Water in Celtic Countries: Quantity, Quality and Climate Variability (Proceedings of the Fourth InterCeltic Colloquium on Hydrology and Management of Water Resources, Guimarães, Portugal, July 2005).  IAHS Publ. 310, 2007, 259-266.

 

Using hydrological models and Geographic Information Systems for water resources evaluation: GIS-VISUAL-BALAN and its application to Atlantic basins in Spain (Valiñas) and Portugal (Serra da Estrela)

 

Javier Samper1, Miguel Angel García Vera2, Bruno Pisani1, Diego Alvares1, Jorge Espinha Marques3, Alberto Varela1 & José Angel Losada2

1       Escuela de Caminos, Universidade da Coruña, Spain

jsamper@udc.es

2       Confederación Hidrográfica del Ebro, Ministerio de Medio Ambiente, Spain

3       Dep. de Geologia (CGUP), Universidade do Porto, Portugal

 

Abstract This paper presents a distributed hydrological model for the evaluation of water resources, which has been obtained by extending the capabilities of VISUAL-BALAN V2, a lumped hydrological code developed by the University of La Coruña, and coupling it to a GIS. VISUAL-BALAN is a lumped hydrological model, which solves the water balance equations in the soil, the unsaturated zone and the aquifer. It requires only a few parameters and incorporates user-friendly interfaces for data input and post-processing of results. It evaluates hydrological components in a sequential manner. Besides the balance in the upper soil the code also solves the water balance equations in the unsaturated zone and the underlying aquifer. This allows the computa­tion of daily groundwater levels, as well as basin water discharge rates. Computed heads and streamflows can be compared to measured values for the purpose of model testing and calibration. VISUAL-BALAN accounts for irrigation sources and return flows. It also allows for snow precipitation, melting and runoff. Two advanced options have been developed: (1) automatic parameter estimation using groundwater level and streamflow data; and
(2) sensitivity analyses of the main components of the water balance with respect to model parameters.

 

Key words  GIS; hydrological models; recharge estimation; VISUAL-BALAN; water balance