西藏高原东部矮西沟流域土壤可蚀性研究

The Preliminary Research on the Model Method of Soil Erodibility in the Aixigou Watershed of Jinsha River

藏东矮西沟流域水土流失严重,土壤抗侵蚀能力差,是金沙江上游大量泥沙的主要来源之一。对研究区的土壤可蚀性的研究,无论是对草地和耕地的保护,还是对金沙江泥沙量的缓减,都具有重大的现实意义,是水土保持工作的基础。该文通过调查研究土壤抗侵蚀能力与土壤侵蚀特征,利用大量的实测资料,比较研究了3种K值模型估算值的数值特征,与调查结果的相关性以及估算值取值范围的可靠性,确定了西藏高原东部土壤K值的最优估算模型为通用流失方程K因子模型,不同土壤的K值大小顺序为灰褐土>高山草甸土>棕壤>暗棕壤,流域K值的平均值为0.005,在全国范围内较小。

In the Aixigou watershed of the Jinsha River, its production capability is backward, soil and water loss is heavy and the anti-erosion ability of soil is not good, all of which cause the Aixigou watershed the main sediment provider of the upper reaches in the Jinsha River. The study on the soil erodibility factor K is the foundation of the soil and water conservation in that area, not only could help to conserve the soil loss of the grassland and farmland, but also could help to reduce the sediment in the Jinsha River. Based on the investigation results of the soil anti-erosion ability and soil erosion characteristics, this paper compared 3 kinds of classical model methods of soil erodibility using various field investigation data. The digital feature, the relationship between the predicted value and the field investigated value and the reliability of the predicted value span were comparative studied. As a result, the best model for soil erodibility estimation in the study area was the USLE-K model, the K value order of different soils was grey cinnamonic soil）alpine meadow soil〉brown soil〉dark brown forest soil, and the average K value of the watershed was 0. 005 which was low around the country.