 Analyses are conducted for six catchments that are global in coverage and feature strong contrasts in spatial scale as well as climatic and developmental conditions. A single GHM, MACPDM.09, is applied to all catchments whilst different CHMs are applied for each catchment. CHMs typically simulate water resource impacts based on a more explicit representation of catchment water resources than that available from the GHM. This article was authored by S. N. Gosling, R. G. Taylor, N. W. Arnell and others.