Description
Keywords:
Catchment hydrology, analysis of flow components, hydrograph separation, lithofazie concept, isotope hydrology, residence time, average residence time, transition compartments, tritium, oxygen-18
Objectives
In order to design a river bed model for the forecasting and controlliing of saline loads in the upper and middle Unstrut river, the following data is necessary: Information at catchment level regarding residence time, transition amounts and the respective transition compartments of especially ground water based flow components.
Approach
Saline transport is coupled with discharge processes within the water cycle. With the help of isotope based hydrological methods we are able to quantify the various fractions of the discharge components and determine their average residence times. This methodology is applied to various research areas within the Unstrut catchment area.
Scheme of isotope method
Between the catchment area of the river Unstrut and the gauge Oldisleben we used the hydrograph separation model DIFGA to separate the discharge components and to calculate the average residence time of the slowest ground water based discharge component with the help of the environmental isotope Tritium. Analogously, in the heart of the area stongly affected by mining induced salinity (i.e. the Wipper catchment area), we analysed the near surface and hypodermic discharge components by the modelling of the transport processes of the oxygen 18 isotope.
For the potash storage dumps of the potash mines we intended to analyse the hydrological processes and decide metholologies to support these.