Assessment of geo-hazards in a rapidly changing landscape: the three Gorges Reservoir Region in China

Abstract

Large dam projects attract worldwide scientific attention due to their environmental impacts and socioeconomic consequences. One prominent example is the Three Gorges Dam (TGD) at the Yangtze River in China. Due to considerable resettlements, large-scale expansion of infrastructure and shifts in land use and management, the TGD project has irreversible impacts on the Upper Yangtze River Basin and strongly challenges the environmental conditions of this fast-developing region. Soil erosion and landslides are major geo-hazards. Knowing the extent and consequences of those geo-hazards for the landscape is essential to predict and evaluate their risk potential and allows for the development of strategies for a sustainable future land use in the Three Gorges Region (TGR). In this context, our research objectives are (1) to better understand the mechanisms of soil erosion, landslides, and diffuse matter fluxes in the TGR and their anthropogenic and environmental control factors, (2) to predict their hazard potential by combining spatial and temporal, scenario-driven high-resolution modeling in combination with multi-scale earth observation data, and (3) to develop a multi-component approach for the assessment and monitoring of geogene structures and processes. The paper describes the workflow of the project and introduces case studies, representing the current state of our research. It is shown that land-use changes as well as the water-level fluctuations of the reservoir are the crucial drivers for the soil erosion and landslide hazard. Furthermore, we present a framework aiming at the establishment of a monitoring and measuring network as well as an early warning system.