The Application Of Hydrochemical Characteristics On Transform Relationship Between Surface Water And Groundwater In The Hotan River Basin

Hotan river,originating from the kunlun mountains and into the Tarim river,is an important origin in the supply of the Tarim river.It has guiding significance to study the relationship between surface water and groundwater in Hotan river for scientific management of water resources and rational exploitation of groundwater,and also promotes the coordinated development of economy and environment in the downstream Tarim river basin.Based on the results of hydrochemical analysis in Hotan river basin,this paper adopts the method of cluster analysis,hydrochemical graphic method and the numerical simulation of groundwater flow in typical section,in combination with hydrogeological conditions in the study area,analyzed the Hotan river upstream basin evolution regularity of chemical composition of groundwater,and according to the distribution law of water chemistr y,the relationship between groundwater and groundwater is determined.The main research contents and conclusions are as follows:?1?From the point of ion composition,Hotan river basin in the surface water and groundwater are the dominant ion for Na⁺cation,surface water and groundwater chemical types gradually made a shift from HCO₃-Ca HCO₃-Ca·Mg to Cl-Na,and low salinity water gradually evolves into high salinity water.?2?Using the cluster analysis method of multivariate statistical analysis,the groundwater of Hotan river's upstream is divided into three classes,C1-1,C1-2 and C2.The C1-1 class are mainly distributed in the alluvial fan and alluvial plain zone in the front of the mountain.The formation is dominated by coarse particles,the runoff intensity is high and the TDS is low.The C1-2 class are located in the interfluvial land,where the water flow is slow and the groundwater level rises,forming a watershed,and the side supply surface water is mainly controlled by concentrated and cationic alter nating adsorption.The C2 class is mainly distributed in desert belt and fine soil plain belt,with high TDS and poor hydrodynamic conditions,and is deep and shallow,and the C2 area is the groundwater discharge area.?3?Using[(Ca²⁺+Mg²⁺)-(SO₄^2-+HCO₃^-)]/?Na⁺-Cl^-?specific value and Alkali index to recognise the strength of Hotan river upstream basin groundwater water rock interaction,the result show that the the dissolving action is mainly hydrochemical action of C1-1underground,the hydraulic gradient is large and the groundwater depth is deep,so that the surface water supplies the groundwater.?4?Based on the numerical simulation of two-dimensional groundwater flow in a typical section,the hydrogeological conceptual model and mathematical model were established to analyze the hydrodynamic field and velocity field of the section,and to judge surface water groundwater conversion relationship and runoff intensity.?5?The groundwater circulation patterns in the study area were determined,and the surface water and groundwater in the area were revealed,and the relationship between surface water and groundwater in Hotan river basin was summarized.