Groundwater resources in the Kouris catchment (Cyprus): data analysis and numerical modelling

Abstract

The Kouris catchment in Cyprus is currently experiencing a scarcity of water resources due to the semi-arid climate across the southern part of the region, a series of dry years, and recent surface/subsurface water over-extraction. The catchment consists of the upper part of an ophiolitic complex in the North, which is considered a very significant aquifer for Cyprus, and an overlying sedimentary complex in the South, which has low water storage capacity. Water balance calculations are conducted using a steady state groundwater model. The recharge rate was calculated to be between 12 and 16% of the total annual rainfall. This agrees, with an estimate based on the mass balance of chloride. When the rate of extraction was increased to a value close to the present water demand, river baseflow was reduced from 25 to 18 Mm 3 per year. Other negative impacts were extreme drawdowns and drying up of springs.

Study of stable isotopes in the Kouris catchment (Cyprus) for the description of the regional groundwater flow

“…The hydrogeology of the area was described in detail by Boronina et al (2003); Jacovides (1979); Afrodisis et al (1986); in the present paper we provide only the most essential information. The Kouris catchment is bounded on the South by the Mediterranean Sea and covers 300 km 2 on the southern side of the Troodos Massif (Fig.…”

“…These rocks contain the major groundwater resources of Cyprus; the water is stored in the fractured and altered zones of harzburgites, dunites, gabbros and diabase dykes. The transmissivities of the gabbros and the diabase dykes vary from 2 and 703 m 2 /day with a geometrical mean of 20 m 2 /day according to the results of 40 pumping tests (Boronina et al, 2003). Groundwater in the ultramafic rocks, gabbros and diabases is generally of CaMg-HCO 3 and Na-HCO 3 types with low to moderate salinities the Kouris catchment (with an estimated average transmissivity of 3 m 2 /day), and it consists of river alluvium (sand, gravel) in the Kryos, Kouris and Limnatis valleys.…”

“…A steady state two-dimensional groundwater model was developed during a previous stage of the research (Boronina et al, 2003). It was based on the MODFLOW code (Harbaugh and McDonald, 1996) and had objectives and limitations discussed by Boronina et al (2003).…”

“…It was based on the MODFLOW code (Harbaugh and McDonald, 1996) and had objectives and limitations discussed by Boronina et al (2003). In spite of a good fit of observed and simulated piezometric heads, the calibration of the model based only on piezometric observations resulted in a reliable relation 'recharge rates-transmissivities' rather than in absolute values of the parameters.…”

“…Deuterium data were also applied for calibrating the recharge rate for the steady state groundwater flow model of the Kouris catchment. The model was developed in previous research (Boronina et al, 2003), while in this study we use isotope data as an independent tool to estimate an optimal range for recharge.…”