The use of the pilot points method on groundwater modelling for a degraded aquifer with limited field data: the case of Lake Karla aquifer

Abstract

Groundwater depletion poses a major threat to global groundwater resources with increasing trends due to natural and anthropogenic activities. This study presents a surface-groundwater framework for water resources modelling of ill-posed problems in hydrogeologically data-scarce areas. The proposed framework is based on the application of a conceptual water balance model and composed of surface hydrological (UTHBAL) and groundwater flow simulation with the integration of a Newton formulation of the MODFLOW-2005 code (MODFLOW-NWT) and PEST suite modules. The groundwater simulation includes a pre-processor tool for automated calibration and a post-processor tool for automated validation. The methodology was applied to a rural region of Central Greece, Lake Karla Basin, which is degraded due to groundwater resources overexploitation to cover irrigation water demands. The aquifer is modelled focusing on precise simulation – validation procedure of the conceptual model. The groundwater model was calibrated with the calibration pre-processor tool for spatially distributed hydraulic conductivity with the pilot points method. The calibration process achieved satisfactory results as validated by the post-process analysis of observed and simulated water levels. The findings for the groundwater budget indicate that the groundwater system is still under intense pressure even though farming activity in recent years has turned to less water-intensive crops. HIGHLIGHT My research deals with the Pilot Points Method on Groundwater Modelling in area with scarce hydro-geologic data.

Optimized Pilot Point Emplacement Based Groundwater Flow Calibration Method for Heterogeneous Small-Scale Area

“…The pilot point placement results expose the applicability of the pilot point calibration methodology in the small-scale heterogeneous area focused on the estimation of hydraulic conductivity field similarly investigated in other literature [10,16,17]. The structural and stratigraphic traits and trends in these research are identical.…”

“…In addition, Baalousha et al [16] used the pilot point for model calibration of regional groundwater flow that investigated the effectiveness of the pilot point method. In contrast, Tziatzios et al [17] applied the pilot point method to overcome the data scarcity in groundwater modeling. However, the pilot point placement remains problematic in the small-scale area because calibration relies on the value of the hydraulic conductivity field of each cell, and there are no set guidelines for how these points should be placed.…”

A Participatory Approach to Exploring Nexus Challenges: A Case Study on the Pinios River Basin, Greece

“…In the past decade, signs of reductions in documented groundwater heads, leading to declining trends and small-scale reversal trends, have been noticed as a result of the rationalisation of the practiced irrigation, the reduction in irrigated land, and the shift to less water-demanding crops [74]. The persistent groundwater deficit underscores the urgent need to develop collective irrigation networks to reduce the excessive reliance on private wells and promote sustainable groundwater resource management [75].…”

Editorial: Could advances in geoinformatics, irrigation management and climate adaptive agronomic practices ensure the sustainability of water supply in agriculture?

“…Specifically, this SI brings advances in precision irrigation techniques adapted to the actual needs of plants at farm and extended scale applications (Filintas et al 2021;Markos & Radoglou 2021;Mousabeygi et al 2021). Also, new modelling approaches to predict and/or monitor water dynamics (Kader et al 2021;Mridha & Rahman 2021;Sihag et al 2021;Tziatzios et al 2021;Xu et al 2021) or pollutants transport such as salinity (Daghari et al 2021;Yuan 2021) and nitrates (Bian et al 2021;Nie et al 2021) are provided. An important part of this SI is covered by optimal water allocation and the newest developments in irrigation management (Cortés-Ruiz & Azuz-Adeath 2021;Lyra et al 2021;Mahdavi 2021;Morianou et al 2021a;Wei et al 2021).…”