基于空间形态类型的密集建成区生态本底评价方法研究--以成都中心城区为例

Studies on Evaluation Method of Dense Built Environment Ecological Background Based on Types of Space Form:A Case on the Central City of Chengdu

研究基于现有生态本底评价方法仅针对现状、无法定量分析建设行为与建成后生态状况关联度的事实,构建密集建设区生态状况评价方法。该方法可对规划建设方案实施后的生态本底状况进行量化分析和预测,逻辑如下:通过对既定空间形态下的典型建成空间进行生态功能评价,获得相应建设模式的生态状况代表性数据,将之赋予同类型规划用地,获得密集建设区的生态本底模拟图。该方法操作的关键有三:一、理清建设管控指标与建成环境空间形态的关系,提炼典型空间形态;二、确立密集建设环境的生态本底评价指标体系;三、构建生态本底评分操作规则。研究以成都为例,基于卫星影像和实地情况,归纳了基于建设分区管控体系的10类典型空间形态;运用专家打分法和层次分析法构建生态评价指标体系;通过分层典型抽样调查,评定不同空间形态的生态本底质量状况阈值,并将之赋予各个地块,生成中心城区生态本底状况模拟图。实证表明:该方法能从整体层面判断密集建设区的生态本底状况;也可依托控规模拟规划建设方案的未来生态本底状况发现生态空间构建和建设控制的生态关键,优化城市生态空间格局。

The purpose of the project is to identify the ways to optimize the ecological quality of urban space under the intensive construction mode.This method is built on the actual state of the ecological function and the mechanism of the ecological service functions.Its research steps are structured in the following three points:Firstly,it follows the space construction management and control logic,and extracts the typical spatial form and construction mode guided by different construction indicators.Secondly,it constructs an evaluation index system for the ecological background of densely built-up areas.Then,by evaluating the environmental quality and ecological service functions of typical samples under different construction modes,it forms the threshold of ecological background conditions for spatial forms.Thirdly,it proves the correlation between the construction mode and the ecological quality of the densely built environment,and summarizes the corresponding influence laws.On this basis,we have designed an ecological evaluation method for condensed construction areas,in order to quantitatively analyze the relationship between construction control and environmental ecological quality after completion.The keys to the operation of the method are as follows:1)to clarify the relationship between control indicators and the formation of environmental space,then sum up the typical space forms;2)to establish the ecological background evaluation index system of urban intensive built-up area;3)to set up specific operation rules for ecological background evaluation.The empirical research operation in Chengdu is divided into three steps:1)The foundations rely on the construction of density zoning and space construction controlling index system,with“construction density”as the main control index,and combine with satellite image analysis and investigation and verification.The built environment of the central city,according to the combination of building height and space,is classified into three typical categories of 10 small categories of space construction models,a total of 1951 samples;2)According to stratifying random sampling,and the field survey under different construction modes,the ecological background of the built space is evaluated and summarized to the typical ecological background quality of the corresponding construction mode.3)The typical data summarized by the sample research institute is given to the plots of the corresponding construction mode,and the ecological background simulation map of the densely built-up area is generated.The similarity between the figure and the remote sensing ecological index map is compared to judge the fitting accuracy.The experiment proves that according to the ecological background presented by the simulation map.So we are able to analyze the spatial problems that may exist in the construction and planning that are not conducive to the optimization of the urban ecological environment,and also to find the key areas and spatial modes that optimize the urban spatial structure.Compared with the past urban ecological environment assessment methods,this method is characterized by the relationship between the planning and control index system and the actual built-up space ecological status through the evaluation of the ecological status of the typical space construction model–not only based on satellites.The image is roughly evaluated on the spatial scale of the environment,and more importantly,the ecological status after the completion of the planting plan can be simulated based on the control indicators to evaluate the spatial decision-making and optimize the ecological spatial planning.This method can be used to simulate the ecological background status of all urban built-up areas based on planning and control and planning schemes at the conceptual level.However,the method based on the spatial construction mode of the typical extraction of the ecological background has undergone two layers of abstraction,so there will be deviations in the reduction of the real situation-it is not as accurate as the remote sensing ecological index analysis.The longitudinal unit division of the method relies on clearer boundaries such as municipal roads,natural boundaries,and cadastral boundaries.The in-depth analysis of the fuzzy sundry plots of the inner city boundary is not sufficient,and further research is required.However,due to the differences in development history,scale,and control systems,the typical longitudinal construction models vary from city to city,and have to be verified and summarized in a targeted manner.The dominant ecological factors of different towns are very different.To ensure the accuracy,it is necessary to select the evaluation elements according to the urban conditions and construct the corresponding weight system.Empirical research in the central city of Chengdu shows that the method can judge the ecological background of the dense construction area from the overall level.It can also be used to simulate the future ecological background of the construction control indicators according to the planning plan,which is conducive to the discovery and construction of the ecological space pattern,and becoming the key to optimization of controlling our city environment,and optimize the urban ecological space pattern.