Interaction Of Surface Water And Groundwater In Yili-Gongnaisi River Valley

Yili- Gongnaisi River Valley is located in the middle of Eurasia, which is far away from ocean, scarce precipitation and intensive evaporation. The area of surface water and groundwater has seriously restricted the regional ecological environment protection and the sustainable development of social economy, which is the major limiting factor of the silk road economic belt and the western development strategy. C urrently, the transformation relationship research of surface water and groundwater is relatively scarce, therefore it restricted the reasonable exploitation, sustainable utilization and protection of water resources, on account of the limitation of special geological landforms, space-time of hydrological and meteorological elements changing great, and the system of the surface water and groundwater complex. Therefore, the investigation of the transformation relationship between surface water and groundwater in Yili- Gongnaisi River Valley not only can effectively guide the rational allocation of water resources, but also can offer theoretical basis for energy base construction in northwest China.Based on the analysis of the Yili- Gongnaisi River Valley geological and rogeological conditions, and the guidance of hydrogeochemisty, rsotope methods, dynamic principle of groundwater, which combined field hydrogeological investigations, field sampling, indoor testing, this paper selected some typical profiles to investigate the transformation relationship between surface water and groundwater by analysis of hydrogeochemisty, rsotope and numerical methods. It can be obtained the following conclusions.(1) The TDS has a tendency of increasing, the geochemistry type is from HCO3?SO4-Ca to HCO3?SO4-Ca?Mg. The TDS of groundwater has a tendency of reducing from piedmont pluvial fan to the alluvial plain, and the geochemistry type is transform HCO3?SO4―Ca?Na to HCO3?SO4―Ca?Mg(Ca?Na).(2) Based on the hydrogeological conditions in the study area and the basis of the groundwater flow field, there have some transformation relationship between sur face water and groundwater. From Gongnaisi upstream to Yili river downstream ——total head will gradually decrease and eventually drain into the Yili river with following the distance decreasing between the river north and south direction by analysis of two-dimensional groundwater flow numerical simulation and hydrogeoche mistry.(3) Isotopic studies shown that the rainfall is very important recharge for the river and groundwater. The river recharge has a increasing trend from kunas stud farm to a re wu si tang xiang. The maximum river recharge reached 69.3% at the a re wu si tang xiang, then the ratio will be decreased.(4) By analysis of the two-dimensional simulation profiles can be seen, the hydraulic gradient of the left is significantly greater than the right bank, it reveals that the left bank of the runoff rate and update speed faster. Alluvial fan is a strong runoff area, the runoff rate is greater than 0.4m/d; alluvial plains area is moderate runoff, runoff speed is 0.1~0.4m/d; al uvial plain is weak runoff area, the runoff rate is less than 0.1m/d.(5) The river leakage of profile I, Ⅱ,Ⅲ and Ⅳ are 6.99 m3/d, 19.15 m3/d,18.8m3/d and 33.49 m3/d, respectively.