Regional scale hydrologic modelling of a karst-dominant geomorphology: the case study of the Island of Crete

Regional scale hydrological modeling plays a significant role in planning and managing water resources efficiently. The SWAT (Soil and Water Assessment Tool) model belongs to the class of models simulating the spatial and temporal variability of hydrologic patterns across a region. The heterogeneity of model inputs such as soils, land use, topography and weather is preserved making SWAT potentially able to reproduce the hydrologic water balance of complex geomorphologies. The aim of this work is the development of a methodology (KSWAT) for the quantification of a spatially and temporally explicit hydrologic water balance of karst-dominated geomorphology using the SWAT model in order to assess the sustainability of water use among the different stakeholders. The application was conducted in the Island of Crete using data from 69 gauged stations (22 streamflow and 47 of spring monitoring stations) that cover the period 1980-2009. The KSWAT model estimated the water balance of the whole island of Crete under normal hydrological condition as follows: 6400 Mm3/y of precipitation, of which 40% (2500 Mm3/y) was evapotranspiration, 5% was surface runoff and 55% percolated into the soil recharging the shallow (11%) and deep aquifer (44%). Part of deep aquifer recharge (9% of precipitation) contributed as spring water to streamflow which flow was approximately 22% of precipitation. The KSWAT model increased our knowledge of water resources availability and distribution in Crete in different hydrologic conditions, and it was able to capture the hydrology of the karst areas allowing for a better management and planning of water resources.

JRC.D.2 - Water and Marine Resources