Estimation of Soil Organic Carbon in Shaanxi Province and Analysis of Its Spatial Difference Based on GIS
Terrestrial ecosystem carbon cycle is considered to be an important issue in the study of global change. Soil organic carbon is a huge carbon library, tiny change of which is likely to cause significant change of atmospheric CO2, thus influencing global climate. Therefore, research on soil organic carbon reserves and its spatial distribution characteristics not only has significant guiding meanings to circulation of materials in all circles and global change, but also has important realistic meanings to agricultural economy and land sustainable development. This article aims to estimate the density and reserves of soil organic carbon in Shaanxi Province, providing reference for accurate evaluation of the land quality and environment quality. With the second soil census data of Shaanxi Province and the soil type method. We have calculated the soil organic carbon density and reserves of different soil types in different soil depth and established soil organic carbon spatial database with soil genus as a unit so as to analyze the spatial distribution of soil organic carbon in Shaanxi Province as well as the natural and human influence factors. The results show that the average density of soil organic carbon in soil layers of 0-20cm, 0-100cm and full soil profile are respectively 3.886kg/m2, 8.955 kg/m2 and 10.548 kg/m2, and the soil organic carbon reserves of them are 774.4 million t, 1784.5 million t and 2102 million t respectively. The spatial distribution of soil organic carbon density presents a trend of increase gradually from the north to the south. Areas with high soil organic carbon reserves are mainly distributed in the southeast of Yulin, Yan＇ an, Xianyang, the north of Baoji and Qinba mountain while areas with low reserves are mainly distributed in the northeast of Yulin, such as Fugu county, Shenmu county, Dingbian county and most parts of Guanzhong region. Soil organic carbon density increases gradually with the growing annual precipitation and temperature. For different land use types, forest land has the lardgest soil organic carbon density, followed by grassland and cultivated land. And the change of land use type is the leading human factor that affects soil organic carbon.
NETL
NSTL
万方数据
维普
