内蒙古岱海水质咸化过程分析

Analysis on Water Salinization Process of Daihai Lake in Inner Mongolia

岱海是我国北方半干旱地区的一个内陆湖,近几十年来,由于受到人类活动的强烈干预,湖泊水位持续下降,湖水水质出现恶化,2004的水质调查数据显示,目前岱海湖水矿化度4 658.6mg/L,已接近咸水湖标准。从近50年的变化历程来看,岱海呈现出明显的咸化趋势,且咸化速度不断加快。利用流域内的水文、气象数据,并结合湖泊及河流的水化学特征,建立岱海盐量平衡方程,对岱海湖水矿化度进行模拟计算,恢复了近50年岱海湖水矿化度的变化序列。依此序列对岱海水质咸化的影响因子进行量化计算,结果显示:湖泊萎缩对水质咸化的影响占到86.5%,而由入湖径流与降水所带入的盐分对水质咸化的影响仅占到13.5%。

Daihai Lake is a typical island lake in the semi - arid region of northern China. In recent years, because of the intensive impacts of human activities, the water level of Daihai Lake descended and the water quality had a tendency of deterioration. The investigation data in 2004 revealed that the content of mineralization was 4658.6 mg/L by far and would approach the standard value of the saltwater lake. Analysis of the variation of mineraliza- tion in the past fifty years it showed a trend of salinization in Daihai Lake, and rate of salinization was becoming faster and faster. Based on the available hydrological and meteorological data and some hydro - chemical data, a salt balance equation was established in the study, the annual mineralization was calculated through salt balance equation, and 47 -years simulated mineralization series was also shown. The simulated mineralization was in good agreement with the observed annual mean mineralization through the analysis of comparison. Using the sim- ulated mineralization series, the factors making Daihai lake become salinization were quantified. The results showed that the lake salinization was mainly induced by the shrinkage of lake, which weight was 86.5%, and influences induced by the basin runoff and precipitation was very little, which weight was only 13.5%.