贵州省山地-坝地系统土地利用与景观格局时空演变

探讨贵州省山地-坝地系统的景观变迁与优化调控具有重要的意义。以贵州省典型的蒲场、洋川山地-坝地系统为例,从一个地貌单元对以万亩大坝为中心的山地-坝地土地系统1960年代到2010年的土地利用变化与格局演变进行系统的研究。把研究区划分成中央坝地、坝中丘陵和坝周山地3个部分,结合遥感技术与实地调查,获得研究区4个时期土地利用的空间分布,基于移动窗口法计算了景观格局指标。坝中丘陵和坝周山地景观多样性高于坝地,土地利用综合程度以坝地最高;平坝耕地从1963年所占比例90.81%下降到2010年的79.94%,坝中丘陵和坝周山地林地减少,灌木林增加,坡耕地仍保持在较高水平;耕地有向经济效益更高的土地利用方式转变的趋势。坝子在土地利用变化和景观格局演变过程中,原有的土地利用格局逐渐被改变,形成新的斑块-廊道-基质格局。研究区中部坝地、坝中丘陵和坝周山地的土地利用变化表明,坝地的土地利用变化和土地集约利用可对坝中丘陵及坝周山地产生影响,坝子与坝中丘陵和坝周山地土地利用存在耦合变化。进一步应加强研究区土地利用优化调控,使坝地、坝周山地和坝中丘陵的土地利用协同演化。研究结果对贵州省山地-坝地系统土地优化利用有参考价值。

Spatial-temporal evolution of land use and landscape pattern of the mountain-basin system in Guizhou Province

Guizhou Province of China is more mountain and less plain, especially basins with a certain size are limited too. The basin and mountains around it constitute of mountain-basin land system, which distribute widely in Guizhou Province. It should be pointed out that, the limited suitable land of basin is confronted with variety of land use requirements to ensure agricultural land, construction land and ecological land use, therefore, it is of great importance to explore the landscape change and optimization of the mountain-basin land system. The purpose of this study is to demonstrate the land use landscape pattern changes from the 1963 to 2010,discuss the optimal regulation of mountain-basin land system centered around the basins which are more than 667 hm² from a geomorphic unit. A typical mountain-basin land system, namely, Puchang and Yangchuan area, located in Suiyang County, Guizhou province, is chose as a typical example. This mountain-basin land system was divided into three parts such as flatlands and hills in the basin and the mountain around the basin. The remote sensing method and field surveys were used to obtain the land use spatial distribution of four periods in 1963, 1979, 2006 and 2010 of the study area, and the landscape pattern indexes of the study area were calculated based on the moving window by use of Fragstats 3.3. The results showed that the landscape diversities of hilly in basin and mountain surrounding the basin are higher than flatlands, at the same time, the comprehensive degree of land use in flatlands are the highest. The woodland of the hills in basin and the mountains around the basin were reduced when the cultivated proportion of flatlands decreased from 90.81% in 1963 to 79.94% in 2010, but shrub forest increased and the slope cultivated land was still maintained at a higher level. What's more, there is a trend that the cultivated distributed in the flatlands would convert into others land use types with the higher economic benefits. In the process of land use change and landscape pattern evolution, the original land use pattern of flatlands changed gradually, a new structure constituted by the construction land patch, road corridor and the cultivated matrix, was formed. The land use change of the flatlands, hills in the middle of study area and the mountain around the basin showed that the land use change and the intensive utilization of the flatlands could impact other two areas, namely, could influence the land use of hills and mountains. There exist a coupling land use changes among the three subareas in the mountain-basin land system. This paper concludes that the land use optimization and regulation of the study area should be strengthened in order to make land use of flatlands, hills in the middle basin and mountains around it evolve in a coordinating mode. The research results of this paper may provide some reference to the land use optimization and management of mountain-basin land system in Guizhou Province.