山地城市土地利用的景观破碎化时空演变与驱动力分析

Spatial-Temporal Evolution and Driving Force Analysis of Landscape Fragmentation in Mountain Urban Land Use

以重庆市万州区为例,本文基于1995年、2005年和2017年3期土地覆盖数据,利用景观指数、空间主成分分析等方法研究山地城市土地利用的景观破碎化时空演变及驱动力。结果表明,城区整体景观破碎化程度加深,空间格局差异明显,主要表现在城区道路附近破碎度高,农村林地与耕地交叉分布区破碎度高;因人类活动尤其是城市化与交通基础设施建设,建设用地不断扩张,导致原有耕地和草地被大面积打破,破碎化程度增加,农村坡度较高区域因政策保护大面积退耕为林地,减弱了小部分区域的景观破碎化程度;人类活动和地形双因子的交互影响是山地城市景观破碎化的主要原因。

Taking Wanzhou District of Chongqing City as an example,this paper studies the spatial-temporal evolution and driving force of landscape fragmentation in mountainous urban land use by using landscape index,spatial principal component analysis and other methods based on land cover data in 1995,2005 and 2017.The results show that the fragmentation degree of the overall urban landscape is deepened,there are obvious differences in spatial patterns,mainly manifested in high fragmentation near urban roads,and high fragmentation in the cross-distribution areas of rural forest land and cultivated land;due to human activities,especially urbanization and the construction of transportation infrastructure,the land for construction has continued to expand,resulting in large-scale destruction of the original cultivated land and grassland,the degree of fragmentation increases,in rural areas with higher slopes,due to policy protection,a large area of farmland has been converted into forest land,which has weakened the degree of landscape fragmentation in a small part of the area;the interaction of human activities and topography is the main reason for the fragmentation of mountainousurban landscape.