Ecosystem Health Evolution And Simulation Research Of Coastal Area

Coastal area is located in the transition zone between marine ecosystem and land ecosystem.Its ecosystem is relatively sensitive and fragile,and vulnerable to external interference.Generally speaking,the coastal area has a high level of economic and social level and strong human activities,which leads to the degradation of ecosystem function and continuous deterioration of ecological environment.The assessment,analysis and prediction of ecosystem health in coastal areas can reflect the impact of human activities on coastal areas,and provide theoretical basis and reference for ecological environment protection and sustainable development in coastal areas.On the basis of DPSRC framework,this paper selects 14 indexes from five levels of driving force,pressure,state,response and control,constructs the ecosystem health evaluation system of coastal area,calculates the ecosystem health index of Yancheng,south bank of Hangzhou Bay and Xiangshan Port by combining Analytic Hierarchy Process and comprehensive index method,and classifies the health level.Then,based on Ca-Markov model,the landscape pattern of different scenarios in 2028 and 2038 in each study area is simulated,and the social and economic data are predicted by the triple exponential smoothing method,so as to evaluate and analyze the future health status of the coastal ecosystem.Based on the comparative study of several regions,the health status of coastal areas with different location,natural conditions and socio-economic development level is evaluated and predicted,and then the comparative analysis is carried out.The results are more representative,which is conducive to a more comprehensive understanding of the health evolution characteristics of the ecological system in coastal areas.The results show that:(1)In terms of land use change,from 1990 to 2018,the land use types in each study area changed frequently.The land use types in Yancheng coastal area are mainly farmland,tidal flat and aquafarm.The land use transfer types are mainly from tidal flat to salt marsh vegetation,and from tidal flat,salt field,salt marsh vegetation to aquafarm.The land use types in the south bank of Hangzhou Bay coastal area are farmland,tidal flat and construction The main types of land use transfer are the transformation from tidal flat to aquafarm and salt marsh vegetation,and the mutual transformation between farmland and construction land;the main types of land use in Xiangshan Port coastal area are forest and sea area,and the main types of land use transfer are farmland to forest and construction land,and forest to farmland.(2)In terms of ecosystem health assessment,from 1990 to 2018,the health status of the three study areas declined to varying degrees,among which the ecosystem health status of the coastal area on the South Bank of Hangzhou Bay coastal area was the most worrying,the health index decreased by 39.34%,from 0.61 in 1990 to 0.37 in 2018,from health status to unhealthy status;the health level of Xiangshan Port coastal area was the highest,the health index decreased by 20.90%,From 0.67 to 0.53,from a healthy state to a sub healthy state;Yancheng coastal area ’s health index decreased the smallest,from 0.54 to 0.45,a total of 16.67% in 28 years,all in a sub healthy state during the research period.The intense economic activities of human beings in the coastal area have caused great pressure on the ecological environment of the study area,which leads to the fragmentation of the landscape pattern,the degradation of wetland resources and the deterioration of the ecological environment.(3)Based on the analysis of the influencing factors of land use change in each study area,and combined with the current situation of landscape pattern in Yancheng coastal area,south bank coastal area of Hangzhou Bay and Xiangshan Port Coastal Area,and the government’s various policy planning.Three different scenarios are set up to simulate the future landscape pattern of the study area based on Ca Markov model,and predict the ecosystem health status of the study area in2028 and 2038 by using exponential smoothing method.By 2028,the ecosystem health of Yancheng coastal area is the worst,only in the sub-health state under the ecological protection scenario,and in the planning development and natural development scenarios,the health index is also significantly lower than that in 2018,which is 0.35,0.36 and 0.40 under the planning development,natural development and ecological protection scenarios respectively;The ecosystem health level of Xiangshan Port coastal area is the highest,and the health index reaches 0.59 under the ecological protection scenario,but it is still in the sub-health status under the three scenarios;the health status of the coastal area on the South Bank of Hangzhou Bay is significantly improved compared with 2018,from the unhealthy status to the sub-health status.By 2038,the ecosystem health status of Xiangshan Port and Yancheng coastal area will continue to decline.The health indexes of Xiangshan Port research area under the scenarios of planning development,natural development and ecological protection are 0.49,0.44 and 0.61 respectively,and the health indexes of Yancheng research area are 0.31,0.32 and 0.34 respectively;Although the south bank research area of Hangzhou Bay is still at the sub-health level,its health index has increased slightly,which is0.48,0.51 and 0.59 respectively under the scenarios of planning development,natural development and ecological protection.In the next 20 years,the health level of the three research areas under the ecological protection scenario is higher than that of other scenarios,reflecting the necessity of ecological protection in the coastal area.Human beings should take into account the ecological security while developing economy,and strengthen the governance and protection of the ecological environment in the coastal area.