Extreme low flows have a number of negative impacts on ecology and economy. Operational monitoring and early warning of droughts, however, is mainly based on a number of different precipitation base drought indices such as the standardized precipitation index (SPI) and the standardized precipitation evaporation index (SPEI). An ongoing question is, how these meteorological indices are linked to drought in those components of the water cycle which allow direct use of the water, i.e. surface water (rivers and lakes) and groundwater.
The main objective of this thesis will be to elucidate how the link between meteorological indices (SPI and SPEI) and river flow varies across large regions with different climates and hydrological regimes. One outcome could be a map showing regional differences in the strength of the link, the time lag between drought defined by meteorological indices and low flow, and the dependence of these on the low flow indices of interest. The regional differences should be explained by the relative relevance of meteorology and basin characteristics on streamflow.
Data for SPI and SPEI at different temporal scales will be made available through the EU project DROUGHT R&SPI. Streamflow time series are available from the European Water Archive. A method to analyse the link needs to be developed. A starting point may be composites of SPI maps preceding defined low flow events in particular regions.
Programming of the analysis and visualisation of large datasets, GIS, basic statistics
English preferred due to the link to EU project
Kerstin Stahl, (Veit Blauhut)
Vicente-Serrano, S. M., S. Beguería, et al. (2010). „A Multiscalar Drought Index Sensitive to Global Warming: The Standardized Precipitation Evapotranspiration Index.“ Journal of Climate 23(7): 1696-1718.
Beguería, S., S. M. Vicente-Serrano, et al. (2010). „A Multiscalar Global Drought Dataset: The SPEIbase: A New Gridded Product for the Analysis of Drought Variability and Impacts.“ Bulletin of the American Meteorological Society 91(10): 1351-1356.
Vicente-Serrano, S. M., S. Beguería, et al. (2012).„Performance of Drought Indices for Ecological, Agricultural, and Hydrological Applications.“ Earth Interactions 16(10): 1-27.