Estimation Of Soil Organic Carbon Storage And Its Spatial Distribution

Affected by the nature and human factors, there existed spatial variability in soil properties. Soil organic carbon is an important indicator of soil fertility. To grasp the changes of soil organic carbon spatial can give guidance for field and forest management measures. Spatial interpolation is an important tool to study soil spatial variability in soil science. Using mathematical modeling methods to improve spatial interpolation, with less samples to reflect the regional spatial variation of soil properties, was hot topic in soil science study.Taking Fujian Province and Jiangle as study area and Landsat 8 remote sensing image, with the 153 soil profiles data in Fujian second soil survey and 55 soil profiles collected in Jiangle, the study established 0-20 cm and 0-100 cm soil layer soil organic carbon model based on remote sensing and GIS technology, and studied the soil organic carbon spatial distribution in Fujian by using Kriging and regression Kriging. Fujian has 44 counties, the second national soil survey did not involve entire country, and study selected the country Jiangle which has the highest forest coverage in the not involve country to complement its soil organic carbon. Results showed below:(1) Vegetation index and terrain as independent variables, soil organic carbon(SOC) of 0-20 cm and 0～100 cm as the dependent variables, simple regression model and multiple regression model were established respectively. Compared them and found that multiple regression model was better, the model satisfied with the demand of T test and the measured and predicted values of the test data were on significant difference. The relative accuracy of estimated SOC respectively reached 68.6% and 87.6%.(2) The Kriging and regression Kriging were used to analysis SOC spatial variability, and the regression Kriging shows higher prediction effect. There was an estimation of 0-20 cm and 0-100 cm soil layer of 624.28×106tons and 1677.472×106 tons. Organic carbon density respectively were 57.23 t/hm2 and 153.781t/hm2. The southwest and northwest showed higher SOC storage.(3) The SOC storage of 0-20 cm and 0-100 cm in Jiangle were 12.622×106 tons and 37.401×106 tons. SOC density were 56.178 t/hm2 and 166.469 t/hm2. Spatial distribution analysis showed, with aspect the SOC storage displayed:southern> west> north>east, with altitude showed:relative low> low> medium> high> relative high, with slope presented:slope> gentle> steep> flat.