Hydrological Tracking Model for Amazon Surface Waters

Abstract

This study presents an alternative model for hydrological tracking of surface waters designed to investigate multiyear storage and movement of water in large river basins. We coupled this model with a background solution from a large-scale hydrological-hydrodynamic model to study the fate of waters in the Amazon River basin (6 million km 2) considering the following: (i) the surface water travel times, (ii) the role of large floodable areas (17% of the basin), and (iii) the relations between water composition and lithological sources. Through numerical experiments, we investigated the spatial distribution of in-stream surface water travel time for the Amazon River Basin (relative to the outlet) and the role of floodplains in seasonal water storage. We estimate that surface water travel time is likely to be less than 90 days (median of 45 days), although about 20% of the flowing water passes through large floodplains. Our modeling exercises indicate that whole-basin monthly water net balance between river and floodplain can reach up to magnitudes of 10 5 m 3 /s; the water exchanged with floodplains during the annual floods can represent a large portion (up to 40%) of the basin discharge during low waters season. Finally, we took advantage of the tracking approach to study the hydrograph composition based on parent river lithology quantifying the role of major tributaries. Parallel to the development of global hydrology databases, new modeling approaches are also required to push advances in the discussion of renewal and travel times of surface waters in large river basins.

Coherent Satellite Monitoring of the Water Cycle Over the Amazon. Part 1: Methodology and Initial Evaluation

“…P drives R season over the upstream sub-basins with a time lag of 1-2 months between P and R. Over northern and central sub-basins, dS becomes negative while R is still increasing (and reaches its maximum 2 months later). This illustrates the floodplain buffer effect that charged water before releasing it into the river (Sorribas et al, 2020). E seasonal variation is weaker than for P but E peak seems to be in phase with P over southern basin arguing for a water-limited behavior (Espinoza PELLET ET AL.…”

“…Over northern and central sub‐basins, dS becomes negative while R is still increasing (and reaches its maximum 2 months later). This illustrates the floodplain buffer effect that charged water before releasing it into the river (Sorribas et al., 2020). E seasonal variation is weaker than for P but E peak seems to be in phase with P over southern basin arguing for a water‐limited behavior (Espinoza et al., 2019; Sörensson & Ruscica, 2018) while E peak follows P minimum month in northern basin depicting energy‐limited system (Espinoza et al., 2019).…”

Amazon Hydrology From Space: Scientific Advances and Future Challenges

“…Sorribas et al. (2020) used particle tracking methods to estimate surface water travel times along the Amazon basin as 45 days (median), with 20% of Amazon River waters flowing through floodplains (Figure 11c). While basin‐scale applications have employed 1D models (longitudinal direction along rivers), the necessity of representing the 2D diffuse flow in floodplains, especially during receding waters, was highlighted by Alsdorf et al.…”

An Integrative Conceptualization of Floodplain Storage

“…Alsdorf et al (2010) Using numerical models∼20% of Amazon's flow passes through large floodplainsSorribas et al (2020) Upper limits of flow onto the floodplain at 200% of peak channel discharge & flow back into the channel at 40% of peak channel discharge daPaz et al (2011) …”