An analysis of the inducing effects of irrigation and the responses of loess landslides in Heifangtai area

Since irrigation started in Heifangtai, a great number of landslides have occurred. However, there have been rare analyses of the landslide history in Heifangtai. In this paper, the landslide history in Heifangtai was analyzed. On such a basis, the relationship between the rising process of the groundwater table and the landslide history was studied, with the purpose of analyzing the impacts of the groundwater table of different periods on corresponding landslide stabilities, landslide volumes, and the failure velocities of the posterior walls. The analyses of historical data show that there is obvious dependency between the rise of groundwater table due to irrigation and the frequency and volume of landslide. The stability calculation results of selected typical landslides show that the landslides have multiple-phase retrogressive characteristics. With the increase of irrigation time, the volumes of landslides gradually decrease while the frequencies of occurrences gradually increase. The deformation results derived from DEM-based calculation also verify the calculation results. The results basically inverse the historical process of loess landslides induced by irrigation and provide data supports for the comprehensive prevention and control of Heifangtai landslides.