乌审旗植被覆盖度动态变化及其与降水量的关系  

Dynamics of Vegetation Cover and Its Relationship with Rainfall in Wushen County of Inner Mongolia

作　　者：于小飞[1] 孙睿[1] 陈永俊[1] 刘绍民[1] 周会珍[1] 张忠山 

机构地区：[1]北京师范大学地理学与遥感科学学院遥感科学国家重点实验室环境遥感与数字城市北京市重点实验室,北京100875 [2]内蒙古乌审旗林业局毛乌素沙地开发整治研究中心,乌审旗017300

出　　处：《资源科学》2006年第4期31-37,共7页Resources Science

基　　金：国家自然科学基金资助(编号:40501045);长江学者和创新团队发展计划资助;国家863计划项目资助(编号:2002AA2Z4271)

摘　　要：利用GIMMS（Global Inventory Modelling and Mapping Studies）数据集的8km的AVHRR NDVI（均一化植被指数）数据,分别用年最大NDVI的平均值和年最大NDVI的斜率对1981年～2003年23年间的内蒙古乌审旗植被覆盖度的空间分布及其动态变化进行了分析,并通过比较降水量与年最大NDVI的年际变化以及分析降水量与年最大NDVI之间的相关系数研究了降水对乌审旗植被覆盖的影响;利用1986年,1994年的TM和2002年的ETM＋数据分析了乌审旗植被的主要变化类型.结果表明,这23年间植被覆盖度和降水量的年际变化趋势基本一致,年最大NDVI与前一年8月至当年7月的降水有最好的相关性,并且在地表覆盖为草地和灌木林地的地区,二者的相关性要高于地表覆盖为耕地和乔木林地的地区;植被覆盖度最低值分布在地表主要覆盖为沙地的乌审旗西北部,植被覆盖度最高值分布在地表覆盖为耕地的东南部;人类活动的积极影响使得植被覆盖度总的趋势是在增加的,但由于气候的干旱趋势使中部一些乡镇的植被覆盖度是在减少的,其余的地区都是在增大的,且变率很大。The dynamic change of 23-years vegetation cover in Wushen County of Inner Monggulia was analyzed using NASA GIMMS（ Global Inventory Modeling and Mapping Studies） Normalized Difference Vegetation Index（NDVI） data set. The average value of annual max NDVI in latest five years and the slope of annual max NDVI were used to analyze the vegetation distribution in Wushen County during the last 23 years. Mean absolute deviation of maximum NDVI was also used to study the change intensity of the vegetation cover. The high-resolution images- Landsat TM data of the year 1986 and 1994 and ETM ＋ data of 2002 were used to find the change patterns of vegetation in Wushen County. The influence of rainfall on vegetation cover in Wushen County was explored through correlation analysis between annual rainfall and annual maximum of NDVI. The result shows that, the change of the vegetation cover in the last 23 years is consistent with the change of rainfall. The annual maximum of NDVI is significantly related to the rainfall during August to July of second year. The significance of correlation in grassland and shrub forest is higher than in cropland and arboreal forest. The lowest rate of vegetation cover is in desert area of northwestern Wushen County; the highest is in cropland in the southwest of the county. Generally human activities have been promoting the increase of vegetation cover. But in some areas the vegetation cover presents a trend of decrease due to dry weather.

关 键 词：植被覆盖度 植被指数 降水量 NDVI 年际变化 

分 类 号：Q948.1[生物学—植物学] P426.61[天文地球—大气科学及气象学]