天山北部地区植被覆盖的时空变化及趋势分析

Temporal and Spatial Variation and Trend Analysis of Vegetation Coverage in Northern Tianshan Mountain Region

根据1982—2006年GIMMS-NDVI数据,采用线性趋势法和Hurst指数法,对天山北部植被覆盖状况的时空变化、发展趋势进行分析。结果表明:天山北部地区整体植被覆盖度不高,山麓地带、河湖沿岸的绿洲农业区植被覆盖较好。研究时段内的植被覆盖有退化的趋势,且退化区域以绿洲边缘区及中低山区为主,主要农耕区在灌溉措施保障下,植被覆盖有改善的趋势。天山北部的植被覆盖变化具有持续性特点,持续增大区主要分布在绿洲农业区;持续减小区主要分布在中低山区;沙漠戈壁区无显著变化特征。

Adopting the linear regression method and Hurst index, the 1982 - 2006 GIMMS NDVI data was used to study temporal and spatial variation and trend of vegetation coverage in northern Tianshan Mountain. The results showed that the overall vegetation coverage in northern Tianshan Mountain, was not high, but in oasis agricultural region along piedmont belt or the banks of rivers were better. Vegetation coverage in the study area had a trend of degradation, and the degradation was mainly distributed in oasis fringes and low mountains area. The vegetation coverage in farming area ensured water conservancy irrigation also had an increasing tendency. Vegetation coverage change shows the continuity characteristics, the vegetation of oasis farming area was continually rising but it was decreasing in low mountain area, and the characteristics of continuous change was not obvious in the Gobi desert area.