Evaluation Of Carbon Storage And Habitat Quality Of Land System Of Bohai Bay Coast Based On InVEST Model

With the rapid development of social economy in recent years,the demand for land resources is increasing,which has led to a series of ecological and environmental problems.At present,ecosystem service research has become a hot topic.A large number of activities such as land reclamation and land reclamation have been carried out of Bohai Bay coast in recent years.The unreasonable utilization of land resources has overloaded the use of land resources and exceeded its own ecological carrying capacity.Service function is degraded.Therefore,the evaluation of ecosystem service functions can provide decision-making basis for ecosystem management,sustainable land use,ecological environmental protection and socio-economic development.Based on this,this paper divides 2000-2015 into four periods to analyze the number of land use/cover types,spatial pattern changes and transfer between land types along the Bohai Bay;using the InVEST model to study carbon storage and biodiversity in the study area The service functions were evaluated separately,and the spatial and temporal distribution characteristics and changes of the ecosystem service functions were discussed from 2000 to 2015;Then on this basis,the reclassification tool of ArcGIS software and the natural breakpoint method are used to classify the importance of the carbon storage and biodiversity function evaluation results along the Bohai Bay.Finally,for the individual service functions of the Bohai Bay coast in 2015,the evaluation results are superimposed and analyzed,and a comprehensive evaluation is carried out,and the importance of the ecosystem service function zoning is obtained.The main conclusions of this study are as follows:(1)Dry-land is the main land use type along the Bohai Bay coast,followed by paddy and construction.According to the land use/cover transfer matrix from 2000 to 2015,the land use changes during the study period were more obvious,mainly due to changes in construction,dry-land,paddy and coastal wetlands.Among them,the construction change is the most significant,the area increased by 1 024.43 km2,mainly from the transformation of coastal wetlands,dry-land and paddy.The area of dry-land has increased,mainly from paddy and grasslands;the area of paddy and coastal wetlands decreased more obviously,which decreased by 786.00 km2 and 663.79 km2,respectively.The paddy mainly flowed to dry-land,construction and reservoir,coastal wetlands are mainly converted into construction,saltpan and reservoir.(2)In terms of carbon storage function,the spatial distribution of carbon storage is relatively stable during the study period.From the perspective of total carbon storage,the study area shows a trend of continuous decrease.The carbon storage in 2000,2005,2010,and 2015 were 24 110.76×104 t,23 886.81×104 t，22 792.16×104 t and 22 676.16×104 t respectively.From the perspective of spatial scale,high carbon storage areas are mainly distributed in northern Shandong and the central and southern areas of Tianjin Binhai New Area.Low carbon storage areas mainly include southern Tangshan in Hebei,southeast Huanghua,northeast Haixing,and Tianjin Binhai New Area eastern and northern parts,the northern part of Wudi in Shandong,and the central and northern parts of Zhanhua County.During the study period,the areas with decreased carbon storage functions were mainly in southern Luannan,Hebei,northeastern Wudi,Shandong,northern Zhanhua,and eastern Hekou,carbon storage in the southeast and central Tianjin Binhai New Area,and Dongli District increased slightly,but overall There was a downward trend.In the past 15 years,the total carbon storage of different land use/cover types has generally been expressed as:dry-land>paddy>coastal>wetland>construction>land>grassland>bottomland>mariculture>saltpan>unused land>reservoir>forest>canal>lake,which may be forest>reservoir or mariculture>bottomland,the rest are in the same order.(3)In terms of biodiversity function,habitat quality is used to characterize biodiversity.The larger the habitat quality index,the richer the biodiversity.In the past 15 years from 2000 to 2015,the overall biodiversity function in Bohai Bay coast has been declining,and the spatial distribution pattern is similar.In 2000,2005,2010 and 2015,the average habitat quality index of the study area was 0.29,0.26,0.24 and 0.23,respectively,and the overall habitat quality showed a downward trend.From a spatial scale,the areas with higher habitat quality are mainly concentrated in the southern part of Hebei Leting,the southeast part of Huanghua,the northeast part of Haixing,the central and northern parts of Tianjin Binhai New Area,and the northern part of Shandong Province.During the study period,the areas of habitat quality decline mainly included the northern areas of Tianjin Binhai New Area,the northeast of Wudi,Shandong,and the northern areas of Zhanhua.In the past 15 years,the average habitat quality index of different land use/cover types(except dry-land,forest,construction,canal,lake,reservoir,and unused land)is:coastal wetland>bottomland>saltpan>paddy>grassland>mariculture,in which the average habitat quality index of coastal wetlands,bottomland and saltpan almost reaches the highest value of the habitat quality index.(4)According to the evaluation of the importance of the two ecosystem functions of carbon storage and biodiversity in Bohai Bay coast from 2000 to 2015,the results show that the spatial pattern of the two service function importance zones is basically stable during the study period,but the two are distributed in it’s different.The research area is roughly divided into three layers,which widens from layer to layer(that is,from east to west).In terms of carbon storage,as ecologically important functional areas,the most important and extremely important areas are the most,accounting for about 60%of the total area of the research area,mainly distributed in the innermost layer of the research area and the outermost layer of the research area.In terms of habitat quality,highly important and extremely important areas account for a relatively small amount,about 14%,mainly distributed in the outermost and middle layers of the study area,and the biodiversity of the study area is generally weak.This paper comprehensively evaluates the ecosystem service function of the research area in 2015 and divides its importance grades.The proportions of generally important,more important,medium important,highly important and extremely important areas in the total area of the research area are 16.41%,14.94%,46.48%,15.76%and 6.41%.Among them,the highly important and extremely important areas as ecologically important areas have a total area of 4 265.95 km2,accounting for 22.17%,Mainly distributed in the southern part of Fengnan in Tangshan,Tanghai and Laoting County,the central part of Tianjin Binhai New Area,the northeastern part of Huanghua and the northern coastal margin of Shandong Province,The evaluation and research on the ecosystem service functions of the Bohai Bay coast can play a positive role for the sustainable use of land,ecosystem protection and ecological construction,and provide a reference for the government and relevant management departments when making planning decisions.The coordinated and sustainable development of coastal land,economy and ecology is of great significance.