Study Of Livestock Feeding And Trampling Track In Xinjiang Mountain Grassland

Grassland plays an important role in the entire national economy and production and daily life of farmers and herdsmen in Xinjiang.At present,grassland degradation of Xinjiang is becoming more and more serious.Overgrazing and farmland reclamationis the main reason of grassland degradation in Xinjiang.The track of livestock feeding and trampling is one of the most intuitive mark to reflect the deterioration of grassland ecology and is the commonest landscape of Xinjiang mountain grassland.It is the minorest geomorphological form by the formation of repeatedly trampling during the process of animals feeding,which reflects the feeding habits of animals to some extent.Studying the Xiaohaizi mountain grassland of Jinghe county,we use Trimble GPS-RTK measuring instrument and the general digital cameras in the wild to obtain three-dimensional space coordinates of image control points and stereoscopic image pairs of four typical sample districts.We use ERDAS digital photography system for stereoscopic measurement indoor and obtain DEM and orthoimage data from which we extract topography and other information of the sample districts,analyzing the morphological characteristics of the track of livestock feeding and trampling, the reshaping role of geomorphology and its impact on the ecology. After a preliminary study we come to the following conclusions:1.We analyze and summarize methods about using Trimble GPS-RTK measuring instrument and the general digital cameras in the wild to obtain three-dimensional space coordinates of image control points of the sample districts and stereoscopic image pairs of the sample districts.2.Through analyzing the trend of feeding and trampling track in the sample districts,we divide the track of feeding and trampling in the Xiaohaizi mountain grassland of Jinghe county into three types: parallel-shape feeding and trampling track,diagonal-shape feeding and trampling track and grid-shape feeding and trampling track.3.Through analyzing the distribution density and the distribution width of feeding and trampling track in the sample districts we conclude that the distribution density and width of grid-shape feeding and trampling track are greater than that of parallel-shape feeding and trampling track and that of diagonal-shape feeding and trampling track. 4.Through the analysis of vegetation coverage in the various sample districts we conclude that vegetation coverage will reduce as the width and density of feeding and trampling track increases; the grazing extent of grid-shape feeding and trampling track are larger than that of diagonal-shape feeding and trampling track, which initially reflects the degree of grassland degradation in the various sample districts.5.According to the analysis of profile in the various sample districts we conclude that the soil erosion in the sample districts of diagonal-shape feeding and trampling track is samller than that in the sample districts of grid-shape feeding and trampling track.6.Making use of the DEM data obtained from stereoscopic measurement ,we extract terrain factors in the various sample districts such as slope,aspect,relief amplitude,surface roughness and variance coefficient in elevation to analyze statistically and conclude that the extent of the surface broken is highest in the sample districts of grid-shape feeding and trampling track, saying that grid-shape feeding and trampling track plays the largest role in transforming the geomorphology.