岷江上游近50a土地覆被的变化趋势

A Study on 50a Land Use and Cover Change of Watershed of Upper Minjiang River

本文的目的是通过典型区的研究 ,揭示我国西南山地系统土地利用 /覆被变化的规律。本文通过对岷江上游大量历史材料和数据的分析确定 :耕地的大幅度增加和林地内部结构的剧变是 5 0a来岷江上游土地利用 /覆被变化的最主要特点。本文在对二者变化过程进行分析的基础上 ,总结了岷江上游山地系统土地利用 /覆被变化的规律 ,有以下结论 :①研究区土地覆被变化受山地自然条件控制 ,将继续以林地与草地为主体 ;②通达性的改善往往是山区土地利用 /覆被大规模变化的开端 ;③土地覆被变化存在一个演替序列 ;④土地利用效益增长潜力较大的土地覆被类型以较快的速度增长。

This paper is to discover some features and rules of land use-cover change in the mountainous area of southert China from the studies on the watershed of upper Minjiang River. From the analyses of the historic data it is identified that the rapid increase of cultivated land and the dramatic change of the forestland structure are the basis of the land use and cover change of the research area during the past 50 a. From the study of the changing course and the analyses of the relationship between the land use changing tendency and some factors such as population or access, this paper comes to the following conclusions: 1.The physical features are still the decision factors of land use and cover. So, forestland and grassland will be the main body of land cover in the area. 2.The improvement of access, especially the new roads, is the starting or new engine of land cover change. 3.The more potential of increasing income a land use pattern has, the faster it increases. These conclusions are helpful in ecological rebuilding in under-developed mountain area.