INVESTIGATING SOIL AND GROUNDWATER QUALITY AT DIFFERENT SCALES IN A FORESTED CATCHMENT - THE WALDSTEIN CASE-STUDY

The impact of anthropogenic depositions on soil and groundwater qualit y has been the subject of numerous studies in the last two decades. Ho wever, the problem of linking results and models at different scales r emains to be solved. A case study has been performed in the Fichtelgeb irge region in South-East Germany. Data from this case study has been used to analyse scale dependences of spatial variance, autocorrelation lengths, and the interdependence of soil hydrological and soil chemic al parameters. For soil suction, spatial variability increases stepwis e with scale. Three different sources of variation could be identified , predominating at different ranges of scale, making a deterministic m apping feasible. Local SO4 deposition explained much of the spatial pa ttern of SO4 concentration in soil solution and in catchment runoff ob served at different scales. This is mainly due to the fact that the so rption capacity of the soils in this region has been exceeded. Decreas ing SO4 deposition in the long term run is likely to enhance the influ ence of the soil, and reduces the correlation between deposition and s oil solution concentration. NO3 showed minimum variation at the county scale. This seems to be a reasonable representative elementary area f or mapping regional NO3 concentration patterns. For protons and Cl, ne ither observed spatial patterns nor the scale dependence of spatial he terogeneity could be explained adequately.