Water Recharge of Jinan Karst Springs, Shandong, China

Abstract

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.

Hydrochemical and Isotopic Difference of Spring Water Depending on Flow Type in a Stratigraphically Complex Karst Area of South Korea

“…Type Ⅱ seemed to discharge both the flow component through the epikarst zone and the baseflow from the lower reservoir, as defined by Tritz et al (2011) who used two reservoirs (i.e., the upper epikarst/soil zone and the lower vadose and saturated zone) to simulate the behavior of a karst system catchment and assumed a fast flow through the epikarst and slow baseflow from the lower reservoir. The deep groundwater rising at springs was also observed by other researchers including Moore et al (2009), Bicalho et al (2012), Demiroglu (2016), Gil-Márquez et al (2019, Lorette et al (2018), andZhu et al (2020). Some implied fast transfer through conduits unlike Tritz et al (2011).…”

“…Given that springs in general originate along geologic contacts, faults, and ground depression (Fiorillo et al, 2018) and the layering of rocks relative to the slope of mountains affect both the number and discharge of springs in mountains (Mocior et al, 2015), the overturned strata (e.g., Cambro-Ordovician Yeongheung Formation (Oy) overlying Jurassic Bansong Formation (Jbs) along the thrust in Figure 1B) in this mountainous area can provide a pathway for deep groundwater upwelling as in Lorette et al (2018) who showed deep water rising at springs through the faulted anticline structure of Périgueux, France. Similarly, Zhu et al (2020) observed ascending springs along secondary tectonic fissures in the contact zone of limestone and magmatic rocks invaded as well as contact springs where the permeability of the local contact zone was enhanced. According to Zhu et al (2020), the two contact springs with relatively large and stable flow rates reflected the high proportion of karst water replenishment from the deep circulation.…”

“…Similarly, Zhu et al (2020) observed ascending springs along secondary tectonic fissures in the contact zone of limestone and magmatic rocks invaded as well as contact springs where the permeability of the local contact zone was enhanced. According to Zhu et al (2020), the two contact springs with relatively large and stable flow rates reflected the high proportion of karst water replenishment from the deep circulation.…”

“…In addition, the epikarst plays a significant role in karst recharge and storage (Aquilina et al, 2005;Aquilina et al, 2006;Doctor et al, 2006;Chang et al, 2019). Moreover, lithologic heterogeneity often makes the flow system in karst aquifers complicated (Mocior et al, 2015;Lorette et al, 2018;Frank et al, 2019;Zhu et al, 2020).…”

The Data Supplement Method of Azimuthal EM LWD Based on Deep Learning

“…The data inversion of azimuthal EM LWD is usually conducted in real-time on the surface computer [10]. Therefore, the downhole data must be transmitted in real-time using remote transmission systems.…”