Spatial correlations of river runoffs in a catchment

Abstract

Hydrological processes are characterised by spatio-temporal patterns with certain correlations in both time and space. Thus, time series of related quantities recorded at different locations show relevant correlations if these locations are influenced by the same patterns. The actual strength and temporal as well as spatial extension of these correlations depend crucially on the considered observable (temperature, runoff, precipitation, etc.). We analyse whether the corresponding interrelationships change significantly in the presence of changing environmental conditions. For this purpose, we systematically study a variety of measures which quantify the statistical dependence between the components of bi-and multivariate hydrological records. As a particular example, we consider runoff time series from an ensemble of gauges in the Upper Main catchment area in southern Germany. The qualitative behaviour of spatial correlations and their changes during extreme weather events are intensively discussed. © 2011 Springer-Verlag Berlin Heidelberg.