| Soil erosion is a common problem in the world and it seriously threatens the sustainable development of the global economy.China is one of the countries with the most severe water and soil erosion in the world.As the largest river basin in China,the Yangtze River Basin has recently become increasingly serious due to natural and human factors.Therefore,the use of modern technology to quickly analyze the status of soil erosion in the Yangtze River Basin has important implications for sub-basin management and sustainable development.At the same time,soil erosion is the only way to migrate and redistribute a large amount of terrestrial readily-mineralized organic carbon,causing a large change in the composition and content of soil organic carbon,and clarifying the rules of soil organic carbon migration and redistribution under the influence of erosion to understand terrestrial carbon.The cycle process and the mechanism of soil carbon emissions are of great significance.This paper uses the Yangtze River Basin as the research object,and estimates soil erosion rate in the Yangtze River Basin from 1992 to 2013 by using soil erosion model USPED combined with GIS technology,using soil attribute data,meteorological site data,land use and vegetation coverage data,and digital elevation.The temporal and spatial changes of soil erosion in the Yangtze River Basin were analyzed,and the redistribution rate of soil organic carbon in the Yangtze River Basin was quantified.The main conclusions are:?1?A database of soil erosion factors in the Yangtze River Basin was established.The soil erosion factor K value in the Yangtze River basin calculated based on the EPIC model ranged from 0 to 0.0435 t·hm-2·h·hm-2·MJ-1·mm-1.According to the annual rainfall model,the average rainfall erosivity between 1992 and 2013 was between 350.02 and 12548.9 MJ mm·hm-2·h-1·a-1.?2?Analyzed the temporal and spatial distribution of soil erosion in the Yangtze River Basin from 1992 to 2013.The average annual soil erosion rate in the Yangtze River Basin in1992 was 49.40 ton·ha-1·a-1.In 2013,the average annual soil erosion rate was 51.70ton·ha-1·a-1,an increase of 3.23%compared with 1992.Model simulation soil deposition and erosion are usually located adjacent to each other.In 1992,the annual average soil deposition rate was 37.81 ton·ha-1·a-1.In 2013,the annual average soil deposition rate was37.62 ton·ha-1·a-1.Compared with 1992,it decreased by 2.70%.Spatially,soil erosion is dominated by slight erosion,mild erosion,and moderate erosion.The sum of the area accounts for 85.48%of the total erosion area.Erosion above the intensity is mainly distributed in the upper and middle reaches of the Yangtze River,including the middle and lower reaches of the Jinsha River,and around the Sichuan Basin.As well as the karst area in the southwest,it is an area that needs to be regulated.?3?The spatial distribution of soil organic carbon redistribution rate in the Yangtze River basin from 1992 to 2013 is consistent with the soil erosion rate.The rate of redistribution of soil organic carbon in most regions is below 0.8ton C·ha-1·a-1.The redistribution rate of organic carbon in the southwest of the basin was between 0.05 and0.8ton C·ha-1·a-1.From the change of time,the rate of redistribution of soil organic carbon was 1.88ton C·ha-1·a-1 in 1992.In 2013,the rate of redistribution of soil organic carbon was1.96 ton C·ha-1·a-1,which increased the 4.25%. |
PDF Full Text Request