Long-term drought monitoring of the Zayandehrud River basin (central Iran) using hydroclimatological models and satellite observations

Drought is one of the most complex and threatening disasters, defined as a period drier-than-normal conditions which results in water-related problems. In addition to climate variation, human activities can cause or intensify drought through groundwater overextraction, unsupervised expansion agricultural lands, etc. One prime example such has been observed Zayandehrud River basin central Iran. We investigate long-term (1986 2019) using meteorological, hydrological, indices. The main focus this research explore impact irrigated area upstream sub-basins on downstream. To end, different indices are employed over whole its sub-basins. indicate that precipitation index snow reserves do not show trend during study period, while combined precipitation–evapotranspiration storage decline. concludes lands river upstream, rising air temperature, increasing population industrial likely driving forces midstream downstream parts basin.