Groundwater capacity of a flysch-type aquifer feeding springs in the Outer Eastern Carpathians (Poland)

Abstract

The aim of the study is to assess the capacity of the flysch aquifer feeding springs in the Outer Eastern Carpathians using spring recession curves. The four selected springs are located in an area generally believed to be poor in groundwater. However, the selected springs were characterized by remarkably high average discharge of 3.2–9.6 L s−1. Recession coefficients were estimated which enabled an aquifer capacity and groundwater residence time assessment. Despite similarities in elevation, precipitation, and lithology in the study area, a substantial variation in the recession coefficients and aquifer parameters was found. The average aquifer capacity of groundwater subsystems strongly varied in the small study area (4.9–49 m3 × 103). The mean groundwater residence time varied from 11 days to 50 days depending on the volume of groundwater drained by the springs. Differences in discharge, recession coefficients, groundwater capacity, and residence time were related to recharge areas of different size. Simple relationships between the topographic catchment areas of springs and their hydrologic parameters can become altered by local structural features: faults and fissures. The study demonstrates that tectonically produced structures may facilitate a larger supply of groundwater and the occurrence of high-discharge springs in a given area.

Spring recharge and groundwater flow patterns in flysch aquifer in the Połonina Wetlińska Massif in the Carpathian Mountains

“…5. Despite their location close to the ridge line and the small areas of topographic catchments (from 0.04 to 0.38 km 2 ), the springs under investigation are characterized by relatively high discharge rates for springs draining a flysch bedrock and they flow almost continuously (Mocior et al 2015;Mostowik et al 2016;Płaczkowska et al 2018). Average spring discharges ranged from 3.3 to 9.6 dm 3 •s -1 in the period 2013-2016, while averages in individual years showed significant differences (Fig.…”

“…2, Table 1), depending on Malata et al 2006;Haczewski et al 2007), a -peaks, b -springs mapped in the zone above 900 m a.s.l. (after Mocior et al 2015), c -numbered studied springs (numbering of springs according to Płaczkowska et al 2018), d -strike and dip, e -streams, f -faults, g -line of cross section, h -sandstone-shale member, i -shale-sandstone member; (C) the weather stations' location (black dots); (D) Geologic cross section through the Połonina Wetlińska, red rectangle shows the extent of conceptual models on Fig. 6.…”

“…Inferring about groundwater storage capacity based on the dynamics of the groundwater depletion process, including the mechanism of recession of a spring recharged by studied aquifer, is indirect and is based on the simple assumption that the greater the groundwater storage capacity, the more slowly its resources are depleted, which manifests itself in a more stable and longlasting recharge of springs (e.g. Maillet 1905;Kovács et al 2005;Buczyński and Rzonca 2011;Płaczkowska et al 2018). In addition to assessing the rate of depletion of aquifer resources during dry periods, the dynamics of spring discharge after periods of recharging the catchment with rainfall are also interpreted.…”

“…Therefore, the identification of springs of discharge periodically exceeding 40 dm 3 •s -1 in the Połonina Wetlińska Massif (the High Bieszczady Mountains, Polish Flysch Carpathians) was a significant change. On the one hand, it shed completely new light on the mechanisms of groundwater flow patterns in flysch rocks (Mocior et al 2015;Mostowik et al 2016;Płaczkowska et al 2018). On the other hand, it provided the opportunity to carry out more detailed research based on the interpretation of hydrographs of these springs, currently treated as valuable observation sites.…”

Numerical Modelling of the Mulino Delle Vene Aquifer (Northern Italy) as a Tool for Predicting the Hydrogeological System Behavior under Different Recharge Conditions

“…The methodology used to derive aquifer parameters from a recession curve is not a novelty. In fact, there are numerous examples in the literature in which the recession curve of springs [63,[66][67][68] or stream baseflow [69][70][71][72] are used to infer aquifer characteristics. Recession curve interpretation is mainly used in karstic contexts, but it can be also used to characterize other types of aquifers [73].…”