Evaluation of Exploitable Groundwater Reserves in Karst Terrain: A Case Study from Crete, Greece

Abstract

Karst systems constitute valuable freshwater resources in Crete island, a region of Greece that is threatened by water scarcity. The present work refers to evaluation of the available groundwater potential in a karst terrain and contributes to providing adequate quantities of fresh water to the central southern Crete (Rethimno prefecture). The available groundwater potential was estimated by combining conventional hydrogeological approaches and an analysis of hydrographs of Kourtaliotis spring that drains the system. The research procedure contributed to the three-dimensional understanding of the karst system and provided reasonable estimates regarding the groundwater reserves in the area. The geological (permanent) storage in the karstified system was estimated to 415 × 10 6 m 3 while the dynamic reserves were calculated equal to 43 × 10 6 m 3 . Based on the research results, it is considered possible to pump annually an amount of 21-29 × 10 6 m 3 over the quantities of water which naturally outflow from Kourtaliotis spring, in order to satisfy the water demands in the region. The study provides a valuable guidance on predicting the groundwater reserves in aquifers with similar hydrogeological regime.

Optimizing the water-ecosystem-food nexus using nature-based solutions at the basin scale

“…Over the past two decades, the Koiliaris River watershed has undergone a comprehensive investigation (Kourgialas and Karatzas, 2011;Vozinaki et al, 2011;Sibetheros et al, 2013;Giannakis et al, 2014;Moraetis et al, 2015;Nerantzaki et al, 2015;Vozinaki et al, 2015;Morianou et al, 2017;Yu et al, 2019;Nerantzaki and Nikolaidis, 2020;Lilli et al, 2020a,b). The geological composition of the region, coupled with a significant fault running in a northeast-southwest direction, directs water movement toward the springs within the Koiliaris River Basin (Steiakakis, 2018;Steiakakis et al, 2023). The study area encompasses karst systems with a distinctive characteristic possessing unique hydraulic properties and transmissivities (Kourgialas et al, 2010).…”

Uncoupled Precipitation and Water Availability: The Case Study of Municipality of Sfakia, Crete, Greece

“…A recent overview of karst system research in Greece is provided by Reference [33] and tested the application of geophysical methods in combination with pumping tests that provide a cost-effective and efficient alternative to estimate aquifer parameters. A recent study provided valuable guidance on predicting the groundwater reserves in aquifers with a similar hydrogeological regime [34]. This is a possible explanation for littoral aquifers; however, in the case of inland mountains, such as Lefka Ori, Lasithi Plateau and Sfakia, deep kartification and high permeability could be due to the sea level lowering by 130 to 150 m during repeated glacial periods in the Quaternary.…”