Research On Geological Hazard Meteorological Risk Forecast And Early Warning Model

Geological disasters are an important disaster in natural disasters. They have the characteristics of high frequency, sudden burst, wide geographical distribution and serious damage caused by disasters. China is a geological disaster-prone countries, the widespread distribution of disasters, the types of disasters in different regions are not the same, in the basic geological and geomorphological conditions remain the same, the geological disasters are basically by the earthquake, rainfall and human engineering activities Factors triggered by landslides and landslides as the representative of the geological disasters, affecting the occurrence of the most important and most direct external factors that is the region of the precipitation process. In this paper, Guang'an City, which is affected by the monsoon climate, concentrated rainstorms, located in the transitional areas of mountainous and hilly areas and frequent occurrence of rainfall-type geological disasters, is aimed at exploring the relationship between landslides and landslides caused by rainfall and the meteorological elements And based on the results of regional geological disaster assessment, in order to establish a disaster prediction model for weather forecasting. The main contents of this paper include the following five parts:(1) Based on the historical data of Guang'an historical disaster in 2008 and 2015, the distribution characteristics of landslide and collapse disaster in time and space are analyzed with the characteristics of topography and geomorphology, hydrological and climatic conditions. The results show that the two types of disasters occur mainly in the process of rainfall Concentrated 6-9 months, in the hills to the small undulating mountain transition zone will have a more obvious spatial differentiation rules.(2) In order to get better disaster evaluation results, in the sorting and extraction of various types of disaster factors, the paper analyzes the relationship between various geological hazard evaluation factors and historical disaster points, and scientifically and rationally optimizes the selection process of disaster evaluation factors. In view of the correlation factors of ASTER GDEM data, the microscopic topographic factors - slope and aspect extraction are analyzed from the perspective of slope factor mathematical statistics.For the extraction of macro-slope factor-terrain undulation, this paper uses the window increment method, which is commonly used in the industry. Based on the fitting analysis window and the maximum terrain fluctuation relation curve, the mean change point method is introduced to get the accurate The results show that when the terrain is extracted from the 45X45 analysis window, the grading results are in accordance with the actual geomorphology.(3) Based on the above analysis of the impact of various types of geological hazards on landslide and collapse, seven factors such as slope, topography, river, soil type, land use type, NDVI index and rainfall were identified as Guang'an City Key Factors in Risk Assessment of Geological Hazards. In order to eliminate the data heterogeneity and resolution difference among different factors, GIS-based platform is used to normalize the various factors, and the resolution of various evaluation factors is unified by using the grid resampling function. Finally, based on the binary nonlinear logistic regression model and the geological disaster point sample data, the weight value of each kind of evaluation factor is obtained, and the geological hazard risk assessment and zoning result in the study area are obtained.(4) Based on the historical disaster data of Guang'an City in 2008-2015, the relationship between historical landslide and collapse geological disasters and the rainfall,rainfall type, rainfall intensity and the amount of rainfall before the disaster occurred, and the effective rainfall model The Combining the results of the risk zoning in the study area with the model, the characteristics of precipitation heterogeneity and the frequency of occurrence of rainfall-type geological disasters in the high, medium and low risk areas of the study area are analyzed synthetically, and the influence coefficient of precipitation is obtained. The critical value of the rainfall process in different risk class areas, and finally the weather forecast and warning criteria, namely, the forecast level, the temporary report level and the alarm level critical rainfall.(5) According to the influence coefficient of precipitation, the critical effective rainfall,combined with the prediction of precipitation in the future, taking full account of the influence of rainfall and rain intensity on different falling area, the model of coupling forecasting of landslide and collapse geological hazard can be established. The possibility of landslides and landslides in the region to predict the occurrence of disasters under the conditions of precipitation, thus realizing the meteorological risk level forecast and early warning of geological disasters. Based on the GIS technology, this paper takes the fine grid as the basic unit information, the comprehensive application forecast model and the early warning model, and combines the short-term forecast, the short-term forecast and the near-warning, and basically realized the Guang'an City, the precipitation of geological disasters - landslide and collapse of the fine forecasting early warning, for similar hilly areas of geological hazards forecasting weather forecast model provides a reference and reference.