The role of slope steepness and soil properties in rill erosion in the hillslopes (a case study: Taham Chai catchment, NW Zanjan)

Document Type : Complete scientific research article

Authors

1 Former, M.Sc. Student of Soil Science, University of Zanjan

2 Ph.D. Student of Soil Science, University of Zanjan

Abstract

Background and objectives: Rill erosion is one of the most important soil erosion types in the hillslopes which occurs due to concentration of surface runoff. In general, rills are a small, ephemeral concentrated flow paths which function as both sediment source and sediment delivery systems for erosion on hillslopes. Rill development is common in overgrazed land where soil water retention capacity is diminished and also in freshly cultivated soil where the soil structure has been loosened. Rill erosion can be a large portion of the channel erosion in these areas, particularly in semi-arid regions. Rill development in the hillslopes can be affected by different factors including topographic characteristics, vegetation cover condition, rainfall characteristics, soil properties, and management practices. Knowledge of factors affecting rill erosion development is necessary to control this erosion in the hillslopes.
Materials and Methods: This study was conducted to find factors influencing rill development in semi-arid rangelands in the TahamChai catchment, north west of Zanjan, Iran. Toward this, ten sparse hillslope as affected by rill erosion were selected and all rill characteristics along with some soil properties were determined in the rills. Rill characteristics, slope steepness, and soil properties were compared among the hillslopes. Effects of slope steepness and soil properties on the rill erosion were recognized using the correlation matrix method. Multiple linear regression analysis was used to develop an equation for estimating rill erosion in the hillslopes.
Results: Results indicated that all rills characteristic expect length were significantly differed among the hillslopes. Significant differences were found among the hillslope soils in sand, silt, clay, saturated hydraulic conductivity, and exchangeable sodium percentage. Rill cross section area varied from 0.01 to 0.29 m2 with an average of 0.07 m2 in the hillslopes. It was recognized to be the most important rill characteristic to describe rill erosion development in the hillslopes. Significant correlations between this rill characteristic were observed and slope steepness, sand, silt, clay and saturated hydraulic conductivity. Rill cross section area was the highest where either the hillslopes tend to have higher slope steepness or they have higher percentage of silt and clay. Multiple linear regression analysis appeared that rill cross section area in the rangeland hillslopes was significantly related to slope steepness and silt (R2= 0.38, p Conclusion: With regarding to the importance of slope steepness and silt in the rill erosion development, maintaining vegetation cover through preventing over-grazing in the hillslopes of the area where slope steepness is higher and the soil is sensitive to water erosion processes is very essential. According to the developed equation there are also other variables which may control rill development in the hillslopes. Land shape, soil profile characteristics and land surface cover can be introduced as unknown variables which can be investigated in the next studies in order to develop a reliable model to prediction of rill erosion in the hillslopes.

Keywords


1.Aksoy, H., Unal, N.E., Cokgor, S., Gedikli, A., Yoon, J., Koca, K., Inci, S.B., Eris, E., and Pak, G. 2013. Laboratory experiments of sediment transport from a bare soil with rill. Hydrol. Sci. J. 58: 7. 1505-1518.
2.Angers, D.A., and Mehuys, G.R. 1993. Aggregate stability to water. P 651-657, In: M.R. Carter (Ed.), Soil Sampling and Methods of Analysis. Canadian,Society of Soil Science, Lewise Publishers, Boca Raton.
3.Bonilla, C.A., and Johnson, O.I. 2012. Soil erodibility mapping and its correlation with soil properties in Central Chile. Geoderma. 189-190: 116-123.
4.Battany, M.C., and Grismer, M.E. 2000. Rainfall runoff and erosion in Napa valley vineyards effect of slope cover and surface roughness. Hydrolo. Proc. 14: 1289-1304.
5.Bryan, R.B. 1987. Processes and Significance of rill development. Catena Suplement, Catena Verlag, Cremlingen. 8: 1-15.
6.Cao, L., Zhang, K., and Zhang, W. 2009. Detachment of road surface soil by flowing water. Catena. 76: 155-162.
7.Casali, J., Loizu, J., Campo, M.A., DeSantisteban, L.M., and Ivarez-Mozos, J.A. 2006. Accuracy of methods for field assessment of rill and ephemeral gully erosion. Catena.
67: 128-138.
8.Cerdan, O., Le Bissonnais, Y., Couturer, A., Bourennane, H., and Souchere, V. 2002. Rill eroaion on cultivated hillslopes during two eztreme rainfall events in Normandy, France. Soil Till. Res. 67: 99-108.
9.Daneshyar, K., Asadi, H., and Mossavi, A. 2013. Effects of soil type and stream power on relative importance of processes from flow in experimental condition. Iran J. Soil Water Res. 44: 4. 373-382. (In Persian) 
10.de Meester, T., and Jungerius, P.D. 1978. The relationship between the soil erodibility factor K (Universal soil loss equation), aggregate stability and micromorphological properties of soils in the Hornos area, S. Spain. Earth Surf. Proc. 3: 379-391.
11.Emmett, W.W. 1970. The hydraulics of overland flow hill slopes. U.S. Geo logical Survey, Pp: 62-68.
12.Favis-Mortlock, D.T., Boardman, J., Parsons, A.J., and Lascelles, B. 2000. Emergence and erosion: a model for rill initiation and development. Hydrol. Proc. 14: 2173-2205.
13.Foster, G.R., Huggins, L.F., and Meyer, L.D. 1984. A laboratory study of rill hydraulics:
I. Velocity relationships. Transactions of ASAE. 27: 790-796.
14.Gee, G.W., and Bauder, J.W. 1986. Particle-size analysis. P 383-411, In: A. Klute (Ed.), Methods of Soil Analysis, Part 1. Physical and Mineralogical Methods. 2nd ed. Agrono.
15.Giménez, R., and Govers, G. 2008. Effects of freshly incorporated straw residue on rill erosion and hydraulics. Catena. 72: 214-223.
16.Govers, G. 1985. Selectivity and transport capacity of thin flows in relation to rill erosion. Catena. 12: 35-49.
17.Hancock, G.R., Crawter, D., Fityus, S.G., Chandler, J., and Wells, T. 2008. The measurement and modelling of rill erosion at angle of repose slopes in mine spoil. Earth Surf. Proc.Land Forms. 33: 1006-1020.
18.Hosseini, M.S., Mosaedi, H., Naseri, K., and Golkarian, A. 2012. Identification of the most effective elements on rill erosion in the hill slope units of mashhad south west, Iran. Geog. Envioron. Hazards. 2: 87-99. (In Persian)
19.Kimaro, D.N., Poesen, J., Msanya, B.M., and Deckers, J.A. 2008. Magnitude of soil erosion on the northern slope of the UluguruMountains, Tanzania: Interrill and rill erosion. Catena.75: 38-44.
20.Klute, A. 1986. Methodes of Soil Analysis. Part1. Physical and Mineralogical Methods. Soil Science Society of America, Wisconsin, USA.
21.Laflen, J.M., Elliot, W.J., Simanton, R., Holzhey, S., and Kohl, K.D. 1991. WEPP soil erodibility experiments for rangeland and cropland soils. J. Soil Water Cons. 46: 1. 39-44.
22.Lal, R. 1994. Soil Erosion Research Methods. St. Lucie Press, Ž. Delray Beach, FL, Soiland Water Conservation Society Ankeny, IA.
23.Le Bissonnais, Y., and Singer, M.J. 1993. Seal formation, runoff, and interrill erosion from seventeen California soils. Soil Sci. Soc. Am. J. 57: 224-229.
24.Lei, T.W., Zhang, Q., Zhao, J., and Tang, Z. 2001. A laboratory study of sediment transport capacity in the dynamic process of rill erosion. Transactions of the ASAE. 44: 1537-1542.
25.Li, J.C., Liu, Q.Q., and Zhou, J.F. 2003. Environmental mechanics in China. Adva. in Appl. Mecha. 39: 217-306.
26.Li, M., Zhan-bin, L., Dingd, W.L., and Yaoa, W. 2006. Using rate earth element tracers and neutron activation analysis to study rill erosion process. Appl. Radi. Isotr. 64: 402-408.
27.Liu, Q.Q., Xiang, H., and Singh, V.P. 2006. A simulation model for unified interrill erosion and rill erosion on hillslopes. Hydrol. Proc. 20: 469-486.
28.Martinez-Casasnovas, J.A., Ramos, M.C., and Ribes-Dasi, M. 2002. Soil erosion caused by extreme events: mapping and quantification in agricultural plots from very detailed digital elevation models. Geoderma. 105: 125-140.
29.Miguel, R., Marcos, J., Schafer, E., Cassol, A., and Darrell Norton, L. 2001. Interrill and rill erosion on a tropical sandy loam soil affected by tillage and consolidation. United State DepartmentAmerica–American Rose Society National Soil Erosion Research Laboratory, Pp: 601-605.
30.Morgan, R.P.C. 2005. Soil Erosion and Conservation. (Third ed.) Blackwell Publishing Ltd.
31.Nicolau, J.M. 2002. Runoff generation and routing on artificial slopes in a Mediterranean–continental environment: the Teruel coalfield, Spain. Hydrol. Proc. 16: 631-647.
32.Page, A., Miller, L., and Keeny, D.R. 1982. Method of Soil Analysis, Part 2, Chemical and Microbiological Properties. American Society of Agronomy, Inc. Soil Science Society of America, Madison, Wisconsin, USA.
33.Page, A.L., Miller, R.H., and Keeney, D.R. 1986. Methods of soil analysis. Part 2. 2nd ed. Agron. Monogr. 9. ASA and SSSA, Madison, WI.
34.Parysow, P., Wang, G., Gertner, G., and Anderson, A. 2003. Spatial uncertainly analysis for mapping soil erodibility on joint sequential simulation. Catena. 53: 65-78.
35.Polyakov, V.O., and Nearing, M.A. 2003. Sediment transport in rill flow under deposition and detachment conditions. Catena. 51: 33-43.
36.Romero, C.C., Stroosnijder, L., and Guillermo, A.B. 2007. Interrill and rill erodibility in the northern Andean Highlands. Catena. 70: 105-113.
37.Sirjacobs, D., Shainberg, I., Rapp, I., and Levy, G.J. 2001. Flow interruption effects on intake rate and rill erosion in two soils. Soil Sci. Soc. Am. J. 65: 825-834.
38.Torri, D., Poesen, J., Borselli, L., and Knapen, A. 2006. Channel width–flow discharge relationships for rills and gullies. Geomorphology. 76: 273-279.
39.U.S. Soil Salinity Laboratory Staff. 1954. Diagnosis and improvement of saline and alkali soils. Agricultural Handbook 60. United States Department of Agriculture.
40.Vaezi, A.R., and Abbasi, M. 2012. The efficiency of runoff curve number method to estimate runoff in the Taham Chay watershed in north west of Zanjan. J. Sci. Tech. Natur. Res. Water Soil Sci. 61: 16. 209-219. (In Persian)
41.Vaezi, A.R., and Gharehdaghlli, H. 2013. Quantification of rill erosion development in marl soils of Zanjan Roud watershed in north west of Zanjan. Iran. J. Water Soil. 27: 872-881.
(In Persian)
42.Vaezi, A.R., Sadeghi, S.H.R., Bahrami, H.A., and Mahdian, M.H. 2008. Modeling the USLE K-factor for calcareous soils in northwestern Iran. Geomorphology. 97: 414-423. (In Persian)
43.Vatani, A., and Vaezi, A.R. 2014. Soil loss in rill and temporal variation during rainfall in different soil textures. Water and Soil Science. 24: 3. 83-92. (In Persian)
44.Walkley, A., and Black, C.A. 1947. Determination of organic matter in the soil by chromic acid digestion. Soil Sci. 63: 251-264.
 45.Wirtz, S., Seeger, M., and Ries, J.B. 2010. The rill exprement as a method to approach a quantification of rill erosion process activity. Zeitschrift fur Geomorf. 54: 1. 47-56.
46.Wischmeier, W.H., and Smith, D.D. 1978. Predicting rainfall erosion losses a guide to conservation farming. Science and Education Administration, U.S. Department of Agriculture, Handbook, (No.537), 58p.
47.Zhang, X., Quine, T.A., and Walling, D.E. 1998. Soil erosion rates on sloping cultivated land on the Loess Plateau near Ansai, Shaanxi Province, China: an investigation using 137Cs and rill measurements. Hydrol. Proc. 12: 171-189.
48.Zhang, G.H., Liu, B.Y., Nearing, M.A., Huang, C.H., and Zhang, K.L. 2001. Soil detachment by shallow flow. Soil and Water Division of ASAE. 45: 1. 1-7.
49.Zhang, Q., Lei, T., and Jun, Z. 2008. Estimation of the detachment rate in eroding rills in flume experiments using an REE tracing method. Geoderma. 147: 8-15.
50.Zhu, X., Risse, L.M., Mccutcheon, S.C., Tollner, E.W., Rasmussen, T.C., and West, V. 2010. Laboratry Investion of Rill Erosion on Compost Blankets under Concentrated Flow Condition. Am. Soc. Agri. Biol. Eng. 53: 1077-1086.