- Geography, Central Asia, Hydrogeography, Arid Land Ecology, Uzbekistan, Water resources, and 19 moreIrrigation water Management, Sustainable Water Resources Management, Central Asian Studies, Benthic macroinvertebrates, Transboundary Water Issues, Irrigation, Water quality, Fisheries Management, Water Pollution, Ecosystem-based Fishery Management, Irrigation & Drainage, Lakes, Fishing, Salinity, Soil and Water Salinity, Fishery, Reservoirs, Mineralization, and Water Quality Assessmentedit
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The analysis of various characteristics and trends of precipitation is an essential task to improve the utilization of water resources. Lake Issyk-Kul basin is an upper alpine catchment, which is more susceptible to the effects of climate... more
The analysis of various characteristics and trends of precipitation is an essential task to improve the utilization of water resources. Lake Issyk-Kul basin is an upper alpine catchment, which is more susceptible to the effects of climate variability, and identifying rainfall variations has vital importance for water resource planning and management in the lake basin. The well-known approaches linear regression, Şen’s slope, Spearman’s rho, and Mann-Kendall trend tests are applied frequently to try to identify trend variations, especially in rainfall, in most literature around the world. Recently, a newly developed method of Şen-innovative trend analysis (ITA) provides some advantages of visual-graphical illustrations and the identification of trends, which is one of the main focuses in this article. This study obtained the monthly precipitation data (between 1951 and 2012) from three meteorological stations (Balykchy, Cholpon-Ata, and Kyzyl-Suu) surrounding the Lake Issyk-Kul, an...
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In combination with the desiccation of the Aral Sea and the formation of the Aral Kum, the dry sea bed became a new source for dust and sand storms. Due to the highly continental climate and the effects of the global climate change in the... more
In combination with the desiccation of the Aral Sea and the formation of the Aral Kum, the dry sea bed became a new source for dust and sand storms. Due to the highly continental climate and the effects of the global climate change in the region, increasing air pressure differences lead to an increasing frequency of high intensity wind events. The resulting aeolian dust movements can be tracked and split into short and long distance transfers using remote sensing approaches, but hard data about the spatial and temporal distribution of the dust deposition requires excessive ground research and thus is scarce. Therefore, we have analyzed the passive dust deposition data from 23 meteorological stations and assessed the spatial and temporal transfer patterns within several transects from the banks of the former Aral Sea in eastern and southern directions covering parts of Kazakhstan, Uzbekistan and Turkmenistan. Dust was collected on a monthly base as well as during specific dust storm events between 2003 and 2012 in the framework of three research projects for both long-term and event based deposition data. Dust transfer in southern direction was the most important trajectory and the newly formed Aral Kum proved to be an important source region for aeolian dust (besides the natural deserts Kyzyl Kum and Kara Kum). Stations close to these source regions frequently showed deposition rates exceeding international thresholds, resulting in possible negative effects on human and livestock health while the mineralogical and chemical composition of the deposited material influences the arable land in this arid region. This presentation will summarize the most important findings from the three research projects and discuss measures to reduce the wind erosion in the Aral Kum.
Research Interests: Soil Science, Irrigation, Dust Hazards, Desertification, Central Asia, and 15 moreEnvironmental Soil Science, Soil Salinity, Irrigation water Management, Uzbekistan, Aral Sea, Salinity, Salinization, Soil Fertility, Grain size distribution, Desertification and Land degradation, Eolian dust, Grain Size Analysis, Aeolian Dust, Post Soviet Politics, and Combatting desertification
The municipal sewage treatment in Germany is traditionally centralized and allows for a high disposal security. The implementation of the EU Water Framework Directive (EU-WFD) showed that the central target, the so-called ‘good ecological... more
The municipal sewage treatment in Germany is traditionally centralized and allows for a high disposal security. The implementation of the EU Water Framework Directive (EU-WFD) showed that the central target, the so-called ‘good ecological state’ has not yet been reached in 90% of all surface water bodies. A common and widespread measure to reach said target is the improvement of sewage treatment plants (STP). A large part of the expenses for that has to be shouldered by local communities. But many rural communities already have to manage high costs caused by the modernization of the sewage pipe system. And as the size of the rural population decreases continuously, the per capita burden increases. This raises the question whether the construction of a new sewage treatment plant is the most efficient way to improve the water quality in rural areas. A comprehensive approach has been developed for answering this question, consisting of 1) biological and physico-chemical wastewater anal...
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Abstract The assessment of the ecological quality of surface water bodies has a long tradition and has become even more important over the last decade. Unfortunately the thorough sampling of the faunistic quality components is too seldom... more
Abstract The assessment of the ecological quality of surface water bodies has a long tradition and has become even more important over the last decade. Unfortunately the thorough sampling of the faunistic quality components is too seldom accompanied by an equally detailed analysis of the hydromorphological structures which form the basis of the aquatic ecosystems. This has led to sophisticated faunistic evaluations based on crude assumptions. The TRiSHa method ( T ypology of Ri verbed S tructures and Ha bitats) was specifically designed to correct this current lopsidedness. It is a hydromorphological mapping method that complements the state of the art hydrobiological methods like PERLODES and thus can provide the missing detailed information about the structural characteristics of riverbeds, which form the basis for the faunistic evaluations. TRiSHa provides a strong focus on the scale of the microhabitats, which are most relevant for the species of the macrozoobenthos, an often used ecological quality indicator. The method is easy to apply, scales well for (wadeable) river stretches of different sizes and is, due to its inductive habitat classification system, fully expandable. It is well suited for a wide range of scientific and water management topics like the high resolution analysis of riverbed structures, their heterogeneity and diversity as well as the spatial and temporal dynamic of individual parameters or whole river stretches. This paper presents the TRiSHa method in detail and exemplifies potential scientific applications through two showcase examples.
Research Interests: Geography, Physical Geography, Environmental Science, Geomorphology, European Law, and 15 moreResearch Methods and Methodology, Research Methodology, Restoration Ecology, Quantitative Methods, Flood Mitigation, Fluvial Geomorphology, Ecological restoration, Integrated Water Resources Management, Biological Sciences, Germany, Environmental Sciences, Ecological Indicators, CHEMICAL SCIENCES, Flood Erosion and Its Impact, and EU Water Framework Directive
Intensive use of European rivers during the last hundreds of years has led to profound changes in the physicochemical properties, river morphology, and aquatic faunistic communities. Rectifying these changes and improving the ecological... more
Intensive use of European rivers during the last hundreds of years has led to profound changes in the physicochemical properties, river morphology, and aquatic faunistic communities. Rectifying these changes and improving the ecological state of all surface water bodies is the central aim of the European Water Frame Directive (WFD), and river restoration measures are the main tool to achieve this goal for many rivers. As the cost-effectiveness of all measures is crucial to the WFD implementation, the approach of the passive river restoration has become very popular over the last decades. But while costs of this approach are minimal, not much is known about the long-term effectiveness of passive river restorations. The research presented here provides essential and in-depth data about the effects of two such restoration measures on the riverbed morphology of a large river of the lower mountain region in Germany (type 9.2). More than 3200 data sets were acquired using the TRiSHa method (Typology of Riverbed Structures and Habitats). The results show a high spatial and temporal diversity and dynamic for all analyzed hydromorphologic parameters — ranging from riverbed sediments, organic structures like dead wood or macrophytes, to the distribution of 32 microhabitat types. The structures and their dynamic depend on the character of the study area (free-flowing or impounded), the location of the study sites within the research area (main channel or restored side channel), and on the occurrence of major flood events (the mapping and sampling were conducted annually from 2006 to 2008 with a 50-year flood event occurring in early 2007). These results show the potential of the passive restoration approach for creating morphologically diverse riverbeds, as habitat diversity and the spatial heterogeneity of the riverbed substrates increased significantly (e.g., more than 40% of all habitat types were only detected in the newly restored side channels). But the results also show the limitations of the passive restoration approach, as impounded river sections do not develop as rapidly as their free-flowing counterparts as more than 78% of the restored riverbed in an impounded river stretch remained completely unchanged — even by the 50-year flood event. These differences have to be taken into consideration when formulating the expectations of any passive river restoration.
Research Interests: Geography, Geology, Geomorphology, Water, Water resources, and 15 moreRivers, Sustainable Water Resources Management, Fluvial Geomorphology, River Ecology, Integrated Water Resources Management, River, Germany, Mapping, River Basin Management, River Restoration, Field Work, Water Framework Directive, River Morphology, SEDIMENT TRANSPORT IN RIVER/DRAIN, and Elsevier
Abstract Originally, a shallow saline depression between the Kyzylkum and the Nurata mountain range the Aydarkul–Arnasay Lake System (AALS) was created in 1969 when a catastrophic flood event in the Syr Darya catchment exceeded the... more
Abstract Originally, a shallow saline depression between the Kyzylkum and the Nurata mountain range the Aydarkul–Arnasay Lake System (AALS) was created in 1969 when a catastrophic flood event in the Syr Darya catchment exceeded the capacity of the Chardarya reservoir. Additional water diversions further increased the volume of the lakes to up to 42.2 mln m3 in 2006. After the breakdown of the commercial fishing in the Uzbek part of the Aral Sea in 1983, the AALS became the most important fishery lake in Uzbekistan with an annual catch of more than 4600 tons (in 1988). In recent years, however, the fish catch experienced a sharp decline (down to 728 tons in 2006) due to the increased inflow of drainage water from the large Golodnaya Steppe (Hunger Steppe) irrigation scheme (e.g., 0.1 km3 in 1960, 1.0 km3 in 1970, 2.3 km3 in 1980, 2.9 km3 in 2000 and 3.6 km3 in 2010) and a decrease in freshwater inflow from the Chardarya reservoir (e.g., 4.0 km3 in 1995, 2.3 km3 in 2005 and 1.8 km3 in 2010). The increasing anthropogenic pressure, as well as the impacts of the climate change (+0.6–0.9 °C between 1950 and 2000, decrease in the long-term precipitation and increase in the variability), is threatening this ecological and economic important lake system. This article presents new data about the temporal dynamic of the lake hydrology (size, volume, water balance), the surrounding climate and its development as well as about the water quality of the lakes and the main drainage water collectors, and the development of the fish fauna over the last decades. This study, based on official data (Uzhydromet, Uzryba), online databases (GHCN) and extensive field work (water quality and fish sampling), provides a complete published analysis of the status quo of the AALS. Therefore, it is an important contribution to the establishment of a stable lake ecosystem system and a sustainable fishing industry.
Research Interests: Globalization, Climate Change, Hydrology, Climate Change Adaptation, Irrigation, and 15 moreFisheries Management, Agriculture, Agricultural extension, Central Asia, Integrated Water Resources Management, Irrigation water Management, Fishing, Aral Sea, Fishery, Hydrology and water resources, Aydarkul, Arnasay, Chardarya, Golodnaya Steppe, and Hungersteppe
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ABSTRACT The aeolian transport of dust is an important process in Central Asia. Anthropogenic desertification and the desiccation of the Aral Sea have increased the overall dust emission and transport from this region and the local dust... more
ABSTRACT The aeolian transport of dust is an important process in Central Asia. Anthropogenic desertification and the desiccation of the Aral Sea have increased the overall dust emission and transport from this region and the local dust storm frequency during the last decades. Reliable ground data, however, are collected only sporadically, so the knowledge about the spatial and temporal distribution and dynamics of the dust deposition in the Aral Sea basin is fragmented and inconsistent at best. A long-term monitoring program was installed and sustained by three research projects. The results included in this article cover the dust deposition between 2003 and 2010 from 21 stations in Uzbekistan, Kazakhstan, and Turkmenistan. They confirm that the aeolian dust transport occurs mainly in the Southern direction. The highest average monthly deposition rate was registered in Uzbekistan (56.2 g m−2), while the percentage of months with a very intense (and potentially harmful) dust deposition flux was highest in Turkmenistan (36.4%). A majority of samples were collected during months with a dust deposition of less than 10.0 g m−2, while only 6% of all samples showed high monthly deposition intensities of more than 100 g m−2. The Kyzyl Kum, Kara Kum, and Aral Kum were identified as the main sources for aeolian dust in the Aral Sea basin. The impact of the Aral Kum as the dominant source of aeolian dust is limited to a region of approximately 500,000 km2 surrounding the former Aral Sea. The Kara Kum is characterized by a very high frequency of dust storms of a local and regional magnitude, and close to the Kyzyl Kum, monthly dust deposition rates of up to 9,600 g m−2 were registered.An analysis of the temporal distribution of the dust deposition showed a slight increase in the dust deposition activity and intensity between 2003 and 2010, with a strong inter-annual and seasonal dynamic. The highest average dust deposition was registered in June, and a second phase of intense dust deposition was identified in February.As this research covers less than a decade, a continuous monitoring program is strongly advised for a better understanding of the processes of aeolian dust transport and the impact of aeolian dust on arable land and human health.
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Research Interests:
Dust and atmospheric particles have been described in southwestern Iran primarily in terms of load, concentration and transport. The passive deposition, however, has been discussed inadequately. Therefore, the relationships between... more
Dust and atmospheric particles have been described in southwestern Iran primarily in terms of load, concentration and transport. The passive deposition, however, has been discussed inadequately. Therefore, the relationships between different climate zones in southwestern Iran and dust deposition rates were quantified between 2014 and 2017 using both space- (second modern-era retrospective analysis for research and applications, version 2 reanalysis model) and ground-based (eolian ground deposition rate) tools. In addition, the surface meteorological records, including the wind patterns favoring the occurrence of dust events, were examined. A hot desert climate (BWh), hot semi-arid climate (BSh), and temperate hot and dry summer climate (Csa) were identified as the three dominant climate regions in the study area, exhibiting the highest average dust deposition rates. In this study, correlations between the most relevant climate patterns and deposition rate weather parameters were fou...
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Dust and atmospheric particles have been described in southwestern Iran primarily in terms of load, concentration and transport. The passive deposition, however, has been discussed inadequately. Therefore, the relationships between... more
Dust and atmospheric particles have been described in southwestern Iran primarily in terms of load, concentration and transport. The passive deposition, however, has been discussed inadequately. Therefore, the relationships between different climate zones in southwestern Iran and dust deposition rates were quantified between 2014 and 2017 using both space- (second modern-era retrospective analysis for research and applications, version 2 reanalysis model) and ground-based (eolian ground deposition rate) tools. In addition, the surface meteorological records, including the wind patterns favoring the occurrence of dust events, were examined. A hot desert climate (BWh), hot semi-arid climate (BSh), and temperate hot and dry summer climate (Csa) were identified as the three dominant climate regions in the study area, exhibiting the highest average dust deposition rates. In this study, correlations between the most relevant climate patterns and deposition rate weather parameters were fou...
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The relationships between monthly recorded ground deposition rates (GDRs) and the spatiotemporal characteristics of dust concentrations in southwest Iran were investigated. A simulation by the Weather Research and Forecasting Model... more
The relationships between monthly recorded ground deposition rates (GDRs) and the spatiotemporal characteristics of dust concentrations in southwest Iran were investigated. A simulation by the Weather Research and Forecasting Model coupled with the Chemistry modeling system (WRF-Chem) was conducted for dust deposition during 2014–2015. The monthly dust deposition values observed at 10 different gauge sites (G01–G10) were mapped to show the seasonal and spatial variations in dust episodes at each location. An analysis of the dust deposition samples, however, confirmed that the region along the deposition sites is exposed to the highest monthly dust load, which has a mean value of 2.4 mg cm−2. In addition, the study area is subjected to seasonally varying deposition, which follows the trend: spring > summer > winter > fall. The modeling results further demonstrate that the increase in dust emissions is followed by a windward convergence over the region (particularly in the sp...
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The desiccation of the Aral Sea ranks among the largest man-made ecological catastrophes and has become a global symbol for the overexploitation of limited resources and the environmental and socio-economic consequences caused thereby.... more
The desiccation of the Aral Sea ranks among the largest man-made ecological catastrophes and has become a global symbol for the overexploitation of limited resources and the environmental and socio-economic consequences caused thereby. Formerly the fourth largest inland lake, large parts of the Aral Sea have been transformed into a salty desert – the Aralkum. The exposed lake bed sediments are subject to wind erosion, resulting in white sand and dust storms which have been tracked over several hundred kilometres using remote sensing images. Dust deposition data, on the other hand, requires excessive field work over prolonged periods of time and thus is scarce. But this kind of ground-based monitoring provides valuable insights into the physical and chemical composition of the transported material. The dust transported from the Aralkum contains, among other things, salts, heavy metals and agrochemicals deposited in the Aral Sea over decades. It can contribute to soil salinization, da...
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Research Interests:
Barren ground and sites with low coverage by vegetation (e.g., dunes, soil surfaces, dry lakes, and riverbeds) are the main source areas of sand and dust storms (SDS). The understanding of causes, processes (abrasion, deflation,... more
Barren ground and sites with low coverage by vegetation (e.g., dunes, soil surfaces, dry lakes, and riverbeds) are the main source areas of sand and dust storms (SDS). The understanding of causes, processes (abrasion, deflation, transport, deposition), and influencing factors of sandy and dusty particles moving by wind both in the boundary layer and in the atmosphere are basic prerequisites to distinguish between SDS. Dust transport in the atmosphere modulates radiation, ocean surface temperature, climate, as well as snow and ice cover. The effects of airborne particles on land are varied and can cause advantages and disadvantages, both in source areas and in sink or deposition areas, with disturbances of natural environments and anthropogenic infrastructure. Particulate matter in general and SDS specifically can cause severe health problems in human respiratory and other organs, especially in children. Economic impacts can be equally devastating, but the costs related to SDS are no...
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India’s largest freshwater ecosystem of the Kolleru Lake has experienced severe threats by land-use changes, including the construction of illegal fishponds around the lake area over the past five decades. Despite efforts to protect and... more
India’s largest freshwater ecosystem of the Kolleru Lake has experienced severe threats by land-use changes, including the construction of illegal fishponds around the lake area over the past five decades. Despite efforts to protect and restore the lake and its riparian zones, environmental pressures have increased over time. The present study provides a synthesis of human activities through major land-use changes around Kolleru Lake both before and after restoration measures. For this purpose, archives of all Landsat imageries from the last three decades were used to detect land cover changes. Using the Google Earth Engine cloud platform, three different land-use scenarios were classified for the year before restoration (1999), for 2008 immediately after the restoration, and for 2018, i.e., the current situation of the lake one decade afterward. Additionally, the NDVI (Normalized Difference Vegetation Index) and NDWI (Normalized Difference Water Index) indices were used to identify...
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Water is the most valuable resource in Central Asia and due to its uneven distribution and usage among the countries of the region it is also the main source of tension between upstream and downstream water users. Due to the rapidly... more
Water is the most valuable resource in Central Asia and due to its uneven distribution and usage among the countries of the region it is also the main source of tension between upstream and downstream water users. Due to the rapidly shrinking glaciers in the Pamir, Tien-Shan and Alai mountains, the available water resources will, by 2030, be 30% lower than today while the water demand of the growing economies will increase by 30%. This will further aggravate the pressure on the water resources and increase the water deficit caused by an unsustainable water use and political agendas. These challenges can only be overcome by an integrated water resource management for the important transboundary river catchments. The basis for such an IWRM approach however needs to be a solid data base about the status quo of the water resources. To that end the research presented here provides a detailed overview of the transboundary Zarafshan River (Tajikistan-Uzbekistan), the lifeline for more than...
Research Interests: Climate Change, Water quality, Water resources, Rivers, Watershed Hydrology, and 15 moreWater Pollution, Central Asia, Tajikistan, Hydropower, Integrated Water Resources Management, Irrigation water Management, Uzbekistan, Irrigation & Drainage, IWRM, River Basin Management, Bukhara, Samarkand, Aini, Water Quality, and Transboundary Water Issues
ABSTRACT The Central Asian countries are particularly affected by the global climate change. The cultural and economic centers in this mostly arid region have to rely solely on the water resources provided by the rapidly melting glaciers... more
ABSTRACT The Central Asian countries are particularly affected by the global climate change. The cultural and economic centers in this mostly arid region have to rely solely on the water resources provided by the rapidly melting glaciers in the Pamir, Tien-Shan and Alay mountains. By 2030, the available water resources will be 30 % lower than today while the water demand will increase by 30 %. The unsustainable land and water use leads to a water deficit and a deterioration of the water quality. Documenting the status quo of the water resources needs to be the first steps towards an integrated water resource management. The research presented here provides a detailed overview of the transboundary Zarafshan River, the lifeline for more than six million people. The findings are based on field measurements, existing data from the national hydrometeorological services and an extensive literature analysis and cover the status quo of the meteorological and hydrological characteristics of the Zarafshan as well as the most important water quality parameters (pH, conductivity, nitrate, phosphate, arsenic, chromate, copper, zinc, fluoride, petroleum products, phenols and the aquatic invertebrate fauna). The discharge of the Zarafshan is characterized by a high natural discharge dynamic in the mountainous upper parts of the catchment and by sizeable anthropogenic water extractions in the lower parts of the catchment, where on average 60.6 % of the available water is diverted for irrigation purposes in the Samarkand and Navoi provinces. The water quality is heavily affected by the unsustainable land use and inadequate/missing water purification techniques. The reduced discharge and the return flow of untreated agricultural drainage water lead to a critical pollution of the river in the lower parts of the catchment. Additional sources of pollutants were identified in the Navoi special economic area and the mining industry in the Tajik part of the catchment. The impact of the global climate change and the socio-economic growth on the water availability and the water demand will aggravate the detected problems and might lead to severe local and transboundary upstream–downstream water conflicts within the next decades.
Research Interests:
Land surfaces poor in vegetation coverage and dried out soils are accelerating factors of sand and dust transport. Dust transport also has considerable impact on the human society if highly populated regions are on the transport pathway... more
Land surfaces poor in vegetation coverage and dried out soils are accelerating factors of sand and dust transport. Dust transport also has considerable impact on the human society if highly populated regions are on the transport pathway or sink areas as dust transport can bring pollutants into residence areas. The quantitative prediction of dust storms is impossible unless the entire dust cycle, consisting of dust emission, transport and deposition, can be correctly assessed. In recent years, dust emission schemes have been developed that account reasonably well for the impacts of atmospheric forcing and land-surface properties on dust emission. The Aral Sea disaster has been caused by the overexploitation of the water and land resources and is related to problems of polluted surface and ground water bodies, the loss of agricultural productivity and biodiversity, the regional climate change and also the human health, especially within the disaster zone. Major consequences of the Ara...
Intensive use of European rivers during the last hundreds of years has led to profound changes in the physicochemical properties, river morphology, and aquatic faunistic communities. Rectifying these changes and improving the ecological... more
Intensive use of European rivers during the last hundreds of years has led to profound changes in the physicochemical properties, river morphology, and aquatic faunistic communities. Rectifying these changes and improving the ecological state of all surface water bodies is the central aim of the European Water Frame Directive (WFD), and river restoration measures are the main tool to achieve this goal for many rivers. As the cost-effectiveness of all measures is crucial to the WFD implementation, the approach of the passive river restoration has become very popular over the last decades. But while costs of this approach are minimal, not much is known about the long-term effectiveness of passive river restorations. The research presented here provides essential and in-depth data about the effects of two such restoration measures on the riverbed morphology of a large river of the lower mountain region in Germany (type 9.2). More than 3200 data sets were acquired using the TRiSHa method (Typology of Riverbed Structures and Habitats). The results show a high spatial and temporal diversity and dynamic for all analyzed hydromorphologic parameters — ranging from riverbed sediments, organic structures like dead wood or macrophytes, to the distribution of 32 microhabitat types. The structures and their dynamic depend on the character of the study area (free-flowing or impounded), the location of the study sites within the research area (main channel or restored side channel), and on the occurrence of major flood events (the mapping and sampling were conducted annually from 2006 to 2008 with a 50-year flood event occurring in early 2007). These results show the potential of the passive restoration approach for creating morphologically diverse riverbeds, as habitat diversity and the spatial heterogeneity of the riverbed substrates increased significantly (e.g., more than 40% of all habitat types were only detected in the newly restored side channels). But the results also show the limitations of the passive restoration approach, as impounded river sections do not develop as rapidly as their free-flowing counterparts as more than 78% of the restored riverbed in an impounded river stretch remained completely unchanged — even by the 50-year flood event. These differences have to be taken into consideration when formulating the expectations of any passive river restoration.
Research Interests: Geography, Geomorphology, Water, Water resources, Rivers, and 13 moreSustainable Water Resources Management, Fluvial Geomorphology, River Ecology, Integrated Water Resources Management, River, Germany, Mapping, River Basin Management, River Restoration, Field Work, Water Framework Directive, River Morphology, and SEDIMENT TRANSPORT IN RIVER/DRAIN
The Central Asian countries are in particular affected by the climate change. The cultural and economic centers in this mostly arid region rely completely on the water resources of the Pamir, Tien Shan and Alay mountain glaciers. But by... more
The Central Asian countries are in particular affected by the climate change. The cultural and economic centers in this mostly arid region rely completely on the water resources of the Pamir, Tien Shan and Alay mountain glaciers. But by 2030 the discharge generated by those glaciers will be 30% less than today while the water demand will be up to 30% higher than today. Already today the unsustainable land and water use causes a water deficit and the impairment of the water quality. In most parts of Central Asia an detailed analysis of the status quo as the basis for the development of an integrated resource management plan is impossible due to fragmented or missing monitoring data. The study presented here provides an detailed overview of the quantity and quality of the water resources of the transboundary Zarafshan River – one of the most important but until now hardly studied rivers in Central Asia. The Zarafshan is characterized by a highly dynamic discharge and is massively impa...
ABSTRACT Many Central Asian river basins are transboundary and are characterized by a combination of extensive irrigation farming and an arid climate in the lower catchments. Both aspects – the transboundary character with different goals... more
ABSTRACT Many Central Asian river basins are transboundary and are characterized by a combination of extensive irrigation farming and an arid climate in the lower catchments. Both aspects – the transboundary character with different goals and demands of the national water management and the overexploitation of the limited water resources lead to environmental, socio-economic and political problems which require – in the light of growing economies and the climate change – immediate solutions. Based on field work (water and soil samples, vegetation mapping and macrozoobenthos assessment) and extensive database evaluation (meteorological, hydrological and statistical data – e.g. RWSA, NEESPI, GRDD, GHCN) from two case studies – the Zarafshan River (Tajikistan/Uzbekistan) and the Tarim River (Kyrgyzstan/China), the status quo of the water resources is assessed and scenarios for the impacts of the climate change on the water availability and the water use are outlined. The results show that the extensive withdrawal of water for the irrigation farming (with cotton being the most important crop) and the discharge of drainage water from the fields lead to severe water stress in the downstream parts of both catchments. The water deficit is so high that both rivers do not reach their tributaries (Amu-Darya and Lop Nor/Taitema Lake) any more. In the lower Zarafshan River (inter-)national thresholds for several pollutants are exceeded permanently, while in the lower Tarim River the falling groundwater level is leading to the deterioration of the valuable Tugai forests. And while short-term measures, like the water transfer from the Boston Lake to the lower Tarim, can improve the situation in the lower reaches, the climate change and the ongoing socio-economic growth in both catchments require a more integrated, sustainable management approach. The rapidly shrinking glaciers in the headwater regions (-50% until 2050) and the drastic increase of the air temperature (and thus the evapotranspiration) will increase the annual water deficit (e.g. in the Zarafshan River catchment from currently 1.6 km³ to up to 5.8 km³), making a more efficient (re-)use of water a necessity.
The Central Asian countries are in particular affected by the climate change. The cultural and economic centers in this mostly arid region rely completely on the water resources of the Pamir, Tien Shan and Alay mountain glaciers. But by... more
The Central Asian countries are in particular affected by the climate change. The cultural and economic centers in this mostly arid region rely completely on the water resources of the Pamir, Tien Shan and Alay mountain glaciers. But by 2030 the discharge generated by those glaciers will be 30% less than today while the water demand will be up to 30% higher than today. Already today the unsustainable land and water use causes a water deficit and the impairment of the water quality. In most parts of Central Asia an detailed analysis of the status quo as the basis for the development of an integrated resource management plan is impossible due to fragmented or missing monitoring data. The study presented here provides an detailed overview of the quantity and quality of the water resources of the transboundary Zarafshan River – one of the most important but until now hardly studied rivers in Central Asia. The Zarafshan is characterized by a highly dynamic discharge and is massively impa...
ABSTRACT The Central Asian countries are particularly affected by the global climate change. The cultural and economic centers in this mostly arid region have to rely solely on the water resources provided by the rapidly melting glaciers... more
ABSTRACT The Central Asian countries are particularly affected by the global climate change. The cultural and economic centers in this mostly arid region have to rely solely on the water resources provided by the rapidly melting glaciers in the Pamir, Tien-Shan and Alay mountains. By 2030, the available water resources will be 30 % lower than today while the water demand will increase by 30 %. The unsustainable land and water use leads to a water deficit and a deterioration of the water quality. Documenting the status quo of the water resources needs to be the first steps towards an integrated water resource management. The research presented here provides a detailed overview of the transboundary Zarafshan River, the lifeline for more than six million people. The findings are based on field measurements, existing data from the national hydrometeorological services and an extensive literature analysis and cover the status quo of the meteorological and hydrological characteristics of the Zarafshan as well as the most important water quality parameters (pH, conductivity, nitrate, phosphate, arsenic, chromate, copper, zinc, fluoride, petroleum products, phenols and the aquatic invertebrate fauna). The discharge of the Zarafshan is characterized by a high natural discharge dynamic in the mountainous upper parts of the catchment and by sizeable anthropogenic water extractions in the lower parts of the catchment, where on average 60.6 % of the available water is diverted for irrigation purposes in the Samarkand and Navoi provinces. The water quality is heavily affected by the unsustainable land use and inadequate/missing water purification techniques. The reduced discharge and the return flow of untreated agricultural drainage water lead to a critical pollution of the river in the lower parts of the catchment. Additional sources of pollutants were identified in the Navoi special economic area and the mining industry in the Tajik part of the catchment. The impact of the global climate change and the socio-economic growth on the water availability and the water demand will aggravate the detected problems and might lead to severe local and transboundary upstream–downstream water conflicts within the next decades.
Research Interests:
The assessment of the ecological quality of surface water bodies has a long tradition and has becomeeven more important over the last decade. Unfortunately the thorough sampling of the faunistic quality components is too seldom... more
The assessment of the ecological quality of surface water bodies has a long tradition and has becomeeven more important over the last decade. Unfortunately the thorough sampling of the faunistic quality components is too seldom accompanied by an equally detailed analysis of the hydromorphological structures which form the basis of the aquatic ecosystems. This has led to sophisticated faunistic evaluations based on crude assumptions. The TRiSHa method (Typology of Riverbed Structures and Habitats) was specifically designed to correct this current lopsidedness. It is a hydromorphological mapping method that complements the state of the art hydrobiological methods like PERLODES and thus can provide the missing detailed information about the structural characteristics of riverbeds, which form the basis for the faunistic evaluations. TRiSHa provides a strong focus on the scale of the microhabitats, which are most relevant for the species of the macrozoobenthos, an often used ecological quality indicator. The method is easy to apply, scales well for (wadeable) river stretches of different sizes and is, due to its inductive habitat classification system, fully expandable. It is well suited for a wide range of scientific and watermanagement topics like the high resolution analysis of riverbed structures, their heterogeneity and diversity as well as the spatial and temporal dynamic of individual parameters or whole river stretches. This paper presents the TRiSHa method in detail and exemplifies potential scientific applications through two showcase examples.
Research Interests: Geography, Physical Geography, Geomorphology, European Law, Research Methods and Methodology, and 27 moreResearch Methodology, Water, Water resources, Restoration Ecology, Quantitative Methods, Sustainable Water Resources Management, Flood Mitigation, Fluvial Geomorphology, River Ecology, Water Resources engineering, Watershed Hydrology, Ecological restoration, Integrated Water Resources Management, River, Germany, River Basin Management, River Restoration, Hydrology, Floods, Hydrological Modelling, Hydraulics, Sediment Transport, Fish Habitat, Water Framework Directive, River Morphology, Flood Erosion and Its Impact, EU Water Framework Directive, Revitalization, River Flood Routing, Wfd, WFD 2000/60/EC, and 1. River Restoration, Training and Bank Protection
The World Summit on Sustainable Development (Johannesburg, 2002) encouraged all countries to "develop plans for Integrated Water Resources Management (IWRM) and Water Efficiency by 2005". The third (Kyoto, 2003) and fourth... more
The World Summit on Sustainable Development (Johannesburg, 2002) encouraged all countries to "develop plans for Integrated Water Resources Management (IWRM) and Water Efficiency by 2005". The third (Kyoto, 2003) and fourth (Mexico City, 2006) World Water Forums furthermore noted that the global water crisis is primarily a crisis of governance, lack of coordination of stake-holders and insufficient funding. In Kazakhstan, the water problems have similar causes and require new and integrated approaches for their solution. Currently, 44% of the country's water resources come from neighboring territories. Due to growing populations and economies in those countries the available water resources in Kazakhstan have been decreasing over the last years. In addition to this the water use and its man-agement are highly inefficient in many regions of Kazakhstan. The results of both developments are frequent water shortages which are increasing as the Kazakh socioeconomic growth le...
All the major river basins of the Republic of Kazakhstan are transboundary - the Ural, the Tobol, the Ishim, the Irtysh, the Ili, the Syrdarya, the Chu and the Talas. Numerous tributaries of these river basins are also transboundary. This... more
All the major river basins of the Republic of Kazakhstan are transboundary - the Ural, the Tobol, the Ishim, the Irtysh, the Ili, the Syrdarya, the Chu and the Talas. Numerous tributaries of these river basins are also transboundary. This presentation examines the range of existing water allocation paradigms and their inherent problems for transboundary river basins. Today most efforts of water resource management and water distribution in Kazakhstan focus main-ly on the following international conventions and protocols: - Rules of water use of international rivers (Helsinki, 1966); - Convention of protection and use of transboundary watercourses and international lakes (Helsin-ki, 1992); - Amendment to Convention of protection and use of transboundary watercourses and internation-al lakes (2003); - Convention about the law of non-navigational uses of international watercourses (New York, 1997); - Berlin rules of water resources (2004); - European Water Directive (2000); - Conventio...
Die EU-Wasserrahmenrichtlinie verpflichtet zu einer kosteneffizienten Verbesserung der biologischen, chemischen und strukturellen Güte der Oberflächengewässer. Dies bedingt eine genaue Kenntnis der Funktionszusammenhänge in den... more
Die EU-Wasserrahmenrichtlinie verpflichtet zu einer kosteneffizienten Verbesserung der biologischen, chemischen und strukturellen Güte der Oberflächengewässer. Dies bedingt eine genaue Kenntnis der Funktionszusammenhänge in den Gewässerökosystemen. Bislang fehlen jedoch Untersuchungen über die ökologische Wirksamkeit konkreter Strukturverbesserungsmaßnahmen. Daher kann der ökologische Erfolg von Renaturierungsmaßnahmen kaum vorhergesagt werden, was eine kosteneffiziente Maßnahmenplanung erschwert. Aus diesem Grund wurde mit TRiSHa (Typology of Riverbed Structures and Habitats) ein Verfahren zur mikromorphologischen Kartierung von Fließgewässern und einer daraus abgeleiteten Habitattypologie erarbeitet, welches in Kombination mit biologischen Bewertungsverfahren eine Einschätzung des Renaturierungserfolges ermöglicht, sich aber auch für die Bearbeitung zahlreicher weiterer Fragestellungen eignet. Der Beitrag stellt die Kartiermethode und die Habitattypologie vor und präsentiert Ergeb...
River catchments of Central Asia show a big variation of peculiarities. A great number of rivers are part of the vast undrained interior Eurasian basin, the biggest inland watershed of the Earth. Therefore a high share of water courses... more
River catchments of Central Asia show a big variation of peculiarities. A great number of rivers are part of the vast undrained interior Eurasian basin, the biggest inland watershed of the Earth. Therefore a high share of water courses flow into terminal lakes, with considerable lake level fluctuations, changing extensions and translocations. Big mountainous parts of the river catchments are covered by snow and ice. These mountains function as Central Asia’s „water towers“. The highly dissected mountain relief with its steep slopes, the relatively negligible water retention by thin soils, and weak evaporation due to low temperatures in high mountains cause a rapid runoff onto the adjacent semi-arid and desert plains, creating a good water supply where little is precipitated. That is why river valleys were and are the main important centers of agricultural and social development in Central Asia. Most of Central Asia’s rivers as well as their tributaries are crossing state borders. Th...
The Central Asian countries are in particular affected by the climate change. The cultural and economic centers in this mostly arid region rely completely on the water resources of the Pamir, Tien Shan and Alay mountain glaciers. But by... more
The Central Asian countries are in particular affected by the climate change. The cultural and economic centers in this mostly arid region rely completely on the water resources of the Pamir, Tien Shan and Alay mountain glaciers. But by 2030 the discharge generated by those glaciers will be 30% less than today while the water demand will be up to 30% higher than today. Already today the unsustainable land and water use causes a water deficit and the impairment of the water quality. In most parts of Central Asia an detailed analysis of the status quo as the basis for the development of an integrated resource management plan is impossible due to fragmented or missing monitoring data. The study presented here provides an detailed overview of the quantity and quality of the water resources of the transboundary Zarafshan River – one of the most important but until now hardly studied rivers in Central Asia. The Zarafshan is characterized by a highly dynamic discharge and is massively impa...
Im Rahmen vierjähriger Staubmessungen in Zentralasien betrug die durch-schnittliche monatliche Probenmenge, die mittels Depositionssammlern erfasst wurde 1,12g. Ton dominiert zu 74% die Korngrößenzusammensetzung der in drei Meter Höhe... more
Im Rahmen vierjähriger Staubmessungen in Zentralasien betrug die durch-schnittliche monatliche Probenmenge, die mittels Depositionssammlern erfasst wurde 1,12g. Ton dominiert zu 74% die Korngrößenzusammensetzung der in drei Meter Höhe über der Erdoberfläche erfassten atmogenen Depositionen; lediglich während besonders starker Stürme wurden dominant Sande deponiert. Die Mineralkomposition der Staubproben ist unspektakulär. Eine Herkunftsanalyse der Stäube ließ sich wegen einer an fast allen Stationen ähnlichen Mineralzusammensetzung nicht durchführen. Die mineralische Zusammensetzung der im Umfeld der Messstellen entnommenen Boden-oberflächenproben wies deutliche Unterschiede zu den Staubproben auf. Zwischen den Messstationen in Kasachstan, Usbekistan und Turkmeni-stan konnten keine großen Differenzen in den Anteilsverhältnissen der Makro-komponenten festgestellt werden, während dagegen die Spurenstoffe in ihren Gehalten je nach Untersuchungsraum deutlich variieren.
The EU Water Framework Directive requires the improvement of the quality of all water bodies in a cost-effective way. Therefore accurate knowledge is needed about the functional connections in aquatic ecosystems. So far research on the... more
The EU Water Framework Directive requires the improvement of the quality of all water bodies in a cost-effective way. Therefore accurate knowledge is needed about the functional connections in aquatic ecosystems. So far research on the effectiveness of measures for structural improvement has rarely been carried out, making it difficult to forecast the ecological results of renaturation measures and hence hampering a cost-effective planning. The study introduces the TRiSHa method (Typology of Riverbed Structures and Habitats) which allows the micro-morphological mapping of water streams and an associated habitat typology. The combination with biological assessment methods enables an evaluation of renaturation measures, but TRiSHa is also suited for a much wider array of questions. The paper presents the procedure of the method and first application results of a case study.
Research Interests:
A complex methodical approach is used for the evaluation of renaturated river sections with special consideration of the streambed morphology and the macrozoobenthos. Therefore already tested and newly developed methods are combined on... more
A complex methodical approach is used for the evaluation of renaturated river sections with special consideration of the streambed morphology and the macrozoobenthos. Therefore already tested and newly developed methods are combined on different spatial levels. First test results confirm the necessity of this approach and reveal deficits within the established evaluation instruments. *** Detailed research on renaturated river sections on several spatial scales revealed, that the methods for mapping the morphological river structure are hardly adequate for collecting data about the structural layout and the habitat suitability of streambeds. These information can be obtained using the TriSHa-instrument, which serves as a link between morphological and faunistic studies. By creating anabranches for the Lahn near Marburg, the structural diversity was improved by new types of habitats for the macrozoobenthos arranged in a small scale mosaic pattern. This advancement is not necessariliy ...
The results of research on the change of a chemical compound in groundwater depending on the time of year and quantity of precipitation and the results of monitoring the condition of irrigated lands of cotton sown regions in Tajikistan on... more
The results of research on the change of a chemical compound in groundwater depending on the time of year and quantity of precipitation and the results of monitoring the condition of irrigated lands of cotton sown regions in Tajikistan on the level and degree of groundwater mineralization are presented. The essential influences of the irrigation of the lands in vegetation periods on quality of groundwater are observed. in the present work the monitoring of influence of the Anzob mountain-concentrating industrial complex wastewaters on quality of water of the river Zeravshan were carried out. For this purpose were made the physical and chemical analysis of tests of water selected from points located above and down from an industrial complex wastewaters dam. Results of comparison of the analysis of waters have shown about absence of essential pollution of waters of the river by wastewaters of the Anzob Mountain-concentrating industrial Complex (AMCIC).
Land surfaces poor in vegetation coverage and dried out soils are accelerating factors of sand and dust transport. Dust transport also has considerable impact on the human society if highly populated regions are on the transport pathway... more
Land surfaces poor in vegetation coverage and dried out soils are accelerating factors of sand and dust transport. Dust transport also has considerable impact on the human society if highly populated regions are on the transport pathway or sink areas as dust transport can bring pollutants into residence areas. The quantitative prediction of dust storms is impossible unless the entire dust cycle, consisting of dust emission, transport and deposition, can be correctly assessed. In recent years, dust emission schemes have been developed that account reasonably well for the impacts of atmospheric forcing and land-surface properties on dust emission. The Aral Sea disaster has been caused by the overexploitation of the water and land resources and is related to problems of polluted surface and ground water bodies, the loss of agricultural productivity and biodiversity, the regional climate change and also the human health, especially within the disaster zone. Major consequences of the Ara...
The channel flow and respectively the discharge of the Tarim River is characterized by strong seasonal differences. Due to the fact, that most of its main tributary headwaters – the Aksu, Muzat (both Tian Shan), Yarkant, Hotan (both... more
The channel flow and respectively the discharge of the Tarim River is characterized by strong seasonal differences. Due to the fact, that most of its main tributary headwaters – the Aksu, Muzat (both Tian Shan), Yarkant, Hotan (both Kunlun Shan) and Kashgar (Pamir) rivers – are located in the high mountains surrounding the Taklamakan desert, the runoff generation between October and April is very limited. High discharge and floods occur between May and September during the snow and glacier melting period. Among the tributaries only the Aksu continuously reaches the Tarim throughout the year. It contributes approximately 70-80% of Tarim’s total discharge, which is mostly generated in the Kyrgyz part of the Tian Shan mountains. The Yarkant River is the longest of the Tarim tributaries and downstream of the city of Aksu, near Yichang, it joins the Aksu and Hotan rivers to form the Tarim River. The Yarkant-Tarim river system is the longest inland river in China, and the second largest i...
Originally a shallow saline depression between the Kyzyl Kum and the Nurata mountain range the Aydarkul-Arnasay Lake System (AALS) was created in 1969, when a catastrophic flood event in the Syrdarya catchment exceeded the capacity of the... more
Originally a shallow saline depression between the Kyzyl Kum and the Nurata mountain range the Aydarkul-Arnasay Lake System (AALS) was created in 1969, when a catastrophic flood event in the Syrdarya catchment exceeded the capacity of the Chardarya Reservoir. Additional water diversions further increased the volume of the lakes to up to 42.2 mln m³ in 2006. After the breakdown of the commercial fishing in the Uzbek part of the Aral Sea in 1983 the AALS became the most important fishery lake in Uzbekistan with an annual catch of more than 4,600 tons (in 1988). In recent years however, the fish catch experienced a sharp decline (down to 728 tons in 2006) due to the increased inflow of drainage water from the large Golodnaya Steppe (Hunger Steppe) irrigation scheme (e.g. 0.1 km³ in 1960, 1.0 km³ in 1970, 2.3 km³ in 1980, 2.9 km³ in 2000 and 3.6 km³ in 2010) and a decrease of freshwater inflow from the Chardarya Reservoir (e.g. 4.0 km³ in 1995, 2.3 km³ in 2005 and 1.8 km³ in 2010). The increasing anthropogenic pressure as well as the impacts of the climate change (+0.6-0.9°C between 1950 and 2000, decrease of the long-term precipitation and increase of the variability) are threatening this ecological and economic important lake system. This article presents new data about the temporal dynamic of the lake hydrology (size, volume, water balance), the surrounding climate and its development as well as about the water quality of the lakes and the main drainage water collectors, and the development of the fish fauna over the last decades. This study, based on official data (Uzhydromet, Uzryba), online data bases (GHCN) and extensive field work (water quality and fish sampling), provides the most complete published analysis of the status quo of the AALS. Therefore it is an important contribution for the establishment of a stable lake ecosystem system and a sustainable fishing industry.
Research Interests: Irrigation, Water quality, Fisheries Management, Water Pollution, Central Asia, and 16 moreIrrigation water Management, Ecosystem-based Fishery Management, Uzbekistan, Irrigation & Drainage, Lakes, Fishing, Salinity, Soil and Water Salinity, Fishery, Reservoirs, Mineralization, Water Quality Assessment, Water governance and management in Central Asia, Salinity Tolerance, Syrdaria, and Aydarkul
In combination with the desiccation of the Aral Sea and the formation of the Aral Kum, the dry sea bed became a new source for dust and sand storms. Due to the highly continental climate and the effects of the global climate change in the... more
In combination with the desiccation of the Aral Sea and the formation of the Aral Kum, the dry sea bed became a new source for dust and sand storms. Due to the highly continental climate and the effects of the global climate change in the region, increasing air pressure differences lead to an increasing frequency of high intensity wind events. The resulting aeolian dust movements can be tracked and split into short and long distance transfers using remote sensing approaches, but hard data about the spatial and temporal distribution of the dust deposition requires excessive ground research and thus is scarce. Therefore, we have analyzed the passive dust deposition data from 23 meteorological stations and assessed the spatial and temporal transfer patterns within several transects from the banks of the former Aral Sea in eastern and southern directions covering parts of Kazakhstan, Uzbekistan and Turkmenistan. Dust was collected on a monthly base as well as during specific dust storm events between 2003 and 2012 in the framework of three research projects for both long-term and event based deposition data.
Dust transfer in southern direction was the most important trajectory and the newly formed Aral Kum proved to be an important source region for aeolian dust (besides the natural deserts Kyzyl Kum and Kara Kum). Stations close to these source regions frequently showed deposition rates exceeding international thresholds, resulting in possible negative effects on human and livestock health while the mineralogical and chemical composition of the deposited material influences the arable land in this arid region. This presentation will summarize the most important findings from the three research projects and discuss measures to reduce the wind erosion in the Aral Kum.
Dust transfer in southern direction was the most important trajectory and the newly formed Aral Kum proved to be an important source region for aeolian dust (besides the natural deserts Kyzyl Kum and Kara Kum). Stations close to these source regions frequently showed deposition rates exceeding international thresholds, resulting in possible negative effects on human and livestock health while the mineralogical and chemical composition of the deposited material influences the arable land in this arid region. This presentation will summarize the most important findings from the three research projects and discuss measures to reduce the wind erosion in the Aral Kum.
Research Interests: Soil Science, Irrigation, Post-Soviet Politics, Dust Hazards, Desertification, and 16 moreCentral Asia, Environmental Soil Science, Water Resources (Environment), Soil Salinity, Irrigation water Management, Uzbekistan, Aral Sea, Salinity, Salinization, Soil Fertility, Grain size distribution, Desertification and Land degradation, Eolian dust, Grain Size Analysis, Aeolian Dust, and Combatting desertification
The Central Asian lowlands are characterized by an arid and continental climate. At the same time, the large streams and rivers have been providing water for the development of flourishing oases and extensive irrigated farming areas.... more
The Central Asian lowlands are characterized by an arid and continental climate. At the same time,
the large streams and rivers have been providing water for the development of flourishing oases
and extensive irrigated farming areas. Bukhara is one of those oases. The population of 1.7 mln.
and especially the agricultural sector (with an irrigated area of 275,000 ha) use a considerable
amount of water. But as the flat topography does not provide sufficient natural drainage, water
logging and raising groundwater tables have become serious problems for the agricultural productivity.
The combination of the high salinity of the irrigation water and the generous application
of fertilizers leads to a widespread soil salinization. Excessive leaching is supposed to reduce the
top soil salinity, but as the drainage system is only covering a small portion of the irrigated areas
and is in need of maintenance, this process only contributes to the ongoing salinization and the
reduction of soil fertility and crop yields. The data presented here for the years 2000 to 2013 indicate
that the groundwater table is rising throughout the region while the groundwater salinity is
decreasing. The soil salinity on the other hand is, after an improvement during the first half of the
study period, slightly increasing since 2009, which also is reflected in the slight worsening of the
condition of the reclaimed land during the same period.
the large streams and rivers have been providing water for the development of flourishing oases
and extensive irrigated farming areas. Bukhara is one of those oases. The population of 1.7 mln.
and especially the agricultural sector (with an irrigated area of 275,000 ha) use a considerable
amount of water. But as the flat topography does not provide sufficient natural drainage, water
logging and raising groundwater tables have become serious problems for the agricultural productivity.
The combination of the high salinity of the irrigation water and the generous application
of fertilizers leads to a widespread soil salinization. Excessive leaching is supposed to reduce the
top soil salinity, but as the drainage system is only covering a small portion of the irrigated areas
and is in need of maintenance, this process only contributes to the ongoing salinization and the
reduction of soil fertility and crop yields. The data presented here for the years 2000 to 2013 indicate
that the groundwater table is rising throughout the region while the groundwater salinity is
decreasing. The soil salinity on the other hand is, after an improvement during the first half of the
study period, slightly increasing since 2009, which also is reflected in the slight worsening of the
condition of the reclaimed land during the same period.
Research Interests:
Water is the most valuable resource in Central Asia and due to its uneven distribution and usage among the countries of the region it is also the main source of tension between upstream and downstream water users. Due to the rapidly... more
Water is the most valuable resource in Central Asia and due to its uneven distribution and usage among the countries of the region it is also the main source of tension between upstream and downstream water users. Due to the rapidly shrinking glaciers in the Pamir, Tien-Shan and Alai mountains, the available water resources will, by 2030, be 30% lower than today while the water demand of the growing economies will increase by 30%. This will further aggravate the pressure on the water resources and increase the water deficit caused by an unsustainable water use and political agendas. These challenges can only be overcome by an integrated water resource management for the important transboundary river catchments. The basis for such an IWRM approach however needs to be a solid data base about the status quo of the water resources. To that end the research presented here provides a detailed overview of the transboundary Zarafshan River (Tajikistan-Uzbekistan), the lifeline for more than 6 mln people. The Zarafshan River is well suited for this as it is not only one of the most important rivers in Central Asia but because the public availability of hydrological and ecological data is very limited, Furthermore the catchment is characterized by the same imbalances in the Water-Energy-Food-Nexus as most river systems in that region, which makes the Zarafshan a perfect model river for Central Asia as a whole. The findings presented here are based on field measurements, existing data from the national hydrometeorological services and an extensive literature analysis and cover the status quo of the meteorological and hydrological characteristics of the Zarafshan as well as the most important water quality parameters (pH, conductivity, nitrate, phosphate, arsenic, chromate, copper, zinc, fluoride, petroleum products, phenols and the aquatic invertebrate fauna). The hydrology of the Zarafshan is characterized by a high natural discharge dynamic in the mountainous upper parts of the catchment and by sizeable anthropogenic water extractions in the lower parts of the catchment, where on average 60.6% of the available water is diverted for irrigation purposes in the Samarkand and Navoi provinces. The water quality is heavily affected by the unsustainable land use and inadequate/missing water purification techniques. The reduced discharge and the return flow of untreated agricultural drainage water lead to a critical pollution of the river in the lower parts of the catchment. Additional sources of pollutants where identified in the upstream (the Anzob ore mining and processing complex) and downstream (the Navoi special economic area) parts of the catchment. The impact of the different water uses on the availability and the quality of the water resources are discussed in detail and outlook for the expected development during the next decades is given. These results form the basis for future investigations and for the conception of an IWRM plan for the Zarafshan River catchment.