| Menyuan Basin is located in the Qilian Mountains kidnapped and Daban mountain. Thegeological environment is fragile, geological disaster-prone areas. And storm-prone areas,precipitation is relatively concentrated, geological disasters occur frequently. Around theseproblems, through literature review, data collection, field investigation and laboratory testmethod of combining conducted hydrological analysis, under the next distribution ofgeological disasters in the basin studies, and rainfall Xia Jiangou landslide stability analysis,aimed at prevention and control of geological disasters of Menyuan region and providescientific basis. The main results are as follows:(1) Linear trend method and multiple regression analysis were used, for analysis oftrends Menyuan basin rainfall, evaporation, runoff and flooding. The results showed that: theMenyuan basin precipitation decreasing trend, the uneven distribution of the year,concentrated in the June to September; evaporation in spring、summer and autumn showed adecreasing trend, increasing trend of winter evaporation, evaporation changes over theseasons outstanding; runoff overall decreasing trend, the uneven distribution of runoff duringthe year, changes during the curve was " peak "; flood occurrence mostly from June toSeptember, mainly caused by the rain.(2) Based on ArcGIS platform, DEM data, extracting river networks basin, sub-basindivide. Select the threshold of4000can reflect the region’s water system. The results showthat the data extracted with basin characteristics with high precision and accuracy. Canprovide geographic information for digitize watershed, water resources planning anddevelopment, building distributed hydrological model and other aspects application.(3) The232geological disasters in the study area,157occurred in the erosion hillyarea, accounting for67.7%of the total; prone to debris flow in the watershed area of morethan0.1-0.5Km2, accounting for86.8%of the total number of debris flow,"V"-shaped debrisflow landslides accounted for79.6%of the total; the slope, channel type two kinds ofgeological hazards are mainly distributed in the1,2level network range; geological hazard ofslope type dispersively distributed, channel type linear distribution; geological disasterdistribution within a year corresponding precipitation、 runoff, concentrated in the month of 6-9.(4) According to the landslide survey data, analyze the factors and mechanisms of XiaJiangou landslide affected; using GeoStudio calculation software to simulate the impact onslope stability during different rainfall intensity and rainfall duration. The slope stability wasevaluated, the results are displayed in two different rainfall intensity settings, landslidessafety factor greater than1, indicating that the landslide is currently in stable condition.Landslide maximum shear stress concentrated in the front, along with the time extension, theslope leading edge deformation intensifies, unstable trend. |
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