武威市草地放牧强度空间差异的研究

Research on Spatial Difference of Grassland Grazing in Intensity in Wuwei City

放牧强度空间化是研究放牧活动区域性差异的方法,能够识别草地等自然环境变化的推动因素,进而为恢复草地生态、适当管控人类活动提供科学依据。放牧强度由放牧压力与放牧概率共同决定,放牧与距居民点、河流、道路的距离、植被覆盖等息息相关。本文以武威市草地为研究对象,选取坡度、坡向、海拔、居民点、道路、河流等地理因子判断放牧适宜性,选取牲畜存栏量及归一化植被指数等因子,通过Arc GIS平台对其进行分析,得到研究区放牧强度的空间分布。结果表明,放牧强度空间分布反映了明显的武威市草地放牧空间特征,武威市放牧强度较高的地区集中于南部的天祝藏族自治县,放牧强度较低的地区集中于民勤县及古浪县北部,由北向南逐渐递增,归一化植被指数与放牧强度有较强的相关关系。

The spatiallization of grazing intensity is the method for studying regional differences in grazing activities.It can recognize the driving factors for changes in natural environments such as grasslands,and thus provide a scientific basis for restoring grassland ecology as well as appropriately controlling human activities.Both grazing pressure and probability determine grazing intensity,and grazing is closely related to distance from settlements,rivers,roads,vegetation cover,etc.In this paper,the spatial distribution of grazing intensity was investigated by taking Wuwei City grassland as the research object,selecting geographical factors such as slope,slope direction,elevation,settlement,road and river to estimate grazing suitability.Additionally,factors such as livestock stock and NDVI were evaluated by the ArcGIS platform.It shows that the spatial distribution of grazing intensity prominently indicated the spatial characteristics of grassland grazing in Wuwei City,areas with higher grazing intensity in Wuwei City are concentrated in Tianzhu Tibetan Autonomous County in the south,while areas with lower grazing intensity are concentrated in Minqin County and the northerm part of Gulang County,gradually increasing from north to south,and there was a strong correlation between NDVI and grazing intensity.