JOURNAL OF NATURAL RESOURCES ›› 2017, Vol. 32 ›› Issue (11): 1892-1904.doi: 10.11849/zrzyxb.20160993

• Resource Evaluation • Previous Articles     Next Articles

Effect of Slope Gradient and Vegetation Cover on Sediment Yielding Characteristics of the Riparian Slope

CAO Zi-hao, ZHAO Qing-he, DING Sheng-yan, ZHANG Yi-fan, LIU Pu, WU Chang-song, BIAN Zi-qi   

  1. Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions (Henan University), Ministry of Education, College of Environment and Planning, Henan University, Kaifeng 475004, China
  • Received:2016-09-18 Revised:2017-02-16 Online:2017-11-20 Published:2017-11-20
  • Supported by:
    China Postdoctoral Science Foundation, No.2015T80766; National Natural Sciences Foundation of China, No.41301197 and 41771202; the Colleges and Universities Key Scientific Research Projects of Henan Province, No.18A170004; Program for Innovative Research Team (in Science and Technology) in University of Henan Province, No.16IRTSTHN012

Abstract: Slope gradient and vegetation cover are important factors affecting slope soil erosion process, thus exploring the response of sediment yielding characteristics to slope gradient and vegetation cover is of great significance to predicate sediment yielding in soil erosion process. In this study, based on the field runoff scouring experiments on the riparian slope of the lower reaches of the Yellow River, the changing processes of runoff coefficient, sediment yielding, runoff sediment concentration, and sediment particle size composition under different slope gradients (5°, 10°, 15°, 20°) and vegetation covers (0, 15%, 30%) were analyzed, and the response of sediment yielding characteristics to the interaction effect of slope gradients and vegetation covers on riparian slope were revealed by using the double factor variance analysis and the relative contribution index. The results showed that runoff coefficient under different vegetation covers increased with duration of scouring time, therein, it increased quickly during the first five minutes and then slowed down and became leveling off. The runoff sediment concentration showed decreasing trend with the increase of scouring time and then began to leveling off. On the slope of less than 15°, the differences of runoff coefficient and runoff sediment concentration between different vegetation covers were obvious, while there were less difference on the slope of more than 15°. The sediment yielding increased with the scouring time and slope gradient. On the same slope gradient, the lower the vegetation cover was, the greater the sediment yielding. The sediment particles were mainly made up of silt, coarse powder grains and very fine sand, and very fine sand and fine sand, which accounted for 10%, 50%, and 90% of the total volume, respectively. The double factor variance analysis showed that slope gradient exhibited the extremely significant effect on the runoff coefficient, sediment yielding, and runoff sediment concentration on the riparian slope (P<0.001), and the vegetation coverage exhibited the extremely significant effect on the slope erosion sediment yield and flow runoff coefficient within the prescribed time (P<0.001). However, the interaction between slope gradient and vegetation cover showed the significant effect only on the runoff coefficient within the prescribed time (P<0.01). Meanwhile, the relative contribution index showed that in the interaction of slope gradient and vegetation cover, the effect of vegetation cover weakened gradually with increasing slope gradient, while the role of slope gradient enhanced gradually and became the dominant factor influencing soil and water loss.

Key words: interaction, riparian slope, slope gradient, soil erosion and sediment yielding, vegetation cover

CLC Number: 

  • S157.1