Extraction And Application Of Deflagration Landform In Mountain And Forest Region

In recent years,the frequent occurrence of forest fires with the occurrence of deflagration phenomenon has caused serious loss of life and property,which has attracted extensive attention in the domestic and overseas.The research on deflagration landform is increasing.Due to the particularity of forest deflagration landform,the feature of landform is rich and it is easy to bring casualty of risk in forest fire protection.How to scientifically and efficiently realize the digital expression and extraction of deflagration landform is an important challenge faced by forest fire protection construction at present.Under the background of digitization,the current researches on deflagration landform is mostly limited to qualitative analysis and lack of systematic quantitative expression and extraction.With the development of Digital Elevation Model(DEM)and Digital Terrain Analysis(DTA),it is urgent to study the potential devolution of deflagration landform in mountain forest area by using Digital Terrain Analysis technology.In view of the problems and shortcomings existing in the expression and extraction of deflagration landform features,based on the theory and method of digital terrain analysis and the source data of forest region grid DEM,this paper formulated the expression scheme of deflagration landform features,carried out extraction experiments,and applied it to the classification of deflagration landform danger grade.The main research work includes:(1)It is revealed that deflagration landform is a special landform which exists objectively.Based on the cause of the fire explosion have combined the technology of DTA analyses the importance of terrain factors affecting fire explosion,and each category of deflagration landform,analyzing the causes of fire explosion research using digital terrain analysis to identify potential deflagration fire in forest area is very important.(2)The feature expression scheme of deflagration landform extraction is established.To solve the problem of lack of feature expression of devolution terrain,this paper proposed a devolution terrain feature expression scheme combining Topographic Position Index(TPI),slope and plane curvature as the main Topographic factors.Using the fire-prone forest area grid DEM as the basic data source,the extraction experiment was carried out.Through the experimental results,the deflagration landform categories of caotanggou,canyon,ridge and steep slope were obtained,and the superposition images were compared and analyzed.The statistical results showed that the deflagration landform area in this region was 25.78 km2,accounting for 8.94%.Considering the influence of different resolutions on the extraction results,5m,15m and 30m devolution terrain with different resolutions were extracted respectively.The extraction results showed that the devolution terrain occupied 25.17km2,25.51km2 and 25.78km2 respectively.With the data source with finer resolution,the devolution terrain area extracted was smaller.(3)Combined with multi-source data,the hazard grade of deignition landform was classified.Especially in the research environment of large scale regions,the prediction results of traditional prediction models are difficult to achieve ideal results.On the basis of integrating all kinds of global models,this study uses spatial location information and geographically weighted regression technology to establish a geographically weighted regression model of forest fire occurrence.In addition,considering the influence mechanism of forest fire devolution,based on the topographic map of devolution topography,the multi-source data integration of devolution topography was carried out,and the multi-scale analysis and research on the risk of devolution topography was conducted by superposing meteorological data and vegetation data.It provides a scientific basis for the accurate classification of deflagration landform danger grade.In this paper,through systematic analysis of the impact of topographic factors on forest fire deflagration and the application of deflagration landform research,forest fire deflagration mechanism research is closely combined with digital topographic analysis,and the research results are applied to the risk classification of forest deflagration landform.A grid DEM terrain extraction method suitable for devolution terrain extraction in mountain forest region was established,and the current devolution terrain system was summarized,which provided an extended idea for further refined classification and extraction of devolution terrain.