Abstract
Although being the second largest biome in South America, the Cerrado biome is understudied in terms of hydrological modeling of the interception processes of its different vegetation types. To better understand its net precipitation components, high-temporal-resolution throughfall data were used to parameterize the Gash Analytical Model on a per storm basis. Two different methods (Single Event Regression—SI, and Particle Swarm Optimization—PSO) for parametrizing the Gash model were tested. Simulated throughfall from 35 events showed the Nash coefficient ranging from 0.779 to 0.989, confirming the good phenomenological approach of the Gash model. One of the most important results presented in this work was the analysis of the variability of the parameters. Considering the PSO method, we observed a mean free throughfall (ρ) of 0.17, with a confidence interval ranging from 0.16 to 0.18. The storage (S) confidence intervals ranged from 1.11 mm to 1.62 mm, with a mean value of 1.37 mm. The observed saturation depth (P′G) mean value was 1.66 mm, with a confidence interval from 1.35 mm to 1.97 mm. Finally, the mean evaporation precipitation rate (E/R) was of 0.20, with confidence bands from 0.15 to 0.24. Overall, there were observed higher losses from the Cerrado compared to other Brazilian biomes such as the Amazon and Atlantic Forest. These findings can contribute to the parameterization of hydrological models applied to the Brazilian Cerrado.
Highlights
According to Véliz-Chávez et al [1], net precipitation in forested areas can be described as the sum of three processes
The present study aims at modeling the interception phenomenon by application of the Gash model on a rainfall event based on data from a Cerrado gallery forest
Conclusions the Gash model incorporates the seasonal variation of ρ, S and evaporation precipitation rate (E/R), average interception errors are noted by Giglio and Kobiyama [12], the understanding of the mechanisms involved in the slightly interception process is still unsatisfactory, especially in tropical forests
Summary
According to Véliz-Chávez et al [1], net precipitation in forested areas can be described as the sum of three processes. The third, and last, process involves part of the rainfall flowing along the branches to the trunk until it reaches the ground This portion of the net precipitation is known as stemflow [1]. On the concept brought by Rutter, the canopy is regarded as capable of storing rainfall water on its surface This storage is subject to evaporation during the rain event and after the end of the event. The current state of the art indicates that most studies (90%) are dedicated to rainforests (the Amazon and Atlantic Forest), and only a few are dedicated to the Cerrado In this regard, the present study aims at modeling the interception phenomenon by application of the Gash model on a rainfall event based on data from a Cerrado gallery forest. We used a novel approach to obtain the model parameters, combining the canopy characterization by hemispheric photos suggested by Zimmermann [13] with Particle Swarm Optimization methods
Sign-in/Register to view highlights & summary 
Published Version (
Free)
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 call