[Objective and methods]In this study,the hydrochemical method and self-organized neural network(SOM-KM)coupling method were employed to identify recharge sources and reveal the water-rich mechanism in the karst groundwater-rich area of the Changxiao karst water system in Jinan City.The contribution ratio of karst groundwater recharge sources in the karst groundwater-rich area was quantitatively calculated using the end-element mixed model.The enrichment mechanism of karst groundwater is explored by combining with topography,geolog-ical structure,stratigraphic lithology,and catchment conditions.[Results]The results showed that the karst groundwater in the catchment drainage area had similar water chemistry to that in the southern recharge area,the karst groundwater in the lateral runoff area,and the Yellow River,indicating a close hydraulic connection.This implies that the karst groundwater in the catchment drainage area is recharged by three sources:The southern mountain area,the karst groundwater in the lateral runoff area,and the Yellow River.The contribution ratios of the three components are 75.09%,21.02%,and 3.89%,respectively.Carbonate rocks are widely distributed,and fissured karst is well developed in the accumulation and discharge areas,especially in the Maji-Xiaoli-Guide area.Moreover,there are abundant karst groundwater recharge sources in this area.During the runoff process of karst groundwater from southeast to northwest,it is impeded by sandstone and mudstone in the north.As a result,it ac-cumulates in the contact zone between soluble rock and insoluble rock,thus forming impeded-type karst groundwa-ter-rich structures.[Conclusion]Revealing the enrichment mechanism of karst groundwater in the Changxiao karst water system can provide scientific support for accurate calculations of recoverable resources and the protection of the springs in Jinan.
关键词
济南/长孝岩溶水系统/岩溶地下水/补给源识别/富水机制
Key words
Jinan/Changxiao karst water system/karst groundwater/recharge source identification/water enrich-ment mechanism