Study on the transformation from vector to raster for soil data with identical data precision in the estimation of Soil Organic Carbon Stocks
土壤碳库研究中土壤数据从矢量到栅格的等精度转换

Soil data transformed from vector to raster data is an important step for data preprocessing in most researches on regional soil carbon stocks.Based on 3 scales of soil vector databases,which are 1:50,000,1:500,000 and 1:4,000,000,a series of raster datasets with different resolutions were converted from these soil vector data.Four indices,soil type number,soil area,soil organic carbon stocks and soil organic carbon density of surface paddy soils(0-20cm)were calculated from all these vector and raster datasets respectively.Subjected to the 4indices from vector data,their relative variability(VIV,%)from raster datasets was used to assess soil data identity between the soil vector data in different scales and their responding raster datasets,respectively.Results show that optimal resolutions of raster datasets converted from these three vector data in different map scales are 0.2km×0.2km,1km×1km and 9km×9km respectively,due to the VIV of all the indices less than 1%,in which soil vector data and the responding raster dataset have an identical data precision.The optimal resolution raster data can not only meet the requisements of data precision in SOC stock researches,but also avoid data redundancy and resources wasting.The relationship between soil vector map scale and the optimal raster resolution under an identical data precision can be modeled as follows:y=0.0225x0.01233(R2=0.999),which can provide valuable reference for research on soil organic carbon stocks at regional scale.