呼伦贝尔草原生态功能区防风固沙功能重要性主要影响因子时空变化特征

以呼伦贝尔草原生态功能区为研究对象，选择了植被覆盖度、地形因子、土壤可蚀性、大风日数和湿润指数作为防风固沙功能重要性的评价指标，综合采用构建专家判断矩阵和层次分析法建立了评价指标体系。利用ETM影像数据和地理信息系统技术对呼伦贝尔草原生态功能区三期(2000—2003年、2004—2007年和2008—2011年)的防风固沙功能重要性进行了评价，并分析了各单因子重要性和综合重要性的动态变化和空间分布格局。结果表明，植被覆盖度是影响防风固沙功能重要性的关键因子。2000—2011年，呼伦贝尔草原生态功能区的防风固沙功能重要性呈先升高后降低的趋势；空间分布由东向西逐渐升高，沙带地区防风固沙功能重要性较高，温性草甸草原区和温性草原区防风固沙功能重要性较低。

Spatial and Temporal Variation of Main Impact Factors and Importance of Wind Break and Sand-fixing Function in Hulun Buir Grassland Eco-function Area

With the eco-function areas of the Hulun Buir grassland as the case study areas, the vegetation cover, topographic factor, soil erodibility, strong wind hours and wetness index were selected as the indicators to assess the importance of wind-prevention and sand-fixing function, and the assessment indicator system constructed using a combination Delphi Method and Analytic Hierarchy Process Method. The function importance of wind break and sand-fixing was evaluated for the eco-function areas in three periods (2000-2003, 2004-2007, 2008-2011) by ETM image data and GIS, and the dynamic change and spatial distribution pattern of single factor importance and comprehensive importance were analyzed. The result indicated that the vegetation coverage played the most prominent role in the wind break and sand-fixing function. From 2000 to 2011, the function importance increased first and then reduced, with the increase trend from east to west. The sand belt area was with highest importance while the temperate meadow steppe area and temperate steppe area were with light importance.