基于水化学、同位素特征的济南岩溶地下水补给来源研究

文章利用水化学、2H、18O同位素、87Sr/86Sr比值、13C和14C同位素对济南岩溶地下水补给来源、地热水补给来源进行研究。结果表明，岩溶冷水水化学类型以HCO3-Ca、HCO3·SO4-Ca型为主、地热水以SO4-Ca型为主。在旱季，间接补给区对泉群地下水补给比率在66.00%~73.58%之间，直接补给区仅占到26.42%~34.00%，旱季泉水的主要来源为间接补给区岩溶地下水。地热水受到了更新世以来的降水补给，是不同时期降水补给所形成的混合地下水，接受补给区域应为高程较高的张夏或者炒米店-三山子组地层，补给高程在350~550 m之间。 

Study on the recharge source of karst groundwater in Jinan city based on hydrogeochemical and isotopic characteristics

Hydrochemistry and isotopes can be used to study the recharge and discharge characteristics of groundwater and make up for the shortcomings of other methods. As a typical karst area in north China, there are many springs in Jinan city. The research on the source of groundwater in this area can provide a reliable basis for the spring protection. In this paper, hydrochemical parameters and isotopes 2H, 18O, 87Sr/86Sr, 13C and 14C are used to examine sources of four springs and geothermal water in Jinan. The results show that the cold karst water are dominated by HCO3-Ca and HCO3·SO4-Ca types, while the geothermal water is mainly SO4-Ca in chemistry. In dry seasons, the recharge ratio of indirect recharge area to springs is about 66.00%~73.58%, and the direct recharge area only accounts for 26.42%~34.00% of the total. The main source of spring water in dry seasons is karst groundwater in the indirect recharge area. Geothermal water is supplied by Pleistocene precipitation since Pleistocene time, which is mixed groundwater formed by precipitation during different periods. The supply area should be Zhangxia or Chaomidian-Sanshanzi formation at high elevations about 350-550 m.