Land Use Change Simulation And Landscape Ecological Risk Assessment Of Haitan Island

Land resources are closely related to human life and have an irreplaceable role in human life and development.Land use/cover change has important implications for climate change,terrestrial ecosystem geophysical and geochemical cyclic processes,and land-ocean interactions and material exchanges.Therefore,the impact of land use change on the ecological environment and the prediction of future changes in land use have become important topics for scholars at home and abroad.The continuous maturation of landscape ecology theories and methods has provided a new approach for the study of land use/cover change.Combining land use changes with landscape ecological benefits can highlight the negative impact of land use change,and can also provide a theoretical basis for government departments' future land use planning and ecological construction.This study is mainly based on the land use status map of Pingtan County in 2000,2005,2009 and 2013.First of all,the changes in the landscape pattern and ecological risk space of Haitan Island from 2000 to 2013 were discussed and analyzed.Secondly,the CLUE-S model was used to simulate the land use status of Haitan Island under different development scenarios in 2021.Finally,based on the land use data of 2013 and simulation,the ecological risk assessment model was used to evaluate the ecological environment and reveal the changing trend of the ecological environment in the study area.The main conclusions are as follows:(1)2000--2013 Haitan Island landscape types were changed in varying degrees,woodland,scrub,grassland,water continues to decrease,construction land and unused land presents an increasing trend,the degree of landscape fragmentation increased and the degree of separation also increased day by day.The number of land for construction and the degree of fragmentation and resolution decreased,The distribution tends to be concentrated;the number of unused land patches shows an increasing tendency,while the degree of fragmentation and the separation performance first increases and then decreases.(2)From 2000 to 2013,the area of different risk grades on Haitan Island changed greatly.In 2000,the study area was dominated by low risk and low risk.By 2013,the area of high and high risk levels in the study area increased significantly.Increased by 6.2%and 73.9%.From the perspective of the transfer matrix,Haitan Island has shown a shift in risk from low to high levels at different stages.The conversion rate from higher risk level to high risk level has been declining from 2009 to 2013,but the situation is still not optimistic.(3)The selected driving factors have good ability to explain the spatial distribution pattern of land use.In the simulation of land use change in Hai Tan Island by using CLUE-S model,the Kappa index is as high as 0.81 and more than 0.75.It is suitable for simulating the spatial distribution of land use in the future of Hai Tan Island.(4)In the natural development and urban planning scenarios,Haitan Island shows the reduction of the area of forests,shrubs,wetlands and farmland,the increase of urban construction land and unutilized land,and the reduction of forest and farmland is larger.Urban construction land increased significantly in the urban planning scenario,up to 31.79%.Urban expansion mainly concentrated in Baqing Township in the northeast,Suao Town in the northwest coast,the surrounding area of the county town and the town of O Qian before along the eastern coast.The construction land under the urban planning scenario mainly shows the outward expansion of the construction land,among which the township The increase of construction land is more obvious.(5)Compared with 2013,the patch number,patch density,boundary density and landscape shape index of Haitan Island in different development scenarios in 2021 all showed an upward trend,while the cohesion and degree of polymerization gradually decreased.The fragmentation of various landscapes in the island The degree of deepening,the overall landscape pattern tends to fragmentation and discretization.Hai Tan Island In 2013,the landscape ecological risk indices of natural development scenarios and urban planning scenarios in 2021 were 0.334,0.377 and 0.351 respectively,and the landscape ecological risk index increased.The ecological security problems are becoming more and more serious.