A Hydrological Perspective on Interpretation of Available Climate Projections for the Upper Indus Basin

Abstract For the water resources of the Upper Indus Basin (UIB), which derive largely from cryosphere-dominated hydrological processes, the key determinants are mass inputs—in the form of snow and rain—and energy inputs (including radiation), which are well indexed by temperature. Because the topographical relief or more precisely the hypsometry, that is, the distribution of surface area with elevation, of the UIB is one of its defining characteristics, the ability of models to accurately represent the variation of climate inputs with respect to elevation is especially crucial. The variable skill of available climate model outputs at representing these determinants under historical conditions provides important insights for interpreting the likelihood and implications of future climate conditions simulated by these models.