Modeling Flow and Nitrate Transport in an Over-Exploited Aquifer of Rural Basin Using an Integrated System: The Case of Lake Karla Watershed

Abstract

The paper proposes an integrated modeling system consisting of a surface hydrology model, a water reservoir model, a Lake-Aquifer Interaction model, aground water model, and a transport and dispersion model to study ground water quality through two different operational management scenarios. The first scenario is examining the existing condition of groundwater quality without the reservoir operation while the second scenario is assessing the impact of the reconstruction of Lake Karla in the groundwater quality. The study highlights the importance of using an integrated hydrological modeling approach to investigate the groundwater quality in a region which is characterized by extensive agricultural activity.

Groundwater Nitrate Contamination Integrated Modeling for Climate and Water Resources Scenarios: The Case of Lake Karla Over-Exploited Aquifer

“…The groundwater quality spatial status for the two water resources operational scenarios in conjunction with the climate change storylines is shown in Figure 9. The above results highlight the necessity of continuous monitoring of groundwater quality in the study area, since many wells are used to supply water for domestic and irrigation uses in the surrounding settlements and in the city of Volos [34].…”

“…Agriculture is the main economic activity and as a result is the major source of income of the local population. The study area is included in the main agricultural region of Greece (i.e., Thessaly) and it is extensively cultivated with crops characterized by increased water and fertilization demands such as maize, cotton, and alfalfa [34]. According to Directive 91/676/EEC, the Thessaly plain area and especially Lake Karla watershed has been identified as Nitrate Vulnerable Zones (NVZs) from agricultural practices.…”

“…The Thessaly plain continues to the west of the study watershed and Halkodonion Mountain is located to the southwest of the study watershed. The underlying aquifer is located at the lower elevation part of the basin, extending in an area of about 500 km 2 [34].…”

An Integrated Modeling System for the Evaluation of Water Resources in Coastal Agricultural Watersheds: Application in Almyros Basin, Thessaly, Greece

“…In nitrate contaminated waters, the "threshold of concern" is 25 NO 3 mg/L, and mostly refers to the suitability of the drinking water. The upper safe concentration is set at 50 NO 3 mg/L while higher nitrates concentrations endanger human health, surrounding ecosystems, and local biodiversity [15,16]. Thresholds of chloride concentrations have been defined as well, for the groundwater systems of more than 10 Member States of the EU.…”

“…The estimation of the mean monthly temperature was estimated with the gradient method and the potential evapotranspiration was calculated with the Thorthwaite method [52]. The UTHBAL model has been successfully applied, calibrated, and validated in various Mediterranean regions, like Crete, Cyprus, Nestos/Mesta Basin, Thessaly [1], and in the neighboring areas of Pinios River Basin and Karla Basin [16,53].…”