Master's Thesis Defense by Mrs Eleftheria Kalaitzaki
09/19/2019
Thesis Title: «A recharge suitability assessment for the Geropotamos aquifer in the Messara area of the island of Crete»
Tusday 26 January 2021, at: 14:00, Venue: https://tuc-gr.zoom.us/j/83917827304?pwd=SWVzbkE2bk5STkt6dm94dVpoMnU1Zz09
Examination Committee
- Professor George Karatzas (advisor)
- Professor Nikolaos Nikolaidis
- Dr Manolis Varouhakis
Abstract
Throughout the Mediterranean region, semi-arid climate in conjunction with intensive agriculture are stressing scarce groundwater supplies which are over-exploited to cover irrigation water demands. Such a case is the Messara Basin in the island of Crete. This has led to increased costs associated with groundwater extraction, seawater intrusion along the coastal zone, and negative environmental impacts (disappearance of wetlands). As a result, and in order to stabilize groundwater levels, managerial measures on groundwater withdrawals were imposed by the government in 2017. These regulations prohibit, among others, the drilling of new wells, the groundwater withdrawals above certain limits and the modification of current infrastructure related to groundwater production. According to the recent Water Resources Management Plan (WRMP) for the Water District of Crete targets for the improvement of the quality and quantity of the degraded groundwater bodies in the Geropotamos Basin have been set based on the EU Water Framework Directive. According to the regional authorities, groundwater pumping is not expected to stop and it was suggested within the WRMP the consideration of appropriate managed aquifer recharge, suitability studies and assessments.
The present study was developed in the framework of the postgraduate studies of the Department of Environmental Engineering at the Technical University of Crete and deals with the identification of the areas that are most suitable for the aquifer recharge, in the area of the Geropotamos basin, using GIS multi-criteria decision analysis (GIS-MCDA) method to identify suitable sites for implementing MAR (Managed Aquifer Recharge) type spreading method.
The criteria combining a high relevance and high data availability, and providing unique information , selected to assess the suitability of MAR spreading methods in Geropotamos basin are slope, land use, hydrogeology, rainfall, groundwater level, soil texture and distance to source water. This study uses the ‘Pairwise comparison’ to assign criteria weights, developed by Saaty (1980) as part of the AHP.
In this study were examined 4 scenarios. In the first scenario was not taken into account the criterion of distance to the water source. In the second scenario was added to the criteria the distance to the dam of Faneromeni. In the third scenario was added the criterion of distance to the river of Geropotamos. Finally, in the fourth scenario, was added to the criteria both, distance to the dam of Faneromeni and the river of Geropotamos.
In all 4 scenarios the areas that are west of the study area and close to the river Geropotamos, coincide as the most suitable for aquifer recharge.
