层次分析法在下垫面因子影响沙尘暴危险度研究中的应用

Application of analytic hierarchy process to dust storm risk assessment

沙尘暴是一种危害严重的气象灾害,其形成依赖于大气环流和沙质地表两种不同密度的物理介质的相互作用,风力条件和下垫面的性质是影响沙尘暴强度和危害程度的两个重要因素。减轻沙尘暴危害的有效方法就是改善沙尘暴源地的下垫面状况,但这需要评估下垫面各因子在不同天气、气候背景条件下对沙尘暴发生的影响程度。从下垫面的角度出发,以内蒙古中西部地区为例,利用气象资料和实测数据,应用AHP方法对下垫面定性与定量因子进行综合分析,得出不同地区下垫面因子对沙尘暴发生作用的权重,为从下垫面角度研究沙尘暴危险度奠定基础。

Dust storm is the synthesize result of the action of atmospheric motion and physical geographic environment. Formation dust storm depends on the interaction between atmosphere and sandiness surface, which are different physics medium in their density. So wind power and the characteristics of land surface are the main factors that affect the intensity and harm degree of dust storm. In this paper, the risk degree of dust storm in different regions with different land surface conditions is researched from the point of view of land surface in the Midwest region of Inner Mongolia, China. This paper presents an analytic hierarchy process （AHP） method for dust storm risk assessment, which can synthesize the qualitative and quantitative factors. The paper gets the weight of the physiognomy, wind speed, soil moisture and soil hardness with the AHP method, and the respective weight is 0. 129, 0. 499, 0.249 and 0. 123 respectively. It shows that wind speed and soil moisture have much contributions to the occurrence of dust storm, especially the wind speed. At the same time, the paper calculates the weight of land surface factors＇ contributions to the occurrence of dust storm in different regions. The result shows the weight in different regions is Erleahot 〉 Wuhai 〉 Wulatezhongqi 〉 Huhehaote, and the weight is 0.4559, 0. 2525, 0. 2116 and 0.0805 respectively. The corresponding risk assessment map of dust storm can be obtained according to the weight of land surface factors in different regions, overlaying the physiognomy map and soil map.