摘要
我国快速推进的城市化进程正对周围生态系统造成现实或潜在的威胁。基于RS和GIS技术,从镇域尺度探讨1984～2004年太湖流域城市化空间过程及其生态效应。（1）城镇用地轴向扩展明显：沿路三级邻域带R1、R2、R3在1984～2004年期间新增城镇用地面积累积平均百分比分别为88.24%、90.23%、94.68%。（2）城镇用地扩展形态指数MFD与城镇公路连接数UR存在关系：UR=UR3时,扩展形态指数MFD〉=1.5;UR=UR1时,1.250高值区占全区面积的66.33%,形成两核两带：两核位于溧阳经济开发区和镇江谏壁镇-丹徒镇附近;两带分别是两核连线地带和溧阳城区-宜兴新街镇附件一带。
Across Taihu Lake watershed in China, landscape change associated with urbanization, particularly urban sprawl, has been significant during the last half century and is expected to continue through the next decades. We organized the study around key questions： how did urban land expand in the study area？ What is the impact of urban spatial change on ecological land quantity and pattern？ We adopted some spatial metrics by use of ArcMap and FragStat to answer these questions： applying Intersect and Buffer functions of ArcMap to analyze spatial relationships between urban land and road corridor; using fractal dimension （FD） based on FragStat to measure urban expansion form; getting the contribution rate to ecological land growth （CRG） and contribution rate to ecological land reduction （CRR） by urban land according to the transition matrix between ecological and urban land to describe impacts of urban land sprawl on ecological land quantity; developing Insulation degree （ID） to measure impacts of urban land sprawl on ecological land pattern. The major results are ： （ 1 ） Urban land sprawled obviously along transportation corridors. Mean percentages of added urban land in buffer belts （ R1, R2, and R3） are 88.24%, 90.23% and 94.68%, respectively. （2） The distribution curve of urban land expansion form （FD） showed a ring and ＂U＂ shape. Towns with MFD 〉 = 1.5 is around one wing Ua where 73.68% of urban nodes UR3 are lied, and towns with 1.2 〈 MFD 〈 1.5 is around the other wing Ub where 57.58% of urban nodes UR1 are lied, and but there is no evident relationship between MFD and numerous urban nodes UR2. （3） Impacts of urban land sprawl on ecological land reduction and growth are not both obvious. The CRR is 9.8% and CRG is only 3.1%. （d） Spatial impacts of urban land expansion on ecological land pattern are very evident. The area percentage of high-value area of MID was 66.33%. Two high-value cores located in Economic Development Area of Liyang city and Jianbi-Dantu town, and two high-value belts located in the area between tow cores and the region between Liyang city and Xinjie town where MID 〉 50, and the highest value of MID was high to 89.32.
出处
《生态学报》
CAS
CSCD
北大核心
2008年第9期4306-4312,共7页
Acta Ecologica Sinica
基金
国家自然科学基金资助项目(40435013
40801222)~~
关键词
城市化
空间过程
生态效应
隔离度
太湖流域
urbanization
spatial process
ecological effect
Insulation degree
Taihu Lake watershed
