Assessment on multi-index agricultural drought vulnerability and spatial characteristics analysis

Drought events have huge harmful impact on socio-economic and environmental conditions and occur when an area does not receive significant precipitation for a sustained period of time. Drought causes damage to agriculture, ecosystems, and freshwater supplies. The increase in drought hazard may result from an increased duration and severity of meteorological drought, which then may lead to increased societal vulnerability to drought. In this study, the spatial analysis of drought severity and duration indices of meteorological droughts in Isfahan Province, Iran was carried out from vulnerability concept. The climatic pattern of study area displayed an arid and semiarid regions and assessment of drought vulnerability was essential due to water deficiency. The annual rainfall varied from 800 mm in western region to 75 mm eastern arid region. A set of 21 weather station with monthly rainfall recording for at least 30 provided a detailed analysis of the spatial distribution to identify drought areas. The SPI method was used to detail geographical variations in the drought vulnerability based on severity and duration of drought events at 3-month time steps. IDW interpolation technique was used to obtain SPI values where no station data existed. Because drought damage differed in the counties of study area, a comparison was made for the amount of damage between counties in agricultural areas. Finally, the agricultural drought vulnerability was evaluated by considering the agricultural areas. The results showed that drought phenomenon created more vulnerable environment for the agricultural sector in Isfahan Province. The maximum severity of drought was observed in counties of west while the spatial analysis of drought duration indicated that counties in east and a part of north and south of Isfahan experienced drought duration more than other areas. To consider both characteristics, the majority of counties such as Kashan, Aran va Bidgol and Semirom were found to be affected by severity and duration of drought. Agriculture vulnerability of drought in counties of Isfahan and Barkhar va Meimeh were maximum while these counties had low vulnerability compared with the entire region. The study also revealed that when agriculture area of each county is taken into consideration, the trend of drought changes.

کلیدواژه ها:

Indices of drought ، Agricultural drought vulnerability ، SPI ، Isfahan Province