基于RS和GIS的合肥市城市绿地景观空间结构的分析评价

Analysis and Evaluation of Spatial Structure of Urban Greenbelt Landscape in Hefei City Based on RS and GIS

在RS与GIS技术支持下,运用景观生态学的原理和方法,选取多样性指数、均匀度指数、景观优势度指数、分离度指数、破碎度指数、绿地廊道密度指数、分维数指数和城市绿化覆盖率等8个评价指标对合肥市城市绿地的空间结构进行了研究和分析,并对该市的城市绿地结构按行政单元进行了综合评价。结果表明,合肥市城3 000 m2的大中型和大型缀块虽然个数较少(仅5.19%),却是构成该市城市绿地景观的主体(总面积占39.05%)。合肥市城市绿地景观多样性指数为0.742,均匀度指数为0.697,景观优势度指数为0.816,总分离度指数为1.839,破碎度指数为0.372,分维数指数为1.265,绿地廊道密度指数为2.391。城市绿地景观空间结构总体表现为各区发展不平衡,绿地类型分布不均,各种类型相差较大,破碎度较小,多样性程度不高,分形维数指数偏低,绿地景观的自然性和复杂性不够等问题。综合评价结果为全市总体上较好;包河区最佳,景观结构最为合理,蜀山区和庐阳区较好,瑶海区一般;针对存在的问题,提出了合肥城市绿地景观空间结构的优化建议。

A study was performed to analyze the spatial structure of urban landscape in Hefei in terms of diversity index,evenness index,dominance index,separation index,fragmentation index,greenland corridor density index,fractal dimension index and urban green coverage rate,with the help of remote sensing and GIS technology.A comprehensive evaluation of the spatial structure was made according to administrative units in Hefei using the theories and methods of landscape ecology.Results show that the structure and distribution of landscape patches in Hefei is not very reasonable.Small patches less than 500 m2 in size are quantitatively dominant,accounting for 85.16%.Medium-large and large patches more than 3 000 m2 in size constitute only 5.19% of the total number,however,they are the principal parts of urban greenbelt landscape,accounting for 39.05% of the total area.The diversity index,evenness index,dominance index,total separation index,fragmentation index,fractal dimension index,and greenbelt corridor density index of the greenbelt landscape in Hefei are 0.742,0.697,0.816,1.839,0.372,1.265 and 2.391,respectively.Unbalanced development in different districts,uneven distribution of green space types,large difference between different types,less fragmentation as well as low diversity,fractal dimension index,naturalness and complexity exist in the spatial structure of greenbelt landscape in Hefei.The spatial structure of greenbelt landscape in Hefei is better on the whole.Baohe is the best district having the most reasonable landscape structure,followed by Shushan and Luyang districts,while the landscape structure of Yaohai district is general.Some proposals for the optimization of spatial structure of greenbelt landscape in Hefei are offered aiming at the existing problems.