Spatial Variability Of Streambed Hydraulic Conductivity In Yurungqash River

Hotan Prefecture is located in the southern edge of Tarim Basin,the Xinjiang Uyghur Autonomous Region,where there is less rain and less groundwater resources.The groundwater resources are largely derived from river infiltration,and the vertical streambed hydraulic conductivity of the river bed is an important factor affecting the transformation,and the vertical streambed hydraulic conductivity of the river bed is complex and changeable in space.Therefore,it is of great significance to study the spatial variabilit y of the permeability coefficient of the river bed.The vertical streambed hydraulic conductivity of three different dimensions of Yurungqash River was measured by the vertical tube method and the seepage meter method.Based on the statistical theory,the spatial variation theory and the correlation analysis method,the spatial variability of the river bed sediments under the three different dimensions was studied.Z direction:Do tests related to the vertical hydrodynamic conductivity in Yurungqash River fine soil zone vertical penetration at different depths,the hydrodynamic conductivity data were measured in 10 groups,with a range of 3.60⁸.50m/d and an average of 6.15m/d.The K values are subject to logarithmic normal distribution,and the K of different depths has medium intensity variability;K has a correlation within 38.1cm,and the correlation of K space in the streambed is much stronger at different depth of the fine soil zone;The factors that cause the difference of riverbed K value at different depths are water level and sedimentation.Y direction:The vertical hydrodynamic conductivity K data of the river bed is measured in 8 groups in the direction of the Yurungqash River fine soil zone perpendicular to the river with an average of 8.35 m/d between the range of 1.58²0.48 m/d.After the test the K value are subject to lognormal distribution,the K of river bed perpendicular to river is of medium intensity variability;K has correlation within 52.5m,and the spatial correlation of K value in river bed perpendicular to river direction is stronger,and the factors affecting the K value of river bed permeability coefficient include the transverse reduction and hydrodynamic effect of the river bed topography.There is a significant linear negative correlation between the LnK of river bed permeability coefficient and clay content,and a significant positive linear correlation with sand content.X direction:The vertical hydrodynamic conductivity K data of the river bed is measured in 7 groups in the direction of the Yurungqash River fine soil zone along the river with an average 3.9m/d between the range of 0.86⁸.35m/d,.After the test the K value are subject to lognormal distribution,K is medium intensity variability;K has correlation within 8.92km and K spatial correlation is strong;the factors affecting the K value of streambed hydrodynamic conductivity include river bed topography and aeolian effect.There is a linear negative correlation between K and d₃₀,C_c in Yurungqash River.The spatial variability of Y direction is strongest,the runner-up and second runner-up are X direction and Z direction.The research of the variability of streambed vertical hydrodynamic conductivity can provide a basis for the parameter zoning of the streambed,and provide a basis for the transformation between surface water and groundwater,which is of great significance to the study of the transformation between surface water and groundwater and the evaluation of water resources.