Research Of Rainfall-induced Geological Disasters Early Warning And Forecasting

Ziyang County of Ankang City, Shaanxi Province is chosen as the research target in thepaper. With the wealth of detailed survey date and rainfall data, based on geologicalbackground by Ziyang and disaster types and characteristics were analyzed in-depth studyof the causes of geological disasters in Ziyang County, a comprehensive analysis of thecollapse, landslides, debris flows and precipitation type, intensity, and antecedent rainfallrelationship. Based on a logistic regression model to explore the method to determine thethreshold of precipitation inducing the regional landslide. It also preliminarily establishesthe precipitation-induced landslide forecast and early warning indicators and methods.（1） In the context of geological environment and disaster types, based on the analysisof the causes of disasters that Ziyang own specific geological structure in the context ofrainfall, earthquakes and human engineering activities are the main cause of geologicaldisasters factors, of which the most severely affected rainfall.（2） In this paper, though the on geological hazard warning forecast criterion studiedhave found that even the rain is caused by geological disasters Ziyang most importantrainfall patterns, and is more likely to lead to disaster or even the rain storm occurred duringthe storm phenomenon.（3）Logic regression model is introduced into the precipitation-induced landslide earlywarning and forecast, based on which, the precipitation-induced regional landslide thresholdexpression and the probability of rainfall’s impact on the landslide is established. Bylandslides and the statistical analysis between the rainfall and the rainfall process,expression considering both the rainfall intensity and rainfall threshold during the rainfall isestablished. Research indicates that the occurrence of landslide in Ziyang district is relevantto the rainfall during the3days, i.e., the rainfall of the same day （1-day rainfall）, the rainfallof the day before （2-day rainfall） and rainfall of the previous two days （3-day rainfall）. Therainfall precipitation expressed by rainfall threshold is determined as the accumulativerainfall of the rainfall on that same day and in the previous3days. Expression of landslide threshold in the rainfall-induced region of Ziyang district:R₁=-0.2546RL₂+105.61（4）Regional precipitation-induced landslide forecast and early warning indicators andmethods is established based on the research on the landslide risk zoning and landsliderainfall threshold. The research proposes the regional precipitation-induced landslide earlywarning and forecast index, including the threshold rainfall index R and landslideoccurrence indices L. Threshold rainfall index R is used to determine the possibility oflandslide occurrence and landslide occurrence indices L can be used to determine thepossible area of landslide occurrence and the likelihood. On this basis to establish theprecipitation-induced landslide forecast and early warning method.