Probabilistic Precipitation Analysis in the Central Indus River Basin

Abstract Few studies exist on the analysis of precipitation and respective trends during past decades in the Central Indus Basin, Pakistan's principal river system. One reason for the lack of such studies is data scarcity. Modern-era reanalysis products offer the possibility to fill this knowledge gap by delivering simulated precipitation, temperature, and other atmospheric variables over poorly monitored areas. Reanalysis products are derived from atmospheric circulation reforecasts, whereby the models are adjusted by means of sequential data assimilation of past observations. Despite the fact that these products improve progressively, it is essential to postprocess the data by performing systematic bias correction and to assess the predictive uncertainty of one or multiple model predictions for specific ground locations. Here we employ six reanalysis products for the Central Indus Basin region with the aim to predict basin-average precipitation and discuss how the suggested approach can be valuable for water resources studies under conditions of climatic change.