基于USLE模型的2001—2015年江西省土壤侵蚀变化研究

Soil Erosion Changes in Jiangxi Province from 2001 to 2015 Based on USLE Model

[目的]准确估算区域土壤侵蚀量并掌握其动态变化,指导区域水土保持规划。[方法]基于通用土壤流失方程(USLE)模型,利用遥感数据、气象数据、DEM等数据测算2001,2015年的土壤侵蚀模数,分析2001—2015年江西省土壤侵蚀强度的动态变化特征。[结果]江西省土壤侵蚀状况在2001—2015年得到一定程度的改善,2001年土壤侵蚀模数为7 042.4t/(km^2·a),2015年土壤侵蚀模数为6 375.3t/(km^2·a),降低了约9.5%;全省大部分地市的土壤侵蚀强度降低,其中抚州市、宜春市、赣州市、萍乡市等4市的平均土壤侵蚀模数下降幅度最为显著;但也有少量地市的土壤侵蚀呈进一步扩大趋势,主要有九江市、南昌市、新余市;土壤侵蚀强度转移矩阵表明江西省大部分区域侵蚀强度等级不变,部分地区侵蚀强度等级向低一级转移;2001—2015年52.7%的面积土壤侵蚀强度等级不变,25.8%的面积土壤侵蚀强度等级降低一级。[结论]江西省土壤侵蚀状况总体上有所好转,但部分地市的土壤侵蚀进一步扩大,水土流失的形势依然十分严峻。

[Objective] To estimate regional soil erosion modulus and the dynamic change accurately for soil and water conservation planning. [Methods] Using USLE （universal soil loss equation） model, the soil erosion modulus in Jiangxi Province in 2001 and 2015 were estimated with remote sensing data, meteorological data and DEM. Then the temporal and spatial changes of soil erosion intensity in Jiangxi Province from 2001 to 2015 were analyzed. [Results] From 2001 to 2015, soil erosion in Jiangxi Province showed a declining tendency. The soil erosion modulus in 2001 was 7 042.4 t/（km2 ~ a） and the soil erosion modulus in 2015 was 6375.3 t/（km2·a）, decreased by 9.5%. The soil erosion intensity has decreased in most of the cities in Jiangxi Province. The soil modulus decreased significantly in Fuzhou, Yichun, Ganzhou and Pingxiang Cities. But soil erosion modulus increased in a few cities such as Jiujiang, Nanchang and Xinyuin. The transformation matrix of soil erosion intensity indicated that soil erosion intensity remained unchanged in 52.7% of the total area of Jiangxi Province from 2001 to 2015. About 25.8% of the total area experienced soil erosion intensity transformation from high level to low level during 2001 2015. [Conclusion] The soil erosion situation in Jiangxi Province has improved in general, but the soil erosion in some cities has expanded further, and the situation of soil and water loss remains serious.