Application of Judgmental Sampling Approach for the Monitoring of Groundwater Quality and Quantity Evolution in Mediterranean Catchments

Abstract

Groundwater monitoring is critically important, even though it is costly and often neglected. In this study, a judgmental monitoring of groundwater offering solutions based on a cost and time-effective research approach is presented. The method was performed in three Mediterranean areas in Greece and Italy to examine its advantages and disadvantages. As a first step, a multi-statistical analysis was practiced to assess and apportion the potential contributions of pollution sources of groundwater. Pearson correlation, principal component analysis, and factor analysis were applied to groundwater samples to characterize the evolution of hydrochemical processes. High concentrations of chlorides and nitrates highlight that salinization and the extensive use of nitrate fertilizers dominate in the coastal part of Eastern Thermaikos Gulf, the dissolution of carbonate rocks and livestock/industrial activities drive the groundwater quality status in the Upper Volturno basin, while in the Mouriki basin thermal power plant and the use of zinc fertilizers are the main factors of groundwater quality degradation. The determination of the critical sampling points was applied, considering the land use and hydrogeological and morphological characteristics of the areas. The application of the judgmental sampling approach provides reliable results regarding groundwater evolution. These results were compared to previous works and found that a non-probability sampling technique can provide the same results as a more costly method in the Mediterranean region. Thus, judgmental sampling is crucial for the optimal application of water resource management and control techniques in basins to avoid gaps in data collection.

Groundwater Depletion. Are Environmentally Friendly Energy Recharge Dams a Solution?

“…This study focused on local aquifers, illustrating that such approaches can help propose local solutions. Additionally, groundwater quality deterioration due to groundwater depletion has been reported in large aquifer systems [51] and deterioration of water quality has also been verified in the studied aquifers by Ntona et al [52]. Within this study, it is shown that the use of dam water for MAR application can significantly reduce the phenomenon.…”

Water Quality Evaluation of Groundwater and Dam Reservoir Water: Application of the Water Quality Index to Study Sites in Greece

“…The piper diagram produced by the determined parameters of the groundwater (GW) samples is presented in Figure 4, showing the variation of the chemical composition during September 2021 and June 2022. The quality of GW samples from the Eastern Thermaikos Gulf (ETG) and Mouriki basin has been analyzed in the previous work of Ntona et al 2023 [30]. In the GW samples from the coastal part of the Marathonas basin, the order of the cation concentrations is Ca 2+ > Na + K + > Mg 2+ and Cl − > HCO 3 − for the anions, similar to the results reported by Papazotos et al, 2019 [31].…”

“…For a successful ASR method, tools such as modeling that technology offers can significantly aid this purpose. Towards that direction, the research team has already applied modeling strategies such as SWAT (Soil and Water Assessment Tool) and DPSIR (Driving Force-Pressure-State-Impact-Response), where they reported that the Eastern Thermaikos Gulf may face drought problems due to climate change and that there will be alterations attributed to runoff, and the predicted evapotranspiration is at high levels that exceed 63.7% [10,30]. The next step of this research was to examine, through modeling, the potential of MAR in the reservoirs and dams located in Greece.…”