Solute mixing in a permeable non-rectangular channel  

作　　者：Sonia Zebardast Sayyed-Hassan Tabatabaei Fariborz Abbasi Manuchehr Heidarpour 

机构地区：[1]Department of Water Engineering,Faculty of Agriculture,Shahrekord University,Shahrekord,Iran [2]Agricultural Engineering Research Institute(AERI),Agricultural Research,Education and Extension Organization(AREEO),Karaj,Iran [3]Department of Water Engineering,College of Agriculture,Isfahan University of Technology,Isfahan,Iran

出　　处：《International Journal of Sediment Research》2020年第2期134-145,共12页国际泥沙研究（英文版）

基　　金：The current study was financially supported by Shahrekord University.

摘　　要：Understanding diffusion and solute transport,is regarded as a main activity in environmental management,sustainable development and sedimentation processes because of their role in diffusion of contaminants.The current paper presents an experimental study which was done in a parabolic channel with permeable and impermeable bed conditions in order to estimate the transverse mixing coefficient(TMC)and the maximum solute mixing length(SML)for different channel bed roughness coefficients and discharges.The cross section of the channel was 0.5 m wide and 0.3 m deep with a parabolic shape(i.e.similar to furrow irrigation).Three levels of bed roughness coefficient of 0.02,0.04,and 0.06,and three discharges of 5,10,and 15 L/s were considered.Bed infiltration channel was applied at a low level and medium level as well as a case without infiltration.In the current experiments,sodium chloride was used as a soluble tracer and was injected into the water at mid depth in the upstream cross section.The tracer concentration profile in the water and velocity profile were measured at eight cross sections in the channel.The results showed that the values of SML ranged between 20 and 46 m in impermeable and permeable beds channel beds respectively.The assessment of usual discharge values,infiltration,and roughness coefficient of a furrow(agricultural field)indicated that the SML of the furrows were less than 20 m.In the current research,the average dimensionless mixing coefficient was found to be 0.17 in the nonrectangular channel.Eventually,equations were developed to explain the TMC and SML in a permeable parabolic channel that could be beneficial in prediction of fertilizer transport in furrow irrigation.Understanding diffusion and solute transport,is regarded as a main activity in environmental management,sustainable development and sedimentation processes because of their role in diffusion of contaminants.The current paper presents an experimental study which was done in a parabolic channel with permeable and impermeable bed conditions in order to estimate the transverse mixing coefficient(TMC) and the maximum solute mixing length(SML) for different channel bed roughness coefficients and discharges.The cross section of the channel was 0.5 m wide and 0.3 m deep with a parabolic shape(i.e.similar to furrow irrigation).Three levels of bed roughness coefficient of 0.02,0.04,and 0.06,and three discharges of 5,10,and 15 L/s were considered.Bed infiltration channel was applied at a low level and medium level as well as a case without infiltration.In the current experiments,sodium chloride was used as a soluble tracer and was injected into the water at mid depth in the upstream cross section.The tracer concentration profile in the water and velocity profile were measured at eight cross sections in the channel.The results showed that the values of SML ranged between 20 and 46 m in impermeable and permeable beds channel beds respectively.The assessment of usual discharge values,infiltration,and roughness coefficient of a furrow(agricultural field) indicated that the SML of the furrows were less than20 m.In the current research,the average dimensionless mixing coefficient was found to be 0.17 in the nonrectangular channel.Eventually,equations were developed to explain the TMC and SML in a permeable parabolic channel that could be beneficial in prediction of fertilizer transport in furrow irrigatio n.

关 键 词：Environmental hydraulics FERTIGATION FURROW IRRIGATION SOLUTE MIXING length Transverse MIXING coefficient 

分 类 号：X131.2[环境科学与工程—环境科学]