مقیاس‌پذیری فرسایش شیاری در یک خاک لومی شنی در شرایط شبیه‌سازی مزرعه‌ای

نوع مقاله : مقاله پژوهشی

نویسندگان

علوم و مهندسی خاک، دانشکده کشاورزی، دانشگاه تهران، کرج، ایران

چکیده

یکی از مهم‌ترین مشکلات در زمینه تحقیقات فرسایش خاک وابستگی نتایج اندازه‌گیری و براوردها به مقیاس است. در سال‌های اخیر مطالعات متعددی در زمینة مقیاس‌پذیری فرسایش خاک صورت‌ گرفته است که حاصل آن ایجاد مدل‌های مختلف است. در این تحقیق که با هدف بررسی مقیاس­پذیری فرسایش شیاری در شرایط مزرعه صورت ‌پذیرفت، شیارهایی با طول 1 تا 8 متر و عرض 5 سانتی‌متر در قطعه زمینی با شیب 5 درصد در یک خاک زراعی با بافت لوم شنی و ساختمان ضعیف ایجاد شد. آزمایش‌ها با دو دبی جریان هدف 11/0 و 24/0 لیتر در ثانیه انجام شد. غلظت رسوب در طی فرایند آزمایش به مدت 30 دقیقه اندازه‌گیری و تغییرات زمانی آن در طول شیارهای مختلف بررسی شد. برای مطالعه مقیاس‌پذیری، تغییرات میانگین غلظت رسوب و شدت جداشدن ذرات در سه حالت ناپایدار اولیه، پایدار نهایی و کل رخداد با طول شیار بررسی و مدل‌سازی شد. نتایج نشان داد که تغییرات زمانی غلظت رسوب به‌صورت نمایی کاهشی است. میانگین غلظت رسوب با طول شیار (تغییرات مکانی) در هر سه حالت در دبی جریان کم‌تر به‌صورت خطی و با دبی بیش‌تر به صورت نمایی (رسیدن به یک حد مشخص) افزایش یافت. همچنین، تغییرات شدت جداشدن با طول شیار در هر سه حالت ناپایدار، پایدار و میانگین رخداد تحت هر دو دبی جریان، به صورت نمایی کاهش یافت. نتایج به طور کلی تایید کننده مدل‌ها و نظریه‌های کاهش تصاعدی شدت جداشدن ذرات با افزایش طول بود. 

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Rill erosion scaling in a sandy loam soil under field simulation

نویسندگان [English]

  • Ahad D. Milan
  • Samaneh Aghaei
  • Hossein Asadi
Soil Science Dep., Faculty of Agriculture, University of Tehran, Karaj, Iran
چکیده [English]

One of the most important problems in the soil erosion research is the dependency of measurements and estimates on the scale. Recently, studies in the field of soil erosion scaling have resulted in development of some different models. This research aimed to investigate the scaling of rill erosion in field conditions. Artifitial rills with length of 1 to 8 meters and width of 5 cm were created in a plot with a slope of 5% in an agricultural soil with sandy loam texture and weak aggregate stability. The experiments were caried out under two target flow rates of 0.11 and 0.24 liters per second. Sediment concentration was measured during the event for 30 minutes, and its time changes were investigated along different rills. To scale rill erosion, the changes with rill length of the mean sediment concentration and particle detachment rate, both at three initial unsteady, final steady and total event conditions, were evaluated and modeled. The temporal changes of sediment concentration exhipited an exponentially decreasing trends almost in all cases. The average sediment concentration increased linearly with rill length (spatial changes) at lower flow rates, and exponentially (reaching a certain limit) under the higher flow rates in all three conditions. Also, the particle detachment rate decreased exponentially with rill length under both flow rates in all three cases of unsteady, steady and total event averages. The results generally confirmed the models and theories of the exponential decrease in the particle detachment rate with increasing rill length.

کلیدواژه‌ها [English]

  • Particle detachment rate
  • Power law equation
  • Rill length
  • Sediment concentration

EXTENDED ABSTRACT

 

Aim:

One of the most important problems in the field of soil erosion research is the dependency of measurements and estimates on the scale. In recent years, several studies have been conducted in the field of soil erosion scaling, which resulted in development of some different models. This research was conducted to investigate the changes in sediment concentration and detachment rate in rills with different lengths under various flow rates in the field conditions.

Methodology:

The research was carried out at the Educational and Research Farm of the University of Tehran located in Karaj (35°48' N latitude and 50°57' E longitude). The average annual temperature and precipitation of the area are 14.2°C and 256 mm, respectively. The soil was a calcareous sandy loam with weak aggregate stability. The rills of 1 to 8 meters lengths and 5 cm width were artificially created in a plot with an area of 140 square meters and a slope of 5 percent after plowing and leveling. The experiments were conducted under two flow rates of 0.12 and 0.25 liters per second. Sediment concentration and flow rate were measured periodically for 30 minutes. The changes with time in sediment concentration were evaluated for different rills and under both flow rate. To scale rill erosion, the changes with rill length of the mean sediment concentration and particle detachment rate, both at three initial unsteady, final steady and total event conditions, were evaluated and modeled.

Results:

The sediment concentration was generally decreased exponentially with time from an initial relatively high level reached to an almost steady level. The initial flashing out of fine and pre-detached particles, and development of a deposited layer are the eventual reasons for decreasing sediment concentration. The changes with time in sediment concentration affected by both flow rate and rill length. The average sediment concentration increased linearly with rill length (spatial changes) at lower flow rate, and exponentially (reaching a certain limit) under the higher flow rate in all three conditions of initial unsteady, final steady and whole event. On the other hand, the particle detachment rate decreased exponentially with rill length under both flow rates in all three cases of unsteady, steady and total event averages. The particle detachment rate induced by flow decreases with increasing sediment concentration, mainly due to consumption of flow energy for transportation. The scaling equation developed by Ban and Lei (2002) was reasonably fitted to the data.

Conclusion:

Soil erosion processes in rills are complex and dynamic affected by several factors such as soil type, flow rate and slope steepness, and as well by rill length. In general, the results of the current study confirmed the models and theories in which particle detachment rate in rills decreases exponentially with length.

Author Contributions

Conceptualization, H.A., S.A. and A.D.M.; methodology, H.A. and S.A.; software, A.D.M.; validation, A.D.M and H.A.; formal analysis, A.D.M., S.A. and H.A.; investigation, S.A.; resources, H. A.; data curation, S.A.; writing—original draft preparation, S.A. and A.D.M.; writing—review and editing, H.A. and A.D.M.; visualization, A.D.M.; supervision, H.A.; project administration, H.A.; funding acquisition, H.A.

All authors have read and agreed to the published version of the manuscript.

Data Availability Statement

Data is available on reasonable request from the authors.

Acknowledgments

The authors would like to thank University of Tehran for providing all the needed facilities.

Ethical considerations

The authors avoided data fabrication, falsification, plagiarism, and misconduct.

Conflict of interest

The authors declare no conflict of interest.

Asadi, H., Aligoli, M., & Gorji, M., (2017). Dynamic changes of sediment concentration in rill erosion at field experiments. Journal of Water and Soil Science. 20(78), 125-139. (in Persian)
Asadi, H., Ghadiri, H., Rose, C. W.,  Yu, B., & Hussein, J., (2007). An investigation of flow-driven soil erosion processes at low streampowers. Journal Hydrology 342, 134-142.
Asadi, H., Moussavi, A., Ghadiri, H., & Rose, C.W., (2011). Flow-driven soil erosion processes and the size selectivity of sediment. Journal of Hydrology 406, 73-81.
Ban, Y. Y., & Lei, T. W. (2022). Mathematical method for physics-based rill erosion process using detachment and transport capacities. Scientific Reports12(1), 4812.‏
Chao, Q., Hongyan, W., & Fenli, Z., (2016). Temporal and spatial variation characteristics of rill erosion and hydrodynamic parameters on loessial hillslope. Trans. Chinese Soc. Agric. Mach. 47 (8), 146–154.
Chen, X., Huang, Y., Zhao, Y., Mo, B., Mi, H., & Huang, C., (2017). Analytical method for determining rill detachment rate of purple soil as compared with that of loess soil. Journal of Hydrology, 549, 236-243.
Chen, X.Y., Zhao, Y., Mo, B., & Mi, H.X., (2016). Estimating rill erosion process from eroded morphology in flume experiments by volume replacement method. Catena 136, 135–140.
Chen, X.-Y., Zhao, Y., Mo, B., &Mi, H.X., (2014). An improved experimental method for simulating erosion processes by concentrated channel flow. PloS One 9(6), e99660.
Feng, R., Chen, J., Xie, Z., Li, D., & Yuan, Z., (2023).  Experimental determination of sediment transport capacity of rill flow over sandified loess slope. International Soil and Water Conservation Research. 11, 301-310.
Foster, G.R., & Meyer, L.D., (1972). Transport of soil particles by shallow flow. Transactions of the ASAE 15, 99–102.
García-Ruiz, J. M., Beguería, S., Nadal-Romero, E., González-Hidalgo, J. C., Lana-Renault, N., & Sanjuán, Y. (2015). A meta-analysis of soil erosion rates across the world. Geomorphology, 239, 160-173
Golkarian, A., Ahmadi, H., Salageghe, A., Jafari, M., & Shahbazi, A., (2015). Effect of slope length on spatially variation of concentration. Journal of Range and Watershed Managment, 67(4), 587-601. (in Persian)
Govers, G., Gimenez, R., & Van Oost, K., (2007).  Rill erosion: Exploring the relationship between experiments, modelling and field observations. Earth-Science Reviews, 84(3-4), 87–102.
Hairsine, P.B., & Rose, C.W., (1992). Modeling water erosion due to overland flow using physical principles: 2. rill flow. Water Resource Research 28(1), 245 –250.
He, J. jun, Sun, L. ying, Duan, G. yao, & Cai, Q. guo. (2023). Slope gradient impacts on rill morphological characteristics: Using indoor simulation experiment on loamy clay under certain rainfall intensity. Catena222. https://doi.org/10.1016/j.catena.2022.106895
He, T., Yang, Y., Shi, Y., Liang, X., Fu, S., Xie, G., Liu, B., & Liu, Y., (2022).Quantifying spatial distribution of interrill and rill erosion in a loess at different slopes using structure from motion (SfM) photogrammetry. International Soil and Water Conservation Research. 10(3), 393-406.
Huang, Y., Chen, X., Luo, B., Ding, L., & Gong, C. (2015). An experimental study of rill sediment delivery in purple soil, using the volume-replacement method. PeerJ3, e1220.‏
Hussein, M., Asadi, H., Kouchakzadeh, S., & Mohammadi, M., (2023). Flow-driven soil erosion processes in a calcareous semiarid soil: Rill length and flow rate impacts. Catena, 221, 106765.ISSN 0341-8162.
Klute, A. (1986). Water retention: Laboratory methods. Methods of Soil Analysis: Part 1 Physical and Mineralogical Methods. 5. 635-662.‏
Lei, T. W., Zhang, Q. W., Zhao, J., Xia, W. S., & Pan, Y. H. (2002). Soil detachment rates for sediment loaded flow in rills. Transactions of the ASAE45(6), 1897.‏
Li, D., Chen, X., Tan, W., Tao, T., Ma, L., Kong, L., & Zhu, P. (2024). Response of erosion rate to hydrodynamic parameters in sheet and rill erosion process on saturated soil slopes. Soil and Tillage Research237. https://doi.org/10.1016/j.still.2023.105996
Li, Z.B., Zhu, B.B., & Li, P. (2008). Advancement in study on soil erosion and water conservation. Acta Pedologica Sinica 45(5), 802-809.
Liu, B.Y., Yang, Y., & Lu, S.J., (2018). Discriminations on common soil erosion terms and their implications for soil and water conservation. Sci. Soil Water Conserv. 16, 9–16. http://doi.org/10.16843/j.sswc.2018.01.002. (In Chinese).
Nelson D.W., & Sommers L.E., (1996). Total carbon, organic carbon, and organic matter. Methods of Soil Analysis, Part 3- Chemical Methods, 961–1010.
Ou, X., Hu, Y., Li, X., Guo, S., & Liu, B., (2021). Advancements and challenges in rill formation, morphology, measurement and modeling. Catena, 196, 104932.‏
Parsons, A.J., Wainwright, J., Mark Powell, D., Kaduk, J., & Brazier, R.E., (2004). A conceptual model for determining soil erosion by water. Earth Surf. Process. Landf. 29 (10), 1293–1302.
Qian, X., Zhao, L., Fang, Q., Fan, C., Zi, R., & Fang, F. (2024). Rill formation and evolution caused by upslope inflow and sediment deposition on freshly tilled loose surfaces. Soil and Tillage Research235. https://doi.org/10.1016/j.still.2023.105868
Shen, H., Zheng, F., Wen, L., L., & Jiang, Y. (2015). An experimental study of rill erosion and morphology. Geomorphology, 231, 193–201.
Shen, N., Wang, Z., Zhang, F., & Zhou, C. (2023). Response of soil detachment rate to sediment load and model examination: A key process simulation of rill erosion on steep loessial hillslopes. Int. J. Environ. Res. Public Health20, 2839.
Shen, N., Wang, Z., Zhang, Q., Wu, B., Wang, D., Zhang, Q., & Liu, J. (2017). Quantifying the contribution of sediment load to soil detachment rate by sediment-laden rill flow. Soil Sci. Soc. Am. J. 81 (6), 1526–1536.
Stefano, C. D., Nicosia, A., Palmeri, V., Pampalone, V., & Ferro, V. (2020). Dye-tracer technique for rill flows by velocity profile measurements. Catena, 185, 104313. https://doi.org/10.1016/j.catena.2019.104313.
Tian, P., Gong, Y., Hao, F., Chen, L., Yang, Y., Guo, W., Wu, H., & Zhang, W. (2022). Comparing erosion and rill development processes by simulated upslope inflow in two red soils from subtropical China. Catena , 213, 106139.
Vaezi, A. R, & Foroumadi, M. (2018). Flow characteristics and rill erodibility in relation to the rainfall intensity in a marl soil. Iranian Journal of Watershed Management Science and Engineering, 12(40), 11-22. (in Persian)
Vaezi, A. R., & Varghaei, L. (2023). Investigating the effect of cultivated furrow length on rill erosion and eroded grain size in a rainfed field. Applied Soil Research, 11(2), 59-70. (in Persian)
Wang, D., Wang, Z., Shen, N., & Chen, H., (2016). Modeling soil detachment capacity by rill flow using hydraulic parameters. J. Hydrol. 535, 473–479.
Wirtz, S.,  Seeger, M.,  Remke, A.,  Wengel, R.,  Wagner, J.-F.,  & Ries, J.B., (2013). Do deterministic sediment detachment and transport equations adequately represent the process-interactions in eroding rills? An experimental field study. Catena, 101, 61-78, 10.1016/j.catena.2012.10.003
Zhang, G.H., Liu, B.Y., Nearing, M., Huang, C.H., & Zhang, K.L., (2002). Soil detachment by shallow flow. Trans. ASABE. 45(2), 351-357.
Zhang, Q., Wang, J., Zhao, L., Wu, F., Zhang, Z., & Torbert, A.H., (2015). Spatial heterogeneity of surface roughness during different erosive stages of tilled loess slopes under a rainfall intensity of 1.5 mm min-1. Soil Tillage Res. 153, 95–103.
Zhou, C., Shen, N., Zhang, F., & Delang, C. O., (2022). Soil detachment by sediment-laden rill flow interpreted using three experimental design methods. Catena, 215, 106332.
Zhu, Q., Liu, J., Qi, X., Cheng, X., & Zhou, Z. (2024). Estimating sediment transport capacity on sloping farmland on the Loess Plateau considering soil particle size characteristics. Geoderma, 446. https://doi.org/10.1016/j.geoderma.2024.116906.