基于MODIS-NDVI的陕西省植被覆盖变化特征分析

为实现人地关系协调发展，为陕西省生态建设政策的制定和实施提供理论依据，本研究基于MODIS-NDVI 影像及高程数据，采用MVC、一元线性回归等方法，分析陕西省2011—2015 年NDVI 的时空变化特征。结果表明：（1）陕西省NDVI值呈现“南高北低”的分布特征，陕南地区及陕北南部森林植被茂密，植被覆盖情况较好，陕北北部属于风沙区，植被覆盖情况较差，关中地区以农作物为主，植被覆盖情况居中；（2）2011—2015 年陕西省NDVI值呈波动变化，整体变化趋于稳定，且有好转趋势，主要分布在关中及陕南地区；陕北地区NDVI值有退化迹象；（3）随着海拔高度的增加，NDVI值呈“降低—升高—降低”的变化，2000~2500 m海拔高度范围内的NDVI值最高，植被覆盖情况较好，主要是分布在秦岭山脉的太白山地区。

Characteristics of Vegetation Coverage Change in Shaanxi: Based on MODIS-NDVI

To realize the harmonious development of human and land, and provide a reference for formulation and implementation of ecological construction policy in Shaanxi, based on MODIS-NDVI image and altitude data, the author analyzed the spatio-temporal variation characteristics of NDVI in Shaanxi from 2011 to 2015 by using MVC and linear regression. The results showed that: (1) the distribution of NDVI in Shaanxi was characterized by“high south and low north”; the forest vegetation was thick in southern Shaanxi, as well as in the south area of northern Shaanxi; the vegetation coverage was poor in the north area of northern Shaanxi, which belonged to sandy area; the vegetation coverage was medium in Guanzhong region, which was mainly dominated by crops; (2) from 2011 to 2015, the NDVI value in Shaanxi fluctuated, the overall change tended to be stable and the trend was improving, mainly in Guanzhong and southern Shaanxi; the NDVI value in northern Shaanxi showed signs of degradation; (3) with the increase of altitude, the NDVI value presented a change of “decrease-increase-decrease”. NDVI value was the highest in the range of 2000-2500 m where the vegetation coverage was better, mainly distributed in Taibai mountain area of Qinling mountains.