Optimization Of Green Infrastructure Layout In Lishui District,Nanjing City

With the advancement of the national urbanization process,urban and rural construction has entered a new stage,and ecological civilization and circular economy have become the main theme of contemporary sustainable development.In this context,green infrastructure(Green Infrastructure,GI)as an important life support system for regulating climate,maintaining biodiversity and mitigating flood disasters,has important significance for achieving the sustainable development strategy.However,due to the unreasonable use of land resources,GI in Lishui District faces problems such as weakened function and structural imbalance.This paper takes GI layout in Lishui District as the research object,and conducts in-depth analysis of GI space from three aspects: GI matrix space,GI network and GI buffer zone.Combining with the existing problems in the current situation,this paper puts forward strategies and methods for optimizing GI layout,aiming to provide scientific theoretical basis and method guidance for GI space planning and management work in Lishui District.Firstly,this paper analyzes the function and spatial structure change of GI matrix space in Lishui District from 2001 to 2021 by using land use data and landscape pattern index respectively.Secondly,this paper adopts Morphological Spatial Pattern Analysis(MSPA)and Minimum Cumulative Resistance Model(MCR),combined with connectivity analysis method,identifies the center and potential corridor of GI network,and grades and optimizes the potential corridor by using gravity model.On this basis,the node position is identified by combining equal resistance circle,thus constructing a comprehensive GI network optimization scheme.At the same time,this paper analyzes in detail the change trend and spatial distribution characteristics of ecosystem service value in Lishui District from 2001 to 2021,and the evolution law of various MSPA landscape spaces in GI space.Finally,this paper quantitatively calculates and analyzes the ecological sensitivity of GI buffer zone,and puts forward corresponding optimization strategies for different sensitivity levels,which creates suitable environmental conditions for GI layout.The main research conclusions of this paper are:(1)In the process of urbanization,Lishui District’s regional GDP grows steadily,but the area of water area and cultivated land continues to decrease,the ecosystem service value decreases continuously,the number of GI corridors decreases,the ecological environment fragmentation intensifies,and the GI space connectivity decreases.(2)This paper constructs a two-level network center,three-level corridor and multi-node GI network system in Lishui District,which is the core content of GI layout optimization.(3)In the buffer zone of GI space in Lishui District,ecological sensitivity shows an uneven spatial distribution,with an average level of moderate sensitivity,and most areas reach moderate sensitivity and high sensitivity levels.The optimization of spatial layout for these areas can help improve the efficiency of GI network construction and ensure the stability of GI space structure.