黄土高原降水入渗方式与引发滑坡研究——以甘肃黄土地区为例

黄土高原是中国滑坡灾害最为发育的地区，降水是引发黄土滑坡的主要因素之一。黄土包气带厚度大，降水入渗方式与引发黄土滑坡的过程和机理问题长期受到广泛关注。以甘肃黄土地区为例，通过实地调查和综合研究认为，黄土高原地区降水入渗方式多样，受地形地貌、气候和降水类型等因素影响，降水入渗方式与引发滑坡特征之间存在地域性差异。在降水量较小的黄土丘陵区，暴雨所产生的地表径流主要通过落水洞和节理裂隙等宏观优势通道点状短期快速入渗，增大黄土含水率，软化黄土体，降低斜坡稳定性，引发黄土滑坡。在降水量较大的黄土塬、黄土台塬和黄土宽梁区，大气降水、灌溉水主要经由黄土包气带中的孔隙呈面状长期缓慢入渗补给黄土潜水，在丰水年连阴雨可引发群发性黄土滑坡。研究结果对黄土高原降水引发滑坡预警阈值的科学设定具有指导意义。

Study on precipitation infiltration modes and landslides in the Loess Plateau -a case study of Gansu loess area

The Northwest Loess Plateau is the most developed area of landslides in China, and precipitation is one of the main factors that cause loess landslides. The precipitation infiltration mode in loess aeration zone and the process and mechanism of causing loess landslides have been widely concerned for a long time. This paper takes the loess region of Gansu Province as an example. Through field investigation and comprehensive research, it is believed that there are various precipitation infiltration modes in the Loess Plateau influenced by landform, climate, precipitation type and other factors, and there are regional differences between precipitation infiltration modes and induced landslide characteristics in the Loess Plateau. In the loess hilly area with small precipitation, the surface runoff generated during rainstorm mainly infiltrates through the macro dominant channels such as sinkholes and joints and fissures in a short time, increasing the moisture content of loess, softening the loess body, reducing the stability of slopes, and finally causing loess landslides. In the loess tableland and loess wide flat area with large precipitation, atmospheric precipitation and irrigation water mainly recharge the loess phreatic water through the pores in the loess aeration zone in the form of areal long-term slow infiltration, and the continuous overcast rain in wet years can lead to mass loess landslides. The study has guiding significance for scientific setting of early-warning threshold of landslides caused by precipitation in the Loess Plateau.