Description: Das Projekt "European Cost Action FP 0601 'Forest Management and the Water Cycle' (FORMAN) - Tracing nitrate in water from the forest to the aquifer using stable isotopes of oxygen and nitrogen" wird vom Umweltbundesamt gefördert und von Eidgenössische Forschungsanstalt für Wald, Schnee und Landschaft durchgeführt. Forests usually supply drinking water of good quality thanks to the filtering of water through the soil. In Switzerland, about 42 percent of groundwater protection zones are located in forested areas. However, the continuous input of atmospheric nitrogen since the 1970s can have led to the saturation of forest ecosystems and resulted in an increased release of nitrate to groundwater. Nitrate originating from agriculture lands can also contribute to increased nitrate leaching into groundwater, even if the catchment is largely forested. A good understanding of flow paths and nitrate sources in catchments is therefore important to assess the forest influence on groundwater quality and to select the most effective practices of land management (forest, agriculture, river) aiming at a sustainable water supply of good quality. Numerous studies have investigated either the chemistry of percolation waters in the forest root zone or the groundwater quality. However, very few have assessed the biochemical transformation of the water composition along its flow path from the forest soil to the well and the mixing in the aquifer with water from other sources within the catchment. This project aims at identifying the different sources of nitrate (atmospheric deposition, nitrification in forest soils and N-fertilizers) in the saturated and unsaturated zones and at a better understanding of the N transformations along the flow paths from the forest to the aquifer by analyzing the oxygen and nitrogen isotopes in nitrate. The study is performed in a riparian zone including different succession stages (gravel bars, river banks, grassland, alluvial and climax forests) along a restored corridor of the river Thur (Canton Thurgau, Switzerland). The relative contribution of the different nitrate sources in water is assessed. The seasonal variations of nitrate concentrations and of oxygen and nitrogen isotope ratios in nitrate are determined in three transects across the riparian zone from the riverbank to the upland agricultural fields, passing through the different succession stages of vegetation. Methods: The experimental site is located along a restored corridor of the river Thur where a monitoring infrastructure (piezometers, wells) has been installed in the framework of the RECORD project (see below). Water samples for isotopic analysis are collected in the river Thur and along three terrestrial transects in the saturated and unsaturated zones. Laboratory experiments are performed to investigate: the effect of soil evaporation and soil respiration on the d18O values of newly-formed nitrate, the effect of source mixing and subsequent denitrification on the d18O values in nitrate. The denitrifier method is used to analyze oxygen and nitrogen isotopes in nitrate. This project is also integrated in the interdisciplinary RECORD project launched in April 2007 within the Competence Center of Environment and Sustainability (CCES) of the ETH domain.
Types:
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Hirsch ? Flussufer ? Denitrifikation ? Nitratgehalt ? Stickstoffelimination ? Ufervegetation ? Tierhaltungsanlage ? Gewässerrandstreifen ? Vegetation ? Nitrat ? Fluss ? Thurgau ? Luftstickstoff ? Sauerstoff ? Rohwasser ? Nitratauswaschung ? Stickstoff ? Biochemie ? Wiese ? Brunnen ? Bodenfilter ? Schweiz ? Nitrifikation ? Bodenatmung ? Schadstoffdeposition ? Filter ? Grünland ? Verdunstung ? Waldboden ? Waldökosystem ? Pflanzenwurzel ? Grundwasserzustand ? Grundwasserschutz ? Kies ? Ungesättigte Bodenzone ? Chemie ? Waldfläche ? Rhizosphäre ? Grundwasserraum ? Grundwasserleiter ? Wasserströmung ? Wasserkreislauf ? Wasserprobe ? Wasserschutzgebiet ? Wasserspeicher ? Wasseranalyse ? Wasserversorgung ? Sauerstoffgehalt ? Isotop ? Schnee ? Filtration ? Grundwasser ? Boden ? Perkolation ? Studie ? Sukzession ? Trinkwasser ? Flächenmanagement ? Trinkwasserqualität ? Nachhaltige Landnutzung ? Monitoring ? Laborversuch ? Forstwirtschaft ? Versickerung ? Infrastruktur ? Gewässer ? Schadstoffquelle ? Landwirtschaft ? Landwirtschaftliche Fläche ? Wald ? Forschungseinrichtung ? Ver- und Entsorgung ? Ablagerung ? Vermehrung ?
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 2008-01-01 - 2011-12-31
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