Speaker
Description
Climate change challenges the water supply as decreasing groundwater recharge meets increasing water demand for agriculture, drinking water, and industry. Managed aquifer recharge (MAR) is widely used as a countermeasure to maintain groundwater levels and quality. However, with increasing rainfall intensity and prolonged drought periods the availability surface runoff as a source for MAR is becoming scarce, and the river flashiness is getting highly dynamic. This calls for very high infiltration capacities of the MAR systems, very fast treatment systems and even for geotechnical measures to control the discharge from the aquifer.
Our study area, the "Gäuboden" in Lower Bavaria is characterized by rich soils on Loess which covers the fluviatile quaternary sediments. The area is intensively farmed and the main crops are corn, sugar beets and potatoes. The spatial distribution of the crops grown manifests in the pattern of pesticides detected in the water of the small streams and in groundwater.
Monitoring of two small streams indicates a very fast response of the streams to heavy precipitation with water levels and turbidity increasing sharply. Total dissolved solids (TDS), on the other hand, are diluted in thunderstorms. During winter surface runoff is connected to the snow cover and the hydrochemistry is influenced by road deicing leading to a positive correlation of the TDS to moderate precipitation. The sediments in the river bed turned anoxic during summer months and at low water levels. The river bed is heavily affected during flash floods.
MAR under these conditions has to cope with high volumes which have to be infiltrated shortly and high sediment load which will lead to clogging of the infiltration systems. Although the water quality of the surface water reflects intensive farming activities, it is still better compared to groundwater. Thus MAR will improve groundwater quality. The conceptual design and model show that the long-term buffer capacity of the aquifer is limited but can be improved by infiltrating at the upstream boundary.
| Country | Germany |
|---|---|
| Acceptance of the Terms & Conditions | Click here to agree |
