Estimating River Depth From Remote Sensing Swath Interferometry Measurements of River Height, Slope, and Width

The Surface Water and Ocean Topography (SWOT) mission is a swath mapping radar interferometer that would provide new measurements of inland water surface elevation (WSE) for rivers, lakes, wetlands, and reservoirs. SWOT WSE estimates would provide a source of information for characterizing streamflow globally and would complement existing in situ gage networks. In this paper, we evaluate the accuracy of river discharge estimates that would be obtained from SWOT measurements over the Ohio river and eleven of its major tributaries within the context of a virtual mission (VM). SWOT VM measurements are obtained by using an instrument measurement model coupled to simulated WSE from the hydrodynamic model LISFLOOD-FP, using USGS streamflow gages as boundary conditions and validation data. Most model pixels were estimated two or three times per 22-day orbit period. These measurements are then input into an algorithm to obtain estimates of river depth and discharge. The algorithm is based on Manning's equation, in which river width and slope are obtained from SWOT, and roughness is estimated a priori. SWOT discharge estimates are compared to the discharge simulated by LISFLOOD-FP. Instantaneous discharge estimates over the one-year evaluation period had median normalized root mean square error of 10.9%, and 86% of all instantaneous errors are less than 25%.

[1]  Son V. Nghiem,et al.  Space‐based measurement of river runoff , 2005 .

[2]  C. Cushing,et al.  Rivers of North America , 2005 .

[3]  Russell G. Congalton,et al.  Evaluating the potential for measuring river discharge from space , 2003 .

[4]  Matthew Rodell,et al.  Contemporary estimates of Pan‐Arctic freshwater discharge from GRACE and reanalysis , 2007 .

[5]  Laurence C. Smith,et al.  RivWidth: A Software Tool for the Calculation of River Widths From Remotely Sensed Imagery , 2008, IEEE Geoscience and Remote Sensing Letters.

[6]  J. Wickham,et al.  Completion of the 2001 National Land Cover Database for the conterminous United States , 2007 .

[7]  Matthew Rodell,et al.  Total basin discharge for the Amazon and Mississippi River basins from GRACE and a land‐atmosphere water balance , 2005 .

[8]  D. Lettenmaier,et al.  A simple hydrologically based model of land surface water and energy fluxes for general circulation models , 1994 .

[9]  P. D. Batesa,et al.  A simple raster-based model for flood inundation simulation , 2000 .

[10]  Marcos Heil Costa,et al.  Surface water dynamics in the Amazon Basin: Application of satellite radar altimetry , 2001 .

[11]  James S. Famiglietti,et al.  GRACE-Based Estimates of Terrestrial Freshwater Discharge from Basin to Continental Scales , 2007 .

[12]  Delwyn Moller,et al.  Temporal Decorrelation and Topographic Layover Impact on Ka-band Swath Altimetry for Surface Water Hydrology , 2008 .

[13]  Delwyn Moller,et al.  Estimation of bathymetric depth and slope from data assimilation of swath altimetry into a hydrodynamic model , 2008 .

[14]  D. Lettenmaier,et al.  Measuring surface water from space , 2004 .

[15]  Delwyn Moller,et al.  Estimating discharge in rivers using remotely sensed hydraulic information , 2005 .

[16]  P. Bates,et al.  Amazon flood wave hydraulics , 2009 .

[17]  L. Smith,et al.  Estimation of Discharge From Three Braided Rivers Using Synthetic Aperture Radar Satellite Imagery: Potential Application to Ungaged Basins , 1996 .

[18]  O. Talagrand,et al.  Bayesian Estimation. Optimal Interpolation. Statistical Linear Estimation , 2003 .

[19]  Michael Eineder,et al.  Current measurements by SAR along-track interferometry from a Space Shuttle , 2005, IEEE Transactions on Geoscience and Remote Sensing.

[20]  Christopher A. Barnes,et al.  Completion of the 2006 National Land Cover Database for the conterminous United States. , 2011 .

[21]  D. Lettenmaier,et al.  Prospects for river discharge and depth estimation through assimilation of swath‐altimetry into a raster‐based hydrodynamics model , 2007 .

[22]  William J. Plant,et al.  measuring stream discharge by non‐contact methods: A Proof‐of‐Concept Experiment , 2000 .

[23]  W. Marsden.  I and J , 2012 .

[24]  D. Alsdorf,et al.  Water slope and discharge in the Amazon River estimated using the shuttle radar topography mission digital elevation model , 2005 .

[25]  T. Pavelsky,et al.  Estimation of river discharge, propagation speed, and hydraulic geometry from space: Lena River, Siberia , 2008 .

[26]  D. Barrick,et al.  Use of radars to monitor stream discharge by noncontact methods , 2006 .