{"title":"Plants Cover Effects on Overland Flow and on Soil Erosion under Simulated Rainfall Intensity","authors":"H. Madi, L. Mouzai, M. Bouhadef","volume":80,"journal":"International Journal of Environmental and Ecological Engineering","pagesStart":561,"pagesEnd":566,"ISSN":"1307-6892","URL":"https:\/\/publications.waset.org\/pdf\/16247","abstract":"
The purpose of this article is to study the effects of
\r\nplants cover on overland flow and, therefore, its influences on the
\r\namount of eroded and transported soil. In this investigation, all the
\r\nexperiments were conducted in the LEGHYD laboratory using a
\r\nrainfall simulator and a soil tray. The experiments were conducted
\r\nusing an experimental plot (soil tray) which is 2m long, 0.5 m wide
\r\nand 0.15 m deep. The soil used is an agricultural sandy soil (62,08%
\r\ncoarse sand, 19,14% fine sand, 11,57% silt and 7,21% clay). Plastic
\r\nrods (4 mm in diameter) were used to simulate the plants at different
\r\ndensities: 0 stem\/m2 (bared soil), 126 stems\/m², 203 stems\/m², 461
\r\nstems\/m² and 2500 stems\/m²). The used rainfall intensity is 73mm\/h
\r\nand the soil tray slope is fixed to 3°. The results have shown that the
\r\noverland flow velocities decreased with increasing stems density, and
\r\nthe density cover has a great effect on sediment concentration.
\r\nDarcy–Weisbach and Manning friction coefficients of overland flow
\r\nincreased when the stems density increased. Froude and Reynolds
\r\nnumbers decreased with increasing stems density and, consequently,
\r\nthe flow regime of all treatments was laminar and subcritical. From
\r\nthese findings, we conclude that increasing the plants cover can
\r\nefficiently reduce soil loss and avoid denuding the roots plants.<\/p>\r\n","references":"
[1] Abrahams, A.D., Parsons, A.J., Wainwright, J., (1994). Resistance to\r\noverland flow on semiarid grassland and shrub land hillslopes, Walnut\r\nGulch, southern Arizona. Journal of Hydrology 156, pages: 431–446.\r\n[2] Adekalu, K. O., I. A. Olorunfemi, and J. A. Osunbitan. (2007). Grass\r\nmulching effect on infiltration, surface runoff, and soil loss of three\r\nagricultural soils in Nigeria. Bioresource Tech. 98(4): 912-917.\r\n[3] Gilley, J.E., Kottwite, E.R., Simanton, J.R., (1990). Hydraulic\r\ncharacteristics of Rills. Transactions of the ASAE 33 (6), 1900–1906.\r\n[4] Govers, G., (1992). Evaluation of transport capacity formulae for\r\noverland flow. In: Parsons,Abrahams. A.J., A.D. (Eds.), Overland flow:\r\nHydraulics and Erosion Mechanics. UCL Press, London, UK. 243–273.\r\n[5] Govers Gerard, Rafael Giménez ,Kristof Van Oost (2007). Rill erosion:\r\nExploring the relationship between experiments, modelling and field\r\nobservations. Earth-Science Reviews 84 87–102\r\n[6] Gyssels G, Poesen J, Bochet E et al. (2005) Impact of plant roots on the\r\nresistance of soils to erosion by water: a review. Prog Phys Geogr\r\n29:189–217\r\n[7] Li, G., A. D. Abrahams, and J. F. Atkinson. 1996. Correction factors in\r\nthe determination of mean velocity of overland flow. Earth Surf. Proc.\r\nLand. 21(6): 509-515.\r\n[8] Ligdi. Etafa Emama, R.P.C. Morgan, (1995) Contour grass strips: a\r\nlaboratory simulation of their role in soil erosion control. Soil\r\nTechnology 8, pages 109-117\r\n[9] Liu. G, F. X. Tian, D. N. Warrington, S. Q. Zheng, Q. Zhang, (2010)\r\nefficacy of grass for mitigating runoff and erosion from an artificial\r\nloessial earthen road. American Society of Agricultural and Biological\r\nEngineers Vol. 53(1): 119-125\r\n[10] Morgan, R.P.C. (1986). Soil erosion and conservation. Longman Group\r\nLimited.\r\n[11] Morgan. R.P.C and R.J.Rickson (1995). Slope stabilization and erosion\r\ncontrol: a Bioengineering approach\r\n[12] Morgan, R.P.C. (2007). Vegetative-based technologies for erosion\r\ncontrol, The Use of Vegetation to Improve Slope Stability) 265–272.\r\n[13] Moussouni, A., Mouzai L. and Bouhadef M. (2012). Laboratory\r\nexperiments: Influence of rainfall characteristics on runoff and water\r\nerosion, Waset, 68. 1540-1543.\r\n[14] Nearing, M.A.,Norton, L.D., Bulgako, D.A., Larionov, G.A., West, L.T.,\r\nDontsova, K.M., (1997). Hydraulics and erosion in eroding rills. Water\r\nResources Research 33 (4), 865–876.\r\n[15] Pan Chengzhong., ZhoupingShangguan. (2006). Runoff hydraulic\r\ncharacteristics and sediment generation in sloped grassplots under\r\nsimulated rainfall conditions. Journal of Hydrology (331), 178– 185.\r\n[16] Tollner, E.W. Barfield, BJ., and Hayes, JC., (1982). Sedimentology of\r\nerect vegetal filters. J. Hydr. Eng. Div-ASCE (108), 1518–1531.<\/p>\r\n","publisher":"World Academy of Science, Engineering and Technology","index":"Open Science Index 80, 2013"}