Assessing the spatial variations of meteorological drought severity in Kurdistan Province at different time scales

Drought as a natural deficiency of precipitation over a period of time is a serious hazard to environment and the life of living species. Spatio-temporal variability of wet and dry spells will affect availability of water resources and management plans. Therefore, the lack of opportunity and sufficient resources causes serious damage in the time of drought occurrence. Drought disaster management includes a set of reactive responses which can reduce or mitigate the consequences of drought events. Thus, the analysis of drought indices is necessary to predict and assess the spatial and temporal variability of this phenomenon. The Standardized Precipitation Index, as a well-known meteorological drought indicator, is the capability of estimating various drought characteristics and can be used to analyze past droughts and predicting future droughts return periods. The Standardized Precipitation Index was selected due to its simplicity, ability of calculating the severity and duration of drought events of drought and mildew.
Materials & Methods In this study, drought condition and its spatio-temporal variations was investigated through Kurdistan province, Iran, using the Standardized Precipitation Index (SPI) calculated by DrinC software in different 3, 6 and 12 months’ time scales. Toward this attempt, the monthly precipitation data of nine synoptic stations of Kurdistan province were obtained at 9 synoptic stations including Sanandaj, Saghez, Zafarabad, Marivan, Baneh, Ghorveh, Bijar, Kamyaran and Dehgolan. The maximum available recorded were used for analysis. The maximum and minimum values of the SPI index in the 3, 6, and 12-month scales were defined in the study period. Also, spatial distribution of drought condition based on the 12-month index was presented alternately in some years of the study period. Then, the most important characteristics of wet and dry periods, including the total number of wet and dry months, were determined in different drought classes. In this research, the inverse distance weighting method was used to determine the spatial pattern of drought characteristics in the study area and zoning maps.
Results & Discussion The results of the study indicated that the severe drought in the three time scales has been occurred across Dehgolan station in 2005-2006 year. The longest period of drought occurrence with high severity level with 17-month length has been related to Qorveh station. The results of the study approved the variability of drought occurrences across the study area in different time scales.
Finally, the zoning maps of the study area indicate that in the North and West regions, there is a higher wet spell occurrence. While the Eastern parts of the province experienced more severe droughts. Accordingly, Dehgolan station has the first priority in terms of drought severity between stations and the lowest drought severity was defined in the Zafarabad (Dyvandreh) station.
Conclusion Also, it can be concluded that, the Dehgolan and Divandare stations assigned as highest and lowest priority in term of drought hazard occurrence in considered temporal time scales. As a result, drought crisis management and prediction can be one of the effective measures in reducing the damages of this climatic phenomenon, especially in drought prone areas. It is suggested that other drought indicators used to identifying drought characteristics and the results compared to obtain a comprehensive understanding on the drought severity and extent over the syudy area.