Hydrologic Validation of MERGE Precipitation Products over Anthropogenic Watersheds

Abstract

Satellite rainfall estimates (SRFE) are a promising alternative for the lack of reliable, densely distributed, precipitation data common in developing countries and remote locations. SRFE may be significantly improved when corrected based on rain gauge data. In the present study the first complete validation of the Tropical Rainfall Measuring Mission (TRMM) 3B42-based MERGE product is performed by means of ground truthing and hydrological modeling-based applications. Four distinct, highly anthropogenic watersheds were selected in the Upper Paraíba do Sul River Basin (UPSRB)—Brazil. The results show that when compared to TRMM Multi-Satellite Precipitation Analysis (TMPA) 3B42V7 at the watershed scale, MERGE has a higher correlation with observed data. Likewise, root mean square errors and bias are significantly lower for MERGE products. When hydrologically validated, MERGE-based streamflow simulations have shown the capacity of reproducing the overall hydrological regime with “good” to “very good” results for the downstream lowland sections. Limitations were observed in the hydrological modeling of the upstream, highly anthropogenic, dammed watersheds. However, such limitations may not be attributed to MERGE precipitation since they were also obtained for the individually calibrated rain gauge-based simulations. The results indicate that the used MERGE dataset as a hydrological model input is better suited for application in the UPSRB than the TMPA 3B42V7.

Quantifying the climate change‐driven impacts on the hydrology of a data‐scarce watershed located in the Brazilian Tropical Savanna

“…The method used to estimate each component of the natural flow is presented in ANA (2011). Naturalized streamflows have been used in several hydrological modelling studies in Brazil, such as those by Nóbrega et al (2011), Jiménez et al (2019), Amorim et al (2020), Cassalho et al (2020), and Mello et al (2021).…”

Evaluation of Satellite Precipitation Products for Hydrological Modeling in the Brazilian Cerrado Biome

“…Naturalized streamflows are those that occur if there is no reservoir in a basin [54], and they are derived from an integrated system that incorporates 96 stochastic models for forecasting the streamflows in each hydropower plant [55]. Naturalized streamflows have been used in several studies of hydrological modeling in Brazil, such as those by Cassalho et al [13], Nóbrega et al [56], and Oliveira et al [55].…”

“…Despite presenting adequate r-factor values (Table 3), the simulation driven by rain gauges presented higher uncertainty when compared to the SPPs, presenting a p-factor slightly lower than 0.7 for the validation period. According to Cassalho et al [13], the local characteristic of rain gauges often limits their ability to represent the spatial structure of precipitation events. Therefore, the low density of rain gauges may be the cause of the greater uncertainties in the simulations [75].…”

Quality Evaluation of the 0.01° Multi-Source Fusion Precipitation Product and Its Application in Extreme Precipitation Event

“…High-resolution and high-quality precipitation data have gradually become an urgent need for the development of modern meteorological business [1]. Multisource fusion precipitation products can combine the advantages of precipitation data from different sources, and have gradually become the mainstream trend in the development of high-quality precipitation products in the world in recent decades [2][3][4][5][6][7][8][9][10][11].…”