Drought Analysis in Right Bank Main Canal Command Area of Dharoi Reservoir using Meteorological and Remote Sensing Indices

Abstract

Drought is characterized by a prolonged and abnormal lack of moisture, often stemming from insufficient or uneven distribution of precipitation, resulting in water shortages in streams or reservoirs, with detrimental impacts on both natural and socioeconomic systems. The paper focuses on the climatic drought patterns within the Right Bank Main Canal Command Area of Gujarat’s Dharoi Reservoir. To evaluate drought conditions, the study employs several indices including the Standardized Precipitation Index (SPI)and Normalized Difference Vegetation Index (NDVI). Daily rainfall data, obtained from IMD gridded data and extracted using ArcGIS software, is utilized to calculate SPI values at a three-month time scale. NDVI is determined using Landsat-8 OLI data spanning from 2013 to 2022 to analyze changes in agricultural vegetation. Comparisons among NDVI and SPI reveal that the year 2018 experienced significant rainfall deficits across the region, leading to severe water scarcity. This shortage impacted agricultural practices, evident in reduced crop cultivation areas as indicated by NDVI results and validated using the crop yield data for the time series. Specifically, the NDVI analysis highlights that 33.5% of the RBMC command area exhibited signs of dryness, with an additional 64.5% showing moderate dryness. The study endeavors to pinpoint drought-affected regions utilizing precipitation data, reservoir storage information, and remote sensing methodologies.