Groundwater is a life-sustaining resource providing water to billions of people, to global industries and agriculture, and to ecosystems. Karst develops from the dissolution of carbonate rock. Due to their high porosity, karst aquifers are commonly used for water supply. China is the country with the widest karst distribution in the world. Karst water management and related environmental geology problems involve a huge territory and a large part of its population (Liu et al., 2016). Therefore karst water resources, and their management, have a great meaning for sustainable development of Chinese groundwater resources.

The aim of this work is to adapt and apply a model hat includes the heterogeneity of selected subsurface characteristics (soil and rock storages and hydraulic conductivities) to the karst regions in Southwest China. A representative karst system (Lingshui Spring,Wuming basin, Guangxi district) is chosen as a pilot site. Available data include daily climatic forcings, spring discharge observations, water level and physiochemical observations, hydrochemistry and water isotopes. Automatic calibration and sensitivity analysis schemes will be applied to evaluate the model before it will be testes at other karst systems in the region (data from Global Karst Data Base).

Finally, the model will be used to assess the sensitivity of karstic groundwater resources to climate variability.

Along the course of the MSc thesis it will be possible to visit the study site and the 2nd advisor of the thesis at the Key Laboratory of Karst Dynamics at the Institute of Karst Geology, Guilin, China. The host will be able to cover the expenses of accommodation and field trips. Support to obtain travel funding will be provided by Dr. Hartmann.

This MSc thesis will require to apply and further develop skills and data processing and analysis (Excel, R), as well as processing and visualizing spatial information (GRASS or ArcGIS). General knowledge about modelling and model evaluation is necessary BUT knowing Matlab programming language is NOT a mandatory skill (a ready-to work version of the model including model diagnostics and support for necessary modifications will be provided by the supervisor). Collaboration with MSc students working with the same model is possible but not required.

The successful conduction of the thesis will prepare the student to work in national and international consultancies, governmental offices and research. The topic and task of the thesis will be adapted to the desired future working field of the student and mentoring for a successful start into the first job will be provided by the supervisor.

Andreas Hartmann, Gou Fang (Key Laboratory of Karst Dynamics at the Institute of Karst Geology, Guilin, China)

Andreas Hartmann andreas.hartmann@hydrology.uni-freiburg.de Tel. +49 (0)761 / 203-3520

Preferably in English.

Hartmann, A., Barberá, J.A., Lange, J., Andreo, B., Weiler, M., 2013. Progress in the hydrologic simulation of time variant recharge areas of karst systems – Exemplified at a karst spring in Southern Spain. Adv. Water Resour. 54, 149–160. doi:10.1016/j.advwatres.2013.01.010

Guo, F., Wang, W., Jiang, G. and Huang, S., 2016: Distribution and stable isotopic compositions of organic carbon in surface sediments in hyporheic zone of karst springs, Environ. Earth Sci., 75(10), 850, doi:10.1007/s12665-016-5672-8.

Berghuijs, W. R., Hartmann, A. and Woods, R. A.,2016: Streamflow sensitivity to water storage changes across Europe, Geophys. Res. Lett., doi:10.1002/2016GL067927.