|
|
Effects of alfalfa coverage on runoff, erosion and hydraulic characteristics of overland flow on loess slope plots |
Shufang WU1,2, Pute WU1,2(), Hao FENG1,2, G. P. Merkley3 |
1. College of Water Resources and Architectural Engineering, China Academy of Water-saving Agriculture on Arid Regions, Northwest A&F University, Yangling 712100, China; 2. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences, Yangling 712100, China; 3. Biological and Irrigation Engineering Department, Utah State University, Logan, UT 84116, USA |
|
|
Abstract An evaluation of the interactions between vegetation, overland and soil erosion can provide valuable insight for the conservation of soil and water. An experiment was conducted to study water infiltration, runoff generation process, rate of sediment erosion, and hydrodynamic characteristics of overland flow from a sloping hillside with different draw-off discharges from alfalfa and control plots with 20° slope. The effect of alfalfa on runoff and sediment transport reduction was quantitatively analyzed. Alfalfa was discussed for its ability to reduce the overland flow scouring force or change the runoff movement. Compared to the bare-soil plots, alfalfa plots generated a 1.77 times increase in infiltration rate. Furthermore, the down-slope water infiltration rate for the bare soil plots was higher than in the up-slope, while the opposite was found in the alfalfa plots. In addition, alfalfa had a significant effect on runoff and sediment yield. In comparison to the control, the runoff coefficient and sediment transportation rate decreased by 28.3% and 78.4% in the grass slope, respectively. The runoff generated from the alfalfa and bare-soil plots had similar trends with an initial increase and subsequent leveling to a steady-state rate. The transport of sediment reduced with time as a consequence of the depletion of loose surface materials. The maximum sediment concentration was recorded within the first few minutes of each event. The alfalfa plots had subcritical flow while the bare-soil plots had supercritical flow, which indicate that the capability of the alfalfa slope for resisting soil erosion and sediment movement was greater than for bare soil plots. Moreover, the flow resistance coefficient and roughness coefficient for the alfalfa plots were both higher than for the bare-soil plots, which indicate that overland flow in alfalfa plots had retarded and was blocked, and the flow energy along the runoff path had gradually dissipated. Finally, the ability to erode and transport sediment had decreased.
|
Keywords
alfalfa
soil erosion
runoff and sedimentation
soil water infiltration
overland flow
hydrodynamic characteristics
|
Corresponding Author(s):
WU Pute,Email:gjzwpt@vip.sina.com
|
Issue Date: 05 March 2011
|
|
1 |
Benito E, Santiago J L, De Blas E, Varela M E. Deforestation of water-repellent soils in Galicia (NW Spain): effects on surface runoff and erosion under simulated rainfall. Earth Surface Processes and Landforms , 2003, 28(2): 145–155 doi: 10.1002/esp.431
|
2 |
Foster G R, Huggins L F, Meyer L D. A laboratory study of rill hydraulics: I velocity relationships. Transactions of the ASAE. American Society of Agricultural Engineers , 1984, 27: 790–796
|
3 |
Huang C H, Bradford J M. Analyses of slope and runoff factors based on the WEPP erosion model. Soil Science Society of America Journal , 1993, 57(5): 1176–1183 doi: 10.2136/sssaj1993.03615995005700050002x
|
4 |
Li M, Yao W Y, Li Z B. Progress of the effect of grassland vegetation for conserving soil and water on loess plateau in China. Advance in earth science, 2005, 20(1): 74–80 (in Chinese)
|
5 |
Kang S Z, Zhang L, Song X Y, Zhang S H, Liu X Z, Liang Y L, Zheng S Q. Runoff and sediment loss responses to rainfall and land use in two agricultural catchments on the Loess Plateau of China. Hydrological Processes , 2001, 15(6): 977–988 doi: 10.1002/hyp.191
|
6 |
Li M, Yao W Y, Ding W F, Yang J, Chen J. Effect of grass coverage on sediment yield in the hill-slope gully side erosion system. Journal of Geographical Sciences , 2009, 19(3): 321–330 doi: 10.1007/s11442-009-0321-8
|
7 |
Neave M, Abrahams A. Influences on water yields from grassland and shrubland ecosystems in the Chihuahuan Desert. Earth Surface Processes and Landforms , 2002, 27(9): 1011–1020 doi: 10.1002/esp.389
|
8 |
Wei X, Li Y G, Li Z B. Experiments on hydraulic characteristics of runoff in slope-gully systems in Loess Plateau. Transactions of the Chinese Society of Agricultural Engineering , 2009, 25(10): 19–25 (in Chinese)
|
9 |
Prosser I P, Dietrich W E, Stevenson J. Flow resistance and sediment transport by concentrated overland flow in a grassland valley. Geomorphology , 1995, 13(1-4): 71–86 doi: 10.1016/0169-555X(95)00020-6
|
10 |
Chatterjea K. The impact of tropical rainstorms on sediment and runoff generation from bare and grass-covered surfaces: a plot study from Singapore. Land Degradation and Development , 1998, 9(2): 143–157 doi: 10.1002/(SICI)1099-145X(199803/04)9:2<143::AID-LDR264>3.0.CO;2-I
|
11 |
Braud I, Vich A I J, Zuluaga J, Fornero L, Pedrani A. Vegetation influence on runoff and sediment yield in the Andes region: observation and modeling. ASCE J. Hydrology , 2001, 254(1-4): 124–144 doi: 10.1016/S0022-1694(01)00500-5
|
12 |
Pan C Z, Shangguan Z P, Lei T W. Influences of grass and moss on runoff and sediment yield on sloped loess surfaces under simulated rainfall. Hydrological Processes , 2006, 331: 178–185
|
13 |
Cerda A. The influence of geomorphological position and vegetation cover on the erosional and hydrological processes on a Mediterranean hill slope. Hydrological Processes , 1998, 12(4): 661–671 doi: 10.1002/(SICI)1099-1085(19980330)12:4<661::AID-HYP607>3.0.CO;2-7
|
14 |
Casermeiro M A, Molina J A, De la Cruz Caravaca M T, Hernando Costa J, Hernando Massanet M I, Moreno P S. Influence of scrubs on runoff and sediment loss in soils of Mediterranean climate. Catena , 2004, 57(1): 91–107 doi: 10.1016/S0341-8162(03)00160-7
|
15 |
Luo R T, Zhang G H, Cao Y, Cao G H. Progress in the research of hydrodynamic characteristics of sediment-laden overland Flow. Progress in Geography , 2009, 28(4): 567–575 (in Chinese)
|
16 |
Li Z B, Qin B S, Kang W. Indoor experimental studies on hydrodynamic characteristics of runoff in rill erosion procession steep slope. Transactions of the Chinese Society of Agricultural Engineering , 2008, 24(6): 64–68 (in Chinese)
|
17 |
Leonard G R. Estimation of runoff critical shear stress for soil erosion from soil shear strength. Catena , 2004, 57 (3): 1–17
|
18 |
Gilley J E, Kottwite E R, Simanton J R. Hydraulic characteristics of rills. Transactions of the ASAE. American Society of Agricultural Engineers , 1990, 33(6): 900–1906
|
19 |
Govers G. Relationship between discharge, velocity, and flow area for rills eroding in loose, non-layered materials. Earth Surface Processes and Landforms , 1992, 17(5): 515–528 doi: 10.1002/esp.3290170510
|
20 |
Abrahams A D, Li G, Parsons A J. Rill hydraulics on a semiarid hill slope in southern Arizona. Earth Surface Processes and Landforms , 1996, 21(1): 35–47 doi: 10.1002/(SICI)1096-9837(199601)21:1<35::AID-ESP539>3.0.CO;2-T
|
21 |
Weltz M A, Awadis A B, Lane L J. Hydraulic roughness coefficients for native rangelands. ASCE J. Irrig. and Drain. Engrg , 1992, 118(5): 776–790 doi: 10.1061/(ASCE)0733-9437(1992)118:5(776)
|
22 |
Zhang G H. Study on hydraulic properties of shallow flow. Advance in Water Science , 2002, 13(2): 159–165 (in Chinese)
|
23 |
Liu Q Q, Li J C, Chen L.Dynamics of overland flow and soil erosion (II) - soil erosion. Advances in mechanics, 2004, 34(3): 493–517 (in Chinese)
|
24 |
Zhang k L. Hydrodynamic characteristics of rill flow on loess slopes. Journal of Sedimentary Research , 1999, 1: 56–61 (in Chinese)
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
Cited |
|
|
|
|
|
Shared |
|
|
|
|
|
Discussed |
|
|
|
|