洛阳市区绿色开放空间系统的动态演变与功能优化

洛阳市区绿色开放空间系统包括生产绿地、农林地、滨河绿地、公园绿地、景观绿地、附属绿地等6种类型。运用景观格局分析法、结构均匀比指数测度法,解析了1988～2008年洛阳市区绿色开放空间系统的面积、斑块、空间布局结构的动态演变。研究表明:城镇化进程中洛阳市区绿色开放空间系统的不同类型要素在不同时期、不同方向、不同梯度上的变化迥异。1988～2008年,滨河绿地、公园绿地、景观绿地、附属绿地面积逐渐增加,生产绿地、农林地大幅度减少;各象限、各圈层不同种类绿地的均匀比指数变化、差异很大;绿地斑块密度逐渐增大,斑块形状指数普遍较低。在此基础上,运用生态功能强度指数测度法和Huff模型等方法,评价了系统的服务功能水平,发现洛阳市区绿色开放空间系统的生态服务功能水平一般,居民访问绿地的成本普遍较高,市区绿地与居民的供需关系不协调。可采用改变人口居住模式、调整绿地分布格局以及多种措施对系统的空间布局结构、服务供需关系、绿地要素等进行功能优化。

Dynamic evolution and optimization of green open space in Luoyang

Optimization of green open space plays a significant role in achieving sustainable development of ecological cities.Green open space system in Luoyang consists of 6 categories: product green area,farmland and forest,riparian area,garden,road landscape area and auxiliary green area.By using landscape pattern analysis,Structure Evenness Radio Index,Ecological Intensity Index,and Huff model,the paper examines the dynamic changes in area,shape and distribution of the green open space from 1988 to 2008.It evaluates service capacity of the green open space system before spatial distribution and demand-supply condition is optimized.Results are shown as follows.1) For the 20 years there is an increase in riparian areas,gardens,road landscape areas and auxiliary green areas,while a decrease in product green area,farmland and forest.Green space is abundant in Quadrants 2-5 and Rings 4-8,and less in Quadrants 7 and 8 and Rings 1,2,and 10.2) There are significant differences in Evenness Radio of all quadrants and rings.However,Quadrant 6 and Ring 5 show stable Evenness Radio,indicating gradual improvement of green space distribution in riparian areas,gardens,road landscape areas and auxiliary green areas.3) There is a notable increase in density of green patches,with areas along the Luohe River and west fringe of the city having the highest value.Many green patches have low Shape Index,though some regions see an increase.The patches generally display regular geometry shapes,which are obvious products of urban planning.4) Ecological Serving Intensity Index of 2008 is 0.288,and falls into Class III,being an ordinary level.Time costs for local residents visiting green open space are high.Demand and supply of green space service are out of balance for both the northern and southern parts of the city.5) The frame of overall design for green open space system optimization is "1 center with 3 rings,4 belts with 3 axes,and 3 mountains with 4 wedges".The four levels of optimizing distribution pattern are "green rings revolving,green corridors interweaving,green dots interspersing and green background extending".Residence location and green space distribution need to be modified to find the balance in demand and supply of green space.Concrete measures should be taken to optimize the distribution and functionality of public open green system.