基于GIS西北干旱区荒漠化危险度的研究

GIS-based Study on the Desertification Fatalness in the Arid Regions in Northwest China

研究区为我国西北干旱区,在行政区划上包括新疆、甘肃、青海、内蒙古、宁夏和陕西6个省、自治区,涉及西北6省的213个县、市、旗,其面积约占西北六省的71.8%.采用的数据包括气象数据、各类环境统计数据、社会、经济人口数据、1∶400万的基础地理数据及NDVI数据。在吸取前人研究成果的基础上,结合研究区的实际情况,确定了影响西北干旱区土地荒漠化危险度的评价指标体系。根据这一评价体系,建立了荒漠化危险度综合评价模型,从自然气候条件、内在危险性、土地现状和社会经济活动四个方面对研究区土地荒漠化危险度进行了评价。结果表明,整个研究区荒漠化程度较为严重——研究区内以中度荒漠化、荒漠和轻度荒漠化为主,其中轻度和中度荒漠化在研究区内均有广泛分布;重度和极重度荒漠化主要分布在荒漠的周围;潜在荒漠化主要分布在阿尔泰山、天山等高大山系的山麓以及内陆河流域流经的地方。

The study area includes the arid regions in northwest China,it covers 213 counties,cities and banners in Xinjiang Uygur Autonomous Region,Gansu Province,Qinghai Province,Inner Mongolia Autonomous Region,Ningxia Hui Autonomous Region and Shaanxi Province,and its area occupies 71.8% of the total area of these 6 provinces and autonomous regions.The data used in the study include the meteorological data,such as the precipitation,air temperature and wind speed; statistical environmental data,such as the farmlands,woodlands,drylands and paddy fields as social well as the social,economic and population data; geographical information data,such as the database of land use on scale of 1: 4 000 000,database of soil types on scale of 1: 4 000 000,and database of vegetation and forests on scale of 1: 4 000 000;and data of NDVI.The evaluation index system of land desertification fatalness in the arid region in northwest China is determined based on the predecessors’ study achievements and the present situation in the study area.On which a comprehensive evaluation model of land desertification fatalness is developed,and the land desertification fatalness in the study area is evaluated from 4 aspects including the natural conditions,internal fatalness,present situation of lands and social and economic development.The results show that the land desertification in the whole study area is serious,the moderate desertification,deserts and slight desertification are dominant in the study area,in which the moderate-slight desertification and the moderate desertification are extensively distributed;the serious desertification and the extremely serious desertification occur mainly in the peripheral regions of the deserts,piedmont zones of high mountains,such as the Altay mountains and Tianshan Mountains,and the regions where the continental rivers flow through.