开采期停采期莱州湾地下卤水盐分来源及盐分组成变化规律

Salt Source and Salt Composition Change Rule of Underground Brine in Laizhou Bay During Mining and Stoppage Period

莱州湾地下卤水资源经历近20年高强度开采后显著衰退,探索其可持续开发模式日益迫切。滨海地下卤水可接受多类盐源的补给,具有可持续开发的潜力,研究地下卤水盐分主要来源及盐分组成变化规律,对规范地下卤水可持续开采模式意义重大。本文基于开采、停采期地下水位监测及地下水样品化学分析结果开展研究,认为莱州湾地下卤水主要受海水以及蒸发盐或盐岩溶解影响,离岸不同距离处地下卤水盐分组成年度变化规律虽然一致,但控制因素存在差异。开采期内补给地下卤水的盐分主要为潮间带生卤下渗的盐分,停采期内蒸发盐或盐岩溶解产生的盐分为地下卤水的主要盐分来源。地下卤水赋存区易受海水或淡水影响,以及处于开采或停采何种状态,是控制地下卤水盐分组成的主要因素。

The underground brine resources in Laizhou Bay have declined significantly after nearly 20 years of intensive mining.It is very urgent to explore its sustainable mining model.The coastal underground brine can be recharged by various salt sources and has the potential for sustainable mining.Clarifying main sources of salt in underground brine and the change law of salt composition affected by human activities can help to standardize sustainable mining mode of underground brine.This research is carried out based on the results of groundwater level monitoring and groundwater sample chemical analysis during the underground brine mining and stoppage periods.The research results show that the underground brine in Laizhou Bay is mainly affected by seawater,evaporative salt or salt rock dissolution.Although the annual underground brine salt composition variation rule is consistent at different distances from the shore,there are differences in controlling factors.The salt recharged to underground brine during the mining period is mainly the salt evaporated and concentrated in the intertidal sediments.During the stoppage period,the evaporative salt or the salt dissolved from the salt rock is the main salt source of the underground brine.The type of water body(sea water or fresh water)that is easy to affect the underground brine storage area,and the working state(mining or stoping mining)of the underground brine mining area are main factors affecting the salt composition of the underground brine.