Design of Drought Monitoring System Based on Integrated Index In Zayanderood River Basin -Iran

Drought is an extended period of low precipitation which resulted in injuries to consumers of water and reducing their performance, especially in agriculture. Different indices have already been proposed for evaluating drought, based on one of the varieties of meteorological, hydrological and agricultural droughts, but no indices has been identified yet, encompassing all factors. This study has been carried out to assess existing indices for drought monitoring and proposing an integrated index including main factors of drought and is applied to the Zayandehrood river basin as study area, because of its sensitive situation in the central Iran plateau. An integrated index includes various drought factors such as meteorological, hydrological, agricultural, socio - economical and environmental factors. In designing of this integrated index, a combination of static and dynamic layers has been used. Static layers include land use, slope and soil type. Dynamic layers include precipitation, evaporation, temperature, surface water storage, groundwater levels position, and environmental needs. All these layers are analyzed in GIS software and drought zoning maps is prepared. Results showed that based on values of integrated index, water year 1371-72 was a wet year and water year 1378-79 was the most critical, in terms of drought.