Study On Water Control Characteristics Of Neotectonics And Groundwater Circulation Pattern In The Western Plains Of The Yili Valley

Western plain of the Yili Valley is located in arid and semi-arid areas innorthwest China,with less precipitation and greater evaporation,and groundwater is of great significance for local development.In recent years,with the improvement of people's production and living level,the demand for water resources is also growing,a series of problems about water quantity and water quality need to be solved urgently,and the basis for solving these problems is to find out the circulation pattern of groundwater in the region.Therefore,it is very important to carry out the study of groundwater circulation pattern in the western plain area of the Yili Valley.In this study,Western plain of Yili Valley was used as the main research area.Based on previous hydrogeological surveys in the Yili Valley,the hydrological properties of active faults in the study area were analyzed.And summarize the controlling effect of faults on the groundwater cycle.By analyzing the water chemistry and isotope characteristics on three typical sections,the groundwater flow system on the typical sections is divided.By analyzing the hydrochemical and isotopic characteristics of different water bodies in the study area,The hydrodynamic and hydrochemical methods were used to divide the regional groundwater system,and the groundwater circulation model in the western plain area of the Yili Valley was summarized.The research results are described as follows:?1?Neotectonic movement has a certain impact on the groundwater circulation runoff in the study area,the most important of which is the effect of active faults generated and resurrected by neotectonic movement on the groundwater circulation runoff.The northern basin-mountain faults are mostly water-blocking faults,causing the bedrock fissure waters in the northern mountainous areas to not adequately recharge groundwater in the plains,while the southern piedmont faults are water-conducting faults,enabling the bedrock fissure waters in the southern mountainous areas to be timely To supplement groundwater in the plains.The internal faults in the plain area mostly raise the groundwater level,causing the groundwater level to cut the surface and drain into a spring.?2?In the north,from the piedmont to the alluvial fine soil plain area of the Yili River,the hydrochemical type changes from HCO₃ type water to HCO₃-SO₄ and SO₄-HCO₃ type water and SO₄ type water,and the cations change from Ca²⁺and Mg²⁺to Na⁺,Ca²⁺,and Mg²⁺.The groundwater hydrochemical type in the frontal alluvial fan area of Qapqal County in the south is complex,and almost all types of groundwater are present.It is presumed to be due to the recharge of bedrock fissure water in the southern mountainous area.The central plain area is dominated by HCO₃-SO₄ water,and the mainly cations are Ca²⁺and Mg²⁺.HCO₃ type water exists in some areas,which is presumed to be due to the sufficient recharge of surface water.The isotope in the groundwater in the study area showed a trend of gradual enrichment during the runoff from the piedmont to the Yili River.However,the isotope in the groundwater fluctuated due to the replenishment of different water sources.?3?Groundwater circulation pattern in the western plain of the Yili Valley:Northern plains:groundwater is mainly supplied by river underflow,precipitation in mountainous areas,and river water from melting snow and ice,it may receive recharge from infiltration of river and irrigation along the way.The groundwater from the Daxigou to Guozigou runoff from north to south.In the area of Demon Mountain by the third line of formation bulge formation blocking or aquifer structure changes,groundwater discharge into spring,and continue to run-off to the south,affected by the water-blocking fault,in the Qingshui River area overflow into a spring,the spring discharge gathered to form a spring collection river,and recharge groundwater in the process of convection to the Yili River.After groundwater of Horgos region receiving the recharge of ice and snow from the north and the infiltration of rivers,when it runs near the edge of the alluvial fan near the edge of the desert,the groundwater level approaches the surface,and drains part of the groundwater through strong evaporation.The remaining groundwater is discharged to the Yili River through the middle or deep circulation.Southern Plain:The groundwater mainly receives the recharge of mountainous precipitation and the lateral recharge of bedrock fissure water as well as the infiltration of rivers during the runoff.Through the influence of the tertiary fractures in the plain,the groundwater drains the groundwater in the form of springs along the fault.In the area where the groundwater level of the Yili River alluvial fine soil plain area is shallow,the groundwater is discharged again through strong evaporation and finally drains to the Yili River.