The Development Regularity Of Landslide And Its Influencing Factors Analysis In The Basin Of Central Gansu Province

The basin of central Gansu Province which located in the western Loess Plateau is one of the regions with serious landslide disasters in China. The paper studied the distribution and the influencing factors of landslides in the basin, indicated the trend of landslides development. It is important to the local government for disaster prevention and reduction.The paper analyzed historical data and survey data of landslides in Longzhong basin, and exported a distribution map of landslides combined Google earth images with DEM.The paper, Using data of physiognomy, geology, earthquakes, rainfall and river valley, analyzed influencing factors of the landslide hazards in Longzhong basin, evaluated with methods of overlay analysis, based on GIS technology.The paper divided the basin into two parts according to the concentration of landslide distribution:A landslide concentration areas of the Yellow river basin, B landslide concentration areas of Weihe river drainage basin; A was divided into north region A1 and south region A2. Landslides of the basin have features of that uniform regional distribution, groups distributed along the river, Strong recurrent, time to focus on and landslides of Weihe river basin more than Yellow river basin.The paper analyzed the impact factors of landslide, from the power of the inner geological environment and external dynamic environment. There are more landslides distribution at the slope of 18°～45°. at the Undulating terrain100～500m in the Loess hilly area, and at the Quaternary loess Underlying the Tertiary mudstone Tectonic movement play an important role for landslide as the inner power. Earthquakes, climate precipitation conditions and river erosion is a induced effect of the landslide.The paper studied the developing trends of landslide in the basin, from the inner power of geological structure and the external power such as climate precipitation conditions, river erosion and human activity. A1 north of the Yellow River basin is low occurred aera of landslide. A2 south of the Yellow River basin is occurred aera of landslide, B Weihe basin is high occurred aera of landslide.