Dynamic monitoring and analysis of ecological quality based on RSEI: a case study of Akkulam-Veli Lake basin of Thiruvananthapuram city, Kerala, India

The world today is experiencing rapid urbanization, leading to prominent urban ecological problems. Evaluating urban ecological quality is crucial for monitoring environment-centered initiatives. The Akkulam-Veli Lake Basin, in Thiruvananthapuram, Kerala, India, is threatened by rapid urbanization. The present study proposes a comprehensive evaluation of the ecological quality by the Remote-Sensing Ecological Index (RSEI), based on the four indexes: greenness (NDVI), wetness (WET), dryness (NDSBI), and heat (LST), from 2000 to 2023. The interrelationship between RSEI and land use has been studied to properly analyze human activities' effects on the study region's ecological quality. Results indicated that the mean values of RSEI experienced a drastic decline from 0.733 in 2000 to 0.645 in 2015, and further declined to 0.611 in 2023, indicating an overall deterioration in the status of ecological quality in the Akkulam-Veli Lake Basin. Moreover, Moran's I index of 0.556 in 2000, 0.554 in 2015, and 0.552 in 2023 show that the sample RSEI values have a strong positive autocorrelation with adjacent values in the study area. The study provides evidence for the need for systematic urban planning and serves as a scientific reference for policymakers to manage the ecological qulaity of urban areas effectively.