| Under different scales,the influence factors of population vulnerability are different,and the evaluation methods are also different.So this paper selected the upper reaches of Min River and the Qipan gully village as the study area,where the the upper reaches of Min River was mid-scale area,another was small scale area,that is a typical area.This paper established the population vulnerability evaluation indexs of the upper reaches of Min River and the Qipan gully,according to the actual situation.Based on the information value model,the mid-scale evaluation of the upper reaches of Min River got the population vulnerability assessment zoning map.With SOM model in MATLAB and ArcGIS,the small scale evaluation of the Qipan gully village was as the typical area and got the zoning map by choosing many effect factors.In this paper,the main research contents and research results were as follows:(1)This article selected the population density,per capita GDP,ten thousand doctors,ten thousand beds,monitoring,labor aged population ratio as the population vulnerability evaluation index,grid was evaluation unit,and the upper reaches of Min River was divided into 9192246 grid cell and got the zoning map through the calculation of vulnerability information model.(2)The research found that the low population vulnerability of the upper reaches of Min River accounted for 91.09%.High population vulnerability area accounted for3.78%.High vulnerability area mainly were Maoxian,Wenchuan and Lixian.(3)Through the various evaluation factors and population vulnerability zoning map of the upper reaches of Min River of contrast analysis,it showed that the population vulnerability was closely relative to the population density,and it was negatively relative to number of ten thousand beds,ten thousand doctors,per capita GDP,monitoring labor population.The greater the population density is,The greater population vulnerability is.Population density would increase population system vulnerability,and under the effect of other factors comprehensive action,population vulnerability can reduce system vulnerability.Population density count,ten thousand doctors,ten thousand beds,per capita GDP were key factors of populationvulnerability,and they had larger influence for population vulnerability,the influence of labor population proportion and the effect of monitoring were relatively low.(4)This paper selected Qipan gully as study area by the field investigation and image interpretation analysis.Family population scale,age structure,physical condition,national characteristics,cultural degree and the distance of resident and the debris flow were as the evaluation factor of population vulnerability assessment in the study area,and the Self organized maps model(SOM)was used,its advantages are the ability to avoid man-made subjective factors to the influence of each evaluation index weight.With the help of MATLAB and ArcGIS,it got population vulnerability degree of study area under debris flow disaster.(5)The research found that population vulnerability of the Qipan gully basin mainly focued on the densely populated place,and the biggest vulnerability was debris flow ditch mouth and decreases to all around;The highest and high vulnerability degree area had the smallest percentages,3.52%,4.90% respectively;The lowest and low vulnerability degree area had big percentages,22.98%?60.06%respectively.According to the U-matrix and 18 variable of planes in SOM,the study found that the higher population vulnerabilities were the households of medium family or big family,national minorities,primary education and from debris flow gully of 0-300m;age structure,physical condition had certain effect,but the influence degree was low for population vulnerability.In this paper,the results of the study had certain reference on reducing the Qipan gully population casualties. |
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