Variability of Soil Erosion under Different Topographical and Vegetation Conditions in Upper Min River Watershed

Abstract:

Soil erosion by water is affected by soil factor, rainfall erosivity, geographical factors, vegetation cover factor, and support practice factors. On the basis of quantitative estimation of soil erosion in the Upper Min River (UMR) watershed (located in the Upper Yangtze River basin, Sichuan, China) by applying the Revised Soil Loss Equation (RUSLE) model, Geographical Information System (GIS) software, and Remote Sensing (RS) technology, we explored the effects of topography and vegetation on soil loss for better erosion control measures, and analyzed ecological restoration approaches for the high soil erosion areas of this mountainous watershed. Totally 625 field plots were sampled for visually verifying soil erosion classification. Zonal statistics in ArcGIS software were used to assess the values of soil loss under different topographic and vegetation gradients. The results showed 58.1% of this watershed suffering moderate, high or extremely high erosion. The average soil erosion values substantially increased as the slope ranges rising. On the slopes of 7 categories (50 degrees), the percent of moderate, high and extreme risks accounted for 12.07%, 21.03%, 36.43%, 62.83%, 82.51%, 91.04%, and 94.02% respectively. The values of soil loss on sunny slopes were higher than those on shady slopes. The mean value was the greatest on the west-facing slope. On each similar slope, vegetation types showed different patterns to soil loss, and higher vegetation cover prevented more soil loss from erosion. In order to alleviate soil loss hazards, conservation measures to change micro-topography including terraces and contour tillage could be implemented in the watershed, and ecological restoration could be effective measure for controlling soil erosion in this degraded mountainous watershed.

• Periodical: Applied Mechanics and Materials (Volumes 260-261)
• Pages: 796-803
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.260-261.796
• Online since: December 2012
• Authors: Zhi Yong Liu, Xin Zhang, Ping Zhou, Dan Wei
• Keywords: Aspect, Slope, Soil Erosion, Topography, Vegetation Types

References

[1] D. Pimentel, World Soil Erosion and Conservation, Cambridge: Cambridge, 1993. University Press.

[2] D. Pimentel, Soil erosion: A food and environmental threat. Environment, Development and Sustainabilit, 8(2006) 119-137.

[3] FAO, Field Measurement of Soil Erosion and Runoff. Rome, 1993, FAO.

[4] W.S. Merritt, R.A. Letcher, A.J. Jakeman, A review of erosion and sediment transport models, Environmental Modelling & Software. 18(2003) 761-799.

DOI: 10.1016/s1364-8152(03)00078-1

[5] J. Peng, D.D. Li, Y.Q. Zhang, Analysis of spatial characteristics of soil erosion in mountain areas of northwestern Yunnan based on GIS and RUSLE, Journal of Mountain Science. 25(2007) 548-556. (in Chinese).

[6] P. Zhou, Landscape-scale Soil Erosion Modelling and Ecological Restoration for a Mountainous Watershed in Sichuan, China. Helsinki, 2008. Viikki Tropical Resources Institute.

[7] P. Zhou, O. Luukkanen, T. Tokola, Effect of vegetation cover on soil erosion in a mountainous watershed, Catena. 75 (2008) 319-325.

DOI: 10.1016/j.catena.2008.07.010

[8] J.P. Zhang, H. Fan, Y. Q. Ye, Studies on soil erosion and countermeasures in upper reaches of Minjiang River, Journal of Soil and Water Conservation, 16 (2002): 19-22. (in Chinese).

[9] W. H. Wischmeier, D. D. Smith, Predicting rainfall erosion losses – a guide to conservation planning. U.S. Washington D. C, 1978. Dept. of Agriculture.

[10] I. D. Moore, G. Burch, Physical Basis of the Length-Slope Factor in the Universal Soil Loss Equation, Soil Science Society of America Journal. 50 (1986) 1294-1298.

DOI: 10.2136/sssaj1986.03615995005000050042x

[11] G.F. Jenks, Optimal data classification for choropleth maps: Occasional Paper No. 2. Kansas, 1977. Dept. Geography, Univ.

[12] C.T. Haan, B. J. Barfield, J. C. Hayes, Design Hydrology and Sedimentology for Small Catchments. San Diego, 1994. Academic Press.

DOI: 10.1016/b978-0-08-057164-5.50004-9

[13] D. Zachar, Soil Erosion—Development in Soil Science VEDA Publication, Bratislava, 1982. House of the Slovak Academy of Sciences.

[14] D. J. Snelder, R. B. Bryan, The use of rainfall simulation tests to assess the influence of vegetation density on soil loss on degraded rangelands in the Baringo District, Kenya, Catena. 25(1995) 105-116.

DOI: 10.1016/0341-8162(95)00003-b

[15] S.J. Goldman, K. Jackson, T.A. Bursztynsky, Erosion and Sediment Control Handbook. New York, 1986. McGraw-Hill Inc.