Studies On Active Degree Forecast Of Debris Flow Based On The Technique Of GIS

Debris flow is a kind of natural disaster which causes extreme loss to human beings. One of the most important measures to defend the debris flow is to make the administration of the related calamity information and make forecast for its active degree. In such research, we need capture, process and analyze the spatial data. As well known as, RS can capture spatial data correctly and rapidly, and GIS is good at storing, administrating, analyzing, calculating and mapping the vast spatial data. So it has great meaning to apply the integration of RS and GIS technology in capturing, managing, analyzing and handling the data of Debris flow.Based on the RS and GIS technology, this paper makes a lot of study in the following aspects for capturing, analyzing and forecasting the Debris flow.(l)Establish the DEM in different phases for the Debris flow drainage area, and the original data is obtained from aerial photograph taken in different period of time.(2) Based on the Debris flow DEM, some research is made in the spatial analysis of terrain factors (slop, aspect) for the Debris flow drainage area and the volume evaluation method; (3) Build the active degree forecast model for the Debris flow; (4)Deduce the method to obtain and calculate the annual average accumulation of solid and the relative sedimentation of the bed of the main drainage basin based on DEM spatial analysis.The volume (using certain level as datum) of the Debris flow drainage area can also be calculated based on the TIN. And by comparing with previous result, it is proved that the accuracy of this method is better than those methods using section or grid.Debris flow active degree forecast model is designed here based on the research of Debris flow factors and the current Debris flow forecast model. Though such model, we can forecast the eruption of Debris flow to certain extent.According to the difference DEM of different phases, the amount of earthworkloss can be calculated, on which Debris flow active degree factor-the evaluationmethod for the annual accumulation of solid matter can also be obtained. In this paper,algorithms are designed for this method.