Modelling nutrient fluxes from diffuse and point emissions to river loads: the Estonian part of the transboundary Lake Peipsi/Chudskoe drainage basin (Russia/Estonia/Latvia)

Abstract

First results are presented of a large-scale GIS-based nutrient transport modelling for the 1985-1999 period in the Estonian part of the transboundary drainage basin of Lake Peipsi (Estonian)/Chudskoe (Russian), one of the largest lakes in Europe, shared by Russia and Estonia. Although the lake is relatively undisturbed by human pollution, it is vulnerable for eutrophication by increased river loads, as shown in the past, when the north-eastern part of the former Soviet Union suffered from intensive agriculture. The collapse of the Soviet Union caused a dramatic decline in fertilizer application rates and widespread abandonment of agricultural land. Although concentration measurements and modelling results indicate a general decrease in nutrient loads, modelling is complicated by the transfer of nutrients from diffuse emissions, which is strongly governed by retention and assumed periodic release from storages within the river basin, like the root zone, tile drains, ditches, channels, bed sediments, floodplains and lakes. Modelling diffuse emission contribution to river loads can be improved by better knowledge about the spatial and temporal distribution of this retention and release within the drainage basin.

In-Stream Nitrogen Attenuation: Model-Aggregation Effects and Implications for Coastal Nitrogen Impacts

“…As a basis for water flow and nitrogen transport quantification in the Norrström basin, we use the POLFLOW model, which has also previously been applied to the Norrström (6) and other relatively large river basins and catchments, such as the Rhine and Elbe (7,8,(11)(12)(13), for a considered five-year simulation period (1995)(1996)(1997)(1998)(1999). The POLFLOW model is embedded in the raster-based Geographic Information System (GIS) modeling tool PCRaster, and allows for spatial process resolution at the finest scale of available site-specific GIS data, by directly integrating these data with mathematical process functions, in a single, readily available, and easy-to-use programming language.…”

“…Nutrient load reductions are therefore required by national and international environmental regulation (such as the European Water Framework Directive) and political agreements (1), and must be based on relevant quantification of natural and anthropogenic nutrient loading to coastal and marine waters by relevant modeling of coupled physical and biogeochemical processes of nutrient transport and attenuation in catchments. Such modeling is therefore the subject of many recent scientific studies (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13) and is crucial for efficient mitigation and management of nitrogen loads causing coastal and marine eutrophication (1,(14)(15)(16)(17).…”

Sucul Ortamlarda Ötrofi̇kasyon Durumu Ve Senaryolari

“…Bu çalışmada yayılı ve noktasal kaynaklardan gelen besin elementleri emisyonlarının bir envanterini yapmışlar, drenaj havzasında uzun dönem su akışlarını modellemiş, toplam azot ve fosfor taşınımını hesaplamışlardır. Yayılı kaynaklardan toplam azot ve fosfor emisyonlarında sırasıyla %66 ve %83 azalmanın nedeninin gübre uygulama oranlarında azalmadan kaynaklandığını, nokta kaynaklardan toplam azot ve fosfor emisyonu miktarlarının nüfus ve atık su arıtma tesisi bağlantısı ve verimlilik oranları arasındaki ilişkilere bağlı olduğunu belirtmişlerdir [14].…”

Changes in Nutrient Emissions, Fluxes and Retention in a North-Eastern European Lowland Drainage Basin

“…PolFlow has successfully been applied to a number of European drainage basins in various climate regions (De Wit, 1999;De Wit and Bendoricchio, 2001;de Wit et al, 2002;Darracq et al, 2005). For this study, we adapted the modelling approach to take account of data-poor areas in Russia and also to compute future scenarios (Mourad and Van der Perk, 2004;Mourad et al, 2005).…”