Study On The Spatial Allocation Of Construction Land Based On The Ecological Nich Theory

Under the context of rapid urbanization,industrialization and increasingly serious ecological problems,the construction land of China is utilized with low efficiency,which is a large challenge for sustainable development of China,because as we know the man-land relationship of China is poor,so nowadays the most important for policy makers in China is to consider how to rise the efficiency of construction land,then achieving the balance of economic society development and ecological environment protection.Up to now the existing studies of construction land allocation(CLA)are almost conducted from the perspectives of economics or geography,and CLA under economics view always pay more attention to efficiency improvement with marginal analysis method,ignoring the environment and resource problems,while the CLA under geography view always is done by the opposite,which we think is caused by limited disciplinary knowledge,thus there is great necessary to improve the CLA method and bridge the gaps.It is clear that during CLA process the construction land quantity of administrative district or the possibility of spatial cell being changed into the attribute of construction land are decided by their socio-economic level and natural endowment together.That is to say,functions and positions of basic units are decided by their disequilibrium distributions of socio-economic level and natural endowment,which is the same as biological species positions decided by their ecological niches.The phenomenon of biological species competing,evolving and symbiosis provides useful references for CLA to coordinate the contradictions between ecology protection and economic growth,base on this,this research will take CLA study from ecological niche view.Generally,this research is conducted like this:firstly we define the contents of ecological niche of construction land with comprehensive consideration of its social economic condition and natural endowment,and also combined with the basic concepts of ecological niche,we develop the method of calculating ecological niche value;secondly according to the results of ecological niche calculation,a non-linear programming model is proposed to allocate construction land to different units for achieving the best comprehensive interest;lastly the construction land quantities of different administrative districts is allocated to its spatial cells to get distinct boundary,releasing spatial effect and then increase CLA efficiency drastically.During the whole research we take Yangzhou city as a case study to demonstrate the application of proposed method,also wanting to provide useful reference for land use policy making,and the concrete research contents are as follows:1.The ecological niche measure of construction land.Firstly the security landscape pattern is built spatially with the common security landscape pattern method,based on which natural ecological niche(NEN)of different towns in Yangzhou are measured;secondly factors influencing economic growth are selected,also influence values of spatial cells are calculated with GIS technology,with that we evaluate the fitness of spatial cells to economic growth with approach of minimum cumulative resistance model,then ultimately we get economic ecological niche(EEN)of different towns;thirdly based on results of NEN,EEN,and the basic formula of nature economic ecological niche(NEEN),the construction land NEEN values of different towns in Yangzhou are measured.Because EEN and NEN could represent only one side demand of CLA and to synthetically reflect economic benefit and nature interest of CLA,the indicator of NEEN is chosen into the quantity allocation model,bigger of that means the corresponding construction land could generate more economic benefit,meanwhile leading to lesser natural capital value loss.2.Construction land quantities optimal allocation based on the results of ecological niche measure.Firstly we bring the NEEN into a non-linear programming model,with which the optimized construction land quantities of different towns could be obtained,where NEEN of Yangzhou will be maximized,meaning construction land is allocated to towns with higher NEEN and could generate good economic benefit,also protect environment effectively.While it should be noticed that the construction land belong to the category of public good,regions with enough construction land supply having promising development opportunity,whereas having no opportunity under the planned management of China,so CLA should not only consider NEEN,but also pay attention to regional equity.Next taking NEN and EEN as indicators,the entropy value method is applied to get the schedule of CLA,considering regional equity.In all the schedules of CLA could provide multiple dimensions recommendations for land use policy making of Yangzhou.3.Layout optimization of construction land under quantities constraint.For land use planning,the quantities allocation of land resource is not the termination,and due to its spatial character,we should allocate construction land to cells for shaping its spatial boundary,then providing distinct basis for land management activities.The possibility of cells being changed into construction land is not only decided by their attribute values,but also depending the neighbor personality—if most of neighbor cells are construction land,then the possibility rising,while if most of them are arable land,the possibility dropping—therefore we use evaluation method based on ecological niche suitability to evaluate the fitness of cells to construction land,and allocate construction land to cells with higher fitness,ultimately the optimized spatial boundary for construction land of Yangzhou is shaped.The main conclusions of this research are as follows:1.The utilization of construction land has the feature of ecological niche.As we know the basic units of construction land utilization are administrative district or spatial cell,construction land number of administrative district depending on its output ability of economic benefit and ecological sensibility,meanwhile the possibility of spatial cell being into construction land depending on its fitness to economic development and ecological restriction,so according to ecological niche concept,we think construction land utilization process have the feature of ecological niche,where the ecological unit is administrative district or spatial cell.Actually the expansion of construction land could be considered as the reflection of economic activities on space,whose scale and expansion path are impacted by EEN,while the NEN is expressed by a serious of physical and energy ecological production,therefore the ecological niche theory can applied for CLA.2.The CLA based on ecological niche theory could well coordinate the economic efficiency and ecological protection.As we described the existing CLA studies rarely bridged the gap between economic efficiency and ecological protection,however in our study we do it well.We first analyze the NEN and EEN contents of construction land utilization and measure them with the developed methods;secondly according to NEN and EEN,we build another ecological niche indicator that is NEEN,which could comprehensively represent the preference of construction land,the higher NEEN value the cell with,the more suitable to construction land will be;lastly we applied the three ecological niche indicators into programming models to achieve the combination of economic efficiency and ecological protection during CLA process.3.This study could provide multiple dimensions references to CLA policy.We establish two optimized models with the three proposed indicators,in one of which,NEEN is implanted into a non-linear programming to get a quantities allocation schedule for Yangzhou,where the town with higher NEEN value is given more construction land,and we call it efficiency priority scheme,in the other of which,NEN and EEN are implanted into the entropy value model to get another quantities allocation schedule,where except the consideration of NEN and EEN of towns,regional equity is also taken into account,and we call it efficiency and fairness balanced scheme.We could see from the two schemes that northern of Yangzhou is suitable for ecological environment maintenance and southern region is more suitable for economic growth,also in first scheme,the incremental construction land is mainly in several towns,while in second scheme,the distribution of incremental construction land among the towns is more uniform,which can provide multiple suggestions for land use planning making of Yangzhou.4.Microscopic CLA to spatial cells could provide explicit boundary for land use management.The spatial boundary of construction land is the key of land use management,not only controlling urban growth,but also protecting arable land and ecological sensitive area.We first evaluate the fitness of cells to construction land,based on which construction land in the two schemes is allocated to spatial cells,where possibility of cell being into construction land is decided by its fitness degree,ultimately we could get spatial boundary of construction land of the two schemes.We could find that the general tendency of construction land spatial distribution of Yangzhou is imbalanced,where most of incremental construction land is allocated to southern towns,while northern area are with rare construction land,also it is more disequilibrium of the first scheme than the second scheme,because in first scheme most of the incremental construction is in only several towns.