Assessment of Catchment Resilience Through Integrated Vegetation and Waterbody Degradation Analysis in Peninsular India

Vegetation and water bodies play a crucial role in regulating the water and carbon cycles, however the climatic disturbances are impacting their functioning leading to the alterations in ecohydrological behavior of catchments. Therefore, it is crucial to identify the degraded ecosystems which are adversely affected under the influence of climate change. This study identifies degraded ecosystems in Peninsular India using remote sensing-based indicators, the Normalized Difference Vegetation Index (NDVI) for vegetation degradation and the Modified Normalized Difference Water Index (MNDWI) for waterbody changes. Sen’s slope trend analysis and Persistent change index (P-value) were applied to NDVI and surface water area (computed using MNDWI) for 90 catchments in Peninsular India to quantify the degradation levels. Results demonstrate that NDVI values range from 0.3 to 0.6 as majority of the Peninsular India is dominated by croplands. The spatial variation of surface water bodies indicates that larger waterbodies (>700 km²) are scattered in the central and north-western part of Peninsular India, while 59 out of 90 catchments have the lowest surface waterbody area (0.4-125 km²). Sen’s slope for NDVI varied from -0.03 year^-1 to 0.03 year^-1 observed across central, north western and north eastern regions of Peninsular India. Sen’s slope of water bodies computed catchment wise is varying from -8 km²yr^-1 in southern part to 35 km²yr^-1 in the Central and Northern Peninsular India. Persistent change analysis of NDVI and surface waterbody area reveals pockets of degradation in the northwest and southern regions of Peninsular India, with nearly 48 out of 90 catchments exhibiting low improvement in surface area of waterbodies. Comparison with climate and drought resilience indicates that resilient catchments experienced modest but stable gains in surface water area, while non-resilient catchments exhibited higher variability, including signs of both degradation and recovery. The findings provide a comprehensive understanding of vegetation and waterbody degradation, offering a scientific basis for prioritizing restoration and adaptation strategies in vulnerable catchments under climate change.