Evaluating Biophysical Impacts of Watershed Interventions Using Time-Series Satellite Data: A Study in Semi-Arid Andhra Pradesh

This study demonstrates the critical role of satellite data in monitoring and evaluating NRM interventions in semi-arid, rain-fed agricultural regions. This study evaluates the biophysical impacts of Watershed level interventions in Bandlapalle village, Anantapur district, Andhra Pradesh, using time-series satellite data. Landsat-TM data (2006–2022) was utilized for seamless temporal analysis, with 2006 as the base year due to the commencement of MGNREGA and IWMP projects during this period. The study focused on the analysis of Land Use Land Cover (LULC), Vegetation Condition Index (VCI), Normalized Difference Water Index (NDWI), and Soil Moisture Index (SMI) across three cropping seasons - Kharif, Rabi, and Zaid. LULC analysis shows an increase in agricultural land from 1839.21 ha in 2006 to 2041.45 ha in 2022, alongside a decrease in scrubland from 464.39 ha to 268.79 ha, indicating shifts in land use patterns. VCI values improved significantly, reflecting healthier vegetation over time, particularly in the Rabi season, where the high vegetation class increased from 287.12 ha in 2007 to 1539.11 ha in 2022. NDWI analysis shows an overall improvement in water availability, with high NDWI class areas expanding notably during the Kharif season, from 214.78 ha in 2006 to 2046.13 ha in 2021. Similarly, SMI analysis indicates enhanced soil moisture levels, especially during the Rabi and Zaid seasons, with medium and high moisture areas showing considerable growth. The results reflects the positive influence of watershed management and water harvesting structures, such as check dams and farm ponds, on improving land use patterns, vegetation health, water availability, and soil moisture retention.