Vulnerability analysis and identification of meteorological drought risk zones (Case research: North Khorasan Province)

Abstract
Background and Objective: Nowadays, decision-makers consider the integrated management of crisis and risk management in the face of drought. So far, the North Khorasan Province has suffered a lot of damage due to the drought risk. Therefore, in this case study, determining drought vulnerability and type of meteorological drought risk condition are major research problem in the last three decades, especially.
Materials and Methods: In this research, the Deciles Index (DI) was used to determine meteorological drought conditions. Firstly the monthly rainfall statistics were collected and tested for accuracy, precision and homogeneity of data from 27 selected meteorological and rain gauge stations during the period from 1990 to 2015. Accordingly, the factor of percentage of droughts occurrence and were determined with yearly time scale for each station, and then the Drought Hazard Index (DHI) was extracted for each of the different intensities. Then, the drought hazard index was extracted by assigning weights and degrees to each drought class based on drought severity. Meteorological drought vulnerability was also calculated using physical and socio-economic indicators. Subsequently, vulnerable areas of drought were identified. Finally, drought Risk quantification was calculated based on two factors:
potential drought hazards and vulnerability rate, and then drought risk areas were specified.
Results: The results of research on drought conditions showed that the most severe droughts occurred in the region in 1990, 1995, 2001 and 2008. Based on the drought hazard index, the results showed that the south western area and part of the northeast of the region, equal to 41.13% of the province, is a region that is prone to severe droughts. The largest of area (64.36% of the area) that located in the eastern part of the province has had severe drought vulnerability. Generally, about 85 percent of the total area of North Khorasan province has been affected by severe to moderate drought vulnerability. Also, about 75 percent of the entire area of the province has a moderate to severe drought risk.
Conclusion: The results of this study indicate that the hazards and vulnerabilities caused by meteorological drought seriously threaten North Khorasan province. The meteorological drought risk maps can be a helpful alert tool at risk reduction plans for all policy makers, managers and stakeholders in the research area. This issue is of particular importance in the planning of agricultural activities, the optimal use of water resources and green water management, especially in this province, where the livelihood of its agricultural also depends on rain-fed agriculture.