South Asia river-flow projections and their implications for water resources

摘要: South Asia is a region with large and rising population, high dependence on water intense industries, such as agriculture highly variable climate. In recent years, fears over the changing Asian summer monsoon (ASM) rapidly retreating glaciers together increasing demands for resources have caused concern reliability of potential impact intensely irrigated crops in this region. Despite these concerns, there lack climate simulations enough resolution to capture complex orography, resource analysis limited by observations cycle paper we present first 25 km regional projections river flow Two global models (GCMs), which represent ASM reasonably well are downscaled (1960–2100) using model (RCM). absence robust observations, ERA-Interim reanalysis also providing constrained estimate balance comparison against GCMs (1990–2006). The RCM routed river-routing allow present-day future flows through available gauge observations. We examine how useful understanding changes general seasonality but overestimate maximum compared probably due positive rainfall bias abstraction model. suggest an trend annual mean some gauges analysis, cases almost doubling end century. river-flow rates still occur during period, magnitude cases, greater than natural variability. Increases could additional irrigation, largest usage region, has implications terms inundation risk. These projected increases be more countered demand depleted groundwater, domestic use or expansion industries. Including missing hydrological processes would make change sign projections.