干旱区地理2011，Vol.34Issue(5)：772-778,7.
金塔盆地地下水演化及地球化学模拟
Geochemical evolution of groundwater and hydrogeochemical modeling in Jinta Basin
摘要
Abstract
Jinta basin is located on the low reaches of Beida River in the northwest of China, which is a typical oasis basin. Water resources are crucial support for regional industry,agriculture,livestock production and peoples daily lives in this region. However,they have been negatively influenced by human activities for a long time. The past researches were focused mostly on the collection of basic information, little modern technologies that could search deeply about water quality and the recharge mechanism of groundwater were used. Through combining hydrochemi-cal method and geochemical modeling, this article studied the water-rock reaction of groundwater in Jinta basin, in order to Sustainable exploitation of groundwater. The study shows that the hydrochemical types of surface water in this area aren 't obvious, which are predominantly bicarbonate and sulfate. The hydrochemical types of deep ground-water in Jinta Basin varied from SO2-4-HCO-3-HCO-3 in the south to SO2-4 - HCO-3 in the north. The total dissolved solid isnot very high, lower than 1 500 mg/L. It increases from 398 mg/L in the south to 5 280 mg/L in the northwest. The salt content has the same trend of variation with the total dissolved solid. The main chemical process of groundwater in Jinta basin is evaporation, and the main recharge resource is leakage water from canal flowing and irrigation. PHREEQC is a hydrogeochemical model that can be applied to calculate the saturation index of groundwater , simulate the interaction of various elements in it, and even predict the possible flowing path of groundwater. It has been widely used for studying water-rock reactions recent years. The simulated results show that there generally occur the precipitation of aragonite, calcite and dolomite, and the dissolution of anhydrite, gypsum and halite in groundwater from southwest to northeast in Jinta Basin. A high content of mNa+ and Ca2+ shows that calcium has a more complex resource, which may not only come from dissolution and infiltration reaction, but also come from cation exchange. The value of Na/Cl is much higher than 1, which illustrates that cation exchange is prominent in the evolution of groundwater in Jinta Basin. At the same time,Ca2+ exchanges with HCO-3 in dolomite,and results in an increase of HCO-30. The calculation and simulation above show that the groundwater in Jinta basin is proper for irrigation , according to its physical and chemical characteristics.关键词
地下水/水化学/模拟/金塔盆地Key words
groundwater/hydrochemistry/simulation/Jinta Basin分类
天文与地球科学引用本文复制引用
张清寰,张彧瑞,赵艳萍,马金珠..金塔盆地地下水演化及地球化学模拟[J].干旱区地理,2011,34(5):772-778,7.基金项目
科技部”973”项目(2009CB421306)与国家自然科学基金项目(40872161)资助 （2009CB421306）
