ALBERT

Description: The spatiotemporal distribution pattern of the surface temperatures of urban forest canopies (STUFC) is influenced by many environmental factors, and the identification of interactions between these factors can improve simulations and predictions of spatial patterns of urban cool islands. This quantitative research uses an integrated method that combines remote sensing, ground surveys, and spatial statistical models to elucidate the mechanisms that influence the STUFC and considers the interaction of multiple environmental factors. This case study uses Jinjiang, China as a representative of a city experiencing rapid urbanization. We build up a multisource database (forest inventory, digital elevation models, population, and remote sensing imagery) on a uniform coordinate system to support research into the interactions that influence the STUFC. Landsat-5/8 Thermal Mapper images and meteorological data were used to retrieve the temporal and spatial distributions of land surface temperature. Ground observations, which included the forest management planning inventory and population density data, provided the factors that determine the STUFC spatial distribution on an urban scale. The use of a spatial statistical model (GeogDetector model) reveals the interaction mechanisms of STUFC. Although different environmental factors exert different influences on STUFC, in two periods with different hot spots and cold spots, the patch area and dominant tree species proved to be the main factors contributing to STUFC. The interaction between multiple environmental factors increased the STUFC, both linearly and nonlinearly. Strong interactions tended to occur between elevation and dominant species and were prevalent in either hot or cold spots in different years. In conclusion, the combining of multidisciplinary methods (e.g., remote sensing images, ground observations, and spatial statistical models) helps reveal the mechanism of STUFC on an urban scale.

Description: Abstract The H‐κ method (Zhu and Kanamori, 2000) has been widely used to estimate the crustal thickness (H) and the ratio of P to S velocities (VP/VS ratio, κ) with receiver functions. However, in regions where the crustal structure is complicated, the method may produce biased results, arising particularly from dipping Moho and/or crustal anisotropy. H‐κ stacking in case of azimuthal or radial anisotropy with flat Moho has been proposed, but not for cases with plunging anisotropy and dipping Moho. Here, we propose a generalized H‐κ method called H‐κ‐c, which corrects for these effects first before stacking. We consider rather general cases, including plunging anisotropy and dipping interfaces of multiple layers, and use harmonic functions to correct for arrival time variations of Ps and its crustal multiples with back‐azimuth (θ). Systematic synthetic tests show the arrival time variations can be well fitted by cosθ and cos2θ functions even for very complex crustal structures. Correcting for the back‐azimuthal variations significantly enhances H‐κ stacking. We verify the feasibility of the H‐κ‐c method by applying it to 40 permanent stations in various geological setting across the Mainland China. The results show clear improvement after the harmonic corrections, with clearer multiples and stronger stacking energy, as well as more reliable H‐κ values. Large differences in H (up to 5.0 km) and κ (up to 0.09) between the new and traditional methods occur mostly in mountainous regions, where the crustal structure tends to be more complex. We caution in particular about systematic bias when the traditional method is used in the presence of dipping interfaces. The modified method is simple and applicable anywhere in the world.

Description: Several single-center studies have investigated whether narrow-band imaging (NBI) cystoscopy is more effective in detecting primary and recurrent non-muscle invasive bladder cancer (NMIBC) compared with white-light imaging (WLI) cystoscopy. In this study, we further evaluated the diagnostic value of NBI cystoscopy compared with WLI cystoscopy for primary NMIBC in a multi-center study. Suspected bladder cancer patients from 8 research centers received both NBI and WLI. Two experienced doctors in each center were responsible for the NBI and WLI assessments, respectively. The number of tumors and position of each tumor were recorded, and suspicious tissues were clamped and histologically examined. The sensitivity, specificity, and false-positive rate of NBI and WLI were evaluated. Of the 384 patients, 78 had a confirmed urothelial carcinoma (UC). The sensitivities of NBI and WLI were 97.70%, and 66.67%, respectively (P 〈 0.0001); the specificities were 50% and 25%, respectively; and the false positive rates were 50% and 75%, respectively. Based on 300 valid biopsy specimens, the NBI and WLI sensitivities were 98.80% and 75.45%, respectively (P 〈 0.0001). These results suggest that NBI has a high sensitivity and has superior early bladder tumor and carcinoma in situ (CIS) detection rates compared with WLI cystoscopy. Scientific Reports 5 doi: 10.1038/srep10905

Description: SKS shear wave splitting measurements from three PASSCAL experiments (BEAAR, ARCTIC, and MOOS), which form a north/south transect across Alaska, show a remarkably simple pattern of two large anisotropy domains. In the northern domain, extending from the 70 km contour of the subducting Pacific plate north to the Arctic Ocean, fast directions are consistently in the NE - SW direction. These directions are essentially parallel to the absolute plate motion direction in northern Alaska and parallel to the strike of the subducting plate above the mantle wedge, suggesting that they represent some combination of plate-scale asthenospheric flow in the upper mantle and flow along the subducting plate in the mantle wedge. A strong wedge component beneath the Alaska Range is required to explain systematics of splitting delay times. In the southern domain, which extends south from the 70 km depth contour to the subducting plate, fast directions are in the NW - SE direction, a 90 degree rotation from the northern domain. These fast directions are parallel to the dip of the subducting plate in the direction of convergence and represent entrained flow beneath the subducting slab; the Pacific Plate absolute motion approximately parallels local convergence. Two major factors seem to control flow in these regions, absolute plate motion in the north and the subduction of the Pacific plate in the south, although both subduction-driven wedge flow and absolute plate motion contribute to the southern part of the northern regime.

Description: Rice is one of the most important crops in the world; meanwhile, the rice field is also an important contributor to greenhouse gas methane emission. Therefore, it is important to get an accurate estimation of rice acreage for both food production and climate change related studies. The eastern plain region is one of the major single-cropped rice (SCR) growing areas in China. Subjected to the topography and intensified human activities, the rice fields are generally fragmented and irregular. How remote sensing can meet this challenge to accurately estimate the acreage of the rice in this region using medium-resolution imagery is the topic of this study. In this study, the applicability of the Chinese HJ-1A/B satellites and a two-band enhanced vegetation index (EVI2) was investigated. Field campaigns were carried out during the rice growing season and ground-truth data were collected for classification accuracy assessments in 2012. A stepwise classification strategy utilizing the EVI2 signatures during key phenology stages, i.e., the transplanting and the vegetative to reproductive transition phases, of the SCR was proposed, and the overall classification accuracy was 91.7%. The influence of the mixed pixel and boundary effects to classification accuracy was also investigated. This work demonstrates that the Chinese HJ-1A/B data are suitable data source to estimating SCR cropping area under complex land cover composition.

Description: ABSTRACT [1]  New constraints on the pattern of crustal flow in SE Tibet are obtained from joint analysis of receiver functions and Rayleigh wave dispersion with a newly-deployed seismic array. The crust in the Sichuan-Yunnan Diamond Block has an average thickness of ~45 km, and gradually thins towards the Indo-China Block to the west and the Yangtze Block to the east. High V P / V S ratios are detected to the west of the Xiaojiang fault, but not in the Yangtze Block to the east. The S-wave velocity profile reveals intra-crustal low-velocity zones (IC-LVZs) are strongly heterogeneous, with two LVZs in the middle and mid-lower crust, respectively, in marked contrast to previous observations of a single LVZ. Combined with other observations, the two IC-LVZs are interpreted as isolated channels of crustal flow at different depths beneath SE Tibet, resulting in the observed complex pattern of radial anisotropy and further elucidating patterns of flow and deformation.

Description: The interaction between two flipping subduction systems shapes the complicated lithospheric structures and dynamics around the Taiwan region. Whether and in what form the Eurasian plate subducts/deforms under Taiwan Island is critical to the debate of tectonic models. Although an east-dipping high-velocity anomaly down to a depth below 200 km has been reported previously, its detailed morphology remains uncertain and leads to different interpretations. With a two-step strategy of nonlinear joint inversion, the slab images of the Eurasian Plate in a geometry that is hyper-thin in the south, becoming massive and steeper in the central, and severely deformed in the north were retrieved. The possible depth and dimension of a slab break were also investigated through synthetic tests of whether the slab had torn. Moreover, the slab deflection found at ~23.2°N latitude seems to correspond well to where the non-volcanic tremors and recent NW-SE-striking structures have occurred in southern Taiwan.

Description: We introduced a P-velocity model into the traditional joint inversion of P receiver function (RF) and surface wave dispersions to reduce model ambiguity. The method was implemented using a global search-based algorithm and a flexible parameterization of a sedimentary layer and spline-based parameterization that can represent sharp discontinuities. We applied the method to a dense array in SE Tibet (longitude ~97.5 °E to 107 °E, latitude ~25.3 °N). Extensive tests using synthetic and real data suggest that the method is suitable and robust for a variety of velocity structures and Moho discontinuities, and can simultaneously provide the crustal Vp/Vs profile and better-constrained Moho depth. The flexibility of the parameterization and the inclusion of the Vp constraint are crucial in the improved model recovery. Artifacts may be created without including the sedimentary layer. Even when it is less perfect, a reasonable Vp model is valuable in such a joint inversion. We showed that crustal multiples in RFs may bias the traditional H-k results when the crust structure is complex and should be avoided in a joint inversion before appropriate corrections can be made. The results from the joint inversion show two low-velocity zones (LVZs) reported previously and were identified as channels of crustal flow. A prominent isolated LVZ is observed in the mid-lower crust under the Xiaojiang fault area, which correlates with anomalously high Vp/Vs ratios, indicating possible partial melting. However, the other LVZ is imaged to be in the brittle shallow upper crust without very high Vp/Vs ratios, which is likely associated with crustal fault zones rather than partial melting. We observe clear low-velocity structures in the mantle beneath the two crustal LVZs, which also correlate with zones of low resistivity. The crust-mantle correlation may suggest influence of mantle processes on crustal deformation.

Description: Remote Sensing, Vol. 10, Pages 521: Individual and Interactive Influences of Anthropogenic and Ecological Factors on Forest PM2.5 Concentrations at an Urban Scale Remote Sensing doi: 10.3390/rs10040521 Authors: Guoliang Yun Shudi Zuo Shaoqing Dai Xiaodong Song Chengdong Xu Yilan Liao Peiqiang Zhao Weiyin Chang Qi Chen Yaying Li Jianfeng Tang Man Wang Yin Ren Integration of Landsat images and multisource data using spatial statistical analysis and geographical detector models can reveal the individual and interactive influences of anthropogenic activities and ecological factors on concentrations of atmospheric particulate matter less than 2.5 microns in diameter (PM2.5). This approach has been used in many studies to estimate biomass and forest disturbance patterns and to monitor carbon sinks. However, the approach has rarely been used to comprehensively analyze the individual and interactive influences of anthropogenic factors (e.g., population density, impervious surface percentage) and ecological factors (e.g., canopy density, stand age, and elevation) on PM2.5 concentrations. To do this, we used Landsat-8 images and meteorological data to retrieve quantitative data on the concentrations of particulates (PM2.5), then integrated a forest management planning inventory (FMPI), population density distribution data, meteorological data, and topographic data in a Geographic Information System database, and applied a spatial statistical analysis model to identify aggregated areas (hot spots and cold spots) of particulates in the urban area of Jinjiang city, China. A geographical detector model was used to analyze the individual and interactive influences of anthropogenic and ecological factors on PM2.5 concentrations. We found that particulate concentration hot spots are mainly distributed in urban centers and suburbs, while cold spots are mainly distributed in the suburbs and exurban region. Elevation was the dominant individual factor affecting PM2.5 concentrations, followed by dominant tree species and meteorological factors. A combination of human activities (e.g., population density, impervious surface percentage) and multiple ecological factors caused the dominant interactive effects, resulting in increased PM2.5 concentrations. Our study suggests that human activities and multiple ecological factors effect PM2.5 concentrations both individually and interactively. We conclude that in order to reveal the direct and indirect effects of human activities and multiple factors on PM2.5 concentrations in urban forests, quantification of fusion satellite data and spatial statistical methods should be conducted in urban areas.