Emanuele Romano

Vulnerability to Drought of a Complex Water Supply System. The Upper Tiber Basin Case Study (Central Italy)

The importance of simulation models to assess the impacts of droughts and the effects of mitigation options on water supply systems is well known. However a common procedure about the exploitation of model results is not established yet. Vulnerability is used to characterize the performance of the system, and it can be a helpful indicator in the evaluation of the most likely failures. In this paper a water allocation model is applied to the water supply system of the upper Tiber Basin (Central Italy) in which both surface waters (rivers, reservoirs) and ground waters (wells, springs) are exploited to feed mainly irrigation and civil users. Drought vulnerability indices are calculated to analyze the performance of the supply system under different climate and management conditions. Water shortage scenarios are simulated as a progressive reduction of mean precipitation, an increase in its standard deviation or a combination of both. The model shows that the safety of the water supply system mainly relies on the reservoirs and that the foreseen increased exploitation of the springs to replace contaminated wells, could be seriously limited by discharge decrease during fall. The vulnerability reduction obtained by a hypothetical augmentation of the storage capacity through additional small reservoirs was positively tested by the model. In conclusion vulnerability indices and synoptic risk maps demonstrated to be useful tools to analyze the model outputs. They provide easy-to-read scenarios to be used in a decision making framework considering negotiating among the main users.

Integration of local and scientific knowledge to support drought impact monitoring: some hints from an Italian case study

According to the Hyogo Framework for Action, increasing resilience to drought requires the development of a people-centered monitoring and early warning system, or in other words, a system capable of providing useful and understandable information to the community at risk. To achieve this objective, it is crucial to negotiate a credible and legitimate knowledge system, which should include both expert and local knowledge. Although several benefits can be obtained, the integration of local and scientific knowledge to support drought monitoring is still far from being the standard in drought monitoring and early warning. This is due to many reasons, that is, the reciprocal skepticism of local communities and decision makers, and the limits in the capacity to understand and assess the complex web of drought impacts. This work describes a methodology based on the sequential implementation of Cognitive Mapping and Bayesian Belief Networks to collect, structure and analyze stakeholders’ perceptions of drought impacts. The methodology was applied to analyze drought impacts at Lake Trasimeno (central Italy). A set of drought indicators was developed based on stakeholders’ perceptions. A validation phase was carried out comparing the perceived indicators of drought and the physical indicators (i.e., Standard Precipitation Index and the level of the lake). Some preliminary conclusions were drawn concerning the reliability of local knowledge to support drought monitoring and early warning.

Long-term climate sensitivity of an integrated water supply system: The role of irrigation.

The assessment of the impact of long-term climate variability on water supply systems depends not only on possible variations of the resources availability, but also on the variation of the demand. In this framework, a robust estimation of direct (climate induced) and indirect (anthropogenically induced) effects of climate change is mandatory to design mitigation measures, especially in those regions of the planet where the groundwater equilibrium is strongly perturbed by exploitations for irrigation purposes. The main goal of this contribution is to propose a comprehensive model that integrates distributed crop water requirements with surface and groundwater mass balance, able to consider management rules of the water supply system. The proposed overall model, implemented, calibrated and validated for the case study of the Fortore water supply system (Apulia region, South Italy), permits to simulate the conjunctive use of the water from a surface artificial reservoir and from groundwater. The relative contributions of groundwater recharges and withdrawals to the aquifer stress have been evaluated under different climate perturbations, with emphasis on irrigation practices. Results point out that irrigated agriculture primarily affects groundwater discharge, indicating that ecosystem services connected to river base flow are particularly exposed to climate variation in irrigated areas. Moreover, findings show that the recharge both to surface and to groundwater is mainly affected by drier climate conditions, while hotter conditions have a major impact on the water demand. The non-linearity arising from combined drier and hotter conditions may exacerbate the aquifer stress by exposing it to massive sea-water intrusion.

Robust Method to Quantify the Risk of Shortage for Water Supply Systems

AbstractConditions of shortage in a water supply system (WSS) occur when the available water resources are unable to satisfy the related demand (failure). The definition of risk of shortage convent...

Analysis of a Subsidence Process by Integrating Geological and Hydrogeological Modelling with Satellite InSAR Data

This paper focuses on a multidisciplinary study carried out in an urban area affected by subsidence. The area is located about 20 km east of Rome (Italy) and is affected by dewatering processes mainly linked to quarry activities. Furthermore, compressible soils are locally present immediately below the ground level. Persistent Scatterer Interferometric Synthetic Aperture Radar (InSAR) analyses carried out with different approaches on ERS and ENVISAT data were performed. The so reconstructed time series of ground displacements were then coupled and compared with a detailed geological model and the variations over time of piezometric levels. Such data overlay allowed us to better understand and constrain the relation among ground displacement, piezometric variations, geological setting and geotechnical properties of subsoil.

Predicting new snow density in the Italian Alps: A variability analysis based on 10 years of measurements

DRST Centro Valanghe di Arabba, ARPA Veneto, Arabba, Italy National Research Council, Water Research Institute (IRSA‐CNR), Rome, Italy National Research Council, Water Research Institute (IRSA‐CNR), Brugherio, Italy National Research Council, Institute for Atmospheric Pollution (IIA‐CNR), Rome, Italy Dipartimento di Scienze, Università degli Studi Roma Tre, Rome, Italy Associazione Interregionale Neve e Valanghe (AINEVA), Trento, Italy Correspondence Nicolas Guyennon, National Research Council, Water Research Institute (IRSA‐CNR), Strada Provinciale 35d, km 0,7, Montelibretti, Rome, Italy. Email: guyennon@irsa.cnr.it