad‐leaved taxa existed between c. 8.1 and 5.5 cal. ka BP. Alder experiences an abrupt increase in the local vegetation c. 7.8 cal. ka BP. The decrease in tree pollen taxa (especially Picea) and the increase in herbs (mainly Poaceae) probably reflect human activity during the last 2.2 cal. ka. Pine forests have dominated the region since that time. Secale and other Cerealia pollen as well as ruderal herbs are permanently recorded since c. 0.8 cal. ka BP.

Beschreibung: We present a high‐resolution reconstruction of the vegetation and climate dynamics during the penultimate interglacial, corresponding with Marine Isotope Stage (MIS) 7, based on detailed palynological analyses of lacustrine sediments from Lake El'gygytgyn, northeastern Siberia. The analysed sediments were deposited between 246 and 181 ka ago (late MIS 8 to early MIS 6.6). The interglacial vegetation was characterized by herb and shrub (mainly alder and birch) dominated plant communities. Pollen‐based biome reconstruction shows a dominance of the tundra (TUND) biome, thus indicating rather open vegetation. Warmer intervals (MIS 7.5, 7.3 and 7.1) were marked by an increase in the cold deciduous forest (CLDE) biome scores and a synchronous decrease in the cold steppe (STEP) biome scores. The thermal maximum occurred during MIS 7.1, as indicated by the highest CLDE biome scores occurring in this period, and lasted ~10 ka, possibly favoured by the high precession‐related summer insolation and the legacy of the preceding mild and dry stadial (MIS 7.2). In contrast, MIS 7.3 and 7.5 were characterized by shorter durations (~4 ka) and lower summer temperatures. The preceding cold glacial and stadial (MIS 8 and 7.4, respectively) might have led to an extensive distribution of permafrost that hindered vegetation development during the subsequent warm intervals. MIS 7.4 and 6.6 were cold and wet, probably triggered by low obliquity values and coevally low precession‐related summer insolation. As a result, these periods were marked by significantly reduced summer temperatures and an enhanced snow‐ice albedo feedback. The obtained reconstructions provide potential scenarios for future climate changes and allow a better understanding of the relationship between vegetation, climate and external/internal forcings in the high latitudes.

Beschreibung: By applying advanced spatial statistical methods, spatial taphonomy complements the traditional taphonomic approach and enhances our understanding of biostratinomic and diagenetic processes. In this study, we elaborate on a specific aspect – spatial anisotropy – of taphonomic processes. We aim to unravel the taphonomic history of the Early Pleistocene vertebrate assemblage of Tsiotra Vryssi (Mygdonia Basin, Greece). Circular statistics are used for the fabric analysis of elongated elements; geostatistics (directional variograms), wavelet and point pattern analyses are applied for detecting anisotropy at the assemblage level. The anisotropy of magnetic susceptibility (AMS) of sedimentary magnetic minerals is also investigated. The results, integrated with preliminary remarks about the differential preservation of skeletal elements, sedimentological and micromorphological observations, suggest multiple dispersion events and recurrent spatial re‐arrangement of a lag, (peri)autochthonous assemblage, consistent with the cyclical lateral switching of a braided fluvial system. Furthermore, this study offers a contribution to the building of a spatial taphonomic referential framework for the interpretation of other fossil vertebrate assemblages, including archaeo‐palaeontological ones.

Beschreibung: 〈b〉The Lituya Bay landslide-generated mega-tsunami – numerical simulation and sensitivity analysis〈/b〉〈br〉 José Manuel González-Vida, Jorge Macías, Manuel Jesús Castro, Carlos Sánchez-Linares, Marc de la Asunción, Sergio Ortega-Acosta, and Diego Arcas〈br〉 Nat. Hazards Earth Syst. Sci., 19, 369-388, https://doi.org/10.5194/nhess-19-369-2019, 2019〈br〉 In 1958, at Lituya Bay in Alaska, the largest tsunami wave ever recorded took place. Since then, its numerical simulation has been a challenge and no numerical model has been able to reproduce, in the real geometry of the bay, the more than 200 m wave and the extreme run-up (climbing of the water up on land) of 524 m. The aim of our research, in the framework of a collaboration between the University of Malága (Spain) and NOAA (US), was to fulfil this gap at the same time as verifying our model.

Beschreibung: 〈b〉Reanalysis of the 1761 transatlantic tsunami〈/b〉〈br〉 Martin Wronna, Maria Ana Baptista, and Jorge Miguel Miranda〈br〉 Nat. Hazards Earth Syst. Sci., 19, 337-352, https://doi.org/10.5194/nhess-19-337-2019, 2019〈br〉 We investigate the source of the 1761 earthquake and tsunami. The reanalysis of the tsunami travel times agrees with an earlier suggested source area. We check the geodynamic setting of the area and place a fault as an extension to an identified fault and use numerical modelling to distinguish between two candidate sources. One of our theories is compatible with the geodynamic setting and reproduces well the observed tsunami parameters.

Beschreibung: 〈b〉Landslides Data Assimilation Using TRIGRS Based on Particle Filtering〈/b〉〈br〉 Changhu Xue, Guigen Nie, Jie Dong, Shuguang Wu, Jing Wang, Xiuzhen Li, and Xiaogang Zhang〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-16,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 This paper provides an approach to apply data assimilation method to stability analysis and parameter update and feedback in a landslide. The experiment is implemented by particle filter algorithm. The result FS sequence of TRIGRS output decreases continuously with time and the assimilation can effectively correct the FS of the model output. The RMSD of FS indicates the assimilation results can correct the estimation of TRIGRS output close to actual observations.

Beschreibung: 〈b〉The impact of topography on seismic amplification during the 2005 Kashmir Earthquake〈/b〉〈br〉 Saad Khan, Mark van der Meijde, Harald van der Werff, and Muhammad Shafique〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-13,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 In 2005, northern Pakistan was hit by a 7.6 magnitude earthquake. The epicenter was located near capital of the Pakistani territory of Azad Kashmir and also affected Pakistan's Khyber Pakhtunkhwa province and Indian-administered Jammu and Kashmir region. It was believed that the local topography might have significant role in direct and indirect damage in the region. This study shows that the local topography played significant role in the earthquake induced damage in the region.

Beschreibung: 〈b〉The impact of topography on seismic amplification during the 2005 Kashmir Earthquake〈/b〉〈br〉 Saad Khan, Mark van der Meijde, Harald van der Werff, and Muhammad Shafique〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-13,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 In 2005, northern Pakistan was hit by a 7.6 magnitude earthquake. The epicenter was located near capital of the Pakistani territory of Azad Kashmir and also affected Pakistan's Khyber Pakhtunkhwa province and Indian-administered Jammu and Kashmir region. It was believed that the local topography might have significant role in direct and indirect damage in the region. This study shows that the local topography played significant role in the earthquake induced damage in the region.

Beschreibung: 〈b〉Brief communication: Remotely piloted aircraft systems for rapid emergency response: road exposure to rockfall in Villanova di Accumoli (central Italy)〈/b〉〈br〉 Michele Santangelo, Massimiliano Alvioli, Marco Baldo, Mauro Cardinali, Daniele Giordan, Fausto Guzzetti, Ivan Marchesini, and Paola Reichenbach〈br〉 Nat. Hazards Earth Syst. Sci., 19, 325-335, https://doi.org/10.5194/nhess-19-325-2019, 2019〈br〉 The paper discusses the use of rockfall modelling software and photogrammetry applied to images acquired by RPAS to provide support to civil protection agencies during emergency response. The paper focuses on a procedure that was applied to define the residual rockfall risk for a road that was hit by an earthquake-triggered rockfall that occurred during the seismic sequence that hit central Italy on 24 August 2016. Road reopening conditions were decided based on the results of this study.

Beschreibung: 〈b〉Brief communication: Remotely piloted aircraft systems for rapid emergency response: road exposure to rockfall in Villanova di Accumoli (central Italy)〈/b〉〈br〉 Michele Santangelo, Massimiliano Alvioli, Marco Baldo, Mauro Cardinali, Daniele Giordan, Fausto Guzzetti, Ivan Marchesini, and Paola Reichenbach〈br〉 Nat. Hazards Earth Syst. Sci., 19, 325-335, https://doi.org/10.5194/nhess-19-325-2019, 2019〈br〉 The paper discusses the use of rockfall modelling software and photogrammetry applied to images acquired by RPAS to provide support to civil protection agencies during emergency response. The paper focuses on a procedure that was applied to define the residual rockfall risk for a road that was hit by an earthquake-triggered rockfall that occurred during the seismic sequence that hit central Italy on 24 August 2016. Road reopening conditions were decided based on the results of this study.

Beschreibung: 〈b〉Study on Site Amplification Factor Correction for Earthquake Early Warning System〈/b〉〈br〉 Quancai Xie, Qiang Ma, Jingfa Zhang, and Haiying Yu〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-400,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 This paper make deep evluation of a new mthod for modelling site amplification factor. Though implement this method and make simulation for different cases, we can find that this method show better performance than the previous method and JMA Report. We will better understanding the advantage and disadvantage of this method, although there are some problems needed to consider carefully and to be solved, it shows good potential to be used in the future earthquake early waring system in the world.

Beschreibung: 〈b〉Characteristics of a Hailstorm over the Andean La Paz Valley〈/b〉〈br〉 Marcelo Zamuriano, Andrey Martynov, Luca Panziera, and Stefan Brönnimann〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-27,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 This work investigates the formation of a hailstorm over the Tropical Bolivian Andes. Using the WRF atmospheric model, we are able to numerically reconstruct it and we assess the main factors (mountains, lake and surface heating) in the storm formation. We propose physical mechanisms that have the potential to improve the forecasting of similar events; which are known to have a big impact over the Bolivian Altiplano, especially the region near Titicaca lake.

Beschreibung: 〈b〉Study on Site Amplification Factor Correction for Earthquake Early Warning System〈/b〉〈br〉 Quancai Xie, Qiang Ma, Jingfa Zhang, and Haiying Yu〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-400,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 This paper make deep evluation of a new mthod for modelling site amplification factor. Though implement this method and make simulation for different cases, we can find that this method show better performance than the previous method and JMA Report. We will better understanding the advantage and disadvantage of this method, although there are some problems needed to consider carefully and to be solved, it shows good potential to be used in the future earthquake early waring system in the world.

Beschreibung: 〈b〉Communicating disaster risk? An evaluation of the availability and quality of flood maps〈/b〉〈br〉 Daniel Henstra, Andrea Minano, and Jason Thistlethwaite〈br〉 Nat. Hazards Earth Syst. Sci., 19, 313-323, https://doi.org/10.5194/nhess-19-313-2019, 2019〈br〉 Flood maps can help stakeholders and the public understand their flood risk. We evaluated the quality of publicly accessible flood maps in Canadian communities designated as flood risk areas. We found that most maps (62 %) are low quality (meeting less than half of the criteria) and the highest score was 78 % (seven of nine criteria met). Canada must make a more concerted effort to produce high-quality flood maps to support its international commitment to disaster risk reduction.

Beschreibung: 〈b〉Communicating disaster risk? An evaluation of the availability and quality of flood maps〈/b〉〈br〉 Daniel Henstra, Andrea Minano, and Jason Thistlethwaite〈br〉 Nat. Hazards Earth Syst. Sci., 19, 313-323, https://doi.org/10.5194/nhess-19-313-2019, 2019〈br〉 Flood maps can help stakeholders and the public understand their flood risk. We evaluated the quality of publicly accessible flood maps in Canadian communities designated as flood risk areas. We found that most maps (62 %) are low quality (meeting less than half of the criteria) and the highest score was 78 % (seven of nine criteria met). Canada must make a more concerted effort to produce high-quality flood maps to support its international commitment to disaster risk reduction.

Beschreibung: 〈b〉Coastal vulnerability assessment: through regional to local downscaling of wave characteristics along the Bay of Lalzit (Albania)〈/b〉〈br〉 Francesco De Leo, Giovanni Besio, Guido Zolezzi, and Marco Bezzi〈br〉 Nat. Hazards Earth Syst. Sci., 19, 287-298, https://doi.org/10.5194/nhess-19-287-2019, 2019〈br〉 This paper reviews the computation of vulnerability levels (VLs) of a coast to inundation with a known model. We refer to the original proposal, detailing the VL computation through an accurate investigation of the local wave climate. We prove that the resulting vulnerability is very sensitive due to the wave features taken into account, which have to be properly assessed. The research is the follow-up of a wider project set along the Bay of Lalzit (Albania).

Beschreibung: 〈b〉From examination of natural events a proposal for risk mitigation of lahars by a cellular automata methodology: a case study for Vascún valley, Ecuador〈/b〉〈br〉 Valeria Lupiano, Francesco Chidichimo, Guillermo Machado, Paolo Catelan, Lorena Molina, Salvatore Straface, Gino M. Crisci, and Salvatore Di Gregorio〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-406,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 A method for risk mitigation of secondary lahars, triggered by violent rainfalls, is proposed as alternative to works for their containment or deviation, that could cause future disasters. It is based on the controlled generation of small lahars as a result of collapse of frail dams by backfill, forming momentary ponds as in natural cases. LLUNPIY verifies by simulation path, velocity, thickness, erosion of lahars, that could be produced; a complex case study for Vascún Valley, Ecuador is shown.

Beschreibung: 〈b〉A method of deriving operation-specific ski run classes for avalanche risk management decisions in mechanized skiing〈/b〉〈br〉 Reto Sterchi and Pascal Haegeli〈br〉 Nat. Hazards Earth Syst. Sci., 19, 269-285, https://doi.org/10.5194/nhess-19-269-2019, 2019〈br〉 We used a revealed preference approach and identified patterns in risk management decisions of mechanized skiing operations. Our results show that terrain choices of experienced guides depend on a much broader set of factors beyond just the avalanche hazard, including skiing experience or accessibility due to weather. The identified high-resolution ski run hierarchies provide new opportunities for examining professional avalanche risk management practices and developing meaningful decision aids.

Beschreibung: 〈b〉Response time to flood events using a social vulnerability index (ReTSVI)〈/b〉〈br〉 Alvaro Hofflinger, Marcelo A. Somos-Valenzuela, and Arturo Vallejos-Romero〈br〉 Nat. Hazards Earth Syst. Sci., 19, 251-267, https://doi.org/10.5194/nhess-19-251-2019, 2019〈br〉 In this work, we propose a novel methodology (ReTSVI) to integrate a social vulnerability index into flood hazard methodologies. ReTSVI combines a series of modules that are pieces of information that interact during an evacuation, such as evacuation rate curves, mobilization, inundation models, and social vulnerability indexes, to create an integrated map of the evacuation rate in a given location.

Beschreibung: 〈b〉Comparing the efficiency of hypoxia mitigation strategies in an urban, turbid tidal river, using a coupled hydro sedimentary–biogeochemical model〈/b〉〈br〉 Katixa Lajaunie-Salla, Aldo Sottolichio, Sabine Schmidt, Xavier Litrico, Guillaume Binet, and Gwenaël Abril〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-381,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 〈p〉In view of future coastal hypoxia widespreading, it is essential to define management solutions to preserve a good quality of coastal ecosystems. The lower Tidal Garonne River (TGR, SW France), characterized by the seasonal presence of a turbidity maximum zone and urban water discharges, is subject to episodic hypoxia events during summer low river flow periods. The future climatic conditions (higher temperature; summer droughts) but also an increasing urbanization could enhance hypoxia risks near the city of Bordeaux in the next decades. A 3D model of dissolved oxygen (DO), which couples hydrodynamics, sediment transport and biogeochemical processes, is used to assess the efficiency of different management solutions on TGR oxygenation during summer low-discharge periods. We have runned different scenarios of reduction of urban sewage overflows, displacement of urban discharges downstream from Bordeaux, and/or temporary river flow support during summer period. The model shows that each option limits hypoxia, but with variable efficiency over time and space. Sewage overflow reduction improves DO levels only locally near the city of Bordeaux. Downstream relocation of wastewater discharges allows to reach better oxygenation level in the lower TGR. The support of low river flow limits the upstream TMZ propagation and dilutes TGR waters with well-oxygenated river waters. Scenarios combining wastewater network management and low water replenishment indicate an improvement in water quality over the entire TGR. These modelling outcomes constitute important tools for local water authorities to develop the most appropriate strategies to limit hypoxia in TGR.〈/p〉

Beschreibung: 〈b〉The effect of cyclones crossing the Mediterranean region on sea level anomalies at the Mediterranean Sea coast〈/b〉〈br〉 Piero Lionello, Dario Conte, and Marco Reale〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-6,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 Large positive and negative sea level anomalies at the coast of the Mediterranean Sea are produced by cyclones moving along the Mediterranean storm track, which are mostly generated in the western Mediterranean. The wind around the cyclone center is the main cause of sea level anomalies when a shallow water fetch is present. The inverse barometer effect produces a positive anomaly near the cyclone pressure minimum and a negative anomaly at the opposite side of the Mediterranean Sea.

Beschreibung: 〈b〉The effect of cyclones crossing the Mediterranean region on sea level anomalies at the Mediterranean Sea coast〈/b〉〈br〉 Piero Lionello, Dario Conte, and Marco Reale〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-6,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 Large positive and negative sea level anomalies at the coast of the Mediterranean Sea are produced by cyclones moving along the Mediterranean storm track, which are mostly generated in the western Mediterranean. The wind around the cyclone center is the main cause of sea level anomalies when a shallow water fetch is present. The inverse barometer effect produces a positive anomaly near the cyclone pressure minimum and a negative anomaly at the opposite side of the Mediterranean Sea.

Beschreibung: 〈b〉The selection of directional sectors for the analysis of extreme wind speed〈/b〉〈br〉 Pedro Folgueras, Sebastián Solari, and Miguel Ángel Losada〈br〉 Nat. Hazards Earth Syst. Sci., 19, 221-236, https://doi.org/10.5194/nhess-19-221-2019, 2019〈br〉 Directional effects are often relevant when studying the extreme values of natural agents, such as wind, waves, or currents. The use of a priori defined divisions is a common but subjective way to address the problem and may not fit data well in certain cases. In this work, a rational method is presented for the selection of directional sectors that, taking into account statistical indicators of the data, leads to the definition of independent and statistically homogeneous sectors.

Beschreibung: 〈b〉Delimitation of flood areas based on a calibrated a DEM and geoprocessing: case study on the Uruguay River, Itaqui, southern Brazil〈/b〉〈br〉 Paulo Victor N. Araújo, Venerando E. Amaro, Robert M. Silva, and Alexandre B. Lopes〈br〉 Nat. Hazards Earth Syst. Sci., 19, 237-250, https://doi.org/10.5194/nhess-19-237-2019, 2019〈br〉 This paper aims to map flood hazard areas under the influence of the Uruguay River, Itaqui (southern Brazil), using a calibrated digital elevation model (DEM), historic river level data and geoprocessing techniques. Assessment of the areas that can potentially be flooded can help to reduce the negative impact of flood events by supporting the process of land-use planning in areas exposed to flood hazards.

Beschreibung: 〈b〉On the nexus between landslide susceptibility and transport infrastructure – an agent-based approach〈/b〉〈br〉 Matthias Schlögl, Gerald Richter, Michael Avian, Thomas Thaler, Gerhard Heiss, Gernot Lenz, and Sven Fuchs〈br〉 Nat. Hazards Earth Syst. Sci., 19, 201-219, https://doi.org/10.5194/nhess-19-201-2019, 2019〈br〉 Landslides are destructive events, threatening the integrity of land transport systems. This paper presents how road networks are vulnerable to landslides, with emphasis on the consequences for affected road users. Results show the merits of using agent-based traffic modelling to assess the impacts of road network interruptions on rural communities by providing insights into the characteristics of the population affected and the effects on its daily routine in terms of detour costs.

Beschreibung: 〈b〉The selection of directional sectors for the analysis of extreme wind speed〈/b〉〈br〉 Pedro Folgueras, Sebastián Solari, and Miguel Ángel Losada〈br〉 Nat. Hazards Earth Syst. Sci., 19, 221-236, https://doi.org/10.5194/nhess-19-221-2019, 2019〈br〉 Directional effects are often relevant when studying the extreme values of natural agents, such as wind, waves, or currents. The use of a priori defined divisions is a common but subjective way to address the problem and may not fit data well in certain cases. In this work, a rational method is presented for the selection of directional sectors that, taking into account statistical indicators of the data, leads to the definition of independent and statistically homogeneous sectors.

Beschreibung: 〈b〉Delimitation of flood areas based on a calibrated a DEM and geoprocessing: case study on the Uruguay River, Itaqui, southern Brazil〈/b〉〈br〉 Paulo Victor N. Araújo, Venerando E. Amaro, Robert M. Silva, and Alexandre B. Lopes〈br〉 Nat. Hazards Earth Syst. Sci., 19, 237-250, https://doi.org/10.5194/nhess-19-237-2019, 2019〈br〉 This paper aims to map flood hazard areas under the influence of the Uruguay River, Itaqui (southern Brazil), using a calibrated digital elevation model (DEM), historic river level data and geoprocessing techniques. Assessment of the areas that can potentially be flooded can help to reduce the negative impact of flood events by supporting the process of land-use planning in areas exposed to flood hazards.

Beschreibung: 〈b〉On the nexus between landslide susceptibility and transport infrastructure – an agent-based approach〈/b〉〈br〉 Matthias Schlögl, Gerald Richter, Michael Avian, Thomas Thaler, Gerhard Heiss, Gernot Lenz, and Sven Fuchs〈br〉 Nat. Hazards Earth Syst. Sci., 19, 201-219, https://doi.org/10.5194/nhess-19-201-2019, 2019〈br〉 Landslides are destructive events, threatening the integrity of land transport systems. This paper presents how road networks are vulnerable to landslides, with emphasis on the consequences for affected road users. Results show the merits of using agent-based traffic modelling to assess the impacts of road network interruptions on rural communities by providing insights into the characteristics of the population affected and the effects on its daily routine in terms of detour costs.

Beschreibung: 〈b〉Global detection of rainfall triggered landslide clusters〈/b〉〈br〉 Susanne A. Benz and Philipp Blum〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-391,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 This study aims to identify clusters of landslide events within a global database that are triggered by the same rainfall event. Results show that 14 % of all studied landslide events are actually part of a landslide cluster consisting of at least 10 events. However, in a more regional analysis this number ranges from 30 % for the West Coast of North America to 3 % in the Himalaya Region. These findings provide an improved understanding for managing landslide mitigations on a larger scale.

Beschreibung: 〈b〉Global detection of rainfall triggered landslide clusters〈/b〉〈br〉 Susanne A. Benz and Philipp Blum〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-391,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 This study aims to identify clusters of landslide events within a global database that are triggered by the same rainfall event. Results show that 14 % of all studied landslide events are actually part of a landslide cluster consisting of at least 10 events. However, in a more regional analysis this number ranges from 30 % for the West Coast of North America to 3 % in the Himalaya Region. These findings provide an improved understanding for managing landslide mitigations on a larger scale.

Beschreibung: 〈b〉Flood risk assessment due to cyclone-induced dike breaching in coastal areas of Bangladesh〈/b〉〈br〉 Md Feroz Islam, Biswa Bhattacharya, and Ioana Popescu〈br〉 Nat. Hazards Earth Syst. Sci., 19, 353-368, https://doi.org/10.5194/nhess-19-353-2019, 2019〈br〉 Bangladesh, one of the most disaster-prone countries in the world, has a dynamic delta with 123 polders. Cyclone-induced storm surges cause severe damage to these polders. This paper presents an investigation of the inundation pattern in a polder due to dike failure caused by storm surges and identifies possible critical locations of dike breaches. Moreover, the risk of flooding was assessed and probabilistic flood maps were generated for the breaching of dikes.

Beschreibung: 〈b〉Significance of substrate soil moisture content for rockfall hazard assessment〈/b〉〈br〉 Louise M. Vick, Valerie Zimmer, Christopher White, Chris Massey, and Tim Davies〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-11,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 Rockfall boulders can travel long distances down slope and it is important to predict how far to prevent fatalities. A comparison of earthquake data from New Zealand during summer and full-scale rockfall experiments in the same soil during winter shows that during dry seasons boulders travel further downslope because the soil is harder. When using predictive tools, engineers and geologists should take soil conditions (and seasonal variations thereof) in to account.

Beschreibung: 〈b〉Flood risk assessment due to cyclone-induced dike breaching in coastal areas of Bangladesh〈/b〉〈br〉 Md Feroz Islam, Biswa Bhattacharya, and Ioana Popescu〈br〉 Nat. Hazards Earth Syst. Sci., 19, 353-368, https://doi.org/10.5194/nhess-19-353-2019, 2019〈br〉 Bangladesh, one of the most disaster-prone countries in the world, has a dynamic delta with 123 polders. Cyclone-induced storm surges cause severe damage to these polders. This paper presents an investigation of the inundation pattern in a polder due to dike failure caused by storm surges and identifies possible critical locations of dike breaches. Moreover, the risk of flooding was assessed and probabilistic flood maps were generated for the breaching of dikes.

Beschreibung: 〈b〉Speeding up and boosting tsunami warning in Chile〈/b〉〈br〉 Mauricio Fuentes, Sebastian Arriola, Sebastian Riquelme, and Bertrand Delouis〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-9,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 This works provides a simple and fast approach to improve tsunami warning systems in the near field. A color-coded warning map is produced almost instantaneously after the seismic information is received. Time is crucial in the near field case, for instance, the tsunami waves generated in the chilean trench arrives at the coastline around 10–15 minutes. Seismic information takes 3–5 minutes to be ready, we produece a first warning map after 6 minutes of the earthquake origin time.

Beschreibung: 〈b〉Speeding up and boosting tsunami warning in Chile〈/b〉〈br〉 Mauricio Fuentes, Sebastian Arriola, Sebastian Riquelme, and Bertrand Delouis〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-9,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 This works provides a simple and fast approach to improve tsunami warning systems in the near field. A color-coded warning map is produced almost instantaneously after the seismic information is received. Time is crucial in the near field case, for instance, the tsunami waves generated in the chilean trench arrives at the coastline around 10–15 minutes. Seismic information takes 3–5 minutes to be ready, we produece a first warning map after 6 minutes of the earthquake origin time.

Beschreibung: 〈b〉Reanalysis of the 1761 transatlantic tsunami〈/b〉〈br〉 Martin Wronna, Maria Ana Baptista, and Jorge Miguel Miranda〈br〉 Nat. Hazards Earth Syst. Sci., 19, 337-352, https://doi.org/10.5194/nhess-19-337-2019, 2019〈br〉 We investigate the source of the 1761 earthquake and tsunami. The reanalysis of the tsunami travel times agrees with an earlier suggested source area. We check the geodynamic setting of the area and place a fault as an extension to an identified fault and use numerical modelling to distinguish between two candidate sources. One of our theories is compatible with the geodynamic setting and reproduces well the observed tsunami parameters.

Beschreibung: 〈b〉Landslides Data Assimilation Using TRIGRS Based on Particle Filtering〈/b〉〈br〉 Changhu Xue, Guigen Nie, Jie Dong, Shuguang Wu, Jing Wang, Xiuzhen Li, and Xiaogang Zhang〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-16,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 This paper provides an approach to apply data assimilation method to stability analysis and parameter update and feedback in a landslide. The experiment is implemented by particle filter algorithm. The result FS sequence of TRIGRS output decreases continuously with time and the assimilation can effectively correct the FS of the model output. The RMSD of FS indicates the assimilation results can correct the estimation of TRIGRS output close to actual observations.

Beschreibung: 〈b〉Annual Characterization of Regional Hydrological Drought using Auxiliary Information under Global Warming Scenario〈/b〉〈br〉 Zulfiqar Ali, Ijaz Hussain, and Muhammad Faisal〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-373,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 Climate change and global warming scenario increase the odds of worsening drought. Therefore, precise characterization and regional monitoring of drought are the major challenge. In this paper, we provide a new way to formulate and improve temporal data of precipitation for the Standardized Drought Index (SDI) type tools. Results show that improved estimates are good candidates for modelling and monitoring hydrological drought with more precision.

Beschreibung: 〈b〉California earthquake insurance unpopularity: the issue is the price, not the risk perception〈/b〉〈br〉 Adrien Pothon, Philippe Gueguen, Sylvain Buisine, and Pierre-Yves Bard〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-29,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 This paper investigates why earthquake insurance in California is so unpopular despite a significant risk. For that, homeowners’ behavior has been investigated based on the evolution of the earthquake insurance industry in California since its premises. This study shows that most of homeowners disregard earthquake insurance because the premium amount is too high and not because they underestimate the risk. We conclude that new insurance solutions must be designed to fill this protection gap.

Beschreibung: 〈b〉Multicriterion assessment framework of flood events simulated with the vertically mixed runoff model in semiarid catchments in the middle Yellow River〈/b〉〈br〉 Dayang Li, Zhongmin Liang, Yan Zhou, Binquan Li, and Yupeng Fu〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-402,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 Flood forecasting and simulation in semiarid regions are always poor, and a single criterion assessment provides limited information for decision making. Here, we propose a multicriterion assessment framework combining the absolute relative error, the flow partitioning and the confidence interval to assess the most striking feature of an event-based flood––the peak flow. Our results show that the accepted rates of flood events improve a lot under the multicriterion assessment framework.

Beschreibung: 〈b〉Simultaneous state-parameter estimation of rainfall-induced landslide displacement using data assimilation〈/b〉〈br〉 Jing Wang, Guigen Nie, Shengjun Gao, and Changhu Xue〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-24,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 It is necessary to do some prevention study of landslide hazard like the early warning and deformation prediction. This research proposes a new strategy to predict displacement of the landslide. Results confirm the accuracy and effectiveness of this method in displacement prediction, which can provide assistance in early risk assessment and landslide forecasting.

Beschreibung: 〈b〉Assessing the tsunami mitigation effectiveness of the planned Banda Aceh Outer Ring Road (BORR), Indonesia〈/b〉〈br〉 Syamsidik, Tursina, Anawat Suppasri, Musa Al'ala, Mumtaz Luthfi, and Louise K. Comfort〈br〉 Nat. Hazards Earth Syst. Sci., 19, 299-312, https://doi.org/10.5194/nhess-19-299-2019, 2019〈br〉 This research aimed to assess the tsunami flow velocity and height reduction produced by a planned elevated road parallel to the coast of Banda Aceh called the Banda Aceh Outer Ring Road (BORR). The Cornell Multi-Grid Coupled Tsunami Model (COMCOT) was used to simulate eight scenarios of the tsunami. One of them was based on the 2004 Indian Ocean tsunami. Two magnitudes of earthquake were used, that is, 8.5 and 9.15 〈i〉M〈/i〉〈sub〉w〈/sub〉. The elevated road can potentially mitigate the impacts of future tsunamis.

Beschreibung: 〈b〉Assessing the tsunami mitigation effectiveness of the planned Banda Aceh Outer Ring Road (BORR), Indonesia〈/b〉〈br〉 Syamsidik, Tursina, Anawat Suppasri, Musa Al'ala, Mumtaz Luthfi, and Louise K. Comfort〈br〉 Nat. Hazards Earth Syst. Sci., 19, 299-312, https://doi.org/10.5194/nhess-19-299-2019, 2019〈br〉 This research aimed to assess the tsunami flow velocity and height reduction produced by a planned elevated road parallel to the coast of Banda Aceh called the Banda Aceh Outer Ring Road (BORR). The Cornell Multi-Grid Coupled Tsunami Model (COMCOT) was used to simulate eight scenarios of the tsunami. One of them was based on the 2004 Indian Ocean tsunami. Two magnitudes of earthquake were used, that is, 8.5 and 9.15 〈i〉M〈/i〉〈sub〉w〈/sub〉. The elevated road can potentially mitigate the impacts of future tsunamis.

Beschreibung: 〈b〉Coastal vulnerability assessment: through regional to local downscaling of wave characteristics along the Bay of Lalzit (Albania)〈/b〉〈br〉 Francesco De Leo, Giovanni Besio, Guido Zolezzi, and Marco Bezzi〈br〉 Nat. Hazards Earth Syst. Sci., 19, 287-298, https://doi.org/10.5194/nhess-19-287-2019, 2019〈br〉 This paper reviews the computation of vulnerability levels (VLs) of a coast to inundation with a known model. We refer to the original proposal, detailing the VL computation through an accurate investigation of the local wave climate. We prove that the resulting vulnerability is very sensitive due to the wave features taken into account, which have to be properly assessed. The research is the follow-up of a wider project set along the Bay of Lalzit (Albania).

Beschreibung: 〈b〉The Lituya Bay landslide-generated mega-tsunami – numerical simulation and sensitivity analysis〈/b〉〈br〉 José Manuel González-Vida, Jorge Macías, Manuel Jesús Castro, Carlos Sánchez-Linares, Marc de la Asunción, Sergio Ortega-Acosta, and Diego Arcas〈br〉 Nat. Hazards Earth Syst. Sci., 19, 369-388, https://doi.org/10.5194/nhess-19-369-2019, 2019〈br〉 In 1958, at Lituya Bay in Alaska, the largest tsunami wave ever recorded took place. Since then, its numerical simulation has been a challenge and no numerical model has been able to reproduce, in the real geometry of the bay, the more than 200 m wave and the extreme run-up (climbing of the water up on land) of 524 m. The aim of our research, in the framework of a collaboration between the University of Malága (Spain) and NOAA (US), was to fulfil this gap at the same time as verifying our model.

Beschreibung: 〈b〉Significance of substrate soil moisture content for rockfall hazard assessment〈/b〉〈br〉 Louise M. Vick, Valerie Zimmer, Christopher White, Chris Massey, and Tim Davies〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-11,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 Rockfall boulders can travel long distances down slope and it is important to predict how far to prevent fatalities. A comparison of earthquake data from New Zealand during summer and full-scale rockfall experiments in the same soil during winter shows that during dry seasons boulders travel further downslope because the soil is harder. When using predictive tools, engineers and geologists should take soil conditions (and seasonal variations thereof) in to account.

Beschreibung: 〈b〉Annual Characterization of Regional Hydrological Drought using Auxiliary Information under Global Warming Scenario〈/b〉〈br〉 Zulfiqar Ali, Ijaz Hussain, and Muhammad Faisal〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-373,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 Climate change and global warming scenario increase the odds of worsening drought. Therefore, precise characterization and regional monitoring of drought are the major challenge. In this paper, we provide a new way to formulate and improve temporal data of precipitation for the Standardized Drought Index (SDI) type tools. Results show that improved estimates are good candidates for modelling and monitoring hydrological drought with more precision.

Beschreibung: 〈b〉California earthquake insurance unpopularity: the issue is the price, not the risk perception〈/b〉〈br〉 Adrien Pothon, Philippe Gueguen, Sylvain Buisine, and Pierre-Yves Bard〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-29,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 This paper investigates why earthquake insurance in California is so unpopular despite a significant risk. For that, homeowners’ behavior has been investigated based on the evolution of the earthquake insurance industry in California since its premises. This study shows that most of homeowners disregard earthquake insurance because the premium amount is too high and not because they underestimate the risk. We conclude that new insurance solutions must be designed to fill this protection gap.

Beschreibung: 〈b〉Simultaneous state-parameter estimation of rainfall-induced landslide displacement using data assimilation〈/b〉〈br〉 Jing Wang, Guigen Nie, Shengjun Gao, and Changhu Xue〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-24,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 It is necessary to do some prevention study of landslide hazard like the early warning and deformation prediction. This research proposes a new strategy to predict displacement of the landslide. Results confirm the accuracy and effectiveness of this method in displacement prediction, which can provide assistance in early risk assessment and landslide forecasting.

Beschreibung: 〈b〉Characteristics of a Hailstorm over the Andean La Paz Valley〈/b〉〈br〉 Marcelo Zamuriano, Andrey Martynov, Luca Panziera, and Stefan Brönnimann〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-27,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 This work investigates the formation of a hailstorm over the Tropical Bolivian Andes. Using the WRF atmospheric model, we are able to numerically reconstruct it and we assess the main factors (mountains, lake and surface heating) in the storm formation. We propose physical mechanisms that have the potential to improve the forecasting of similar events; which are known to have a big impact over the Bolivian Altiplano, especially the region near Titicaca lake.

Beschreibung: 〈b〉Reducing uncertainty bounds of two-dimensional hydrodynamic model output by constraining model roughness〈/b〉〈br〉 Punit Kumar Bhola, Jorge Leandro, and Markus Disse〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-369,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 The paper study investigates the use of measured water levels to reduce uncertainties bounds of a two-dimensional hydrodynamic model output. Uncertainty assessment generally is not reported in practice due to the lack of best practices and too wide uncertainty bounds. Hence, a novel method to reduce the bounds by constraining the model parameter, mainly roughness, is presented. The operational practitioners as well as researchers benefits from the study in the field of flood risk management.

Beschreibung: 〈b〉Reducing uncertainty bounds of two-dimensional hydrodynamic model output by constraining model roughness〈/b〉〈br〉 Punit Kumar Bhola, Jorge Leandro, and Markus Disse〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-369,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 The paper study investigates the use of measured water levels to reduce uncertainties bounds of a two-dimensional hydrodynamic model output. Uncertainty assessment generally is not reported in practice due to the lack of best practices and too wide uncertainty bounds. Hence, a novel method to reduce the bounds by constraining the model parameter, mainly roughness, is presented. The operational practitioners as well as researchers benefits from the study in the field of flood risk management.

Beschreibung: 〈b〉Multicriterion assessment framework of flood events simulated with the vertically mixed runoff model in semiarid catchments in the middle Yellow River〈/b〉〈br〉 Dayang Li, Zhongmin Liang, Yan Zhou, Binquan Li, and Yupeng Fu〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-402,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 Flood forecasting and simulation in semiarid regions are always poor, and a single criterion assessment provides limited information for decision making. Here, we propose a multicriterion assessment framework combining the absolute relative error, the flow partitioning and the confidence interval to assess the most striking feature of an event-based flood––the peak flow. Our results show that the accepted rates of flood events improve a lot under the multicriterion assessment framework.

Beschreibung: A sudden release of large volumes of water during a glacier outburst flood (GLOF) is a major hazard worldwide. Here, we identify the sedimentary signature of glacial and non‐glacial processes, including GLOFs, based on lacustrine sediments from the distal glacier‐fed Lake Buarvatnet in western Norway. Historically documented GLOFs in 2002 CE and during the 1980s CE are identified in the 210Pb‐ and 14C‐dated sediments. These events have the same sedimentary signature as 12 earlier events throughout the Holocene interpreted to represent previous GLOFs in the catchment. The GLOFs are interpreted to have occurred during periods when the glacier extent was similar to the modern positions, and the events are thus used to pinpoint past positions of the glacier terminus and, hence, the equilibrium line altitudes (ELAs). The results indicate that the glacier Svartenutbreen, located at the eastern part of Folgefonna, had a similar size in 2002 CE as c. 8200–8300 cal. a BP, corresponding to the 8.2 ka event in the North Atlantic region. The regrowth of Sørfonna after the Holocene Thermal Optimum occurred at c. 6900 cal. a BP and Svartenutbreen was at modern size and extent in the periods c. 6400, c. 5450, c. 4850, c. 3850, c. 3550 and c. 1650 cal. a BP. Since 1650 cal. a BP, we infer that the glacier was larger than the 2002 CE glacier extent until 1910 CE when a GLOF occurred. Svartenutbreen has been retreating since 1910 CE, which led to the ice damming of the two historical GLOFs in the 1980s and 2002 CE separated by a glacier advance in the 1990s CE. The findings are discussed and compared to other regional glacier reconstructions in Norway, and emphasize the value of identifying and utilizing GLOFs as an indicator of past ELA variability.

Beschreibung: 〈b〉A stochastic event-based approach for flood estimation in catchments with mixed rainfall and snowmelt flood regimes〈/b〉〈br〉 Valeriya Filipova, Deborah Lawrence, and Thomas Skaugen〈br〉 Nat. Hazards Earth Syst. Sci., 19, 1-18, https://doi.org/10.5194/nhess-19-1-2019, 2019〈br〉 This paper presents a stochastic event-based method for analysis of extreme floods, which uses a Monte Carlo procedure to sample initial conditions, snowmelt and rainfall. A study of 20 catchments in Norway shows that this method gives flood estimates that are closer to those obtained using statistical flood frequency analysis than a deterministic event-based model based on a single design storm.

Beschreibung: 〈b〉Culture matters: Factors influencing natural hazard risk preparedness – a survey of Swiss households〈/b〉〈br〉 Elisabeth Maidl, David N. Bresch, and Matthias Buchecker〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-393,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 Natural hazard risk management today aims to involve all actors possibly affected by damage. Citizens are regarded as responsible actors in risk mitigation. Practitioners therefore face the challenge of building social capacity towards such a culture of risk. Research on capacity building in Alpine countries, however, so far lacks empirical evidence on individual preparedness in the common population. This study for the first time provides insights for research and practice.

Beschreibung: 〈b〉Culture matters: Factors influencing natural hazard risk preparedness – a survey of Swiss households〈/b〉〈br〉 Elisabeth Maidl, David N. Bresch, and Matthias Buchecker〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-393,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 Natural hazard risk management today aims to involve all actors possibly affected by damage. Citizens are regarded as responsible actors in risk mitigation. Practitioners therefore face the challenge of building social capacity towards such a culture of risk. Research on capacity building in Alpine countries, however, so far lacks empirical evidence on individual preparedness in the common population. This study for the first time provides insights for research and practice.

Beschreibung: 〈b〉Probabilistic seismic hazard analysis using logic tree approach – Patna District (India)〈/b〉〈br〉 Panjamani Anbazhagan, Ketan Bajaj, Karanpreet Matharu, Sayed S. R. Moustafa, and Nassir S. N. Al-Arifi〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-328,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 〈p〉PGA and SA distribution for Patna district is presented considering both classical and zoneless approach through logic tree frame work to capture the epistemic uncertainty. Seismicity parameters are calculated by considering completed and mixed earthquake data. Maximum magnitude was calculated using three methods namely incremental method, Kijko method and regional rupture characteristics approach. Best suitable GMPE was selected by carrying out 〈q〉efficacy test〈/q〉 using log likelihood. Uniform hazard response spectra have been compared with Indian standard BIS 1893. PGA varies from 0.38 g to 0.30 g from southern to northern periphery considering 2 % probability of exceedence in 50 years.〈/p〉

Beschreibung: 〈b〉Efficacy of using Radar Induced Factors in Landslide Susceptibility Analysis: case study of Koslanda, Sri Lanka〈/b〉〈br〉 Ahangama Kankanamge Rasika Nishamanie Ranasinghe, Ranmalee Bandara, Udeni Gnanapriya Anuruddha Puswewala, and Thilantha Lakmal Dammalage〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-335,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 Through the developments of radar and optical remote sensing in temporal, spectral, spatial, and global coverage, availability of images either at low cost or free of charge, large variety of applications are possible. This study assessed efficacy of Radar Induced Factors in identifying landslide susceptibility regions by considering the significance of radar inherent characteristics for disaster studies. With integration of radar factors, high and very low susceptibility regions are increased.

Beschreibung: 〈b〉Impacts of Horizontal Resolution and Air–Sea Flux Parameterization on the Intensity and Structure of simulated Typhoon Haiyan (2013)〈/b〉〈br〉 Mien-Tze Kueh, Wen-Mei Chen, Yang-Fan Sheng, Simon C. Lin, Tso-Ren Wu, Eric Yen, Yu-Lin Tsai, and Chuan-Yao Lin〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-333,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 In this study, we show that both the model horizontal resolution and air-sea flux parameterization can exert large influence on tropical cyclone intensity simulation but with different impacts on wind structures. We highlight the intensification and contraction of TC eyewall in response to the reduction of grid spacing. We also suggest that a well-developed eyewall is more conducive to the positive effect of flux formulas on TC development.

Beschreibung: 〈b〉Probabilistic seismic hazard analysis using logic tree approach – Patna District (India)〈/b〉〈br〉 Panjamani Anbazhagan, Ketan Bajaj, Karanpreet Matharu, Sayed S. R. Moustafa, and Nassir S. N. Al-Arifi〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-328,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 〈p〉PGA and SA distribution for Patna district is presented considering both classical and zoneless approach through logic tree frame work to capture the epistemic uncertainty. Seismicity parameters are calculated by considering completed and mixed earthquake data. Maximum magnitude was calculated using three methods namely incremental method, Kijko method and regional rupture characteristics approach. Best suitable GMPE was selected by carrying out 〈q〉efficacy test〈/q〉 using log likelihood. Uniform hazard response spectra have been compared with Indian standard BIS 1893. PGA varies from 0.38 g to 0.30 g from southern to northern periphery considering 2 % probability of exceedence in 50 years.〈/p〉

Beschreibung: 〈b〉Efficacy of using Radar Induced Factors in Landslide Susceptibility Analysis: case study of Koslanda, Sri Lanka〈/b〉〈br〉 Ahangama Kankanamge Rasika Nishamanie Ranasinghe, Ranmalee Bandara, Udeni Gnanapriya Anuruddha Puswewala, and Thilantha Lakmal Dammalage〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-335,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 Through the developments of radar and optical remote sensing in temporal, spectral, spatial, and global coverage, availability of images either at low cost or free of charge, large variety of applications are possible. This study assessed efficacy of Radar Induced Factors in identifying landslide susceptibility regions by considering the significance of radar inherent characteristics for disaster studies. With integration of radar factors, high and very low susceptibility regions are increased.

Beschreibung: 〈b〉Study on the combined threshold for gully-type debris flow early warning〈/b〉〈br〉 Jian Huang, Theodoor Wouterus Johannes van Asch, Changming Wang, and Qiao Li〈br〉 Nat. Hazards Earth Syst. Sci., 19, 41-51, https://doi.org/10.5194/nhess-19-41-2019, 2019〈br〉 Wenjia gully is a typical gully-type debris flow, which has a large-scale catchment and great hazard risk to the local people. Based on the monitoring data for almost 6 years until now, the characteristics of debris-flow-triggering parameters (pore pressure and rainfall) have been analyzed, especially the relationship with debris flow occurrences. Then, a combined threshold has been presented and tested in order to provide a method for safeguarding the population in the region.

Beschreibung: 〈b〉Study of the threshold for the POT method based on hindcasted significant wave heights of tropical cyclone waves in the South China Sea〈/b〉〈br〉 Zhuxiao Shao, Bingchen Liang, Huajun Li, Ping Li, and Dongyoung Lee〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-349,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 〈p〉An assessment of extreme significant wave heights is performed in the South China Sea (SCS), which is crucial for the coastal and offshore engineering in this area. Two significant factors influencing the assessment are the initial database and the assessing method. The initial database is a basic for assessment, and the assessing method is used to extrapolate appropriate return significant wave heights based on this database during a period. In this study, a 40-year (1975–2014) hindcasted significant wave height of tropical cyclone waves is adopted as the initial database. Based on this database, the peak significant wave height of every tropical cyclone wave is directly extracted as the initial sample; the independent and identically distributed assumption is satisfied; and the interference for the selection of the sample is avoided. The peak over threshold (POT) method with the generalized Pareto distribution (GPD) model is employed to extract the sufficiently large and high sample for model estimation. The peak excesses over a sufficiently high value (i.e., threshold) are fitted; thus, the return significant wave heights are highly dependent on the threshold. To determine the unique threshold for the POT method, characteristics of tropical cyclone waves are researched. The research results reveal that the separation value shown in the distribution of the initial sample is suitable for sampling in the SCS. Because the separation value is within the stable threshold range and the asymptotic tail approximation and estimation uncertainty are reasonable, the selected threshold is suitable and the corresponding return significant wave height is reliable.〈/p〉

Beschreibung: 〈b〉Ensemble flood simulation for a small dam catchment in Japan using nonhydrostatic model rainfalls. Part 2: Flood forecasting using 1600 member 4D-EnVAR predicted rainfalls〈/b〉〈br〉 Kenichiro Kobayashi, Apip, Le Duc, Tsutao Oizumi, and Kazuo Saito〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-343,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 1 comment)〈br〉 Feasibility of flood forecasting with 1600 rainfall forecasts was investigated. The rainfall forecasts were obtained from an advanced data assimilation system. The high probability of flood occurrence was predicted, which could not be possible by the operational forecast. The necessity of emergency flood operation was shown with a long leading time. This suggests it is worth to invest on increasing numbers of meteorological ensembles to improve flood forecasting.

Beschreibung: 〈b〉Study on the combined threshold for gully-type debris flow early warning〈/b〉〈br〉 Jian Huang, Theodoor Wouterus Johannes van Asch, Changming Wang, and Qiao Li〈br〉 Nat. Hazards Earth Syst. Sci., 19, 41-51, https://doi.org/10.5194/nhess-19-41-2019, 2019〈br〉 Wenjia gully is a typical gully-type debris flow, which has a large-scale catchment and great hazard risk to the local people. Based on the monitoring data for almost 6 years until now, the characteristics of debris-flow-triggering parameters (pore pressure and rainfall) have been analyzed, especially the relationship with debris flow occurrences. Then, a combined threshold has been presented and tested in order to provide a method for safeguarding the population in the region.

Beschreibung: 〈b〉What's streamflow got to do with it? A probabilistic simulation of the competing oceanographic and fluvial processes driving extreme along-river water levels〈/b〉〈br〉 Katherine A. Serafin, Peter Ruggiero, Kai A. Parker, and David F. Hill〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-347,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 In coastal environments, extreme water levels driving flooding are often generated by many individual processes like storm surge, streamflow, and tides. To estimate flood drivers along a coastal river, we merge statistical simulations of ocean and river forcing with a hydraulic model to produce water levels. We find both ocean and river forcing are necessary for producing extreme flood levels like the 100-yr event, highlighting the need for considering compound events in flood risk assessments.

Beschreibung: 〈b〉Study of the threshold for the POT method based on hindcasted significant wave heights of tropical cyclone waves in the South China Sea〈/b〉〈br〉 Zhuxiao Shao, Bingchen Liang, Huajun Li, Ping Li, and Dongyoung Lee〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-349,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 〈p〉An assessment of extreme significant wave heights is performed in the South China Sea (SCS), which is crucial for the coastal and offshore engineering in this area. Two significant factors influencing the assessment are the initial database and the assessing method. The initial database is a basic for assessment, and the assessing method is used to extrapolate appropriate return significant wave heights based on this database during a period. In this study, a 40-year (1975–2014) hindcasted significant wave height of tropical cyclone waves is adopted as the initial database. Based on this database, the peak significant wave height of every tropical cyclone wave is directly extracted as the initial sample; the independent and identically distributed assumption is satisfied; and the interference for the selection of the sample is avoided. The peak over threshold (POT) method with the generalized Pareto distribution (GPD) model is employed to extract the sufficiently large and high sample for model estimation. The peak excesses over a sufficiently high value (i.e., threshold) are fitted; thus, the return significant wave heights are highly dependent on the threshold. To determine the unique threshold for the POT method, characteristics of tropical cyclone waves are researched. The research results reveal that the separation value shown in the distribution of the initial sample is suitable for sampling in the SCS. Because the separation value is within the stable threshold range and the asymptotic tail approximation and estimation uncertainty are reasonable, the selected threshold is suitable and the corresponding return significant wave height is reliable.〈/p〉

Beschreibung: 〈b〉The impact of drought on the productivity of two rainfed crops in Spain〈/b〉〈br〉 Marina Peña-Gallardo, Sergio Martín Vicente-Serrano, Fernando Domínguez-Castro, and Santiago Beguería〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2019-1,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 Drought events are of great importance in most Mediterranean climate regions and the impacts caused on rainfed crops are particularly evident. In this study the impacts of drought on two representative rainfed crops in Spain (wheat and barley) are assessed by testing various worldwide drought indices and two datasets at different spatial resolution.

Beschreibung: 〈b〉Ensemble flood simulation for a small dam catchment in Japan using nonhydrostatic model rainfalls. Part 2: Flood forecasting using 1600 member 4D-EnVAR predicted rainfalls〈/b〉〈br〉 Kenichiro Kobayashi, Apip, Le Duc, Tsutao Oizumi, and Kazuo Saito〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-343,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 1 comment)〈br〉 Feasibility of flood forecasting with 1600 rainfall forecasts was investigated. The rainfall forecasts were obtained from an advanced data assimilation system. The high probability of flood occurrence was predicted, which could not be possible by the operational forecast. The necessity of emergency flood operation was shown with a long leading time. This suggests it is worth to invest on increasing numbers of meteorological ensembles to improve flood forecasting.

Beschreibung: 〈b〉What's streamflow got to do with it? A probabilistic simulation of the competing oceanographic and fluvial processes driving extreme along-river water levels〈/b〉〈br〉 Katherine A. Serafin, Peter Ruggiero, Kai A. Parker, and David F. Hill〈br〉 Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2018-347,2019〈br〉 〈b〉Manuscript under review for NHESS〈/b〉 (discussion: open, 0 comments)〈br〉 In coastal environments, extreme water levels driving flooding are often generated by many individual processes like storm surge, streamflow, and tides. To estimate flood drivers along a coastal river, we merge statistical simulations of ocean and river forcing with a hydraulic model to produce water levels. We find both ocean and river forcing are necessary for producing extreme flood levels like the 100-yr event, highlighting the need for considering compound events in flood risk assessments.