Comparison on flow transport capacity of overland flow between cohesive and non-cohesive sand
YU Xianju, LIU Chenguang, FU Suhua, MU Hongli, WU Sinan, LIU Yingna, ZHANG Guanghui
1. Beijing Key Laboratory of Environmental Remote Sensing and Digital City, Faculty of Geographical Science, Beijing Normal University, 100875, Beijing, China;
2. State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Institute of Soil and Water Conservation of Chinese Academy of Sciences and the Ministry of Water Resources, 712100, Yangling, Shaanxi, China
Abstract：[Background] Flow transport capacity refers to the maximum flux of sediment that can be transported under specific hydrodynamic conditions, and is an important parameter of soil erosion process model. Domestic and foreign scholars have carried out research works on the flow transport capacity of overland flow; however, the experimental materials are relatively simple, and the soil is not fully considered in the object of the overland flow and the experimental object is concentrated in the non-cohesive sand. Therefore, it is necessary to compare the flow transport capacity of overland flow between cohesive and non-cohesive sand.[Methods] The cohesive sand (sampled from black soil of Nenjiang county in Heilongjiang province and the median particle size of 0.28 mm) was used as experimental material. The experiment was designed with 5 slope degrees (3°,6°,9°,12°,and 15°) and 6 flow rates(0.25, 0.50, 0.75, 1.00, 1.50, and 2.00×10-3 m3/s), totally 30 experiments. The experiments were carried out in a flume with 5.0 m long and 0.4 m wide. Dyeing method was to measure the flow rate. The hydraulic parameters and the flow transport capacity of cohesive sand were processed using SPSS software and Origin software, and graphed to obtain the relationship between the flow transport capacity of the cohesive sand and the different hydraulic parameters. The measured results were compared with the ones calculated by equations previously from non-cohesive sand in our laboratory.[Results] 1) Flow transport capacity of both the cohesive sand and the non-cohesive sand increased with the increase of the flow velocity, shear stress and stream power. 2) Under the same hydrodynamic conditions, the flow transport capacity of the cohesive sand was greater than that of non-cohesive sand. 3) The relationship between the flow transport capacity of the cohesive sand and the flow velocity, shear stress and stream power was expressed as a power function, and the coefficients of determination were 0.91, 0.72 and 0.80, respectively. The flow velocity was the best hydraulic parameter for calculating the flow transport capacity of cohesive sand. The shear stress and stream power provided the higher accuracy for calculating the flow transport capacity of the non-cohesive sand. The coefficients of determination were 0.98 and 0.98. 4) The measured critical flow velocity of cohesive sand was 0.245 m/s, <0.309 m/s calculated by the equation from the non-cohesive sand previously. The coefficient of determination and Nash-Sutcliffe efficiency coefficient of cohesive sand were 0.72 and 0.78 respectively, while the shear stress equation of non-cohesive sand was used to calculate the flow transport capacity of the cohesive sand. The coefficient of determination and Nash-Sutcliffe efficiency coefficient of cohesive sand were 0.80 and 0.43 respectively, while the stream power equation of non-cohesive sand was used to calculate the flow transport capacity of the cohesive sand. The coefficient of determination of cohesive sand was 0.20 while the relationship between the flow transport capacity of the cohesive sand and the unit stream power was fitted by a power function.[Conclusions] There are differences in flow transport capacity of a slope between cohesive and non-cohesive sand, he flow transport capacity equation obtained from non-cohesive sand is not suitable for cohesive sand.
于现举1, 刘晨光2, 符素华1,2, 母红丽1, 吴思南1, 刘瑛娜1, 张光辉1. 有黏性和无黏性沙坡面流的挟沙力比较[J]. 中国水土保持科学, 2018, 16(6): 9-14.
YU Xianju, LIU Chenguang, FU Suhua, MU Hongli, WU Sinan, LIU Yingna, ZHANG Guanghui. Comparison on flow transport capacity of overland flow between cohesive and non-cohesive sand. SSWC, 2018, 16(6): 9-14.
张红艺, 周赤建, 张欧阳,等.高含沙水流挟沙力计算公式研究[J].水力发电学报,2004,23(1):74. ZHANG Hongyi, ZHOU Chijian, ZHANG Ouyang, et al. Study on the formula of silt transport capacity or hyper-concentrated silt-laden flow[J]. Journal of Hydroelectric Engineering, 2004, 23(1):74.
[2]
张光辉.退耕驱动的近地表特性变化对土壤侵蚀的潜在影响[J].中国水土保持科学,2017,15(4):143. ZHANG Guanghui. Potential effects of changes in near soil surface characteristics driven by farmland abandonment on soil erosion[J]. Science of Soil and Water Conservation, 2017, 15(4):143.
[3]
王玲玲,刘兰玉,姚文艺.水流挟沙力计算公式比较分析[J].水资源与水工程学报,2008,19(4):33. WANG Lingling,LIU Lanyu,YAO Wenyi. Comparison analysis for the formula of silt transport capacity[J]. Journal of Water Resources & Water Engineering,2008,19(4):33.
[4]
钱宁,万兆惠.泥沙运动力学[M].北京:科学出版社,1991. QIAN Ning, WANG Zhaohui. Mechanics of sediment transport[M]. Beijing:Science Press, 1991.
[5]
ALI M, SEEGER M, STERK G, et al. A unit stream power based sediment transport function for overland flow[J]. Catena, 2013, 101:197.
[6]
李文杰,李丹勋,王兴奎.坡面流挟沙力计算公式及其评价[J].泥沙研究,2012(2):26. LI Wenjie, LI Danxun, WANG Xingkui. Equations and evaluations of sediment carrying capacity of overland flows[J]. Journal of Sediment Research,2012(2):26.
[7]
GUY B T, DICKENSON W T, SOHRABI T M, et al. Development of an empirical model for calculating sediment-transport capacity in shallow overland flows:Model calibration[J]. Biosystems Engineering, 2009,103(2):245.
[8]
张光辉.坡面薄层流水动力学特性的实验研究[J].水科学进展,2002,13(2):159. ZHANG Guanghui. Study on hydraulic properties of shallow flow[J]. Advances in Water Science,2002,13(2):159.
[9]
LEI Tingwu, ZHANG Qingwen, ZHAO Jun, et al. A laboratory study of sediment transport capacity in the dynamic process of rill erosion[J]. Transactions of the ASAE, 2001,44(6):1537.
[10]
ZHANG Guanghui, LIU Yumei, HAN Yanfeng, et al. Sediment transport and soil detachment on steep slopes:I. transport capacity estimation[J]. Soil Science Society of America Journal, 2009,73(4):1291.
[11]
ABRAHAMS A D,LI G,KRISHNAN C,et al.A sediment transport equation for interrill overland flow on rough surfaces[J].Earth Surface Processes and Landforms,2001,26(13):1443.
[12]
ALI M,STERK G,SEEGER M,et al.Effect of hydraulic parameters on sediment transport capacity in overland flow over erodible beds[J].Hydrology and Earth System Sciences,2012,16(2):591.
[13]
ZHANG Guanghui,WANG Lili,TANG Keming,et al.Effects of sediment size on transport capacity of overland flow on steep slopes[J]. Hydrological Sciences Journal,2011,56(7):1289.
[14]
ZHANG Guanghui,WANG Lili,LI G,et al.Relationship between sediment particle size and transport coefficient on steep slopes[J].Transactions of the American Society of Agricultural Engineers,2011,54(3):869.
[15]
栾莉莉,张光辉,王莉莉,等.基于水流功率的坡面流挟沙力模拟[J].泥沙研究,2016(2):61. LUAN Lili, ZHANG Guanghui, WANG Lili, et al. Study on sediment transport capacity of overland flow based on stream power[J]. Journal of Sediment Research, 2016(2):61.
[16]
韩其为.水库淤积[M].北京:科学出版社,2003:8. HAN Qiwei. Reservoir sedimentation[M]. Beijing:Science Press, 2003:8.
2018, Vol. 16 
