146 / 2024-02-20 17:41:00

Study on land cover and exposure pattern of the Three Gorges Reservoir water-level fluctuation zone based on multi-source spatio-temporal datasets

Three Gorges Dam,water-level fluctuation zone,water surface line,Sentinel-2,ecological protection

Abstract: The Three Gorges Dam, as the largest comprehensive hydropower project at home and abroad, reached the designed maximum storage level (175 m) for the first time in October 2010, marking the achievement of the 145m~175m water-level fluctuation zone (WLFZ). Under the current water level scheduling mode of the reservoir, the WLFZ of the Three Gorges Reservoir also shows periodic inundation and re-exposure characteristics due to water level fluctuations. As an integral part of the Three Gorges Reservoir, the ecological and environmental health of the WLFZ directly affects the stability of the reservoir bank and the safe operation of the reservoir. The ecological restoration of the WLFZ is not only beneficial to ecological environmental protection, but also the carbon sequestration can improve the carbon neutral contribution by the Three Gorges Reservoir. In this paper, based on the long series of measured water level data in the Three Gorges reservoir area, combined with Landsat, Sentinel and other multi-source satellite remote sensing data sources, we reconstructed the water surface line of the Three Gorges reservoir using the remote sensing water body extraction method, and based on this, we investigated the land exposure or inundation episode in the WLFZ by analyzing the land use/cover pattern of different elevation intervals in the WLFZ of Three Gorges Reservoir and carried out the remote sensing mapping. The results of the study can provide data basis and theoretical support for the ecological restoration of the WLFZ in the Three Gorges Reservoir, and have guiding significance for the ecological evolution, ecological protection and vegetation restoration of the WLFZ in this reservoir.