Preliminary Hillslope River Routing (HRR) model results
based on NLDAS runoff

Ed Beighley
October 3, 2016

Hillslope River Routing (HRR) Model• Combines hydrologic and hydraulic processes• Topographic based, irregular computational grid (parallel processing)• Vertical water/energy balance• Lateral surface & subsurface routing• Channel and floodplain routing• Lake/reservoirs routing• Model has ability to track ALL water stores
References• Beighley, R.E., K. Eggert, T. Dunne, Y. He, and V. Gummadi, 2009. Simulating hydrologic and hydraulic processes
throughout the Amazon River Basin, Hydrological Processes 23(8):1221-1235.
• Beighley, R.E. and V. Gummadi, 2011. Developing Channel and Floodplain Dimensions with Limited Data: A
Case Study in the Amazon Basin, Earth Surface Processes and Landforms 36(8):1059-1071.
• Beighley, RE, R.L. Ray, Y. He, H. Lee, L. Schaller, M. Durand, K.M. Andreadis, D.E. Alsdorf, C.K. Shum, 2011.
Comparing satellite derived precipitation datasets using the Hillslope River Routing (HRR) model in the CongoRiver Basin, Hydrological Processes 25(20):3216-3229.
• Beighley, R.E., K. Eggert, C.J. Wilson, J.C. Rowland, H. Lee., 2015. A hydrologic routing model suitable for climate
scale simulations of arctic rivers: application to the Mackenzie River Basin, Hydrological Processes.

HRR (Surface & Subsurface) Runoff Generation & Routing•

Surface runoff & routing– Lateral routing  non-linear– es = (surface runoff and baseflow from NLDAS)– Kinematic wave w/ explicit solution– Based on Manning’s eq. (wide rect. ch.)– Parameters:

N = surface roughness; S = ground slope
Lp = hillslope length (scale dependent)

qsysq s  ys eS ( t )xt 1.49 1/ 2  5 / 3qs  S  ys
 N

Channel and Floodplain Routing• Muskingum-Cunge (Diffusion Wave) channel routing– Finite difference over space and time
– C’s  f(Courant & Reynolds Nos., & Reference Q)

Q A
 qs  qss  ql
x tQ

1AR 2 / 3S1 / 2nn1n1nn
Qj1  C1 Qj  C2 Qj  C3 Qj1  C4 QL• Each model unit defined as "Open Book“– Channel receive lateral flow from 2 planes plus any upstream flown = channel roughness
A = cross-sectional area
R = hydraulic radius (A/w)
S = channel slope
Qref = reference discharge

Characterizing flowpaths and scales• Channel network– Defines model unit boundaries– Sets Hillslope Lengths & Slopes– Sets River Lengths & Slopes• Model Scale vs. Real Scale– How to estimate parameters in model scale tocapture physical process scale?
– Depending on model scale, hillslope flowpaths
represent hillslope and channel flowpaths
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HRR model units  “open book”

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Hillslope Parameters• Runoff  NLDAS 2 (VIC Hourly) Dai’s extremely awesomebinary files for surface and subsurface runoff(http://hydro.iis.u-tokyo.ac.jp/~yamadai/tmp/SWOTMIP/grads.tar.gz)• NLDAS_VIC0125_H: NLDAS VIC Land Surface Model L4 Hourly
0.125 x 0.125 degree V002
• Hillslope Slope  mean pixel slope in catchment based onhydrosheds DEM• Hillslope Length  based on river network resolution(Threshold area = 100 pixels; roughly 20.25 km2), Lp = A/2/Lc• Surface roughness  0.8 x (1.5, sinuosity)
7Channel Parameters• Channel Slope  mean pixel slope along channel basedon hydrosheds DEM• Channel Length  based on river network resolution(Threshold area = 100 pixels; roughly 20.25 km2), sameas hydrosheds• Channel roughness  0.025 x (4.0, sinuosity)• Channel width  Andreadis et al. (2013)• Reference Discharge  Andreadis et al. (2013)
Andreadis, K. A., G. J.-P. Schumann, and T. Pavelsky (2013), A simple global river bankfull
width and depth database, Water Resour. Res., 49, 7164–7168, doi:10.1002/wrcr.20440.
https://zenodo.org/record/61758#.V_IoR_ArJaS (Zenodo Link, IDs match Hydrosheds) 8

Compare to data sources• HRR Rivers = 102,229• Hydrosheds Rivers = 102,229• Andreadis et al. (2013) Rivers = 102,229• HRR max pixels = 19,595,996• Hydrosheds max pixels = 19,595,996• Andreadis et al. (2013) max pixels = 19,595,996
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Compare to data sources• HRR Area = 3,183,250 km2• Hydrosheds Area = 3,179,517 km2• Andreadis et al. (2013) Area = 4,201,681 km2
Processing of HRR length/area using:North America Albers Equal Area Conic.prj(per comparison study table)10

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