Estimation of the density and spatial distribution of soil organic carbon in urban vegetation based on Senti-nel-2 imagery data
Soil organic carbon density(SOCD)is an important index to evaluate the carbon sink function of soil.Studying vegetation SOCD is of great significance for exploring the impacts of human activities on soil carbon cycle in urban areas.Based on the SOCD data of 206 sampling points(0-20 cm)and Sentinel-2 remote sensing images in the main urban area of Xi'an,we established the optimal SOCD estimation models of trees,shrubs,and grass-lands by using multiple linear,quadratic fitting,and exponential models.The vegetation SOCD in the study area was estimated based on the optimal models,the spatial distribution of vegetation SOCD were further analyzed.Re-sults showed that the SOCD of the urban vegetation ranged from 0 to 16.47 kg·m-2,with an average of 3.24 kg·m-2.Overall,the SOCD showed a spatial distribution characteristic of"high on the edge and low in the mid-dle",with high spatial heterogeneity.There were large differences in SOCD among different vegetation types.The average SOCD of the three vegetation types followed a pattern of trees(3.75 kg·m-2)＞shrubs(2.72 kg.m-2)＞grasslands(2.04 kg·m-2).There was a negative correlation between urban vegetation SOCD and urbanization intensity(P＜0.001),and the average SOCD was higher in areas with higher vegetation coverage.In general,urbanization had a negative impact on vegetation SOCD.Increasing urban vegetation coverage is one of the effective means to improve SOCD.The combination of remote sensing technology and field survey methods can quickly and effectively estimate SOCD of trees,shrubs and grasslands in the study area,which provides a reference for soil car-bon management in future urban development.
soil organic carbon densitySentinel-2Xi'an Cityremote sensing estimationregression model
国家科技期刊平台
NSTL
万方数据
