陕西省植被覆盖时空演变特征及其与气候因子的关系

Temporal and Spatial Evolution of Vegetation Cover and Its Relationship With Climate Factors in Shaanxi Province

利用2000-2012年SPOT-VGT NDVI数据,通过差值及相关分析法,对陕西省植被覆盖的时空演变进行研究,并对植被指数(NDVI)与气候因子的关系进行分析。结果表明:(1)2000-2012年,陕西省植被覆盖改善区域明显大于退化区域,植被覆盖增加区域主要分布在陕北风沙过渡区和黄土高原地区,减少区域主要分布在关中平原地区和陕南部分地区。(2)月平均NDVI与月平均降水量和气温呈极显著相关关系(P<0.01),相关系数分别为0.875、0.885。(3)2000-2012年,陕西全省NDVI增长速率为0.109·10a-1,说明生态恢复建设取得一定成效。(4)陕西NDVI变化具有明显的季节性,夏季和秋季NDVI增加最快,冬季增长最慢,且NDVI对降水、气温的响应存在时滞性。

Based on SPOT-VGT NDVI data during 2000-2012, temporal and spatial evolution of vegetation cover and its relationship with climate factors in Shaanxi province were analyzed by using difference and correlation analysis method. The results showed that the vegetation improvement area were significant greater than the degradation area, the increased area of vegetation coverage was mainly distributed in sandstorm transition region and the Loess Plateau in Shaanxi province. The decreased area was mainly distributed in Guanzhong Plain region and parts of southern Shaanxi province. There was significant relationship between monthly average NDVI and monthly average precipitation and temperature （P 〈 0.01 ）, with the correlation coefficients 0. 875 and 0. 885. The NDVI growth rate in Shaanxi province was 0. 109 · 10y-1, which indicated that the ecological restoration of vegetation construction made progress. In addition, the NDVI showed obvious seasonal variation. The NDVI developed faster in summer and autumn than that in winter, but the responses of vegetation variation to precipitation and temperature had time lag.