Loess landslides triggered by diversion irrigation on the South Jingyang Platform in China

Continuous use of diversion irrigation has been associated with an increase in the frequency of loess landslides on the South Jingyang Platform in China. These landslides were classified into three types: loess flowslides, loess slides, and loess falls. Geological investigations revealed that cracks penetrated into the saturated zone from the ground surface. These cracks played a dominant role in the infiltration of surface water and led to a rise in the groundwater table. When the infiltration recharge exceeds the holding capacity of the paleosol, the latter behaves as aquifuge under relatively undrained conditions. This results in the accumulation of water at the bottom of the loess layer, thereby contributing to soil liquefaction and landslide initiation. Causing flowslides characterized by high speed and long distance. After the first flowslide occurs in an area, the seepage field and stress field of the slopes surrounding the flowslide changes, resulting in a decrease in slope stability. This, in turn, leads to the occurrence of retrograde loess slides in the same position that early flowslides occurred. These failures lead to a evolution of the platform. Besides, these landslides exhibit strong interactions with the substrates of the terrace of the Jing River during their movement. Shear liquefaction occurs in the terrace sand layers, resulting in the liquefied sand layer flows in a non-uniform and irregular manner. This leads to the formation of a thrust nappe structure over a long distance at the distal part of the deposits.