2000～2015年丹江口库区植被覆盖时空变化趋势及其成因分析

基于MODIS NDVI、Landsat遥感影像及气象观测数据,应用趋势分析、偏相关分析和土地利用转移矩阵等方法,阐明了2000~2015年丹江口库区植被覆盖时空变化趋势,并探讨了气候变化和人类活动对库区植被覆盖的影响。结果表明：（1）近16 a来丹江口库区植被覆盖度呈增加的趋势,增速为4.73%/10 a（p < 0.001）;（2）40.94%的区域植被覆盖度增加显著,主要分布在库周丘陵和平原地带;10.04%的区域植被覆盖度减少显著,主要位于西北部伏牛山区及库区建成区周边;49.02%的区域变化不显著;（3）丹江口库区植被覆盖度受气候变化影响不显著,但受人类活动影响较大,其中灌草地和农业用地转变为林地是库区植被覆盖度升高的主要原因,农业用地转变为水体和建设用地是部分区域植被覆盖度降低的重要因素,这些土地利用/覆被变化主要受造林、退耕还林、水库蓄水以及建设活动的驱动;（4）生态建设工程和项目的实施对库区植被覆盖度的稳步增加起到了积极作用。 关键词： 植被覆盖度;变化趋势;土地利用;丹江口库区

Spatio-Temporal Trends of Vegetation Coverage and Their Causes in the Danjiangkou Reservoir Region During 2000 to 2015

Based on time-series remote sensing imagery (MODIS NDVI, Landsat ) and meteorological observation data,this study analyzed spatio-temporal trends of vegetation coverage and their responses to climate change and human activities in the Danjiangkou Reservoir Region between 2000 and 2015 with the application of trend analyses,partial correlation analyses and transfer matrixes of land use. The results showed as follows: 1) There was an increasing trend of annual average vegetation coverage in the Danjiangkou Reservoir Region in the past 16 years,with a growth rate of 4. 73％ /10 a (p ＜ 0. 001). 2) 40. 94％ of the area increased significantly,which were mainly distributed in hilly lands and alluvial plains around the reservoir; 10. 04％ of the area showed significant decreasing results,which were primarily located in the northwest of Funiu Mountains and surrounding regions of built-up areas; 49. 02％ of the area had nonsignificant changes. 3 ) Vegetation coverage in the Danjiangkou Reservoir Region was not notably affected by climate change,but was greatly influenced by human activities. Shrub-grassland or farmland transformed into forestland was the main reason for the overall increasing trend of vegetation coverage in the reservoir region. Moreover,farmland converted into water body or built-up area was the important factor for the decreasing trend of vegetation coverage in local regions. These changes in land use were mainly driven by afforestation,project of returning farmland to forest,reservoir impounding and construction activities. 4) The implementation of ecological construction projects has played a positive role in the steady increase of vegetation coverage in the Danjiangkou Reservoir Region to a certain extent.