ALBERT

Description: The impact of beaver ponds on tree stand in a river valley The number of beavers in Poland rapidly increases which may result in conflicts between man and beavers. Despite the fact that beaver ponds play important role in increasing of biodiversity, water retention and soil moisture, they may also cause the die out of tree stands in river valleys and lead consequently to disappearance of typical riparian forest communities. Field studies demonstrated that long term flooding inhibited tree growth. Many trees died after 2 years of flooding. Long flooding caused the death of 80% of trees.

Description: An analysis of tree stand stability relative to Institute of Meteorology and Water Management (IMGW) classification of maximum wind velocities Analysing tree susceptibility to uprooting one has to compare external power acting on a tree with its resistance to uprooting (critical moment). The critical uprooting moment for a tree depends on both plant parameters and substratum. Results of an assessment of critical moments of studied pine and black alder tree stands are presented in this paper. Field studies consisted of uprooting trees with parallel measurements of critical moments. Results were compared with the moments of uprooting power of extreme winds. These moments were related to classification of maximum wind velocities proposed by the Institute of Meteorology and Water Management (IMGW).

Description: Bankfull discharge determination using the new Invertebrate Bankfull Assessment MethodAlong the paper the new method called Invertebrate Bankfull Assessment method (IBA method) of determination of bankfull discharge is presented. The investigation of bankfull discharge using IBA were performed within one Polish Carpathian stream in the mountain region: the Ochotnica Stream. As an index of bankfull the existence of certain species of invertebrates was used which are present and resistant to specific water discharge conditions. The borders within a cross section of the mountain stream with a gravel bed were defined where characteristic invertebrates are present which are recognized as bankfull borders. Finally three invertebrates benches (IB-ms) were recognized which are characterized by very specific invertebrate species. Bankfull discharge was calculated up to this IB-ms and corelated using Canonical Correspondence Analysis with other values of bankfull calculated for a cross section using different bankfull.

Description: Automated calibration of the simulation model of irrigation projects by harmony search optimizationThe paper deals with calibration of the simulation models of hydraulic part of an irrigation project. Calibrated simulation model can be used in design, reconstruction, enlargement or maintenance of the pressurized irrigation systems. Computer model of the water distribution system is a valuable tool which can assist engineers and planners in analyzing the hydraulic performance of water delivery systems. Calibration of the water distribution model consists in comparison of pressures and flows predicted with observed pressures and flows for known operating conditions (i.e., pump operation, tank levels, pressure-reducing valve settings), and adjustment of the input data for the model to improve agreement between observed and predicted values. In practice, given a set or sets of measured state variables, engineers apply trial and error techniques with their judgment to vary the parameters and accomplish this task. Trial and error techniques are tedious do not guarantee reasonable results. The paper introduces the methodology of determination of calibrated parameters automatically. Described methodology of calibration is based on optimizing procedures using the harmony search approach.

Description: Estimation and economic valuation of the forest retention capacities Based on results concerning the forest impact on water cycling an attempt was undertaken to evaluate water retention in forests. The economic value of water retention was established assuming the cost of water storage in small reservoirs built in forest areas. Calculations did not account for differences resulting from different functions of naturally retained water and that stored with the use of technical methods. Considering volume and time of water retention in forests, the annual value of natural water retention in forests calculated per average hectare of the country area was estimated at 800 zł.

Description: Concentrations and loads of N-NO3, N-NH4, PO4 and BOD5 in waters of the upper Dunajec (in the years 1985-1998) Loads of N-NO3, N-NH4, PO4 and BOD5 carried in surface waters of the upper Dunajec catchment basin (at the section in Krościenko) in the years 1985-1998 are presented in this paper. Water quality of the Biały Dunajec (in Szaflary), Czarny Dunajec (in Ludźmierz) and Dunajec (in Krościenko) was characterised. Annual loads discharged from the area per km2 of the catchment were calculated from mean annual flows (SQ) and concentrations of studied components in river waters. Concentration of N-NO3 in waters of the Biały Dunajec was more than two times higher and that of phosphates - over seven times higher than the respective concentrations in the Czarny Dunajec and Dunajec. Different population density, numerous tourists and low level of water and sewage infrastructure were responsible for these differences.

Description: Landscape alteration in view of soil protection from water erosion - an example of the Mielnica watershed The paper pertains to landscape management in eroded areas. Erosion processes, especially water erosion of soils, change the existing landscapes and make them less attractive or even hostile to people. Such situation calls for protective actions e.g. an appropriate management of agricultural landscape to minimise negative consequences of such phenomena. The paper presents a concept of counter-erosion measures to be implemented in the Trzebnickie Hills and comments their effect on the landscape. The concept was applied to an agricultural watershed of the Mielnica River. Particular attention was paid to visual aspect of this landscape and to functioning of its elements. Changes in the landscape were visualised and set up with the present status of the watershed.

Description: Forestry and water budget of the lowlands in northeast Germany — consequences for the choice of tree species and for forest management The lowlands in northeast Germany are among the driest and at the same time the most densely wooded regions in Germany. Low annual precipitation between 500 and 600 mm and the light sandy soils with their low water storage capacity and high porosity lead to limited water availability. Therefore the hydrological functions of forests play an important role in the fields of regional water budget, water supply and water distribution. To investigate the water consumption of different tree species, lysimeters were installed at Britz near Eberswalde under comparable site conditions. Nine large-scale lysimeters, each with an area of 100 m2 and 5 m deep, were built in the early 1970s. In 1974 the lysimeters were planted with Scots pine (Pinus sylvestris L.), common beech (Fagus sylvatica L.), larch (Larix decidua L.) and Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) as experimental stands of 0.3 ha each according to the usual management practices. The areas surrounding the lysimeters were planted similarly. The tree species is of outstanding importance for deep seepage under forest stands. Under the given precipitation and soil conditions, the course of interception and hence, the amount of seepage water depend on the crown structure in the stand. Depending on the amount of interception of the tree canopy and the duration of the leaching phase in spring, the mixed stands range between pure pine and pure beech. Making use of silvicultural methods and adequate stand treatment, forestry is able to control the water budget of landscapes.

Description: Premises for the construction of balance equations of water reserves in the saturation zone of forest soil Premises for the construction of balance equations of water reserves in the saturation zone of forest soil are presented in this paper. Changes of soil water reserves are dealt with as an effect of the atmosphere-tree stand-soil balance at the assumption of constant ground water flow and negligibly small losses for infiltration down the soil profile below saturation zone. These assumptions are met in permeable lowland forest soils, particularly in areas where the aquifer is situated on relatively shallow impermeable substratum. Then, for snow-free periods, it is possible to: 1) combine the increment of soil water reserves with precipitation above tree crowns and with plant and litter interception and 2) combine the losses of soil water reserves with plant transpiration and evaporation from the soil surface. The periods of increments and losses of soil water reserves are determined from limnigraph records of ground water table depth in piesometers. Examples are given in the paper of equations identified by long term data from 13 soil profiles localised in pine forests on Pleistocene flood-plain of the Dunajec River. The data included: ground water table depth, physical properties of grounds in soil profiles, and hydro-climatic conditions. The equations combine increments and losses of water reserves in the saturation zone with rainfall and deficits of air humidity measured on a mid-forest meadow.

Description: Changes of springs' yield of Lublin Upland and Roztocze Region in 1998-2008 Lublin Upland and Roztocze region are known for the occurrence of a large number of springs of high yield. These springs are fed mainly from Cretaceous or Tertiary water-bearing horizon. In order to determine variability of springs' yield, 61 selected springs were analysed in spring periods of the years 1998-2008. Collected hydrometric materials allowed for comparing average and extreme yield values of springs in various physiographic regions within the period of 11 years. Average value was 76.1 dm3·s−1, while the mean of the minimal yields was 44.7 dm3·s−1 and of the maximal - 132.7 dm3·s−1. Coefficient of irregularity of the springs' yield ranged from 1.5 to 5.0, which may lead to the conclusion that the springs' yield is constant or varies slightly. In some cases the irregularity was higher but it was determined by hydrogeological, meteorological and local factors.

Description: Methods of estimating the elements of water balance in a forested catchment basin The paper presents basic hydrological processes of rainfall-runoff transformation in experimental watershed of the Trzebuńka stream. Several field experiments were made to determine basic hydrological parameters, The influence of atmospheric circulation on spatial distribution of precipitation was investigated. Attempt was made to determine the influence of forest vegetation, undergrowth, forest litter retention and surface retention on water loss in the catchment. Water retention capacity of soil was also estimated. Developed mathematical model of rainfall-runoff transformation was used in several simulations. This allowed evaluating the effect of atmospheric circulation and spatial rainfall distribution on water balance, the influence of vegetation cover with forest litter on water runoff and the effect of forest litter alone in a hypothetical scenario of forest cutting.

Description: The role and importance of forest watercourses and water reservoirs in designing landscape values of forestsThis paper presents some issues related to designing forest landscape located close to the areas of watercourses and water reservoirs. Surface waters, beside forests and diverse terrain relief, constitute the main element deciding about tourist and recreation attractiveness of every such area. Some surveys on the evaluation of forest recreational potential prove that the forest attractiveness is closely connected with the quantity and quality of water reservoirs and watercourses. Due do their functions (environmental, hydrological, economic and social), and the fact that over the past decades both their number and surface area have decreased, water areas require particular protection and concern. The aim of this paper is to highlight the necessity of defining the principles of designing forest landscape, with the consideration of the role of forest water areas in recreational and tourist development of forests.

Description: Change in the number of ponds in the Wyskoć catchment basin in the years 1980-2003 and characteristics of the newly excavated pondsThe article presents the results of analyses of changes in the number of ponds in the Wyskoć catchment basin carried out in the years 1980-2003 and the characteristics of ponds excavated in that period. Only water reservoirs of an area less than 2 ha were considered. Analyses were based on topographic maps in the scale of 1:10 000 and aerial photographs taken in 1996. The results indicated that the number of filled ponds increased, especially those located in fields and grasslands. However, forest and wetland ponds were the most resistant to the processes of quantitative degradation because not even a single pond was filled during the analysed period. Over 70% newly excavated water bodies were made as an effect of exploitation of mineral and peat resources. However, nowadays ponds are more often created as a result of intentional human activities and are used for fish farming, recreation and as water retention reservoirs used in irrigation of small agricultural and gardening areas.

Description: Impact of the WFD on agriculture in the Netherlands and possible effect-specific hydrological measures: the Dutch approach The European Water Framework Directive can have enormous consequences for agriculture in the Netherlands. In parts of the country agriculture should be taken out of production because the nutrient loads to the surface water system are far too high. This doom scenario is of course undesired and a number of source-specific and effect-specific measures are necessary. The fate of nutrients in the soil is strongly interrelated with its hydrology. Directly, because nutrients are transported by water and the distribution of the residence time of drainage water is a good measure for the time behaviour of the nutrient loads to the surface water system. Longer residence time in the soil means more of nutrients applied by farmers but also a longer recovery period, after applying source-specific measures. In this paper three promising effect-specific hydrological measures are described buffer strips, retention strips, and controlled drainage.

Description: Assessment of water pollution by nitrates in the Middle Odra Basin The objective of the study was to characterise the quality of surface waters in order to determine their vulnerability to pollution by nitrogen compounds from agricultural activity, as well as to specify the areas with increased exposure, where nitrogen runoff from agricultural sources has to be reduced. It was necessary to determine surface waters liable to pollution by these compounds due to the fact that agricultural production should be carried out in the way which limits and prevents water pollution by nitrogen compounds of agricultural origin. The study addressed the following issues: the concentration of nitrogen compounds in the surface waters of the Middle Odra Basin, and the extent of eutrophication in flowing inland waters (with nitrogen as the main nutrient). The results have been plotted in figures and gathered in tables.

Description: Technical solutions for water damming structures in forest streams Small dams are basic elements of water retention systems in agricultural landscape and in forest ecosystems. Despite small water raising and location across small streams, these constructions should conform to security regulations and be resistant to destructive effect of flowing water. Moreover, they shouldn't be a strange element to the natural landscape of the river valley or forest ecosystem. Attention is also focussed in this paper on providing unobstructed flow in natural and artificial streams and on the possibility of migration for aquatic organisms. Examples of dams that do not hamper fish migration are given.

Description: Evaluation of the hydrological role of wetlands in the Włodawka River catchment (Polesie Lubelskie) The Włodawka River catchment of an area of 725 km2 covers the central and eastern part of the Łęczna-Włodawa Lake District. Evaluation of the role of hydrogenic areas in runoff creation was based on materials of the Department of Hydrography and the Institute of Meteorology and Water Management data. The analysis was conducted for selected catchments in which additional hydrometric measurements and water quality tests were done. Such parameters as: the share of hydrogenic surfaces in total catchment area, types of wetlands, their hypsometric location and position with reference to drainage streams were taken into consideration for evaluation. The degree of anthropogenic transformation of the marshland was expressed in terms of density and depth of the drainage ditches that dissect it. It was found that the drained gyttja of Krowie Bagno plays a considerable role in increasing the minimum discharge. Wetlands in the Włodawka River catchment influence the conditions of the runoff and water quality, which is noticeable, primarily, in the concentration of organic carbon, and of nitrogen and phosphorus compounds.

Description: Measures for soil water control in Poland Polish water resources depend on precipitations, which are variable in time and space. In dry years the water balance is negative in central parts of Poland but sudden thaws and downfalls may result in periodical water excess and dangerous floods almost in the entire country. The retention capacity of artificial reservoirs in Poland permits to store only 6% of the average annual runoff, which is commonly considered insufficient. Another method to increase retention is soil water control. About fifty percent of soils in Poland consist of light and very light sandy soils with low water capacity. Loams and organogenic soils cover approximately 25% and 8.5% area of the country, respectively. Almost half of agricultural lands (48%) have relatively good water conditions, but the rest requires soil water control measures. An increase of the soil water content could be achieved by changes of soil properties, water table control and soil water management. Modernization and reconstruction of drainage and irrigation systems, which were built mainly in the period 1960-1980, is needed.

Description: Changes of the nutrient loads of the Odra River during the last century - their causes and consequencesNutrient emissions by point and diffuse sources and their loads were estimated for the Odra catchment over the time period of the last 50 years by means of the model MONERIS. For nitrogen a change of the total emissions from 38 kt·a−1N in the mid of 1950s a maximum of 105 kt·a−1N in the early 1980s and a recent value of about 84 kt·a−1N were estimated for the total Odra Basin. The share of the point source discharges on the total N emissions varied between 24% (1955) and 35% (1995). The emissions from groundwater and tile drained areas represent the dominant pathway (37-56% of total N emissions) during all investigated time periods. Emissions from tile drained areas increased from the mid of 1950s to end of 1980s by a factor of 20 and reached in this period the same amount as emissions by groundwater. For phosphorus the emissions changed from 4 kt·a−1P in 1955 to 14 kt·a−1P in 1990 and a recent level of 7 kt·a−1P. Point source discharges caused between 36 to 66% of total P emissions and represent the dominant pathway for all investigated time periods. Erosion and discharges from paved urban areas and sewer systems was the dominant diffuse pathway of the total P emissions into the river system. The comparison of calculated and observed nutrient loads for the main monitoring stations along the Odra River shows that the average deviation is 12% for total phosphorus (1980-2000) and 15% for dissolved inorganic nitrogen (1960-2000). From the analysis it can be concluded that the present load of dissolved inorganic nitrogen (DIN) and total nitrogen (TN) of the Odra into the Baltic Sea is about 2.3 times higher than in the mid of 1960s. The maximum DIN load (1980s) was more than 3 times higher than in the 1960s. The change of the total phosphorus (TP) load is characterized by an increase from the 1955s to 1980 from 2 to 7 kt·a−1P (factor 2.6). Around 2000 the TP load was 4 kt·a−1which is only the double of the level of the 1955s.