The effect of climate change on watershed water balance

Abstract

Climate change refers to a statistically significant long-term shift in the pattern (mean state and variability) of regional or global climate. This phenomenon is attributed to human activities, which have resulted in an increased concentration of greenhouse gases in the global atmosphere. Climate change is already having major effects on the physical environment and biota. The highlighted study investigated the effects of climate change on the sustainability of water resources at a watershed scale, by defining different patterns of climate change (i.e. ideal, medium, and critical) and weighing the output of different general circulation models (GCM). Based on given climate change patterns, the meteorological data (particularly near and far future temperature and precipitation data) were downscaled to the local or regional scale using stochastic weather generators (WGs). The link between climate change and surface runoff was then developed by modelling unit hydrographs within the conceptual framework of rainfall-runoff models. This allowed a reasonable estimate of the future state of surface water resources in the face of climate change to be made; as well as an assertion of the impact of climate change on intra-watershed water consumption (e.g. agricultural, industrial, domestic). Water resource sustainability indices were used to assess the impact of climate change on water resource dynamics within watersheds.