Mangrove Extraction And Carbon Storage Estimation By Using Sentinel-2 Images

Mangrove plays an important role in maintaining the carbon balance in the atmosphere.The research on the extraction method,biomass estimation and carbon storage estimation method of mangrove is conducive to better evaluate the carbon sequestration function of mangrove.At present,the research of mangrove extraction seldom considers the extraction of mangrove under the tide level.In the estimation of mangrove carbon reserves,it is often necessary to measure the biomass through field data measurement and mangrove specimen weighing to estimate the carbon density.In view of these problems,this paper takes mangrove in jiulongjiangkou reserve as the object,based on sentinel-2 image,analyzes After the spectral characteristics of the exposed mangrove,the high tide level submerged mangrove and the sea water,this paper proposes an inter tidal mangrove index extraction method suitable for the exposed and submerged mangrove,compares it with various mangrove extraction aspects,analyzes the extraction effect of the method proposed in this paper,and obtains a new mangrove through a number of different growth equation fitting in the study area The growth equation is used to estimate the biomass and carbon storage of Mangrove in the study area.By comparing the carbon storage results obtained from the carbon density collected from the reference data,the reliability of carbon storage obtained from the reference data is analyzed.The results of the research show that:(1)Compared with the normalized water body index,normalized vegetation index and random forest method,and compared with the results of visual verification and field investigation of high-resolution image 2,the accuracy of the intertidal mangrove index method to extract mangrove users is 93.98%,which is significantly better than the results of the normalized water body index(NDWI),normalized vegetation index(NDVI)and random forest It can reduce the influence of tide level on the extraction effect of mangrove.(2)Compared with the texture information,the spectral information has a greater contribution to the mangrove extraction results.According to the spectral characteristics of mangrove,the red edge band with high absorption rate of mangrove and high reflectivity of water body can be selected.In order to reduce the interference of other factors and ensure the robustness of the method,the red edge band 2 of vegetation with high reflectivity of mangrove and high absorption rate of water body can be selected,and the red edge band 3 of vegetation is not However,the normalized form of near-infrared band is dimensionally independent,which is used as the vegetation index of intertidal mangrove.(3)A new allometric growth equation can be obtained by interpolating several biomass allometric growth equations,which can be used to estimate biomass and weaken the effect of accidental error in estimating biomass with only one growth allometric equation.R2 of the above ground biomass growth allometric equation is 0.72,and R2 of the underground biomass is 0.75.(4)The method of carbon density obtained by consulting literature is simple and convenient,saves manpower and material resources,and has certain reliability.The results obtained by consulting can be used as the basis for evaluating the results of this paper.The carbon density of mangrove estimated by this method is within 90%confidence interval.