Study On Landslide Hazard Assessment In Linyou County In SHAANXI Province

Relying on the national science and technology support project "the geological disaster risk assessment engineering research" and the China geological survay project "Geo-hazard detailed investigation in Baoji city",the paper study the geology hazard of Linyou County by the research methodology of field survey, remote sense interpretation and laboratory test, we establish the Linyou County geology disaster database at last.More attention was paid on the sliding prosess reseach by lab test and numerical modeling.With the ARCGIS software, we use the information content model to calculate and zone the geological hazard susceptibility area and dangerous area.Trough these studies,the major progress and conclusion are obtained in this thesis as follows:1)The main factors which control the distribution of geo-hazards and its background:In the South of Linyou County is the Qi-mountain, the west is Liupan mountain and Long-mountain, northeastern is the loess plateau, the watershed of Wei river and Jing river from east to west was in the middle of this area, The underlying bedrock show the monocline shape, and to Northwest dip at low angle in this area, the appearing area of bedrock was controlled by the degree of river erosion,On underlying bedrock was the red clay and the loess, the red clay sliding surface sees much,, and the intensity index of the loess increases along with the water content.2) the distribute the characteristic of Linyou County geology disaster:The Linyou County geology disaster's characteristic is that the landslide and loess rockout show middle and small scale, small disaster is frequently, the plague are few, it happen associated with the rainstorm, the landslides in both sides of the watershed are centralized; Nearby the loess plateau collapsing is serious, The landslide along the watershed is strong sensitivity to the continuous rain, and the distortion sign is obvious.3) rainfall is the main factor which results to Linyou County geology disasterGEO-SLOPE software was used to slove the stress arid strain of the Lingnan landslide,ansys the stability in different conditions,such as different rainfall intensity, rainfall duration of flow, the resulit show that the scope of the landslide will bigger and increase the depth of sliding surface under long rainfall,. In addition, the landslide will move at a low speed.4) susceptibility and dangerous zonesWith the ARCGIS software,the geological disaster susceptibility degree was divided to four levels by spatial analysis function:,high susceptibility zones in this district account for 681.35km2, middle susceptibility zones include 294.24km2, low susceptibility zones have 454.12km2, In the county approximately 274.80km2 have no disaster.Under the ARCGIS platform's spatial analysis function, by computing the disaster growth dot density,we divide the area into two kinds of the dangerous rank, the most dangerous zones approximately has three regions.