International Research Fellowship Program: Uncertainty Analysis in Solutes Transport at Basin Scale

Franceschini Samuela, 36100 Vicenza

Investigators

Abstract

0855840 Franceschini This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad. This award will support a twelve-month research fellowship by Dr. Samuela Franceschini to work with Drs. Andrea Rinaldo and Marco Marani at the Universita degli Studi di Padova in Italy. Researchers at the Università degli Studi di Padova have implemented a model ? the Mass-Response Function (MRF) model to simulate solute transport at the basin scale. The MRF model is based on linking the solute travel times ? the time the dissolved contaminants take to travel from the injection point to a control point in the watershed, with the global, basin-scale contact times between phases controlling mass exchanges ? the time it takes the dissolved contaminants that are in contact with soil and/or water to undergo chemical or physical transformation. The relatively large contact times between the soil and the runoff flow, favors the conditions for chemical and physical processes of solute transformation. The researchers guided by Prof. Rinaldo and Prof. Marani have successfully applied the MRF model to several sub-basins draining into the Venice Lagoon. However, due to the inherently uncertain character of the natural processes and the fluctuating values of the model input variables, the described deterministic approach is not sufficient to accurately assess the reliability of the system to support management decisions. This is particularly true of water quality policies regarding the Venice Lagoon and its watershed. Local administrators, scientists and engineers must carefully manage the closing of the inlets to the sea to preserve the city of Venice from the high tie while at the same time providing a means of exchange between the lagoon water (receptor of pollutant loadings from the mainland) and the Adriatic Sea. The randomness of the studied natural phenomenal and the need for more reliable information to support the management decisions suggest that a systematic approach to account for uncertainty in modeling solute transport a basin scale is essential. In an attempt to provide more realistic representations of solute transport at basin scale, The PI couples the MRF model first to probabilistic techniques ? the Point Estimate Methods (PEMs) and then to time series analysis methods to evaluate the field measurements. The main goal is to assess the uncertainty of the estimated results for both runoff flow and solute concentrations. The broader impact of this research is linked to the possibility of providing more reliable results that may be used to support future water resources management decisions. The objective is to develop a robust physically-based mathematical model to represent catchment-scale hydrologic and solute responses. The use of uncertainty and time series analyses allow for better understanding of the physicochemical processes involved in the solute transport and provide supporting results to optimize future field work. The results of this research can be broadly applied to benefit the local community and the work of local agencies and districts to maintain or to improve the quality of water sources in heavily fertilized agricultural areas. To this end, this study will help in effectively assess the contaminant loadings to the lagoon of Venice, further helping in establishing management practices to improve the water quality of this body of water.