Acta Geographica Sinica ›› 2017, Vol. 72 ›› Issue (3): 432-443.doi: 10.11821/dlxb201703006

• Climate Change and Surface Processes • Previous Articles     Next Articles

Comparative analysis of the effect of rainfall pattern and land use pattern on soil erosion in different-scale watersheds: A case study in hilly and gully area of the Loess Plateau

Lina ZHONG1,2(), Jun WANG2(), Wenwu ZHAO3   

  1. 1. School of Land Science and Technology, China University of Geosciences, Beijing 100083, China
    2. Key Laboratory of Land Consolidation and Rehabilitation, Ministry of Land and Resources, Beijing 100035, China
    3. College of Resources Science and Technology, Beijing Normal University, Beijing 100875, China
  • Received:2016-04-06 Revised:2016-10-14 Online:2017-03-15 Published:2017-05-03
  • Supported by:
    National Natural Science Foundation of China, No.41171152, No.41171069

Abstract:

Soil erosion has become one of global environmental problems, especially in the Loess Plateau. Controlling soil erosion is of great significance to improve the ecosystem, and protect the ecological security and maintain the harmonious relationship between human beings and nature. We compare the effect of rainfall pattern and land use pattern on soil erosion in different watersheds to improve soil erosion models. Currently, the effect of rainfall and land use on soil erosion is the hot research topics. However, most of the studies are aimed at one single study area, and there is less comparative analysis of rainfall and land use pattern on soil erosion in different-scale watersheds. The neglect of comparative analysis of the effect of rainfall pattern and land use pattern on soil erosion would inevitably influence the further study of the mechanism of soil erosion. And it would affect the simulation accuracy of soil erosion models. The investigation of the effect of land use pattern and rainfall pattern on soil erosion would have great significance to soil erosion research and comprehensive governance of soil erosion problems. With reference to the concept of soil erosion evaluation index, this paper proposed the use of rainfall pattern index and land use pattern index for predicting soil erosion in different watersheds. Otherwise, this paper identified more important factors for soil erosion between rainfall patterns and land use pattern in different-scale watersheds. It has positive significance for carrying out the comprehensive management of soil erosion and land use pattern optimization design. The study areas of this paper are Qingjian River basin, Fenchuan River Basin, Yanhe River Basin and Dali River Basin. The main results are as follows. (1) From 2006 to 2012, the rainfall erosivity factor R in the study area showed an upward trend, while the vegetation cover and management factor C showed a downward trend. (2) When watershed area was small, the effect of rainfall pattern was greater than that of land use pattern on soil erosion. In contrast, when watershed area was large, the effect of land use pattern was greater than that of rainfall pattern on soil erosion. In other words, with the increase of the watershed area, the effect of rainfall pattern on soil erosion was gradually reduced while land use pattern indicated a contrasting effect. (3) With the increase of the watershed area, the proportion of woodland decreased and steep slope vegetation cover types tend to be homogenous, thus increasing the effect of land use pattern on soil erosion in larger-scale watersheds. With the increase of the watershed area, however, loose soil properties and craggy terrain increases the possibility of gravitational erosion, which enhances the effects of soil and topography.

Key words: soil erosion, rainfall, land use, pattern, multi-watershed, Leoss Plateau