As the main scavenge port of groundwater in the karst water system, most of the karst springs affected by human activities experienced discharge attenuation phenomenon in the north of China. Whilst artificial replenishment measures have been taken to keep water spewing, the results are not ideal in many karst springs. This is mainly because of poor understanding about the recharging water sources. This paper used the Jinan Spring region as an example to discuss about different spring water supply sources. Based on a wide range of methods (e.g., dynamic observation of spring water level, real-time monitoring of water temperature and electrical conductivity (EC), tracer test, and frequency analysis), this study obtained several findings. First, the maximum karst-fractured water proportion that Cambrian Zhangxia Formation contribute to the Zhenzhu Spring is 57–59%, and the Heihu Spring only recharges 25–31%. Second, the proportion of fracture-karst water to the Heihu Spring from the Fengshan Formation to the Sanshanzi Formation of the Ordovician is 69–75%, while the proportion of the Tanxi spring is 15–17%. Third, the Baotu Spring and Heihu Spring mainly receive karst-fractured water from the Cambrian Zhangxia Formation and fracture-karst water from the Cambrian Fengshan Formation to the Ordovician Sanshanzi Formation. The supply sources of the Zhenzhu Spring and Tanxi Spring are more diverse, including karst-fractured water of the Cambrian Zhangxia Formation and fracture-karst water of the Cambrian Fengshan Formation to the Ordovician Sanshanzi Formation, as well as a small amount of pore water and fissure water, artificial recharge water supply. Fourth, the frequency analysis of spring water temperature indicated that the Zhenzhu Spring and Tanxi Spring are mainly in deep circulation, while the Baotu Spring and Heihu Spring are predominantly in shallow circulation. The differences in the sources of the four largest spring groups suggest that the karst water movement in Jinan has heterogeneous characteristics. The determination of the mixing ratio of the sources of spring water supplies provides a scientific basis for the protection of spring water, and the implementation of artificial recharge projects.

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In order to protect the four spring groups in Jinan, it is very important to study the formation characteristics of the karst spring in Jinan. Based on the geological and hydrogeological conditions of Jinan spring group outcropping area, this paper makes a comprehensive study on the karst aquifer void type, spring water supply source, spring water gushing state, spring water flow, spring water temperature and conductivity, spring water chemistry data in the recharging area, so as to determine the genetic types of four spring groups. The results are as follows: (1) Baotu spring and Heihu spring have a similar genetic structure, their circulation depth is relatively shallower, and they are greatly affected by Ordovician karst water in the direct recharging area. Tanxi spring and Pearl spring have a similar genetic structure with a deeper circulation depth, which are greatly affected by Cambrian karst water in the indirect recharging area. Tanxi spring and Pearl spring have a similar genetic structure with a deeper circulation depth, which are greatly affected by Cambrian karst water in the indirect recharging area; (2) Baotu spring and Heihu spring are long-running cold springs recharged by confined water, which belong to erosion rising spring; Pearl spring and Wulongtan are long-running large and medium-sized cold springs recharged by pressurized water, which belong to contact rising spring. The research on the genetic characteristics of spring provides a scientific basis for spring protection in Jinan.

In order to protect Jinan spring. This article is based on the research and analysis of the observation water level, extraction volume, spring water level, and observation data of water sources in West Jinan, western suburbs, and urban areas. It is concluded that: (1) According to the analysis of the dynamic type of groundwater level, there is a close hydraulic connection between the groundwater of West Jinan and Baotu spring spring group, which is a unified body of water with strong connectivity. (2) From the analysis of multi-year water level, spring discharge and mining volume, the impact of karst water mining in the western suburbs on the water level and spring discharge of urban spring water is very obvious.(3) The increase in the amount of karst water in the urban area and the decrease in the flow of spring water are very similar. Therefore, Jinan spring water is obviously affected by artificial mining. Controlling the amount of groundwater extraction, especially in urban areas, is of great significance to ensure the spring water gushing all year round. At the same time, it is necessary to make a good mining layout for the water sources in the western suburbs, West Jinan and eastern suburbs.