INWAT - Quality and management of intermittent rivers and associated groundwaters in the Mediterranean basins

The Mediterranean region is increasingly affected by water scarcity because of rising demand (population growth and land-use changes) and decreasing availability (Climate change led rainfall decreases). This situation leads to an increasing proportion of temporary waterways , as well as to the depletion of aquifers. Water scarcity has a dramatic impact on ecosystem health, hydrology, river chemistry , and those economic sectors that strongly rely on water availability such as agriculture and tourism (70% of available worldwide freshwater is used in irrigated agriculture) . The worst-case scenario is encountered in the regions of southern Mediterranean area, which are characterized by high spatial and temporal imbalances of water demand and availability, seasonal water uses, and inadequate water resources management. Therefore, in order to supply water to human settlements in arid or semi-arid countries the over-exploitation of water resources is common. Non-sustainable practices are globally widespread and manifest themselves in the over pumping of aquifers, seawater intrusion, river flows composed mainly by wastewater, and the salinization of irrigated soils. To counteract these trends, many research and policy initiatives have been launched to better estimate water resources, ecological status or ecosystem services in the Mediterranean region, as well as initiatives to foster integrated water management. However, none of those has put all these pieces together to solve this puzzle and to support decision-makers in the struggle they face in reconciling the various demands on decreasing water resources.

INWAT will develop and improve tools to analyze, understand and predict hydrology, chemical and ecological status, and services in the Mediterranean area characterized by temporary waterways, and will integrate all these pieces in a decision-support system that will be co-developed with stakeholders from different case-studies reflecting different socio-environmental settings from the northern and southern shores of the Mediterranean Sea.

1. Designing new modelling routines for determining the basic components of the water cycle, including economic, social and technical aspects (e.g. groundwater accumulation storage and recharge) and for forecasting droughts. INWAT will design and apply new modelling routines in the areas of pollution (WP1), hydrology (WP2), ecology (WP3), and ecosystem services (WP4) for temporary waterways. These will enable water managers to better predict and manage hydrological extremes and their consequences on water quantity and quality, as well as on biodiversity and ecosystem services. The decision support system developed in WP4 will provide water manager with a tailor-made tool for linking process-based spatially explicit models, GIS-based biophysical and socioeconomic information, expert knowledge and practitioner’s needs. It will allow for the evaluation of the effects of management actions on multiple benefits, thus assessing trade-offs among services, ecological status and water quantity and quality issues. 2. Mitigating pollution processes by better assessing water management policies and the impact of anthropogenic activities. The decision support system developed in WP4 will take into account the water management policies and governance structures of the various involved countries. This will be ensured by the close involvement of stakeholders, who will co-develop the decision support system for the case-study basins, thus enabling a swift implementation into practice. INWAT will cover all components of the Driver-Pressure-State-Impact-Response (DPSIR) chain, thus linking human water uses to pollution and hydrological changes, alterations of the rivers’ physico-chemistry and biology to possible mitigation and restoration measures. Uniform guidelines for basin management with temporary waterways among the Mediterranean countries do still not exist and these are required for better and better comparable management policies. For instance, few national guidelines in non-EU countries focus on risks from pathogens together with heavy metals, while organic microcontaminants have been largely overlooked. Establishing common guidelines for the management of temporary waterways with a large proportion of temporary waterways connecting various components of water quality and water quantity will be a major contribution of the INWAT project. 3. A reduction in the risk of saline intrusion and improved management of salt accumulation in overexploited underground water bodies. INWAT approach: Seawater intrusion is a relevant pressure in various case study basins, e.g. in the Riera de Llançà, and will be addressed in the monitoring methods of physico-chemistry and biology. Diatoms, as an indicator group specifically responding to salinization, have been included into WP3 to account for seawater intrusion pressures.