The effects of soil clay content, surface rock fragments and their interactions on runoff and sediment yield during rainfall simulation

Document Type: Original Article


1 Department of Range and Watershed Management, Faculty of Agriculture and Natural Resources, University of Torbat Heydarieh, Razavi Khorasan, Iran

2 Department of Watershed Science and Engineering, Faculty of Natural Resources and Marine Sciences, Tarbiat Modares University, Noor, Mazandaran, Iran

3 Soil Conservation and Watershed Management Research Institute, Tehran, Iran

4 Department of Statistics, Faculty of Mathematical Sciences, Tarbiat Modares University, Tehran, Iran



In the present research, the effects of surface rock fragments and soil clay content on surface runoff and soil loss was investigated under the laboratory conditions. The aim of the test was to increase the general understanding of how soil clay content and surface rock fragments affect the soil erosion process. A rainfall simulator was added to an erosion plot and these apparatuses were used to investigate the effects of varying soil clay content (SCC) and soil rock fragments (SRF) on soil erosion by measuring runoff volume and sediment yield at regular time intervals during the simulation. The results indicated that the main effects of soil clay content and surface rock fragments were all significant at the 0.95 level (p<0.05) for the runoff and sediment yield. Also, the most significant factor was the quantity of soil clay content in comparison with the surface rock fragments. The interaction effect between surface rock fragments and soil clay content was not significant for the runoff volume, but in case of sediment yield it had a great influence. The repeated measures analysis of variance for time intervals revealed that the main effects of sampling time and its interactions with soil clay content and surface rock fragments were all significant (p<0.05) as well, although the effects of time intervals reduced gradually while the rainfall simulation proceeded. The results indicated that the main effects and interactions must be accounted for any simulation study of soil erosion and modeling, and the multiple effects should be studied in research rather than the isolated effects of single variables.


Main Subjects

1. Armfield Ltd., 1998, Instruction manual of rainfall simulator FEL3, Formerly fesissue 8, 24 pp.

2. Asadi, H., Ghadiri, H., Rose, CW. and Rouhipour, H, 2007. Interrill soil erosion processes and their interaction on low slopes, Earth Surf Process Landforms, Vol 32: 711–724.

3. Asadi, H., Ghadiri. H., Rouhipour, H. and Rose. C, 2006. Interaction between rain and runoff processes during rainstorm erosion events, 14th International soil conservation organization conference. Marrakech. Morocco, 5pp.

4. Beca, P, 2002. Temporal variability of suspended sediment availability during rainfall-runoff events in a small agricultural basin, ERB and Northern European FRIEND Project 5 Conference, Demanovska dolina, Slovakia, 3pp.

5. Bennewitz, EV. and Aladro J. 2017. The effects of rainfall intensity and rock fragment cover on soil hydrological responses in Central Chile.Journal of Soil Science and Plant Nutrition, Vol 17 (3): 781-793.

6. Ben-Hur, M., Shainberg, I., Bakker, D. and Keren, R, 1985. Effect of soil texture and CaCO3 content on water infiltration in crusted soils as related to water salinity, Irrig Sci, Vol 6: 281–284.

7. Bestelmeyer, BT., Ward, JP. and Havstad, KM, 2006. Soil-geomorphic heterogeneity governs patchy vegetation dynamics at an arid ecotone, Ecology, Vol 87: 963-973.

8. Biox-Fayos, C., Calvo-Cases, A., Imeson, AC. and Sorianosoto, MD, 2001. Influence of soil properties on the aggregation of some Mediterranean soils and the use of aggregate size and stability as land degradation indicators, Catena, Vol 44: 47–67.

9. Bruce-okine E. and Lal R. 1975. Soil erodibility as determined by a raindrop technique. Soil Sci. Vol 119: 149-159.

10. Bunte K. and Poesen J. 1994. Effects of rock fragment size and cover on overland flow hydraulics, local turbulence and sediment yield on an erodible soil surface. Earth Surf Process Landforms. Vol 19: 115–135.

11. Chartier, MP., Rostagno, CM. and Videla, LS, 2013. Selective erosion of clay, organic carbon and total nitrogen in grazed semiarid rangelands of northeastern Patagonia, Argentina. J Arid Environments, Vol 88: 43-49.

12. Chen, H., Liu, J., Wang, K. and Zhang, W, 2011. Spatial distribution of rock fragments on steep hillslopes in karst region of northwest Guangxi, China, Catena, Vol 84:  21–28.

13. Ekwue, EI., Bharat, C. and Samaroo, K, 2009. Effect of soil type, peat and farmyard manure addition, slope and their interactions on wash erosion by overland flow of some Trinidadian soils, Biosyst eng, Vol 102: 236–243.

14. Ekwue EI. and Harrilal A. 2010. Effect of soil type, peat, slope, compaction effort and their interactions on infiltration, runoff and raindrop erosion of some Trinidadian soils. Biosyst eng. Vol 105: 112–118.

15. Evans, M., 2017, MINITAB manual for David Moore and George McCabeís introduction to the practice of statistics, University of Toronto, Ontario, Canada, 256pp.

16. Feng-Ling, Y., Zhi-Hua, Sh., Chong-Fa, C. and Zhao-Xia, L. 2010. Wetting rate and clay content effects on interrill erosion in ultisols of southeastern china, Pedosphere, Vol 20(1): 129–136.

17. Field, A., 2009, Discovering Statistics Using Spss, 3rd Edition. Sage Publications Ltd, London, 856pp.

18. Figueiredo T. and Poesen J. 1998. Effects of surface rock fragment characteristics on interrill runoff and erosion of a silty loam soil. Soil Till Res. Vol 46: 81-95.

19. Fox DM. and Bryan RB. 1999. The relationship of soil loss by interrill erosion to slope gradient. Catena. Vol 38: 211–222.

20. Gan, F., He, B. and Wang, T, 2018. Water and soil loss from landslide deposits as a function of gravel content in the Wenchuan earthquake area, China, revealed by artificial rainfall simulations, Plos One, Vol 13(5): 1-19.

21. Gong, T., Zhu, Y. and Shao, M, 2018. Effect of embedded-rock fragments on slope soil erosion during rainfall events under simulated laboratory conditions, Journal of Hydrology, Vol 563: 811-817.

22. Govers, G., Van-Oost, K. and Poesen, J, 2006. Responses of a semi-arid landscape to human disturbance: A simulation study of the interaction between rock fragment cover, soil erosion and land use change, Geoderma, Vol 133: 19–31.

23. Heng, BCP., Sander, GC., Armstrong, A., Quinton, JN., Chandler, JH. and Scott, CF, 2011. Modeling the dynamics of soil erosion and size-selective sediment transport over non-uniform topography in flume-scale experiments, Water Resour Res, Vol 47, 11pp. doi:10.1029/2010WR009375

24. Jomaa, S., Barry, DA., Brovelli, A., Heng, BCP., Sander, GC., Parlange, JY. and Rose, CW, 2012. Rain splash soil erosion estimation in the presence of rock fragments, Catena, Vol 92: 38–48.

25. Jomaa, S., Barry, DA., Brovelli, A., Sander, GC., Parlange, JY., Heng, BCP. and Tromp-van Meerveld, HJ, 2010. Effect of raindrop splash and transversal width on soil erosion: Laboratory flume experiments and analysis with the Hairsine–Rose model, J Hydrol, Vol 395: 117–132.

26. Jones, A., Stovin, V., Guymer, I., Gaskell, P. and Maltby L, 2008. Modelling temporal variations in the sediment concentrations in highway runoff, 11th International conference on urban drainage. Edinburgh. Scotland. UK, 10pp.

27. Lal, R, 1981. Soil erosion problems on Alfisols in western Nigeria, VI - Effects of erosion on experimental plots, Geoderma, Vol 25: 215-230.

28. Mandal, UK., Rao, KV., Mishra, PK., Vittal, KPR., Sharma, KL., Narsimlu, B. and Venkanna, K, 2005. Soil infiltration, runoff and sediment yield from a shallow soil with varied stone cover and intensity of rain, Eur J Soil Sci, Vol 56: 435–443.

29. Maroufpoor, E., Faryabi, A., Ghamarnia, H. and Moshrefi, G, 2010. Evaluation of uniformity coefficients for sprinkler irrigation systems under different field conditions in Kurdistan province (Northwest of Iran), Soil Water Res, Vol 5 (4): 139–145.

30. Mazaheri MR. and Mahmoodabadi M. 2012. Study on infiltration rate based on primary particle size distribution data in arid and semiarid region soils. Arab J Geosci. Vol 5:1039–1046.

31. Mbagwu JSC. and Bazzoffi P. 1998. Soil characteristics related to resistance of breakdown of dry soil aggregates by water-drops. Soil Till Res. Vol 45:133-145.

32. Meng, C., Niu, JZ., Yin, ZC., Luo, ZT., Lin, XN. and Jia, JW, 2018. Characteristics of rock fragments in different forest stony soil and its relationship with macropore characteristics in mountain area, northern China, Journal of Mountain Science, Vol 15 (3): 519–531.

33. Moradi HR. and Saidian H. 2010. Comparing the most important factors in the erosion and sediment production in different land uses (Case study: Gachsaran and Aghajari Formations). J Environ Sci Eng. Vol 4 (11): 1-12.

34. Muukkonen, P., Hartikainen, H. and Alakukku, L, 2009. Effect of soil structure disturbance on erosion and phosphorus losses from Finnish clay soil, Soil Till Res, Vol 103: 84–91.

35. Poesen J. and Lavee H. 1994. Rock fragments in topsoils: significance and processes. Catena. Vol 23: 1–28.

36. Poesen, JW., Wesemael, BV., Bunte, B. and Benet, AS, 1998. Variation of rock fragment cover and size along semiarid hillslopes: a case-study from southeast Spain, Geomorphology, Vol 23: 323–335.

37. Poesen, J., De Luna, E., Franca, A., Nachtergaele, J. and Govers, G, 1999. Concentrated flow erosion rates as affected by rock fragment cover and initial soil moisture content, Catena, Vol 36: 315–329.

38. Richardson CW. and King KW. 1995. Erosion and nutrient losses from zero tillage on a clay soil. J agric Engng Res. Vol 61: 81-86.

39. Rieke-Zapp, D., Poesen, J. and Nearing, MA, 2007. Effects of rock fragments incorporated in the soil matrix on concentrated flow hydraulics and erosion, Earth Surf Process Landforms, Vol 32: 1063–1076.

40. Rimal BK. and Lal R. 2009. Soil and carbon losses from five different land management areas under simulated rainfall. Soil Till Res. Vol 106: 62–70.

41. Sadeghi, SHR., Bashari-Seghaleh, M. and Rangavar, AS, 2011. Plot sizes dependency of runoff and sediment yield estimates from a small watershed, Catena, Vol 102: 55-61.

42. Salehi, F., Pesant, AR., Berard, A. and Lagace, R, 1993. Preliminary estimates of the erodibility of 10 Quebec eastern townsips soil series, Can Agric Eng, Vol 35: 157–164.

43. Srinivasan, MS., Kleinman, PJA., Sharpley, AN., Buob, T. and Gburek, WJ, 2007. Hydrology of small field plots used to study phosphorus runoff under simulated rainfall, J Environ Qual, Vol 36: 1833–1842.

44. Tetegan, M., Nicoullaud, B., Baize, D., Bouthier, A. and Cousin, I, 2011. The contribution of rock fragments to the available water content of stony soils: proposition of new pedotransfer functions, Geoderma, Vol 165(1): 40-45.

45. Vanelslande, A., Rousseau, P., Lal, R., Gabriels, D. and Ghuman, BS, 1984. Testing the applicability of a soil erodibility nomogram for some tropical soils, Challenges in African Hydrology and Water Resources. Proceedings of the Harare Symposium. IAHS Pub. No. 144: 463-473.

46. Wang, X., Li, Zh., Cai, Ch., Shi, Zh., Xu, Q., Fu, Zh. and Guo, Zh, 2012. Effects of rock fragment cover on hydrological response and soil loss from Regosols in a semi-humid environment in South-West China, Geomorphology, Vol 151-152: 234–242.

47. Wischmeier WH. & Smith D.D, 1978, Predicting rainfall erosion losses-a guide to conservation planning, U.S. Department of Agriculture, Agriculture Handbook No. 537, 67pp.

48. Zhang, MK., Wang, L.P. and HE, Z.L, 2007. Spatial and temporal variation of nitrogen exported by runoff from sandy agricultural soils, J Environ Sci, Vol 19: 1086–1092.