晋陕蒙接壤区林草覆盖变化的遥感分析

Remote Sensing Analysis on Forest and Grass Cover Changes in the Contiguous Region of Shanxi, Shaanxi and Inner Mongolia

以晋陕蒙接壤区1986年和2000年的TM影象为信息源,运用遥感技术与地理信息系统技术,结合建立了两期全区土地资源数据库,从中提取林草覆盖空间数据。分析得出2000年全区有林草地面积332.19×104hm2,占总面积的56.87%,其中林地占13.72%,草地占86.28%。14年间林草植被净增加了2.29×104hm2,占林草面积的0.69%,总的变化趋势是林草覆盖对生态环境的保护和调节功能趋向衰减。林地被毁、草地开垦和沙漠化是林草覆盖减少的主要原因,而其新增部分主要是实施植树造林、退耕还林还草等生态环境建设措施的结果。

With the assistance of remote sensing and geographic information systems, the land resource databases in 1986 and 2000 have been established through interpreting the Landsat TM images of the two times, and the extent of the databases includes the contiguous region of Shanxi, Shaanxi and Inner Mongolia in the northern China. According to the information of forest and grass cover derived from the databases, the following points can be (concluded:) in the whole (region,) there was (3 321 860) ha of forestland and grassland in (2000,) occupying 56.87% of the total area, the forestland occupied 13.72% of them, and grassland occupied 86.28%. Although the forest and grass cover had increased by 22 829 ha from 1986 to 2000, accouting for 0.69% of its total area, the function of protection and regulation of forest and grass cover had decreased and the size, acreage and shape complexity of their patches also declined. At the same time, only the low cover grassland had increased among all types of forestland and grassland. The decreasing factors of vegetation cover change were mainly deforestation, reclamation of grassland, and desertification of grassland, and the increasing factors were the completion of eco-environment construction projects, such as afforestation, returning farmland back into forestland or grassland and so on.