Modelling hydrological characteristics of Mediterranean Temporary Ponds and potential impacts from climate change

‘Mediterranean Temporary Ponds’ (MTP) constitutes a priority, substantially vulnerable and unstable habitat (Natura code: 3170*). In this article, the influences of climate change on the hydroperiod of two MTPs in Crete, have been quantitatively explored by using: (i) a physically based, semi-distributed lake basin model of Lake Kourna, where the hydrology of the lake is directly related to that of the adjacent MTP and (ii) a conceptual/mathematical model of an MTP in Omalos plateau. A water balance model was also set up to estimate net groundwater inflows for Lake Kourna and the basin. The water balance estimates and GIS tools were then used to set up the physically based model which was calibrated for the hydrological year 2005–2006 and validated for two periods: April–September 2005 and the hydrological year 2006–2007 (two split-sample tests). Calibration of the mathematical model was very good, while for the physically based model calibration was satisfactory. The two models were then setup and simulated for two future Intergovernmental Panel for Climate Change (IPCC) scenarios: A2 (pessimistic) and B2 (more optimistic). The responses of Lake Kourna and Omalos MTP water levels and their hydroperiods were then predicted. Results for IPCC B2 and A2 climate scenarios show longer hydroperiod and smaller decreases in the future for Omalos MTP than in Lake Kourna MTP. Results for Lake Kourna MTP demonstrated a hydroperiod decrease of more than 52 days after the application of the IPCC scenarios. Scenario A2 does not present a significantly different higher impact on the MTPs’ hydroperiod.