Assessment Of Wind Erosion Hazard Of A Typical Transect In Farming-Pastoral Ecotone Of Northern China

The most serious environmental problem in Inner Mongolia is land degradation and sand storm caused by wind erosion. The evaluation of wind erosion in regional scale are puzzling problem in wind erosion research. Based on review of the wind erosion, taking typical transect, Erenhot—Zhangjiakou, as study area, the environmental database of wind erosion was constructed by using remote sensing, geographical information system and studying in the transect, erosion—environment knowledge was obtained by using fuzzy clustering method (FCM, fuzzy c-means clustering) and expert knowledge, by which the model of wind erosion was set up, finally the spatial pattern of wind erosion in the transect was obtained, and then analysis the natural environment and land use of different wind erosion hazards in the transect combining with land use data; Attempt to evaluate wind erosion hazard in the Inner Mongolia through BP neutral network on the basis of the above result, the main research results are summarized as following.(1) Considering climatic and geographical backgrounds in Farming-Pastoral Ecotone of Northern China and the characteristics of wind erosion research on the regional scale, the research transect, Erenhot—Zhangjiakou transect from Erenhot to Zhangjiakou, was constructed. There are obvious grading changes in aspects such as water and heat combination and land use intensity along the research transect. The transect passed through Erenhot, Suniteyou banner, Xianghuang banner, Zhengxiangbai banner, Taipusi banner and Zhangjiakou. It covers the main ecological areas affected by wind erosion in Inner Mongolia such as plain desert, plain desert steppe, mountain desert steppe, mountain meadow and so on.(2) The wind erosion environmental factors of research transect were derived and clustered using fuzzy clustering method (FCM, fuzzy c-means clustering), and then the knowledge of wind erosion-environment relationships was obtained through relating unique environmental combination classes to unique wind erosion type by the help of expert knowledge, therefore, the spatial patterns of soil erosion hazard in the transect was obtained. The result shows that the mainly pattern of wind erosion hazard in the research transect gradually strengthen from Southeast to Northwest, which are the same as the natural,climate and land use in the area. The sever area is mainly on the high plains in the northwest, elevation varies from 500~1500m, the area is 1.80×104km2;the strong area is at the southeast of the sever area, northeast of Ulanqab plateau and around Hunshandake, which is 7.58×104km2;the moderate area situates middle of research area, which is 2.85×104km2; the light and no risk area is mainly in the southeast of research transect, the area is 2.97×104km2 and 1.46×104km2 respectively.(3) Attempt to evaluate wind erosion hazard in the Inner Mongolia through BP neutral network, taking the each kind of data of wind erosion hazard in typical transect as sample to construct neutral network model of wind erosion hazard evaluation, and then the spatial pattern of wind erosion hazard was obtained, which is consistent with remote sensing data of wind erosion strength. All of these show the way used in the paper is feasible.