Vegetation topographic coupling effect in the Yellow River arsenic sandstone area based on Landsat images

Research on the dynamic changes in vegetation coverage and itscoupling effect with terrain factors can provide theoretical support for vegetation restoration in the Yellow River arsenic sandstone area, a fragile ecological environment affected by severe erosion. We examined the vegetation coverage characteristics and trends in the Yellow River arsenic sandstone area over the past 25 years using Landsat series data and linear regression analysis. Terrain data were used to explore the coupling law of vegetation coverage for terrain factors such as elevation, slope, slope direction, and topographic index, and combined with geographic detectors to reveal the driving mechanism of terrain factors on vegetation coverage. (1) From 2000 to 2024, the average vegetation coverage in the Yellow River arsenic sandstone area was between 0.34 and 0.52, showing an overall upward trend; (2) Vegetation coverage was generally high in the soil-covered and sand-covered areas and low in exposed arsenic sandstone areas; (3) With increasing altitude and slope, vegetation coverage in the arsenic sandstone areas showed a trend of initial increase followed by a decrease, reaching the maximum at 1200-1300 m and 5°-15°, respectively, and showing strong fluctuation; in terms of topographical position, vegetation was mainly distributed at the medium topographical position between 0.38 and 0.7; (4) The factors driving vegetation coverage were ranked in the following descending order based on their degree of influence: elevation>slope>topographic index>slope direction. The relationship between any two factors was nonlinear enhanced, with the largest q value (0.22) being observed for elevation vs. topographic index. The overall vegetation coverage in the Yellow River arsenic sandstone area is currently increasing, and the coupling effect with topographic factors is obvious. The results of this study provide scientific support for precise vegetation allocation in the Yellow River arsenic sandstone area, contributing to the high-quality development of the Yellow River Basin.