Pattern-process relationships in surface hydrology: Hydrological connectivity expressed in landscape metrics

Abstract

The degree of hydrological connectivity is mainly determined by the spatial organisation of heterogeneity. A meaningful and aggregate abstraction of spatial patterns is one of the promising means to gain fundamental insights into this complex interaction and can, moreover, be used as a tool to acquire a profound understanding of the major controls of catchment hydrology. In order to disclose such controls, pattern-process relationships and the explanatory power of landscape metrics were tested by simulating the runoff of differently patterned virtual basins, generated by neutral landscape models and fractal networks and solved by a surface hydrological model composed of kinematic wave routing and Green-Ampt infiltration. A total of 23 landscape metrics quantified the spatial patterns and were subsequently related to the functional connectivity, assessed as the proportion of internal runoff generation constituting the hydrological response at the outlet. Landscape metrics allowed the identification of dominant features of heterogeneity that explained the observed connectivity, and to disclose changes in control with class abundance. Therefore, landscape metrics are a useful tool for basin comparison and classification in terms of the dominant processes and the corresponding model structure requirements. © 2011 John Wiley & Sons, Ltd.