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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。
Based on the data of remote sensing images, digital elevation and topography in Guanzhong area, using the theory and method of geo-information atlas, the change maps of forest and grass coverage in Guanzhong region from 1986 to 2007 were generated with the support of RS and GIS. , Slope belt, geomorphy unit and administrative area and so on, the spatio-temporal variation characteristics of forest-grass coverage in the past 22 years have been analyzed. The research shows that from 1986 to 2007, the coverage of forest and grassland in Guanzhong area increased by 15.25%, and the growth rate from 2000 to 2007 was about 2.60 times of that from 1986 to 2000. The coverage of forest and grass coverage of each landform unit showed as follows: mountain> Loess Plateau> Loess Plateau> Loess Plateau> plain; the coverage of forest and grass in each slope segment increased with the increase of slope gradient; the growth rate of forest and grass coverage in each city was Xi’an> Weinan> Xianyang City> Tongchuan City> Baoji City. The temporal and spatial variation of forest and grass cover in the study area is the result of land use / cover change. The implementation of the policy of “returning farmland to forestland” has contributed to the improvement of forest cover and grass cover in this area.