Hydrological Particle-Tracking of Amazon Rivers and Floodplains

Abstract:

Water storage in large rivers and floodplains of the Amazon basin results from the integration of temporal and spatial variable drainage processes that occur across the basin, such as rainfall-runoff transformation, flow routing and water fluxes between river and natural reservoirs. Quantification of surface water storage and river-floodplain exchanges in different regions of the basin is needed to understand important ecological and biogeochemical processes on large basins as the Amazon. And large scale hydrology-hydraulic models can provide the technical basis to answer such questions. In order to investigate the hydrological pathways, water sources and in-stream travel time in drainage basins, we developed a probabilistic hydrological particle-tracking model. This model considers water volumes generation and tracking along river networks using probabilities based on water storage and discharges obtained by hydrologic-hydraulic models. In this study, we coupled the tracking method with the MGB-IPH large-scale hydrological simulation of the Amazon River Basin. The particle-tracking approach captures the large scale basin in-stream water dynamics and provides information on river and floodplain flow variability along the basin. The method is used to study (i) volumes and sources of water flowing through Amazon floodplains and (ii) evaluate in‑stream travel time distribution of both river and floodplain waters.