Study On The Evaluation And Forewarning Of Wetland Landscape Ecological Security For The Coal Resource-based Cities Based On Scenario Simulation

The dissertation is a part of the Natural Science Foundation of China project(41671524): Research on Space-Time Evolution Laws and Optimization Model of Green Infrastructure for Coal Resource-based Cities.Wetland,as an important component of green infrastructure network,has important ecological functions.The landscape pattern evolution of wetland has an important impact on the overall ecological security of the city.Due to the special natural environment and economic-social development mode,the significant changes of wetland composition and spatial pattern have become a common issue to the coal resource-based cities of eastern Huanghuai.In these cities,human activities such as urbanization and agriculture result in the loss of a large number of natural wetlands,while a large number of mining subsidence wetlands are formed due to the mining of coal.This phenomenon threatens the landscape ecological security of wetland and restricts the sustainable development of the cities seriously.From the perspective of optimizing wetland ecological planning,the dissertation builds up a research paradigm which is composed of scenario simulation,landscape ecological security evaluation,forewarning and feedback for the issue of wetland landscape ecological security of the coal resource-based cities of eastern Huanghuai.This research paradigm integrates the theories and methods of landscape ecology,wetland science and ecological planning.Huaibei,a resource exhausted city is taken as a case study.First of all,based on the remote sensing data of 1988,2002,2018 and the geographic information system(GIS),a wetland landscape evolution monitoring database for Huaibei is established by which the evolution of wetland from growth period,maturity period to recession period is simulated.Then the driving mechanism for wetland landscape evolution in the past 30 years is analyzed quantitatively,based on the spatial statistical data of economy society,nature,location and policy.After that,the evolution trend of wetland in the scenario of current development,rapid urbanization,farmland restoration and wetland ecological protection is predicted by the scenario simulation model.Based on the results,the level of wetland landscape ecological security in different periods are evaluated.Finally,the forewarning mechanism of wetland landscape ecological security is set up,and the regulation measures are put forward.The main conclusions are as follows:First of all,the landscape evolution process of the wetland which is in coal resource-based cities of eastern Huanghuai has significant dynamic and stage differences.Overall,the area of wetland in Huaibei increased continuously in the past 30 years,with the fastest growth between 1988 to 2002.Intensity analysis and superposition analysis model are used to analyze the transformation process of wetland,it indicates that the conversion intensity of wetland is active and the main types of wetland conversions are transferring to farmland land and to construction land which mainly occurs in the mining area.The centroid function model,spatial autocorrelation analysis model and landscape metrics are adopted to analyze the changes of wetland spatial distribution.The results show that the centroid of wetland moved to northeast firstly and then to southwest,which is consistent with the mining process.From 1988 to 2018,the aggregation of wetland is more obvious.In addition,the dominance and fragmentation of wetland increase and the stability of the patch decline.Secondly,driven by natural and human factors,the area of wetland in Huaibei will increase continually,but there are significant differences in the landscape pattern of wetland in each development scenario.By the logistic regression model,the key driving factors that affected wetland landscape evolution in the past 30 years are identified.Among the economic and social factors,the mining of coal,urbanization and farmland reclamation are the key driving forces.Moreover,policy factors play an important restrictive role,and elevation is an important explanatory variable in natural factors.The CA-Markov model is used to predict the dynamic development of wetland landscape pattern in different scenarios,which indicates that the area of wetland is the largest in the scenario of wetland ecological protection,and the wetland rate reaches 7.71%,which is higher than the scenario of current development.In scenario of rapid urbanization and farmland restoration,the area of wetland that converts into construction land and farmland increases,which result in the wetland rate lower than the scenario of current development.Thirdly,the landscape ecological security level of wetland in Huaibei is improved,except the evaluation result of rapid urbanization scenario.Considering the characteristics of the wetland in the coal resource-based cities of eastern Huanghuai,an evaluation model is established to calculate the wetland landscape ecological security index(LESI),based on PSR model.The results show that the LESI of 2018 is higher than that of 2002.The LESI of current development scenario will continue to improve,but still stay in the ? warning level.The LESIs of wetland ecological protection scenario and farmland restoration scenario rise to the II warning level.But the LESI of rapid urbanization scenario is down.In different scenario,the changes of LESI for each town are different which indicates that various regulation strategies should be taken in the wetland ecological planning.Fourthly,the forewarning mechanism of wetland landscape ecological security is established.In the background of land spatial planning reform,the purpose,principle and main function of forewarning mechanism are proposed.After that,the operational procedure of forewarning mechanism is set up,including the trigger of forewarning,the analysis of forewarning source and the feedback of forewarning.At last,the overall regulation strategies for wetland protection special planning and land space planning are proposed.Wetland park protection mode,small wetland protection mode and low impact development mode are chosen for the regulation measures.Through the simulation and prediction of wetland landscape evolution and the landscape ecological security forewarning mechanism,this dissertation provide foundation for the improvement of wetland ecological planning analysis methods and planning system which are applied to the coal resource-based cities of eastern Huanghuai.The results have important theoretical innovation significance.In addition,in the background of ecological civilization construction,the results also have important practical significance for ecological restoration of resource-based cities.