Hydrological analysis of the Monday River Basin using the distributed hydrological model MGB - IPH

Abstract

The applicability of the Large Basins Model (MGB, for its acronym in Portuguese) for water balances and other hydrological studies in watersheds of Paraguay is evaluated. A compilation of hydro-meteorological and physical data available for the basin was performed. The Monday River basin was selected considering the availability of rainfall and water level data of over 20 years; Physical data was obtained by processing satellite images, topographic data and existing taxonomic maps. The basin was divided in two subbasins in order to coincide with existing water level sites. The model was calibrated using the Nash Sutcliffe parameter as a valoration of the model. A Nash coefficient of 0.39 was obtained for the upper basin, which is considered very low; however, a value of 0.74 was obtained for the entire basin, which is considered good given the scarcity of data, the complexity of the model and the scope of the thesis. The MGB_IPH has proved to be a very capable model with many potential applications for hydrologic simulation, especially with respect to assessments of changes in land use and occupation and scenarios of climate variability and change. It can be used in basins with reliable precipitation information, to perform water balance, and as a decisions support for the implementation of the Water Resources Law, especially in relation to allocation of permits and granting of water use.