QUANTITY AND QUALITY OF GROUNDWATER OF INTERMOUNTAIN BASIN OF KORÇA IN ALBANIA AND IMPLICATION FOR SUSTAINABLE MANAGEMENT

Abstract

Korça intermountain basin is the largest of its kind in Albania and from the hydrogeological point of view represents a semiclosed intermountain basin developed in Pliocene-Holocene granular unconsolidated deposits, which maximal thickness is about 300 m. The aquifer consists of intergranular gravelly to sandy layers containing artesian groundwater and the drilling wells are free flowing on most of the basin surface. The main recharge of the intergranular aquifer comes mainly from the rivers and torrents flowing from mountain gorges around the Korça Plain. The natural groundwater drainage of Korça basin is realized through the vertical leakage in the area of the former Maliq marsh. Hydrochemistry of the aquifers show the presence of four main hydrochemical facies which are related mainly to the hydrochemistry of the recharge sources and to the solution processes and ion exchange. In the central part of the basin the water supply wells of the cities Korça and Maliq are located. The natural renewable groundwater resources of the basin are relatively restricted, but the volume resources (or static water resources) are abundant (about 1.1 × 10–9 m3). The perspective of their exploitation is very important, but respecting the “basin yield” concept that is defined as the maximum rate of withdrawal that can be sustained by the hydrogeological system of groundwater basin without causing unacceptable changes to any other environmental component of the basin. To face the problems related to the intensification of the groundwater pumping systematic observations of the hydraulic reaction of the basin and of the possible groundwater quality deterioration and other negative environmental impacts must be organized. The purpose of the present study is for the first time to analyze the abundant basin wide hydrogeological data and to evaluate: (1) geometry and hydraulic parameters of the aquifers: (2) groundwater hydrodynamic conditions; (3) their chemical composition and (4) the natural groundwater resources and the possibility to intensify the groundwater pumping in close relation to the environmental impact.