摘要
基于遥感和GIS技术手段,分析研究了近12年来柴达木盆地尕斯库勒湖流域MODIS-NDVI变化的空间差异.分析得知:2000-2011年柴达木盆地尕斯库勒湖流域NDVI最大值年际变化趋势中,改善区、稳定区、退化区和无植被生长区的面积分别占总面积的17.64%,37.31%,0.57%,44.48%;生长季NDVI平均值变化趋势中,改善区、稳定区、退化区和无植被生长区的面积分别占总面积的31.11%,24.09%,0.36%,44.48%.近12年来,研究区山地NDVI最大值呈不显著的增长趋势,生长季NDVI平均值呈显著的增长趋势;绿洲NDVI最大值呈不显著的减小趋势,生长季NDVI平均值呈不显著的增长趋势.在各海拔高度带上,NDVI值越大的区域,植被改善趋势越强烈;NDVI值越小的区域,植被改善趋势越微弱.各变化趋势在不同海拔高度带上所占的面积百分比分布都为单峰型,海拔由低到高出现峰值的依次为轻度改善区、稳定区、轻度退化区.轻度改善区主要分布在坡度较小的区域,轻度退化区主要分布在坡度较大的区域.轻度改善区和稳定区在北坡面积百分比最大,而轻度退化区在北坡所占的面积百分比最小.
Base on RS and GIS technology, the spatial difference of NDVI variations in Gasikule Lake basin was analyzed and the results showed that the greening area, stable area, degraded area and bare area accounted for 17.64%, 37.31%, 0.57% and 44.48% of the total area respectively in the variation trend of vegetation NDVI maxima. The greening area, stable area, degraded area and bare area accounted for 31.11%, 24.099, 0.36% and 44.48% of the total area respectively in the variation trend of growing-season vegetation NDVI averages. In the past 12 years, vegetation NDVI maxima in mountainous regions had a significant growth trend and growing- season vegetation NDVI averages in the mountainous region had a nonsignificant trend; vegetation NDVI maxima in the oasis region had a significant growth trend and the growing-season vegetation NDVI averages in the oasis region had a nonsignificant trend. In all the altitude rings, the bigger the NDVI value, the more intense the vegetation greening trend; the smaller the NDVI value, the weaker the vegetation greening trend. In all altitude rings, the area percent of every variation trend was of single-peak form. The peak values appeared in turn from greening area, table area to degraded area. Greening area was mainly distributed in gentle slopes while degraded area was mainly distributed in steep slopes. The area percent of greening area and table area in the north slopes was maximum while the area percent of degraded area in north slope was minimum.
出处
《兰州大学学报（自然科学版）》
CAS
CSCD
北大核心
2013年第1期7-12,共6页
Journal of Lanzhou University(Natural Sciences)
基金
国家自然科学基金项目(40901056)
中央高校基本科研业务费专项资金项目(lzujbky-2010-95)
