陕西关中地区植被指数变化多尺度分析

以关中地区遥感影像、数字高程(DEM)、地貌类型等资料为依据，运用地学信息图谱理论和方法，在RS和GIS的支持下生成关中地区1986-2007年NDVI变化图谱，并从栅格、地貌单元、坡度带及行政区划等多个尺度上，分析该区近22 a来NDVI的时空变化特征。研究表明：1986-2007年，关中地区年度NDVI]增加了20.91%，2000-2007年年均增幅约为1986-2000年的2.31倍；各地貌单元NDVI增幅表现为：黄土台塬＞黄土墚峁＞山地＞平原＞黄土塬；各坡度带NDVI]基本随坡度的增加而加大，且均呈增大态势；各地市年度NDVI增速为：渭南市>铜川市>宝鸡市>西安市>咸阳市。关中地区NDVI的时空变化是土地利用/覆被变化的结果，“退耕还林”政策的实施，促使了植被覆盖状况的改善。

Analysis on the Change of NDVIin the Guanzhong Region,Shaanxi Province

Based on remote sensing images,digital elevation model(DEM) and other information of the Guanzhong region,in this paper the spatiotemporal change of NDVI at different scales(such as the grid units,terrain units,slope units and administrative units) in the Guanzhong region during the period from 1986 to 2007 was analyzed using the theory of geographic information images and RS and GIS means.The results show that the NDVI in the Guanzhong region was increased by 20.91% during the period of 1986-2007,and its increase rate was about 2.31 times of that during the period of 1986-2000.The NDVI in all the geomorphologic units was increased in an order of loess tableland > loess ridge > mountain > plain > loess plateau.The NDVI in all the slope zones was also increased,and its increase rate was increased with the increase of slope.The increase rate of NDVI in all the prefectures and cities was in an order of Weinan City > Tongchuan City > Baoji City > Xi’an City > Xianyang City.The spatiotemporal change of NDVI in the Guanzhong region was caused by land use/cover change,and the improvement of vegetation coverage in the study area was brought about by implementing the project of returning land for farming to forest and grassplot.