摘要
利用 1981至 2 0 0 1年 8kmAVHRR数据 ,采用均值法、差值法和一元线性回归模拟法 ,分析西北植被年内变化、年际变化特征 ,并模拟近 2 1aNDVI最大化值的变化趋势线和NDVI增长幅度 .统计结果表明 ,中国西北植被覆盖在 7～ 8月达到年内最丰盛 ;近 2 1a来植被覆盖存在普遍退化的趋势 ,且后 10a变化幅度大于前 10a变化幅度 ;在局部区域有植被改善的趋势 ,改善幅度小于退化幅度 .模拟结果表明 ,植被改善的区域主要分布在新疆西部和北部地区 .
The study area of this paper is Northwest China. The data is 8 km AVHRR from 1981 to 2001. The average value method, difference value method were used to analyze the annual and interannual changes. The linear regression of one variable was used to simulate the change trend of the maximal NDVI values and calculate the change quantity. As a result, the vegetation cover reaches the best condition between July and August in each year. During the last 21 years, the vegetation degradation is popular in most of Northwest China. However, there are some regions where vegetation cover is increasing. But the increasing range is smaller than the decreasing range on the whole. The simulating results indicate that the improved regions of vegetation cover mainly appear in west and north parts of Uygur Autonomous Region of Xinjiang.
出处
《冰川冻土》
CSCD
北大核心
2003年第2期232-236,共5页
Journal of Glaciology and Geocryology
基金
中国科学院知识创新工程重大项目 (KZCX1 10 0 6
KZCX2 3 0 1)
中国科学院知识创新工程重大项目 (KZCX1 SW 0 4)
中国科学院寒区旱区环境与工程研究所知识创新工程项目 (CACX2 10 0 18)资助
