Study On Groundwater Flow System In Delingha Fault Area Of Qaidam Basin

The groundwater exists in the underground porous media,and its flow characteristics are concealed and complex,susceptible to the developmental distribution characteristics of the strata,the buried depth distribution properties and the topographic features such as the impact of terrain.The stratigraphic structure of the Delingha fault zone in the Qaidam Basin is complicated and developed.The two-dimensional groundwater flow model can better reflect the characteristics of the groundwater flow system in the study area when the lithology of the strata changes greatly and the depth of burial is large.In this paper,a two-dimensional stable flow model was established on the profile by GMS software.The groundwater flow system in the Delingha fault zone was studied in detail.Combined with the section water chemistry,the groundwater recharge Characteristics and groundwater flow system to make a reasonable analysis,which is more realistic to restore the Delingha fault area of groundwater circulation law.From the simulation results of the flow on the section,we can know:?1?before the ancestral dragon mountain through the precipitation and ice melt water supply to become the main groundwater recharge area,piedmont slope plain part of the groundwater overflow,the lowest section of the island of Tuosu Lake and Crook Lake into groundwater The main excretion area,the intensity of excretion is more concentrated.?2?In the process of migration of aqueous media,the groundwater flow in the regional circulation system is about 5% of the total flow in the circulation system.The other two-level system of groundwater flow accounted for about 95%,groundwater flow to local and central circulation.?3?The results of the hydrological analysis of the profiles correspond to the characteristics of the profile water cycle revealed by the model.There are obvious changes in the flow pattern of groundwater from the front of the mountain to the middle of the basin.In the former of Zong wu Longshan Mountain,groundwater vertical alternately strong,good water quality,mostly below in 550 mg / L TDS of HCO₃ type of water,water speed,faster update rate,the cycle strength was significantly higher than the deep water.Shallow aquifermain water chemical type is greater than 3000 mg / L TDS of SO_4-HCO₃ type of water,there are groundwater discharge surface evaporation.In the discharge area of Tuo Su Lake,groundwater is mainly vertical flow,and the water type of shallow groundwater is Cl-Na water with TDS greater than 2000 mg / L.?4?From the migration time and the velocity profile of groundwater in the Carboniferous aquifer,the average migration time of the groundwater at the regional cell B is the longest and the average penetration rate is very slow,so that the groundwater cycle renewal capacity is the slowest and closed Sex is relatively good.