Spatiotemporal analysis of standardized precipitation index for eastern Rajasthan, India
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Date
2023-01
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G. B. Pant University of Agriculture and Technology, Pantnagar
Abstract
The present study consists of spatiotemporal analysis of Standardized Precipitation Index (SPI) for Eastern Rajasthan, India. The total geographical study area is 42,857 km2 with a spatial extent from latitude 24°6' N to 27°15' N and longitude 75°83' to 77°54' E respectively. It covers 12.52% of Rajasthan’s total geographical area. The study area consists of seven districts namely Baran, Bharatpur, Kota, Jhalawar, Karauli, Dholpur and Sawai Madhopur. Using monthly precipitation data from 1991 to 2022, the Standardized Precipitation Index values were calculated by DrinC software. SPI values were calculated for the 3-Month (April-June), 3-Month (July-Sep), 6-Month (April-Sept), 6-Month (Oct-march) and for 12-Month. Further, trend between rainfall deviation and Standardized Precipitation Index was calculated. Spatial variation of drought was done by QGIS software for the study area. Drought was classified as mild, moderate, severe, or extreme category according to the value of SPI. Based on 3-Month SPI (April-June), it was noticed that all of the districts were severely and extremely affected by drought during the years 1991, 1992, and 1995. In the years 2006 and 2017 nearly all the districts experienced severe drought and all the districts experienced worst condition in the year 2002 as calculated by 3-Month SPI (July-Sept). Four districts out of seven districts experienced extreme drought in the year 2000 and 3 districts hit by drought severely in 2011 as calculated by 6-Month SPI (Oct-March). The drought faced in the state was of severe condition nearly in the entire study area in the year 2017 in April-Sept season as calculated by 6-Month SPI method. In the year 2017 nearly all the districts experienced severe drought and all districts were tremendously affected by extreme drought in 2002 (calculated using 12-M SPI). The value of coefficient of determination in April-June season was not good as in other seasons (calculated using 3-M, 6-M and 12-M SPI) for all the districts under study area. Drought may affect one district or group of districts depending on rainfall occurrence during the vegetative season. Thus, it is important to understand which area are prone to drought. So that adequate actions can be taken to resolve the problem.