Inferring Land Conditions in the Tumen River Basin by Trend Analysis Based on Satellite Imagery and Geoinformation

Abstract

The aim of this study was to map the land condition within the area of the Tumen River Basin (TRB), located on the Sino–North Korean border, using trend analysis of environmental factors. The normalized difference vegetation index (NDVI) and land surface temperature (LST) trends over the past 30 years were analyzed to identify areas that have undergone degradation, restoration, and/or a transition. Landsat NDVI and LST were obtained using the Google Earth Engine (GEE) platform. Erosion was also gauged over the same period using the Revised Universal Soil Loss Equation (RUSLE). Our results showed that only 0.3% of the land within the TRB underwent change that can be characterized as statistically significant within the study period. We therefore infer that land degradation may not be a major concern in the study area. Areas with a significant upward trend of soil loss accounted for 0.8% of the basin’s footprint and were mainly distributed upstream of North Korea. However, more than 80% of the area was found to be suffering from water stress, 10% of these areas were statistically significant and most were located downstream.