呼和浩特盆地地下水流系统变异机制及其资源效应

A study on variation mechanism of groundwater flow system in the Hohhot basin and its resources effect analysis

几十年的高强度开采致使呼和浩特盆地地下水流系统发生了很大变化。在对含水系统结构特征分析的基础上,结合地下水流场及水位动态特征,对地下水流系统演化模式进行了分析总结,基本可归纳为3个演化阶段,地下水人工开采及沟谷水利工程的修建是地下流系统变异的主要驱动因子。采用均衡法对现状条件下地下水均衡情况进行了定量计算,通过与历史时期均衡情况对比分析,发现在不同水流系统演化阶段,各含水层地下水补排量差异较大,从而导致地下水资源量发生变化,与历史时期相比,潜水含水层资源量明显减小,承压含水层资源量有所增加,但总资源量一定程度减小,地下流系统变异的资源效应明显。

There are significant changes in the groundwater flow system of the Hohhot basin as the consequences of the intensive groundwater extractions during the recent decades. This study summarizes and analyses the procedure of the groundwater evolution pattern in this area based on the integrated analysis of the structural features of aquifers, the groundwater flow field and the dynamic characteristics of groundwater level. This procedure can be simplified into three evolutionary phases, and the groundwater exploitation is the primary factor inducing the changes in groundwater flow system. Groundwater budget approach is applied in this study to evaluate the status of the groundwater. After the comparison between these status and the historical records at the same area, dramatic differences between the recharge and discharge are observed in different evolutionary phases. This kind of differences are indicated extensively by the record of the aquifers which is a highly potential cause of the dramatic variations of the quantity of groundwater resources. Specifically, compared by the historical records, the quantity of the shallow groundwater resources decrease significantly, in contrast, there is slightly increase in the quantity of deep groundwater resources. The overall quantity of groundwater resources is decreasing. In summary, these changes demonstrate that the changes of the groundwater flow system in Hohhot basin have a significant influence on the local groundwater resources.