基于GIS的城市绿化生态服务量及其均等化评价

摘要

城市绿地是城市生态系统重要的组成部分,具有重要的生态服务功能,为了客观科学地评价城市绿地的绿化效果和生态服务均等化水平,以天津市滨海新区汉沽区河西区块为例,采用生态绿量测度城市绿化的生态服务量,以GIS作为城市绿化生态服务量的分析工具,并结合距离衰减模型及源叠加模型,计算不同斑块所承接到的不同绿化源的生态绿量;构建可视化系统,展现各斑块生态绿量的空间分布情况.结果显示,从整体水平看,研究区生态绿化建设效果良好,大部分斑块达到了生态绿量的基准线51.848,只有西南角部分斑块没有达标.从分布情况来看,研究区生态绿量分布并不均匀,表现为同一纬度上东部比西部生态绿量的接收量高,且呈现由东到西逐步递减的趋势;而同一经度上北部比南部生态绿量的接收量高,呈现由北到南逐步递减的趋势.其中,研究区东北区块与西南区块的接收量差距最大,斑块接收的生态绿量最大值为161,最小值仅为46,均等化水平较低.应用文中的研究方法可以精准找出城市绿化生态服务较为薄弱的斑块,对城市绿地系统规划具有一定的参考价值.%Urban green space is a significant part of urban ecosystem, which has important ecological service function. In order to objectively and scientifically evaluate the effect of virescence and the equalization level of ecological service of urban green space, this paper measures the ecological service quantity of urban virescence with the quantity of ecological green and applies GIS as a tool to analysis urban green ecological services quantity, then combines range attenuation model with source superposition model to calculate the green quantity of different source carried by different patches,. Furthermore, the paper builds a visual system to show the spatial distribution of each patch. And then appraise the greening effect and equalization evaluation of Tianjin Binhai new area. The result shows that the ecological greening construction of the case area is good in the whole view demonstrated by most of the patches in the evaluation area reaching the standard of ecology 51.848, except some patches in the southwest corner. However, it is nonuniform that the distribution of the ecological green quantity received by the patches in Hexi block, showing that the eastern area can receive more ecological green quantity than the western in the same latitude, and the trend of gradual decline from east to west. The northern part in the same longitude is higher than the southern, showing the trend of gradual decline from north to south. The greatest difference of the quantity of reception between northeast and southwest in the study area have the maximum value of ecological green quantity is 161, and the minimum value is 46 that the equalization level is lower. From above study and results analysis, we can see that this method can find the frail patch of urban green ecosystem accurately, which has certain reference value to project urban green space system.