基于遥感和ULSE模型评价1995～2005年江西土壤侵蚀

Evaluating soil erosion in Jiangxi Province with USLE model and remote sensing technology during 1995～2005

为了定量评价近10年江西省土壤侵蚀的时空变化,采用USLE模型的月模式,耦合1995年的NOAA-AVHRR归一化植被指数(NDVI)和2005年的Terra-MODIS增强型植被指数(EVI),定量评价了江西省1995年和2005年的土壤侵蚀空间分布.研究结果表明:(1)江西省土壤侵蚀主要受地形条件的影响,存在明显的空间差异,强烈侵蚀级别以上的土壤侵蚀主要发生在鄱阳湖流域各子流域的上游;地形平坦的鄱阳湖平原和吉泰盆地,土壤侵蚀强度低;(2)江西省土壤侵蚀在1995～2005年间得到一定程度的改善,年土壤侵蚀总量由1995年的1.494亿t下降为2005年的1.268亿t,全省平均土壤侵蚀模数由894.68t/(km2.a)下降为759.31t/(km2.a);中度以上侵蚀面积由1995年的16 945km2下降为2005年的13 833km2;(3)全省绝大多数县(市、区)的土壤侵蚀强度降低,其中德兴县、玉山县、婺源县、上饶县、浮梁县、横峰县等赣东北5县的平均土壤侵蚀模数下降最为显著;但也有少量县(市区)的土壤侵蚀呈进一步扩大趋势,主要有井冈山市、永新县、莲花县、瑞昌县、广昌县和永丰县.

Soil erosion in Jiangxi Province has enlarged caused by human activities during 1950s-1980s.With the Mountain-River-Lake Project carried out by Jiangxi government since 1980s,the aggravating trend of soil erosion was stopped.In this paper,the USLE model was used to evaluate the intensity of soil erosion by integrating the remotely sensed NDVI in 1995and EVI in 2005.Results showed that：（1） soil erosion in Jiangxi Province is mainly controlled by the topographic factor LS,and the area with above intense soil erosion are mainly distributed in the upstream of Poyang watershed with mountainous terrain,while there are very few soil erosion happened in the alluvial plain of Poyang and Jitai basin（2） the soil erosion has a decreasing trend with the annual amount of soil erosion decreased from 149.4million tons in 1995to 126.8million tons in 2005,the average soil erosion modulus decreased from 894.68tons/（km^2.a） to 759.31tons/（km^2.a）,and the soil erosion area for above moderate intensity decreased from 16945km^2in 1995to 13833km^2in 2005;（3） The soil erosion intensity lowered in most of counties in Jiangxi Province.And the soil erosion modulus decreased significantly in these counties such as Dexing,Yushan,Wuyuan,Shangrao,Fuliang and Hengfeng.But the soil erosion modulus increased in few counties such as Jingangshan,Yongxin,Lianhua,Ruichang,Guangchang and Yongfeng in varying degrees.