Remote Sensing of Water Balance in Pantanal

Abstract

Pantanal, located in the Upper Paraguay basin, is the world’s largest tropical wetland. The maintenance of this ecosystem depends on the water balance since precipitation is seasonal and high losses of water occur due to the high evapotranspiration. Water balance assessment using in situ data is still a challenge due to the large extension of the area and the complexity to be represented. In this study, the water balance in the Upper Paraguay basin was investigated based on hydrological variables derived from remote sensing data. Precipitation, evapotranspiration, and water storage change data were estimated with accuracy by the water balance, but the same was not possible for the discharge. However, high uncertainties in the estimates were verified, mainly during the rainy season. The remote sensing data allowed the identification of the seasonality of hydrological variables in the Pantanal system and in the different regions of the basin: Chaco, Pantanal and Planalto. Water deficit in the basin was observed from March/April to September as well as a positive water balance due to precipitation during the rest of the year. The spatial analysis of the basin showed that in the northern region, the precipitation, the evapotranspiration, and the water storage variation are higher than in the southern region. Results demonstrated that remote sensing data can help in the comprehension of hydrological systems operation, especially in large wetland regions.

Classification of Potential Wetlands using the Random Forest in Google Earth Engine in Geomorphological Units - Rio Grande do Sul, Brazil

“…In addition, evapotranspiration is a reliable indicator of wetland health (CERON et al, 2015). Expected behaviors for temperature, ET and PET, described in Ceron et al, (2015); Moreira et al, (2019), were observed in our results for the two mapped geomorphological units. Although, they have distinct maximum values, wetlands show lower temperatures than the other No Wetlands regions, while the results for ET and PET are higher.…”

Estimating water balance in a Brazilian semiarid watershed using different spatial data

“…The evaluation of remote sensing data, or spatial data, as an alternative to hydrological data can still present many challenges, such as choosing the best database of estimated variables in regions with outstanding characteristics, such as humid regions (MOREIRA et al 2019b) or semi-arid (RAMOELO et al 2014;RIBEIRO, 2020). Satellite missions provide a promising and cost-effective way to estimate the individual components of the hydrological cycle, however when combined they do not close the water balance due to uncertainties in the hydrological datasets ).…”

“…Closing the water balance is still a challenge and the re nement of information on the variation of its components has been an alternative to obtain better estimates (MOREIRA et al 2019b). Considering that the information from remote sensing and spatial databases can lead to the process of obtaining more representative hydrological variables, the analysis of these products is extremely important.…”