Study On Seepage Law Of Riverbed In Desert Section Of Hotan River

The infiltration law of riverbed sediments is an important factor affecting the surface groundwater transformation ability,and is a necessary index for scientific research of river water leakage,solute transport and other activities in the hydrological process.In this paper,the vertical permeability coefficient of three different reaches of Hetian River is measured by double ring infiltration meter method,and the permeability rate and permeability coefficient are measured by field test and field sampling,so as to analyze the permeability characteristics of riverbed sediment,so as to clarify the leakage volume of each reach under different incoming water conditions.The main conclusions are as follows:(1)Before stabilization,the river bed of Hetian River Bridge has the highest infiltration rate,followed by Hongbai mountain,and Xiaokan river has the lowest.The water infiltration of Hetian River Bridge is the largest,Hongbai mountain and Xiaojian are close,Xiaojian is slightly smaller.Among the three commonly used soil infiltration calculation formulas,the koctakob formula is most suitable for the study of water infiltration in desert section.(2)The permeability coefficient of Hetian river bed has spatial variability.In the horizontal direction,from the center of the river to the Bank of the river,the permeability coefficient of the bed sediments decreases gradually in different positions of the same reach;in the vertical direction(from upstream to downstream),the permeability coefficient of the bed sediments in the upstream is the largest,slightly larger in the middle and the smallest in the downstream.(3)Particle analysis can reveal the properties of particles,which is the main factor to explore the permeability rate and permeability coefficient.The larger the value of permeability rate and permeability coefficient,the larger the particle size.The particle size of upstream,middle and downstream soil samples is 73 ? m,65 ? m and 51 ? m respectively,and the corresponding stable infiltration rate is 28.71mm/min,21.23mm/min and 18.48mm/min respectively.With the decrease of soil particle size in the upper,middle and lower reaches of Hetian River,the steady infiltration rate also shows a decreasing trend.(4)Under the three inflow frequencies of 12.50%,50% and 87.5%,the water consumption,leakage and leakage per unit length of the reach all show a decreasing trend.The water consumption of section 2 is relatively the least,and its proportion in the total water consumption is less than 20% under the three inflow frequencies.Under the same inflow frequency,the order of water leakage is segment 1 > segment 2 > segment 3,while the order of water leakage per unit length is segment 1 > segment 3 > segment 2.