CitarumView: A Google Earth Engine–based application for Citarum River monitoring

Abstract

The Citarum River is a vital waterway in West Java, Indonesia, that sustains life along its sub-watershed. However, the river is facing significant environmental challenges, such as deforestation, and land-use changes, which have led to a decline in its ecosystem quality. To address this issue, the study aimed to develop an application called “CitarumView” that uses remote sensing methods to assess changes in index values focused on the condition of vegetation, built-up, soil moisture, water body, and surface temperature and obtain a description of the Citarum watershed condition in 2019 and 2020. The Google Earth Engine was used to collect and process satellite imagery data, including visual bands B4 (red), B3 (green), B2 (blue), Near-infrared (NIR), thermal infrared (B10 Landsat-8), and short-wave infrared (SWIR), from Sentinel-2 and Landsat-8 satellites. The CitarumView application provides a tool for decision-makers, researchers, and the general public to continuously monitor the river’s condition. The application also provides information on the changes in the ecosystem quality over time, allowing for more informed decisions to be made concerning river management. The analysis conducted using CitarumView revealed that the average of vegetation index increased by 6% with low to mid vegetation level, the max of water index increased by 4.5%, the average of moisture index increased by 39% with mid canopy water, the average of built-up index decreased by 28%, the average of soil adjusted vegetation index increased by 12% with mid to high vegetation, and the average of surface temperature decreased by 5% for 2019-2020.