ABSTRACT
The Climatic Water Balance (CLIMWB) is very used in the climatic characterization and can also offer important contribution in the identification of the water demand for irrigation of a region. For this, reliable precipitation data with good spatial coverage is required. The Tropical Rainfall Measuring Mission satellite -TRMM-3B43-v7 is a partnership between NASA (National Aeronautics and Space Administration) and Japan's Aerospace Exploration Agency (JAXA), which estimates rainfall data for the tropics region. The aim of this study is to evaluate the CLIMWB obtained by the Thornthwaite & Mather method (1955)Thornthwaite C, Mather J (1955) The water balance. Publications in Climatology. New Jersey, Drexel Institute of Technology, 144p., with estimated rainfall data with the 3B43 product versus those generated with rainfall data and to map pixel-by-pixel water availability with good spatial coverage for the Doce River basin, located in the Atlantic Hydrographic Region, Southeastern Brazil, between the states of Minas Gerais and Espírito Santo. The CLIMWB variables generated with 3B43, together with the precipitation, showed a good correlation with those fed with surface rainfall data. The largest differences between the two datasets were found in some stations in the southeast and northeast of the basin. The CLIMWB variables presented a good correlation, with the best water excess (0.94), followed by water deficit (0.88), water availability (0.84) and real evapotranspiration (0.82). With TRMM - 3B43, we can characterize the CLIMWB in a similar way to that obtained with data observed by the gauges, providing much more extensive coverage. The use of the TRMM - 3B43 precipitation data allows a consistent characterization of the regional water availability, contributing to the agricultural planning and management, mainly to fill the gaps left due to the absence of rain gauges and to possible failures in the rain gauges' data series.
KEYWORDS
orbital data; rainfall; water deficit; water availability
