Research On Determining The Floor Area Ratio Of Residential Land In Old City Renewal

In recent years,China's urban development has gradually shifted from an extension to an intensional growth.The renewal of old city has become an important part of urban construction.Compared with the new area,the construction environment of the old city is more complex,and the intensity of the develo pment of residential land is constrained by multiple factors.Therefore,the determination of the Floor Area Ratio(FAR)for residential lands in the old city renewal needs to be very cautious.However,in the current planning practice,the method of deter mining the FAR of residential land plots is too subjective and lacks scientificity.At the same time,the elasticity of indicators is insufficient,which leads to frequent breakthroughs in the FAR of residential lands when the old city is renewed.Based on the situatuon,a method of determining the FAR for residential lands in the Old City renewal is proposed.Combing the relative research references on the FAR at home and abroad,existing relatively reasonable method is improved and applied in the particul ar situation.Quantitative analysis and qualitative evaluation are combined,and impact factors are comprehensively considered to enhance the scientificity and practicability of the solution.This article follows the research ideas of “discovery problem-analysis problem-solve problem-case analysis”.The research content includes the following parts:The first chapter points out the necessity of reasonably determining the FAR of residential land in the old city,and then analyzes the concept of FAR,FAR of residential plots,and renewal of old cities.The purpose,significance,and technical route of the study are highlighted.The second chapter reviews the domestic and foreign relative literature,sorting out the main researches of the domestic determination and management of the FAR from 1991.The relative methods of FAR determination are also analyzed and evaluted in multiple aspects.At the same time,the case studies of the FAR of renewed residential lands in the old city are analyzed,which provide refer ences for the following method construction of FAR determination in residential lands.The third chapter summarizes the method of the FAR deternimation for residential lands in planning practice as three types.And then both their advantages and disadvantages are evaluted.The evalution demonstrates that the existing method of the FAR determination for residential lands is too subjective and the scientific basis is insufficient.The corresponding index lacks elasticity and cannot satisfy the planning and management.Then the main affecting factors of FAR values are analyzed in depth from the aspects of economy,society and environment.Combining previous researches,the fourth chapter establishes a method system of the FAR determination for residential lands in the old city.The method system consists of two steps: preminilary determination of the FAR interval and the interval optimiaztion.Based on the image processing by Matlab and genetic algorithm,a method for determining the maximal FAR value under the sunlight constraint is proposed considering the shape of the land.And then the value interval of residential land FAR is preminilary determinited from the requirements of sunshine standard,traffic capacity,municipal carrying capacity,and economic feasi bility.On this basis,external traffic,service facilities,environment landscape factors,which are not directively related to the residential land FAR in quantity,are extracted.The Delphi method and the AHP method were used to evaluate and a comprehen sive score are given to the factors of the land.Based on the score,the former FAR interval is further optimized.The fifth chapter takes the residential block in Laojie District of Loudi City as an example to illustrate how to use the constructed method to quantitatively obtain the FAR value interval.And a reasonable interval of the FAR is obtained at last.