近22年关中地区林草覆盖率时空动态研究

以关中地区遥感影像、数字高程、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的支持下生成了关中地区1986～2007年林草覆盖率变化图谱,并从栅格、坡度带、地貌单元及行政区等多个尺度上分析了该区近二十二年来林草覆盖率的时空变化特征。研究表明:1986～2007年,关中地区林草覆盖率增加了15.25%,2000～2007年段增速约为1986～2000年段的2.60倍;各地貌单元林草覆盖率增幅表现为:山地>黄土梁峁>黄土塬>黄土台塬>平原;各坡度段的林草覆盖率增加,增速随坡度增大而加大;各地市林草覆盖率增速为:西安市>渭南市>咸阳市>铜川市>宝鸡市。研究区的林草植被覆盖率的时空变化特点是土地利用/覆被变化的结果,"退耕还林"政策的实施促使了该区林草覆被情况的改善。

Temporal-spatial changes of the vegetation coverage in Guanzhong area,Shaanxi Province in recent 22 years

Based on remote sensing images,digital elevation model(DEM),and other information of GuanZhong area,choosing some suitable models,using the theory of geographic information images and supported by RS and GIS,we analyzed the temporal-spatial changes of the vegetation coverage in different scales such as grid units,terrain units,slope units,and administrative units of Guanzhong area in recent 22 years.Study showed: In 1986-2007,the vegetation coverage of forest and grass in Guanzhong area increased by 15.25%,and the growth rate of the vegetation coverage in 2000-2007 was as about 2.60 times faster as that in 1986-2000.The vegetation coverage in all geomorphologic patterns increased,and the order of the growth rate was as follows: mountains > loess mountain ridge > loess tableland > loess plateau >plain.The vegetation coverage in all slope zones increased,whose growth rate expanded with the slope increasing.The vegetation coverage in all cities raised,and the order of the growth rate was as follows: Xi’an city >Weinan city >Xianyang city >Tongchuan city> Baoji city.Land use/cover change resulted in the temporal-spatial changes of vegetation coverage of Guanzhong area,and replacing farmland with forest helped the vegetation situation here better.