TY - JOUR
T1 - Flooding dynamics on the lower Amazon floodplain
T2 - 1. Hydraulic controls on water elevation, inundation extent, and river-floodplain discharge
AU - Rudorff, Conrado M.
AU - Melack, John M.
AU - Bates, Paul D.
PY - 2014/1
Y1 - 2014/1
N2 - Modeling the routing of flood waters across large floodplains is challenging because flows respond to dynamic hydraulic controls from complex geomorphology, vegetation, and multiple water sources. In this study, we analyzed the topographic and hydrologic controls of inundation dynamics of a large floodplain unit (2440 km2) along the lower Amazon River. We combined land topography derived from the Shuttle Radar Topography Mission (SRTM) with underwater topography derived from an extensive echo-sounding survey to generate a seamless digital elevation model (DEM). Floodplain inundation was simulated using LISFLOOD-FP, which combines one-dimensional river routing with two-dimensional overland flow, and a local hydrological model. For the first time, accurate simulation of filling and drainage of an Amazon floodplain was achieved with quantification of changes in water elevation, flooding extent, and river-floodplain exchange. We examined the role of diffuse overbank versus channelized flows on river-floodplain exchange. Diffuse overbank flows represent 93% of total river to floodplain discharge and 54% of floodplain to river discharge. Floodplain discharge during high-water was four times higher than field observation values when the SRTM v.4 DEM with no correction was used for simulation because of a -4.4 m elevation bias originating from residual motion errors of the SRTM interferometric baseline. Key Points Topographic and hydrologic controls of inundation dynamics were analyzed Diffuse overbank flows represent 93% of total river to floodplain discharge Position of SRTM interferometric baseline is an important source of DEM error
AB - Modeling the routing of flood waters across large floodplains is challenging because flows respond to dynamic hydraulic controls from complex geomorphology, vegetation, and multiple water sources. In this study, we analyzed the topographic and hydrologic controls of inundation dynamics of a large floodplain unit (2440 km2) along the lower Amazon River. We combined land topography derived from the Shuttle Radar Topography Mission (SRTM) with underwater topography derived from an extensive echo-sounding survey to generate a seamless digital elevation model (DEM). Floodplain inundation was simulated using LISFLOOD-FP, which combines one-dimensional river routing with two-dimensional overland flow, and a local hydrological model. For the first time, accurate simulation of filling and drainage of an Amazon floodplain was achieved with quantification of changes in water elevation, flooding extent, and river-floodplain exchange. We examined the role of diffuse overbank versus channelized flows on river-floodplain exchange. Diffuse overbank flows represent 93% of total river to floodplain discharge and 54% of floodplain to river discharge. Floodplain discharge during high-water was four times higher than field observation values when the SRTM v.4 DEM with no correction was used for simulation because of a -4.4 m elevation bias originating from residual motion errors of the SRTM interferometric baseline. Key Points Topographic and hydrologic controls of inundation dynamics were analyzed Diffuse overbank flows represent 93% of total river to floodplain discharge Position of SRTM interferometric baseline is an important source of DEM error
KW - Amazon River floodplain
KW - digital elevation model
KW - inundation modeling
KW - river-floodplain discharge
UR - http://www.scopus.com/inward/record.url?scp=84896716590&partnerID=8YFLogxK
U2 - 10.1002/2013WR014091
DO - 10.1002/2013WR014091
M3 - Article (Academic Journal)
AN - SCOPUS:84896716590
SN - 0043-1397
VL - 50
SP - 619
EP - 634
JO - Water Resources Research
JF - Water Resources Research
IS - 1
ER -