DRYP 1.0: a parsimonious hydrological model of DRYland Partitioning of the water balance

Abstract. Dryland regions are characterised by water scarcity and facing major challenges under climate change. One difficulty is anticipating how rainfall will be partitioned into evaporative losses, groundwater, soil moisture, runoff (the balance) in the future, which has important implications for resources dryland ecosystems. However, order to effectively estimate balance, hydrological models drylands need capture key processes at appropriate spatio-temporal scales. These include spatially restricted temporally brief rainfall, high evaporation rates, transmission focused groundwater recharge. Lack of available input evaluation data computational costs explicit representation ephemeral surface–groundwater interactions restrict usefulness most these environments. Therefore, here we have developed a parsimonious distributed model DRYland Partitioning (DRYP). The DRYP incorporates partitioning with limited requirements, tested it data-rich Walnut Gulch Experimental Watershed against measurements streamflow, evapotranspiration. Overall, showed skill quantifying main components balance including monthly observations streamflow (Nash–Sutcliffe efficiency, NSE, ? 0.7), evapotranspiration (NSE > 0.6), moisture 0.7). that consumes 90 % total precipitation catchment < 1 leaves as streamflow. Greater than overland flow generated lost through channels losses. only 35 losses percolate aquifer recharge, whereas rest atmosphere riparian modular, versatile, Python-based can used anticipate plan climatic anthropogenic changes fluxes storage regions.