Abstract
Remote sensing allows for the continuous and repetitive measurement of rainfall values. Satellite rainfall products such as Tropical Rainfall Measurement Mission (TRMM) 3B42 and the Hydroestimator (Hydroe) can be potential sources of data for hydrologic applications, mainly in areas with irregular and sparse spatial distributions of traditional rain gauge stations. However, the accuracy of these satellite rainfall products over different spatial and temporal scales is unknown. In this study, we examined the potential of the TRMM 3B42 and Hydroe rainfall products to provide reliable rainfall estimates for a mountainous watershed in a humid subtropical climate region of Brazil. The purpose was to develop useful guidelines for future hydrologic studies on the potential and uncertainties of the rainfall products at different spatial and temporal resolutions. We compared the satellite products to reference rainfall data collected at 11 rain gauge stations irregularly distributed in the area. The results showed different levels of accuracy for each temporal scale evaluated. TRMM 3B42 performed better at the daily, monthly, and seasonal scales than Hydroe, while Hydroe presented a better correlation at the annual scale. In general, TRMM 3B42 overestimated the rainfall over the watershed at all evaluated temporal scales, whereas Hydroe underestimated it except for June–August at the seasonal scale. An evaluation based on contingency tables indicated that TRM 3B42 was better able to represent the local rainfall than Hydroe. The findings of this study indicate that satellite rainfall products are better suited for applications at the monthly and annual scales rather than the daily scale.
Highlights
Hydrology is the study of the distribution and circulation of water and its interaction with the environment, including interactions with living things and human beings [1]
The satellite rainfall estimates were evaluated through analyses of the error (P3B42 − Prain gauge for Tropical Rainfall Measurement Mission (TRMM) data and PHydroe − Prain gauge for Hydroe data), linear correlation coefficient (r), bias, mean absolute error (MAE), and root mean square error (RMSE) based on the work of Curtarelli et al [18] and Duan and Bastiaanssen [10]
The ability of a product is based on a conRtienmgoteenSecnys.t2a0b17l,e9,(s12e4e0 Table 2), which includes four variables calculated from the set of obser7voaft1io8 ns and estimated values [38,39]. of gauge observations) [4] and days without rain (p = 0 mm day−1)
Summary
Hydrology is the study of the distribution and circulation of water and its interaction with the environment, including interactions with living things and human beings [1]. The most important variable for hydrologic applications is the accurate spatial rainfall data [6], which is a critical input for hydrologic models [3,4,7]. Because of the high spatiotemporal variability of rainfall, a dense monitoring network is required with rain gauges distributed regularly throughout the watershed to generate a reliable estimate [8]. Traditional rain gauge stations provide the most accurate rainfall data, their spatial distribution is irregular, sparse, or missing in some areas, which may limit the accuracy of hydrologic studies [9]. Rainfall products derived from remote sensing have reached a good level of maturity [11]; even for watersheds with rain gauges, these products are considered an important complement for gauge-based observations [9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
