Application of the MGB-IPH model in the Pardo River hydrographic basin in different scenarios of use and occupation of the soil

ABSTRACT

The changes caused to the environment by human actions can influence the availability of water in hydrographic basins, and measuring the impacts caused by these actions is essential for decision-making by management bodies. Thus, the aim of this study was to perform the calibration and validation of the MGB-IPH model to simulate the flow behavior of the Pardo River hydrographic basin in different scenarios of use and occupation of the soil. For this purpose, we used information on the use and occupation of the soil, revealing a reduction in the forest area of the hydrographic basin under study and an increase in the areas dedicated to agricultural activities, between 2001 and 2016. With this information about the basin, with the climatic data and the types of soils available, the model was calibrated and validated, and its performance was verified. The changes in the average, total, maximum, and minimum monthly flow rates simulated by the different scenarios were compared by average test for dependent samples, and we performed the evaluation of the maximum, average, and minimum annual flow rates of the values tested. The MGB-IPH has been satisfactorily validated for the Agência Nacional de Águas, station 53880000, presenting problems with the underestimation of maximum peak flow rates, but managing to adequately represent the observed data in terms of flow rate seasonality, differentiation between wetter and drier years, and between medium and small intensity peak floods. The model was sensitive in identifying the impact of changes in the use and occupation of the soil in simulated flow rates for the Pardo river basin, with the 2016 scenario showing higher values of average, total, maximum, and minimum monthly flow rates compared to those found in the 2001 scenario.

Keywords:
Hydrological model; Flow rate; MapBiomas