• Energy Research

The most critical impacts of climatic change on the Mediterranean society and environment are likely to be associated with water availability. The whole area is expected to become vulnerable to the scarcity and irregular availability of water resources. In the framework of the FP6 EU CIRCE project (http://www.circeproject.eu/), a Regional Assessment of Climate Change in the Mediterranean (RACCM) was produced in 2013 to support the design of adaptation and mitigation policies on the whole region including Europe, North Africa, and the Middle-East. To this end, a set of coupled models has been developed to produce regional climate change projections. These projections allow assessment of the response of the Mediterranean Sea to climate change over the period 1950-2050 under the A1B hypothesis and to a large extent, the associated uncertainty. Some results concerning the use of CIRCE scenarios for the assessment of impacts on water resources are presented with an emphasis on the methodological approach to bridge the scale gaps between climate model structure and the resolution of basin-scale hydrology. Focusing on Southern Italy, the sustainability of surface and groundwater resources is explored. Additional results concerning a coastal catchment in Lebanon are presented. In this case study regarding a snow-dominated hydrological system, the combined effect of changes in temperature and precipitation is highlighted. The above methodological approach set-up for the Mediterranean area could be adopted for regions in Southeast Asia where in order to undertake similar impact studies, the local scale of investigation plays a determinant role for water resources assessment and flood protection.

A methodology to use climate change information in water resources evaluation is developed through a meaningful case study in southern Italy (the Apulia region). The problem of the effective information of climate model simulations with respect to small scale impact studies is developed taking into account the limited predictive capability of climate models. Therefore downscaling and biascorrection requirements are treated through a specifi c methodology based on a quantile variable correction adopting ground based observation of climate variables. The meteorological forcing for the impact study are obtained through the downscaling of atmospheric variables produced by a Regional Climate Model (RCM) called Protheus. The impact assessment on the water balance of the Apulia region (southern Italy) revealed a marked increase in the variability of hydrologic regimes (both runoff and groundwater recharge) as consequence of the increased rainfall variability predicted for the twenty-fi rst century, while preserving a decreasing in the annual trend. Moreover, the analysis of climate change effects was performed focusing on the rainfall-discharge process of a strategic karst spring supplying the Apulia aqueduct. In this case study, no substantial variations in the annual mean discharge are recognized, although a marked decrease in the mean monthly discharge was found between October and December, which represent the start of the recharge period of Apennine aquifers. Such results represent a crucial water management issue that has to be addressed in terms of adaptation to meet future water resources requirements.

The hydrological monitoring of springs is an auxiliary and indispensable tool that goes alongside investigations in wells to reconstruct a conceptual phenomenological model of an aquifer–groundwater system and its interactions with surface waters. There are manifold ways to carry out this monitoring, but the choice of which way is significant for a correct qualitative and quantitative knowledge of spring systems. The present work focuses on the characterization of the thermo-saline and flow regimes of the Tara spring system along the northern coast of Taranto (southern Italy), where a karst groundwater basin is the major source of the Tara River and the surrounding coastal wetland. A series of measurements was carried out on the spring system to support a technical feasibility study on the possible use of the brackish water of this river to feed a future desalination plant. To estimate the flow rate, a comparison was made between different flow measurement methods in a derivation channel. Through an analysis of the available dataset, the response of the aquifer to the autumn–winter recharge, for which updated hydrologic measurements were not available, is highlighted.

The aim of this paper is to explore the effects and linkages between snow cover areas, distribution, probability and measured water discharge along east Mediterranean coastal watershed using moderate-resolution satellite images (MODIS-Terra). The Nahr Ibrahim River is a typical Lebanese watershed with an area of 326 km2 stretching between the sea and mountainous terrain to the east. The largest snow cover often exists in January-February with snow-free conditions between June and November. Image analysis enabled to analyze the temporal variability of the mean and maximum monthly areas of snow cover between 2000 and 2013. Snow cover dynamics were compared with the discharge from main springs (Afqa and Rouaiss) feeding the river and the probability of snow cover was estimated. The mean monthly snow cover, snow melting rates and springs discharge were found to be in direct relationship. In addition, the measured water discharge at the river mouth was found to be higher than the discharge of the two main feeding springs. This indicates a contribution of groundwater to the stream flow, which is again in direct connection with snow melting at the upper bordering slopes and probably from neighboring watersheds. Considering the characteristics of the mountainous rocks (i.e. Sinkholes, fissured and karstified limestone), the pedo-climatic and land cover conditions affect the hydrological regime which is directly responding to the area and temporal distribution of snow cover, which appears after two months from snowing events. This is reflected on water productivity and related disciplines (Agricultural yield, floods). This study highlights the potential of satellite snow detection over the watershed to estimate snow cover duration curve, forecast the stream flow regime and volume for better water management and flood risk preparedness.

Abstract. The accuracy of rainfall predictions provided by climate models is crucial for the assessment of climate change impacts on hydrological processes. In fact, the presence of bias in downscaled precipitation may produce large bias in the assessment of soil moisture dynamics, river flows and groundwater recharge. In this study, a comparison between statistical properties of rainfall observations and model control simulations from a Regional Climate Model (RCM) was performed through a robust and meaningful representation of the precipitation process. The output of the adopted RCM was analysed and re-scaled exploiting the structure of a stochastic model of the point rainfall process. In particular, the stochastic model is able to adequately reproduce the rainfall intermittency at the synoptic scale, which is one of the crucial aspects for the Mediterranean environments. Possible alteration in the local rainfall regime was investigated by means of the historical daily time-series from a dense rain-gauge network, which were also used for the analysis of the RCM bias in terms of dry and wet periods and storm intensity. The result is a stochastic scheme for bias-correction at the RCM-cell scale, which produces a realistic representation of the daily rainfall intermittency and precipitation depths, though a residual bias in the storm intensity of longer storm events persists.