近20多年来西北绿洲植被指数的变化及其成因  

Analyses on the Vegetation Index Variation and Its Formation Causes in the Oases in Northwest China in Recent 22 Years

作　　者：郭铌[1] 王小平[1] 蔡迪花[1] 倾继祖[1] 

机构地区：[1]中国气象局兰州干旱气象研究所,甘肃省干旱气候与减灾重点实验室,中国气象局干旱气候与减灾重点实验室,甘肃兰州730020

出　　处：《干旱区研究》2010年第1期75-82,共8页Arid Zone Research

基　　金：国家自然科学基金(40375011);科技部科研院所社会公益研究专项“西北农作物对气候变化的响应及其评价方法(2005DIB3J100)

摘　　要：利用NASA GIMMS 1982-2003年逐月的标准化植被指数NDVI数据集以及相关的气候资料,选黄河、河西内陆河以及新疆内陆河的典型绿洲为代表,分析了22年间各绿洲春、夏、秋季NDVI的变化和绿洲面积变化,比较了不同年代间NDVI的年变化特征,并研究了绿洲NDVI与气候和人类活动的关系。结果表明:①近22年来,各绿洲夏季和秋季NDVI均呈显著增加趋势,以夏季NDVI增加幅度最大。从地域上看,新疆塔里木盆地南侧绿洲和河西走廊绿洲各季NDVI增加较其他绿洲明显。②不同年代间各绿洲NDVI年变化较大,主要表现为年代间植被生长季NDVI的增加和NDVI峰值出现时间的改变。③近22年来,西北绿洲面积均呈现增加趋势,以河西走廊和新疆内陆河绿洲面积增加最为显著,黄河绿洲面积扩大趋势不太显著。④绿洲NDVI增加的主要原因为绿洲面积的扩大、种植结构的调整,气温的升高和降水量的增加,对绿洲NDVI增加有正效益,但降水量的变化对不同绿洲NDVI的驱动作用随着降水量在地域上的减少而变弱。This paper analyzes the variation of Normalized Difference Vegetation Index （NDVI） in spring, summer and autumn and the area change of some typical oases in the Yellow River Basin, the Hexi Corridor and Xinjiang Uygur Autonomous Region in recent 22 years using the monthly datasets of NDVI during the period of 1982 - 2003, compares the annual change characteristics of NDVI in 3 decades, and researches the relations between the NDVI, climate and human activities in the oases. The results are as follows ： （ 1 ） The NDVIs of all the oases were increased significantly in autumn, especially in summer in recent 22 years. Regionally, the increasing rate of NDVI was the highest in the Shihezi Oasis （0. 0075/a）, and that of the oases in the Hexi Corridor and the southern marginal zone of the Tarim Basin were higher than that of others oases ; （2） The variations of NDVI of all the oases in different decades were obvious, especially in the increase of NDVI in plant growth season and the change of occurring time of the peak value of NDVI ; （3） The areas of the oases in northwest China were all enlarged in recent 22 years, especially in the Hexi Corridor and Xinjiang; （4） The NDVI increase was mainly caused by the enlargement of oases and the regulation of farming structure, and both temperature increase and precipitation increase had posi- tive effects on the NDVI increase.

关 键 词：绿洲面积 NDVI GIMMS 气温 降水量 西北地区 

分 类 号：Q948[生物学—植物学]