Variation of δ18O and δD in precipitation and stream waters across the Kashmir Himalaya (India) to distinguish and estimate the seasonal sources of stream flow

► Strong spatial and temporal variation in isotopic composition was found. ► A mean altitude effect was observed. ► The LMWL for the Kashmir Himalaya was established. ► Snowmelt dominantly contributes to the runoff. ► The mean residence time of the surface water was estimated.