Research On Methods For Spatial Optimization Of Territory Development

The sustainable development of the society and economy in China has been facing the dilemma of resource constraints,environment deterioration,disordered space development,etc.Therefore,the Chinese government has proposed the strategy of constructing an ecological civilization across the country.The optimization of the land space is regarded as the primary task and fundamental pathway to achieve the construction of the ecological civilization,including both the macro-and micro-scale optimization of the land space.The macro-level optimization pays attention to the coordination of regional main functions and the matching of spatial elements,such as coordinated development of land and sea,the regional balanced development,urban and rural integration development.While,the micro-level optimization pays attention to the specific use and spatial allocation of different functions,such as the layout and spatial coordination of urban,agricultural and ecological functional spaces.The connotation and demand of land space optimization in the new era is changing along with the deepening of China's ecological civilization construction.In this context,how to guide the practice of land space optimization from the perspective of ecological civilization is now the key issue we are facing with.One of the challenging problem that we have to address is how to delineate the bottom line of space development,including the rational arrangement of the agricultural production space and ecological protection space according to the natural,social,economic and ecological attributes of the national land space,and how to base the rational spatial layout of urban construction space on the constraints and guidance of the development bottom line.The final layout of national land space development should promote the coordination of regional population,resources,and environment,as well as the integration of the social,economic and ecological benefits.So,the spatial optimization of the agricultural production space,the ecological protection space,and the urban construction space is the key to solve the problems facing China's current social and economic development,and it is also an urgent task in the current construction of ecological civilization.The purpose of the study is to propose a framework for the micro-level(countylevel)optimization of the land space from the perspective of ecological civilization through the coupled application of a spectrum of state-of-the-art approaches,such as system dynamics,many-objectives optimization,spatial statistics,spatial modeling,and machine learning.Our research questions mainly focus on the optimization of the quantitative structure of the national land space,the delineation of space development boundaries,and the spatial arrangement of the urban construction space.We base our study on the selection of the appropriate method to answer the above questions as well as the identification and improvement of the shortcoming these methods.We use the capital city of Hubei province as the study case to verify the feasibility and applicability of our framework.The main results and associated conclusions are presented as follow:First,we identified the research gaps in the methods that were used to address the above three questions through a comprehensive review of the relevant literatures.Also,we clarified the definition of ecological civilization and other concepts about space development.In particular,we clarified the connotation and requirements of the optimization of land space development from the perspective of ecological civilization.Second,understanding the characteristics of land space development in history and thus to improve planner's spatial cognition of the optimization of land space development is the basis of this study.This study proposes to use a improved hierarchical intensity analysis framework to accurately analyze and visually reflect the stability and systemic patterns in the transformation process of various land space utilization types to help decision makers grasp the systematic feature in the process of land space development.These systematic processes can help planners to make informed space development strategy,and to assist researchers in constructing targeted models for optimization of the quantitative structure and models for spatial layout simulation thus to improve the reliability of model results.Third,the traditional optimization method for quantity structure of land space development regards the formation of the quantitative structure as the derivation of mathematical equations,which ignores the coupled and integrated relationship between the dynamics of the quantitative structure and the evolution of the natural,social and economic environment.It only stays in the objective narrative of the area and proportion of the land space development,lacks the considerations of drivers and mechanism,and thus have little implementation for practice.In response to this shortcoming,this study deeply couples the system dynamics model with the manyobjective evolutionary optimization algorithm to optimize the quantity structure of land space development.In the proposed model,the system dynamics model is used to couple the formation of the quantitative structure of the land space development with the evolution of social,economic and resource environmental factors.The coupled model runs in accordance with the basic principles of “optimizing policies,adapting to the environment,improving efficiency,and striving for stability”.Moreover,we leverage the high-performance parallel computing technology to facilitate the search for robust decision-making factors that maximize the social,economic and ecological benefits of land space development.Afterwards,historical experience and expert knowledge was used to identify external environmental factors in which the land space development system can operate stably and fluently.Therefore,we can finally construct a simulation model for the simulation of the quantitative structure of the land space development and conduct scenario analysis.Fourth,delineating the bottom line of land development,anchoring the agricultural production space and the ecological protection space,and strengthening the bottomline constraint are the inherent requirements for the optimization of land space development under the background of ecological civilization.The development constraints include the delineation of permanent basic farmland protection areas and the construction of ecological network space.The traditional method bases the delineation of the permanent basic farmland protection area on ranking the farmland parcels in order of their quality,thus does not consider the spatial aggregation information,which will make the demarcated protection zone decentralized and fragmented.The resulting farmland protection zone is not conducive to the large-scale operation,protection and management of basic farmland.In this study,we used a spatial irregular clustering algorithm(AMEOBA)to identify permanent farmland protection regions that are both have high farmland quality and is spatially clustered in space.The farmland quality was estimated using the LESA system.The AMEOBA algorithm outputs a ranking index that can not only reflect the quality of farmland but also indicating the degree of spatial aggregation of farmland.The “patch-corridor-matrix” pattern has become the main pathway to construct the ecological network space.However,the patches will have a high risk of being too fragmented in space if they are directly identified by using a threshold segmentation method based on the results of suitability evaluation in GIS.Moreover,if we identify landscape corridors based on the fragmented patches and the minimum cumulative resistance model,we will result in too many corridors being identified and the width of corridors cannot be specified.In response to these shortcomings,this study proposes an improved strategy for the identification of ecological source patches and corridors based on the concept of “looseness”.Its improvement is mainly reflected in: 1)In the process of ecological suitability evaluation,we follow the principle of grading the factors into less categories;2)Using the moving window method to smooth the difference of the ecological suitability between neighboring cells;3)Clustering source patches into “patch zones” so as to reduce the number of corridors;4)The minimum cumulative resistance value is gradually increased based on the minimum cumulative resistance value corresponding to the minimum cumulative resistance pathway,thus to create the contour of the cumulative resistance value to increase the width of the corridors.Fifth,spatial simulation is an important method to optimize the layout of urban construction space.And,multi-scenario simulation and optimization of urban construction space based on the cellular automata(CA)model has been developed and widely accepted.However,conventional CA models for urban growth simulation usually utilize a cell-based simulation engine in which urban expansion is expressed as the state transition of an individual pixel.While,in reality,urban developments are typically implemented in parcels.To alleviate this biased representation of the urban development procedure,a new form of CA model,which is patch-based CA,was proposed.In a patch-based CA,urban land parcels are represented by irregular raster patches.A raster patch is a collection of regular lattices that has the same state and is spatially connected.The CA model uses two parameterized and self-organized patch growing functions to represent two different spatial progress of urban development: organic urban growth which dedicates the expansion of existing urban patches and spontaneous urban growth which depicts the initialization and self-growing of isolated urban patches.These two spatial progresses of urban development occur and agglomerate to generate various urban landscapes.The key model parameters in the CA model were optimized utilizing a genetic algorithm(GA).The patch-based CA model can be combined with the optimization results of the quantitative structure of the national land space and the results of the development bottom line to simulate the spatial layout of urban construction space under different decision scenarios.Finally,the application in Wuhan City,Hubei Province,verify the feasibility of the proposed technique framework for optimization of land space from the perspective of ecological civilization.Based on the application results,the paper proposes the optimization pathway for the future development of land space in Wuhan.Firstly,it is necessary to adhere to the ecological bottom line for urban development.We should optimize the layout of land space development based on the ecological network space optimization.It is suggested that Wuhan should adopt an ecological network space construction strategy that complements the “ring-lane-wedge-zone” in the future,and create an ecological network space of “two axes,two rings,six wedges,multiple corridors and multiple districts”.Secondly,the layout of cultivated land should be adjusted to give full play to the multiple functions of agricultural production space.The agriculture production space should be integrated with urban construction space.Third,efforts should be made to build a multi-center,networked,and spatially grouped urban construction space,conforming to the constraints and guidance of bottom line for the national land space development.And finally,to achieve the goal of spatial optimization of the agricultural production space,the ecological protection space,and the urban construction space using the proposed technique framework.