Continuous Remote Sensing Ecological Index (CRSEI): Unveiling Annul Eco-Environmental Quality Changes of the Continental Coast of East and Southeast Asia

Abstract

The eco-environmental quality of East and Southeast Asian coastal regions has undergone substantial changes in the 21st century in response to extensive urbanization and escalating anthropogenic pressures. Assess such changes and achieving regional sustainable development goals requires quantitative monitoring of the eco-environment, posing a significant challenge. The remote sensing ecological index (RSEI) was recently proposed and applied to quantitatively monitor the eco-environmental quality, but bias during multitemporal observations is a major limitation. Thus, a novel method, Continuous Remote Sensing Ecological Index (CRSEI), was developed in this study to enable constant and objective monitoring of large-scale and long-term environmental changes. By implementing the change detection algorithm to mitigate multitemporal bias stemming from imaging conditions and sensor status, CRSEI is expected to enhance our current understanding of environmental changes and serve as a reliable scientific reference for environmental protection across diverse scales. The CRSEI results of our study region indicate that the distribution and status of eco-environmental quality decreased slightly from 2009 to 2021. On a regional level, each area revealed different conditions. First, the Korean Peninsula exhibits relatively stable and well-preserved eco-environmental quality. Second, the North China coast starts with a lower baseline, but experienced the most substantial improvement. Third, South China and Myanmar’s coastal regions maintained relatively stable eco-environmental quality. Fourth, the continental coast of Southeast Asian countries witnessed a significant decline, particularly in the western border regions of Cambodia, where unrestricted cultivation led to the destruction of tropical rainforests.