Characterization of the denitrification potential of aquifers in Saxony-Anhalt

摘要

In order to evaluate groundwater quality in Saxony-Anhalt with respect to nitrate, aspatially-discrete sampling approach was developed, combined with spatial assessment relative to defined thresholds of different contaminants. The assessment was completed based on data from the national monitoring network in Saxony-Anhalt. First, groundwater recharge areas for the monitoring points were identified. For this purpose, groundwater measurement point and water quality data were combined with pedological-hydrogeological data in context to retention times along the complete flowpath in the aquifer and then analyzed by land use distribution and nitrogen inputs in the recharge zones. Evaluation of the subsurface processes could then be related not only to specific locations but also to the proximity of the monitoring points. In addition, time series methods for characterizing the nitrate attenuation capacity were derived from existing data. These included hydrograph analysis and emission-immission-analysis as well as various hydrochemical evaluation methods. Furthermore, new methodological approaches were developed. The methods were weighted and compared with the aim of estimating the site-specific nitrate reduction potential.