Modeling the Mississippi River
Basin with RAPID
Cédric H. DavidJames S. Famiglietti
Zong-Liang Yang
Victor Eijkhout
Continental scale hydro model inter-comparison forSWOT
31 Aug 20161

Outline• RAPID• Some dataprocessing• Simulations• Discussion

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RAPID is based on theMuskingum methodA
k is a time (k ≥ 0) related to the celerity of theflow wave

Direction of flow

x is a non-dimensional parameter (0 ≤ x ≤ 0.5)
related to diffusion of the flow wave

Flow(m3/s)
AB

x = 0.5x=0kkFlow(m3/s)
BTime (s)ABTime (s)3© 2015 Cédric H. DavidAll Rights Reserved

Relationship between rivers andtheir catchments in RAPID

1 river reach

1 catchment

From David et al. 2011 (JHM)

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River network connectivity inRAPID
Downstream
River ID
River ID

UpstreamRiver ID 1

Number ofupstream
River IDs

UpstreamRiver ID 3

UpstreamRiver ID 2

UpstreamRiver ID 4

Numberof riverreaches
Max number of
upstream reaches

From David et al. 2011 (JHM)

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Compute the inflow to rivers
from runoff• Superimpose withmap of catchments• Using runoff value atcatchment centroid
and catchment area
David, Hong and Yang (2013, EMS)
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RAPID website anddocumentation

RAPID (Routing Application for Parallel
computatIon of Discharge)

Animations, tutorials, publications:
All on the RAPID website:
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http://rapid-hub.org

Fostering communitydevelopment••••

Parallel performance
Reservoirs/diversions
Large-scale modelingPreparation for SWOT

• Coupling with
WRF-Hydro

33 previously released
versions of the RAPID code
• Computation of water
elevation• Two new flow wave
propagation schemes

Revisions tracked with

4 official releases• Online coupling with
Noah-MP• Reservoir work• Cloud computing• Floodforecastingapp• National Flood
Interoperability
experiment• Processingtoolbox• Optimization ofwater allocations • Online coupling withgroundwater model

RAPID is now on GitHub!!!

Fork RAPID on GitHub
Star RAPID on GitHub
Follow me on GitHub
8Outline• RAPID• Some dataprocessing• Simulations• Discussion

9HydroSHEDS

Lehner et al. (2008)10

http://hydrosheds.cr.usgs.gov/index.php

HydroSHEDS for North America

Rivers (vector file)

Flow direction (raster file)

Also DEM, conditioned
DEM, and Flow
accumulation

Major Basins (vector file – beta)

11Computing the length of eachriver reach

Geographic Coordinate System

Projected Coordinate System(Because RAPID flow wave celerity based on length)12

HydroSHEDS river IDs

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HydroSHEDS cumulative
catchment size

The unit for catchment size is number of 15-second grid cells

14Compute the non-cumulative
catchment area

Cumulative

Non-cumulative15

Some statistics about thecomputing domain
102,229 river reaches and catchments

River reaches vary in size from 0.29
to 101.50 km (mean: 6.20 km,
median: 4.79 km, standard deviation
5.29 km).

Contributing catchments vary insize from 0.14 to 542.78 km2 (mean:31.11 km2, median: 24.79 km2,standard deviation 25.66 km2).
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Compute the inflow to rivers
from NLDAS2David, Hong and Yang (2013, EMS)

• Download
NLDAS2 .grb files• Convert .grb to .nc
files and extract runoff
fields• 3-hourly average• 6-hour shift (UTCCST)• Superimpose withmap of catchments
17Advantages of using
HydroSHEDS for SWOT
Derived from SRTM
measurements
Vector-based (blue lines andnot grid cells) à SWOT will
see actual water bodies(10-100 m swath resolution),not 1° grid cells
Some existing preliminaryinterest from the SWOT
community
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Selecting gauging stations
2000 is the driestand 2008 is thewettest(UpperMississippi
Floods of 2008)

Selection
based on 6
publishedstudies
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Ready to run!

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Outline• RAPID• Some dataprocessing• Simulations• Discussion

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Missouri

Arkansas

RedMississippi

OhioAftermaths: flow statistics

Missouri River: poor simulations (modeling system produces twice the observed flow)
Upper Mississippi River: good simulations (better stats when slow wave)
After confluence of Upper Mississippi and Missouri: poor simulations
Ohio River: good simulations (better stats when fast wave)
Arkansas and Red River: poor simulations (modeling system produces twice the observed flow)

Animation

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SWOT data look alike

Thickness of blue lines is function of simulated discharge
10-year simulation using RAPID (2000-2009), 15-min time step, output every 3-hr
Sub-sampling based on orbit at 890 km altitude, 77.6° inclination, 20.86 days repeat
No observational error accounted for here

Outline• RAPID• Some dataprocessing• Simulations• Discussion26

Aftermaths: hydrographs

Not bad!

RAPID lacks
reservoir moduleBackflow? Flood?
Not bad!
June 2008 Upper
Mississippi floods27

8 of the 15 largest U.S. lakes/
reservoirs are in domain

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Thank you!
Questions?

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