Das Projekt "Antimony leaching from contaminated soil under different water regimes" wird vom Umweltbundesamt gefördert und von Eidgenössische Technische Hochschule Zürich, Institut für terrestrische Ökosysteme, Ökosystemmanagement durchgeführt. Antimony (Sb) is a rather rare element in the earth's crust, but in the recent past, human activities have led to highly elevated Sb concentrations in soils and sediments at many locations and, as a consequence, to increased exposure of biota to this toxic element. Soil contamination by Sb has recently become an urgent issue in particular on shooting ranges. In Switzerland, all shooting ranges are currently examined and will be remediated within the next decade. This implies the removal of large quantities of contaminated soil. Large fractions of these soils are not heavily contaminated but have to be treated because they are located in pollution-sensitive areas such as groundwater protection zones. This soil can potentially be reused for less sensitive types of land-use, saving high treatment costs and precious hazardous waste disposal space. Knowledge about the risks of Sb leaching from such soils is very limited, however. One key factor regarding solute leaching is the water regime, particularly in soils subject to permanent or periodic water-logging. Water-logging strongly inhibits soil aeration, and this can have a strong influence on the entirety of chemical and biological conditions affecting solute transport in soil. This holds all the more for elements that are sensitive to changes in their oxidation state under environmental conditions such as Sb. Given that there is very little information available on the transport behavior of Sb in soils, particularly under dynamic water regimes, this project has the aim to investigate the influence of water-logging on Sb leaching from contaminated soil. For this purpose, we carry out experiments with a relocated shooting range soil as well as with a comparable synthetic soil in order to identify and model the role of sorption and redox processes on Sb mobilization and leaching. Special attention will be given to the speciation of Sb in the soil solution. The results will be relevant beyond providing a scientific basis for the risk assessment of Sb leaching from contaminated soil, as it will also further the mechanistic understanding of how water-logging affects the transport of redox-sensitive solutes in soils in general.
Das Projekt "The effect of water storage variations on in-situ gravity measurements and their use for hydrology (HYGRA)" wird vom Umweltbundesamt gefördert und von Helmholtz-Zentrum Potsdam Deutsches GeoForschungsZentrum durchgeführt. Water storage variations in the soil, groundwater, snow cover and in surface water bodies cause a gravitational effect due to mass attraction. Thus, there exists a strong interrelation between hydrology and gravity. From a hydrological perspective, the estimation of water storage and its spatio-temporal changes is essential for setting up water balances and for effective water use and management. However, direct measurements of local water storage changes are still a challenging task while time-variable gravity observations are a promising tool as an integrative measure of total water storage changes. From a geodetic perspective, the hydrological gravity effect is an interfering signal, which imposes noise on gravimetric measurements and thus has to be eliminated from the gravity records. Superconducting gravimeters (SG) enable the in situ observation of the temporal changes of the earth gravity field. These SG data contain information about polar motion, earth tides, oscillations of the earth, atmospheric pressure and hydrology. But still variations in local water masses have a significant influence on SG measurements. Hence, the question is: How does local water storage change influence the signal of SG measurements? Objective: The objective of the HYGRA project is to separate the local hydrological signal from the integral signal of the SG records. From the geodetic perspective, this will provide a tool to remove the unwanted hydrological noise in SG recordings. At the same time, the hydrological gravity signal bears the potential to estimate hydrological state variables (ground water, soil moisture). Study Area: The HYGRA project focuses the relation of local hydrology and gravity in following study areas: Geodätisches Observatorium Wettzell, Deutschland; South African Geodynamic Observatory (SAGOS). Method The investigation of the interrelation between hydrology and geodesy is done by following worksteps: 1. 4D Simulation of the influence of water storage changes on the superconducting gravimeter; 2. Measuring and modelling of the different water storages; namely groundwater, soil moisture and snow; 3. Transformation of the water storage changes to a gravimetric signal; 4. Comparison between the measured gravity change by the SG and the estimated hydrological gravity response.
Das Projekt "Effects of different tillage methods on runoff, soil loss, and erosion related soil quality indicators on sloped cropland" wird vom Umweltbundesamt gefördert und von Universität für Bodenkultur Wien, Institut für Hydraulik und landeskulturelle Wasserwirtschaft durchgeführt. Soil erosion is a major threat to the resource soil. Loss of topsoil as well as deposition of eroded material affect all functions a soil has to fulfill including soil productivity, filtering, buffering, de-grading and detoxifying. In 1994 a field experiment started at three locations in Lower Austria to investigate the effect of different tillage practices on crop yield, surface runoff, soil erosion, and nutrient and pesticide losses. The tillage practices include 1) conventional tillage, 2) conservation tillage with cover crop, and 3) no-till with cover crop. Eight years after initiation of this field study this project will investigate the impact of these tillage practices on soil quality. Overall objectives of this study are 1) to collect data to evaluate best management practices (BMP) for Austrian farming conditions, 2) to investigate the effect of conventional tillage, conservation tillage and no-till on soil physical, chemical and biological properties, 3) to investigate temporal and spatial variability of soil properties induced by soil management along a slope, and 3) to collect data to evaluate best management practices for Austrian conditions. The study design of the erosion measurements consists of 4 m wide and 15 m long runoff plots for each management variation. Inclination of hillslopes varies between 6 and 16 percent. Runoff and sediments are collected for each erosive rain storm event with an automated measuring device. Nutrient (nitrogen and phosphorus) and pesticide losses associated with runoff and sediment are determined. To asses long-term effects of soil tillage/management on soil quality undisturbed and disturbed soil samples are taken at all three sites in different soil depths over the root zone and main physi-cal, chemical and biological soil properties are investigated. To investigate the effect of time and location along the hillslope on soil quality, three slope positions (summit, middle slope, footslope) are selected at each site. Soil moisture and soil tension are measured in weekly intervals to invest-igate possible differences in hydrologic condition. Soil samples are taken in appr. 4 weeks intervals and some physical, chemical and biological soil parameters are investigated. Crop yields are determined for each hillslope position. Improved soil physical, chemical and biological properties upgrade the ability of a soil to fulfill all functions like productivity, storage, filtering and buffering aso. Increased soil quality reduces also environmental risks like contamination of surface and groundwater bodies with nutrients or contaminants. The results of this project will also provide data for evaluation of BMPs and information about sensitive areas in watersheds with respect to groundwater contamination.
Das Projekt "Verification of the designation of sensitive areas under the urban wastewater treatment directive and nitrate vulnerable zones under the nitrate directive." wird vom Umweltbundesamt gefördert und von Universität für Bodenkultur Wien, Institut für Hydraulik und landeskulturelle Wasserwirtschaft durchgeführt. Die seit 1990 vorliegenden Wassergütemessdaten Österreichs werden nach vorgegebenen EU-Richtlinien ausgewertet und entsprechende Schutzzonen ausgewiesen.
