The global hydrodynamic model
CaMa-Flood (version 3.6.2)
Dai YAMAZAKI
JAMSTEC – Japan Agency for Marine-Earth Science and Technology

5d-yamazaki@jamstec.go.jp
September 2014

NOTE:
10

Please contact to the developer (Dai Yamazaki) for the acquisition of the CaMa-Floodpackage. Do not re-distribute the package to someone else without a notice to the developer.
This is because the developer wants to keep the list of users for making a notice of the
updates and bugs of the CaMa-Flood package.

15

INDEX
1. Introduction ............................................................................................................. 3
1.1 Model Overview ................................................................................................. 3
1.2 Recent Change History ...................................................................................... 4
2. CaMa-Flood Package & Instruction ........................................................................ 620

2.1 Contents of the Package .................................................................................... 6
2.2 Quick Instruction for global simulation ............................................................ 6
2.3 Runoff forcing setting ........................................................................................ 8
2.4 Global Width Database for Large Rivers (GWD-LR) ........................................ 9
2.5 Channel Bifurcation Scheme ............................................................................. 925

2.6 Downscaling ..................................................................................................... 10
2.7 Regionalization ................................................................................................ 1012.8 River network map at different resolutions .................................................... 11
2.7 Visualization with sub-grid information ......................................................... 11
2.9 ArcGIS format .................................................................................................. 1230

3. Main Program Source Codes ................................................................................. 13
3.1 Code Tree ......................................................................................................... 13
3.2 Codes for hydrodynamic calculations .............................................................. 15
4. River Network Map ............................................................................................... 19
4.1 Global 15 minute river network map (global_15min/) .................................... 1935

4.2 Fully-grid-based Map (within global_15min/) ................................................. 23
4.4 Channel Cross-section Parameters ................................................................. 24
5. Input Runoff Forcing ............................................................................................. 25
6. Output Files........................................................................................................... 26
7. Shell Script to execute simulations ....................................................................... 2740

8. Simulation Settings ............................................................................................... 29
8.1 Restart Mode .................................................................................................... 29
8.2 Simulation Time .............................................................................................. 29
8.3 Fully-grid-based map ....................................................................................... 29
8.4 Runoff Interpolation ........................................................................................ 30

45

8.5 Compressed Vector Output .............................................................................. 30
8.6 Routing Scheme ............................................................................................... 30
8.7 Adaptive and Constant Time Step Schemes ................................................... 31
8.8 Usage of netCDF .............................................................................................. 31
References.................................................................................................................. 32

50

Version History ......................................................................................................... 34
2

1. Introduction
1.1 Model Overview
This document is the user’s manual for the global river model, CaMa-Flood

55(Catchment-based Macro-scale Floodplain model).
The CaMa-Flood model is designed to simulate the hydrodynamics in continental-scalerivers. The entire river networks of the world are discretized to the hydrological units named
unit-catchments for achieving efficient flow computation at the global scale. The water leveland flooded area are diagnosed from the water storage at each unit-catchment using the60

sub-grid topographic parameters of the river channel and floodplains. By adapting“gird-vector hybrid river network map” which corresponds one irregular-shaped
unit-catchment to one grid-box, both realistic parameterization of sub-grid topography andeasy analysis of simulation results are achieved. The river discharge and flow velocity arecalculated with the local inertial equation [Bates et al., 2010] along the river network map

65which prescribes the upstream-downstream relationship of unit-catchments. The time
evolution of the water storage, the only one prognostic variable, is solved by the waterbalance equation which considers inflow from the upstream cells, outflow to the downstream
cell and input from runoff forcing at each unit-catchment. Bifurcation of river channels can bealso represented by analyzing high-resolution topography. The detailed description of the70

CaMa-Flood model is found in the description papers [Yamazaki et al., 2011; 2013; 2014a]
The major advantage of the CaMa-Flood simulations is the explicit representation offlood stage (water level and flooded area) in addition to river discharge. In addition to
traditional model validation with gauged river discharge, it is possible to make a directcomparison between model simulations and satellite observations. Observations of water75

surface elevation by satellite altimeters and/or flooded area by SAR and microwave imagers
are very useful to enhance the calibration/validation of the global river model [e.g. Yamazaki
et al., 2012a; Biancamaria et al., 2013]. Explicit representation of flooded area is helpful forflood damage assessment by overlaying it with socio-economic datasets [e.g. Hirabayashi
et al., 2013]. The assimilation of observed flood stage into the CaMa-Flood simulation is a3

80

potential research topic, for optimizing model parameters and extending the forecast skill fornear future flooding.
Another advantage of the CaMa-Flood model is its high computational efficiency of the
global river simulations. The complexity of the floodplain inundation processes is reasonably
approximated to a diagnostic scheme at the scale of a unit-catchment by introducing the85

sub-grid topographic parameters. The cost of the prognostic computation of river discharge
and water storage is optimized by implementing the local inertial equation [Bates et al.,2010] and the adaptive time step scheme [Hunter et al., 2005]. The high computational
efficiency of the CaMa-Flood model is beneficial for computational demanding experiments
such as ensemble/long-term experiments [Pappenberger et al., 2012; Hirabayashi et al.,90

2013] and dynamic coupling between river routine and other hydrological schemes [Cohenet al., 2013].

1.2 Recent Change History- Bug fix [v3.6.2]. OUTFLW output (changed from snapshot to daily ave.), netCDF
restart (2D to 1D conversion), storage only restart (RIVDPH_PRE initialization), netCDF

95

runoff input (SAVE statement).
- River network maps are updated [v3.6.1]. Seamless connection of HydroSHEDS(below 60N) and GDBD (above 60N). Flow direction modification to keep consistency to
GWD-LR [Yamazaki et al., 2014b].
- Simplified restart option only using river and floodplain storages [v3.6.1].

100- Channel bifurcation scheme is included [v3.6.1]- Satellite-based river width (GWD-LR) is included [v3.6.1]- A code for floodplain depth downscaling is included [v3.4.4].
- High resolution regional simulation [v3.4.4].
- Change in the source code structure. Diagnosed variables are moved to the module

105“mod_diag”. The names of some subroutine at “Control Level” are changed. [v3.4.3]

4

- A bug in DEM (25-30E, 10-15N) was fixed. [v3.4.2].
- Floodplain flow along river network is introduced. It is represented by thesubroutine “calc_fldout”. [v3.4.0]. [bug fixed in v3.4.3].
- Stabilized version of the local inertial equation is introduced. The previous hybrid

110

routine is replaced with the new local inertial equation. [v3.3.1].
- The adaptive time step scheme to calculate the maximum acceptable time step length
to avoid the numerical instability is implemented. [v3.0].
- The grid-vector-hybrid river network map (the river network maps in previous versions)is updated in order to optimize the computational efficiency of simulations using the local

115

inertial equation. The simulation speed with the new grid-vector-hybrid map is about 150%
faster than the simulation using the previous maps.
- The vector-based river network map is introduced. The simulation speed using thevector-based map is about 90% faster than that of the grid-vector-hybrid map. [notsupported in v3.6 and later]

120- The simulation using the fully-grid-based river network map is stabilized. The
fully-grid-based map uses the rectangular grid boxes as unit-catchment area, which makes
the coupling of the CaMa-Flood model and another model (e.g. a land surface model)
easier.
- The runoff interpolation considering mass conservation is realized by introducing

125

the input matrix. It is more realistic compared to the nearest point interpolation used in theprevious versions.

5

130

2. CaMa-Flood Package & Instruction
2.1 Contents of the Package
The package of the CaMa-Flood model contains the main programs of global river
simulations, some sets of river network map and its sub-grid topography parameters, asample dataset of input runoff forcing, and some tools used for analysis.

135

Please extend the CaMa-Flood_$(version)_$(date).tar.gz package on your computer.
The you will find the following directories under the main directory $(CaMa-Flood)/ .
Table 2.1: List of directories in the CaMa-Flood package
Directories

Purpose$(CaMa-Flood)/

140

adm/

Administration Directory, contains Mkinclude

gosh/

Shell Scripts Directory, for executing simulations

src/

Main Source Code Directorylib/

Library Code Directorymod/Module Code directorymap/

Map Directory, contains river netwrok maps

inp/

Input Directory, contains a sample inut dataout/

Output Directory, contains some programs for data processing

etc/

Various programs for analysis, visualization, etc

2.2 Quick Instruction for global simulation
The quick instruction to execute a test run with the CaMa-Flood model is described in thissection. The test run is global hydrodynamic simulation at the 15 minute resolution(map/global_15min/) for the period from 1990 to 1991 with the sample input runoff forcing(inp/ELSE_GPCC/Roff/). The local inertial equation is used for the calculation of river145

discharge and flow velocity, and the adaptive time step scheme is activated in order to
optimize the time step. Bifurcation channels are not considered.
(1) Please edit the Mkinclude file, $(CaMa-Flood)/adm/Mkinclude , according to thecomputer environment. If you do not use the MPI or netCDF, comment out the lines#DMPI=-DUseMPI and #DCDF=-DUseCDF, respectively. (NOTE: MPI is not fully supported

6

150

in v3.6 and later). If endian conversion of input map or input runoff is needed, pleaseactivate DEND=-DConvEnd.
(2) The shell script to automatically compile all the source codes is prepared. Go to$(CaMa-Flood)/gosh/ directory, and execute the command:% compile.sh (yes)155

Then, the source codes mod/ lib/ src/ map/ out/ directories are compiled with thecommand % make all. When you put the argument “yes”, the command % make clean is
executed before compiling.
(3) Go to the map directory (map/global_15min/), then execute the following commands tocalculate river discharge climatology and channel cross-section parameters (rivwth.bin and160

rivhgt.bin)% ../s01-channel_params.sh
Note that all the dataset in the CaMa-Flood archive is prepared in “little endian” byteorder. If the default byte order of your computer environment is “big endian”, you have toconvert the endian of the sample dataset. The endian conversion program for 4 byte data165

format, endian4.f90, is prepared in the library directory (lib/).
(4) Go to the shell script directory (gosh/), and edit the executable script global_15min.sh ifneeded. You can modify, for example, the experiment name, the number of OpenMP nodes,
the usage of the adaptive time step scheme, the interpolation with the input matrix, and thelist of output files.

170

After editing the executable shell script, type the command to run the simulation.
% ./global_15min.sh(5) The simulation results are outputted to the running directory specified in the script,$(CaMa-Flood)/out/global_15min/ in the default setting. The progress of the simulation is
written to the log file, run_YYYY.log.

7

175

(6) The output file is in the “plain binary” format, which consists of the sequence (nx*ny) of 4byte real data without any header. The data array is from 180W to 180E (1440 grid cells)
and from 90N to 90S (720 grid cells).

2.3 Runoff forcing setting
180

CaMa-Flood requires daily runoff forcing in plain binary format or netCDF format.
Runoff forcing data should be prepared in “plain binary format” (or Fortran direct access,
GrADS binary, ArcGIS EHdr), and should be named as $(PREFIX)yyyymmdd$(SUFFIX).
The sample runoff data prepared in inp/ELSE_GPCC/Roff/ directory. The runoff file isnamed Roff____yyyymmdd.one by setting PREFIX=”Roff____” and SUFFIX=”.one”.

185

Default runoff data is prepared in the unit [mm/day], and converted in CaMa-Flood to [m3/s]
by setting the seconds in runoff time step DTIN=86400 (daily) and unit conversion ratio
DROFUNIT=1.D-3 (from [mm] to [m]).
NetCDF runoff input can be used by setting LINPCDF=.TRUE., NetCDF runoff directory
CROFDIR, NetCDF runoff file CROFCDF, NetCDF runoff variable name CROFVAR,

190

NetCDF data start date SYEARIN, SMONIN, SDAYIN shoule be specified.
If prepared runoff forcing is different from the default grid coordinate system (i.e. global
domain in Cartesian grid coordinate at 1 degree spatial resolution), a new input matrix
should be generated. Please go to $(map)/ directory, and edit s03-generate_inpmat.sh if therunoff forcing is at linear Cartesian grid coordinate. By executing ../s03-generate_inpmat.sh in

195

map/grid_15min/ directory, a new dimension file “diminfo.txt’ and a new input matrix“inpmat.bin” are generated. Please specify these files in executable shell scripts.
If runoff forcing is prepared at other grid coordinate, Please edit generate_inpmat.F.
There is a part which relates the (lon,lat) of each sub-grid high-resolution pixel to the (ixin,iyin) of input runoff forcing. Please edit these lines according to the grid coordination of your200

runoff forcing.

8

2.4 Global Width Database for Large Rivers (GWD-LR)
Instead of river width parameter estimated by empirical equation (rivwth.bin),satellite-based river width (GWD-LR) can be used. Please go to map/global_15min directory,205

and execute ../s01-channel_params.sh (this step is automatically done when channel
parameter is calculated). The river width parameter based on GWD-LR (rivwth_gwdlr.bin) is
generated. Please Specify the map file rivwth_gwdlr.bin in the shell script gosh/${go_script}.
Note that the GWD-LR has large error in river width above 60N, due to the baseline data
(MODIS water mask at 250m resolution, GDBD flow direction at 1km resolution). Also,

210

simulation is not stable when large lakes exists in target domain. Please do not use
GWD-LR river width in such a case.

2.5 Channel Bifurcation Scheme
Chanel bifurcation scheme is activated by setting LPTHOUT=.TRUE. in the go script.

215

Bifurcation channel can be automatically delineated by analysing the high-resolution
topography.
In order to delineate bifurcation channel, you have to get the original high-resolution
database (HydroSHEDS + GWD-LR + SRTM3 DEM) used to generate river network mapsby FLOW algorithm. The original high-resolution database is not included in the CaMa-Flood220

packagebecause

of

its

data

size

(30GB).

Pleasedownloadthedatabase(sheds_0.005_140807) separately and locate the high-resolution database to map/ directory.
Go to map/global_15min/ directory and make a link % ln –s ../sheds_0.005_140807 sheds .
Then, go to map/global_15min and execute ../s02-set_bifurcation.sh. The list of bifurcation
channels (fldpth.txt) and channel depth map with modification associated with bifurcation

225

channel (rivwth_pth.bin) are generated. Please specify fldpth.txt and rivhgt_pth.bin in thego script.

9

2.6 Downscaling
Simulated floodplain depth can be downscaled onto the original high-resolution DEM.

230

The sample code for downscaling is prepared in etc/downscale_flddph/ directory. The
sample file downscale_flddph.f90 is used to downscale simulated floodplain depth onto theoriginal high-resolution DEM. In the sample file, constant flood depth of 5 m is assumed.
Please specify the map directory and output directory in s00-set_directory.sh . And thenexecute s01-downscale.sh . You have to modify the script s01-downscale.sh to specify the235

simulated flood depth file and target time. The downscaling is performed separately for eachhi-res domain domain because of the RAM limitation. The sample monthly flood depth file isprepared (sample/flddph1990.mon).

Figure 2.1 Example of downscaled floodplain depth.

240

2.7 Regionalization
For regional simulations, tools to extract regional maps from the global maps areprepared. Please go to the sample regional map directory “map/region_15min/”. Go to“map/region_15min/src” directory, and edit the file to specify the domain of regional maps

245

“region_info.txt”. (sample is prepared for the Amazon River)
Execute s01-regional_map.sh which includes cut_domain.f90 (extract regional maps),
combine_hires.f90 (extract sub-grid high-resolution info), set_map.f90 (calculate associate10info from river network maps), and generate_inpmat-1deg.f90 (generate input matrix forregional simulations for 1deg input file). Then, execute s02-wrte_ctl.sh and s03-hires_ctl.sh to250

generate CTL file for GrADS.
In case of delineating bifurcation channels (or high-resolution original database isneeded), execute s04-set_sheds.sh and s05-sheds_ctl.sh in order to regionalize originalhigh-resolution database.
Another procedures (e.g. generate channel cross-section parameters, use GWD-LR river

255

width, set bifurcation channels) are same as the global river network map.
Regional simulations can be executed by just changing map descriptions in theexecutable shell scripts. Sample shell scripts (region_15min) is prepared in gosh/ directory.

2.8 River network map at different resolutions
260

The river network map at different resolutions (6min, 30min) is prepared. The higher
resolution map is mainly developed for regional simulations. Note that the quality of the river
network map above 60N is not ensured because of the uncertainty in baseline topography
data. The lower resolution map is prepared for faster simulations, but the accuracy may belower compared to the simulation with 15min map. Please ask the developer for the access265

to the higher and lower resolution river network map, which is not included in the package.
River network maps at other spatial resolutions or other grid coordination are notavailable at current stage. The developer is currently preparing the package for
automatically generating river network maps at any grid coordination.

270

2.7 Visualization with sub-grid information
The river network maps and simulation results be visualized as raster-grid data, but it canalso be visualized as vector-shape data using sub-grid information of the river network map.
A sample GMT (Generic Mapping Tool) script combined with Fortran90 codes is prepared in$CaMa-Flood/etc/visualization/ directory. Please go to visualization/bin/ directory, and

11

275

compile Fortran90 programs by % make all. Then you can execute GMT script
s01-draw-rivmap.sh. The river network map is visualized in psfile rivmap.ps.

Figure 2.2 Visualization of river network map with sub-grid information using GMT.

280

2.9 ArcGIS format
The plain binary file (Fortran direct access format) is same as the ArcGIS .bsq format (forinteger variable) and .flw format (for real/float variable). These files can be open in ArcGIS
by changing the suffix to .bsq/.flw and by making .hdr file. Information on the domain gridcoordination can be found in GrADS .ctl files prepared in the map directories.

285

12

3. Main Program Source Codes
The programs of the CaMa-Flood global river model are written in Fortran90. The
programming structure follows the basic coding guidelines of Fortran90 as much as possible

290(this was achieved under the collaboration with Dr. Emanuel Dutra in ECMWF). The
program includes the parallelization by OpenMP and MPI. Note that the parallelization by
MPI is only effective in global simulations, and OpenMP must be used for regional
simulation. The netCDF input/output is also supported. The MPI and netCDF schemes
sometimes cause trouble when compiling the codes, so these schemes can be excluded295

from the program by preprocessing of the codes.
The program building is supported by the “make” function, and compiling rules are written
in the “Makefile” in the mod/ lib/ src/ directories. The original files with the suffix (*.F) are
firstly converted to Fortran90 source codes with suffix (*.f90) by preprocessing, and then themain executable program (MAIN_DAY) is built from *f90 source codes using Fortran90

300

compiler. The lines related to the MPI and netCDF schemes are excluded in the
preprocessed *.f90 files if the options for using MPI and netCDF are commented out inMkinclude of $(CaMa-Flood)/adm/ directory.

3.1 Code Tree305

The code trees of the CaMa-Flood program are shown in Table 3.1, Table 3.2 and Table
3.3. The programs are divided into: (1) main program (src/), (2) modules to save variablesin (mod/), and (3) libraries of common and small programs (lib/).
The main program consists of the main executable (MAIN_DAY.F), job control program(CONTROL0.F), initialization programs (INIT_*.F) and programs within the time step loop

310

(called by CONTROLSTEP.F). The main hydrodynamic calculations are written in the sourcecode CALC_*.F, which are called by the control program for physics schemes(CONTROLPHY.F).

13

Table 3.1: The code tree of main programs (src/ directory)
src/

Main program source codes

MAIN_DAY

Main executable program

CONTROL0

Controls the job at level 0

INIT_INPUTNAM

Read namelist

INIT_MAP

Read a river netwrok map

INIT_TOPO

Read topography parameters

INIT_COND

Set initial condition

INIT_TIME

Set simulation time period

CONTROLTSTEP

Iontrols time step integration

315

CREATE_OUTBIN

Create output bunary file

CREATE_OUTCDF

Create output netCDF file

CONTROL_INP

Controls input forcing

CONTROL_PHY

Controls physics, main calculation

CALC_FLDSTG

Calculate flood stage from water storage

CALC_RIVOUT

Calculate river discharge

CALC_FLDOUT

Calculate floodplain flow

CALC_PTHOUT

Calculate bifurcation channel flow

CALC_STONXT

Calculate storage change

CALC_WATBAL

Calculate global water balance error

CONTROL_OUT

Controls output data

CONTROL_REST

Controls restart files

Table 3.2: The code tree of modules (mod/ directory)mod/

Modules to save shared variables

PARKIND1

Variable type setting to avoid machine dependancy

MOD_INPPUT

for input namelist

MOD_TIME

for date and time steps

MOD_MAPfor river netwrok map and sub-grid topography

MOD_PROG

for prognostic variables

MOD_DIAG

for diagnostic variables

MOD_PARAM

for parameters

MOD_OUTPUT

for output files

14Table 3.3: The code tree of libraries (lib/ directory)

320

lib/

Libraries

LIB_DATES

Library to manage time

IGETDAY

function to calculate days in (year month)

LEN_TRIM

function to count the lenggth of a string

ENDIAN4

subroutine to convert the endian of 4byte data

LIB_NETCDF_UTIL

Library to use netCDF

3.2 Codes for hydrodynamic calculations
The main scheme of hydrodynamic calculation is controlled by CONTROLPHY.F. The flowof the hydrodynamic calculation is as follows:

325(1) Diagnose flood stage (CALC_FLDSTG.F).
In CALC_FLDSTG.F, the flood stage is diagnosed from the water storage at each grid cell.
River channel water storage, Sr, floodplain water storage, Sf, river water depth, Dr, floodplain
water depth, Df, and flooded area, Af, are diagnosed from the total water storage of a grid
point, S, by solving either of simultaneous equations (3.1) or (3.2). Either of the330

simultaneous equations (3.1) or (3.2) is chosen by comparing the total water storage, S, andthe flood initiation storage, Sini. The flood initiation storage is given as, Sini=BWL, where B ischannel depth, W is channel width, and L is channel length. For the case that the total water
storage, S, is less or equal to the flood initiation storage, Sini, the simultaneous equations(3.1) are applied:335

Sr  SSrDr 
WL
Sf  0
Df  0Af  0(3.1)

For the case that the total water storage, S, is greater than the flood initiation storage,
Sini, the simultaneous equations (3.2) are applied:15

Sr  S  Sf
Sr
Dr 
WL
Af

Sf   ( Df  D ( A))dA
0

(3.2)

Df  Dr  B
Af  D 1 ( Df )The equation Df=Dr-B in (3.2) means that the water surface elevations of the river

340

channel and the floodplain are same. This equation is based on the assumption that watermass is instantaneously exchanged between the channel and the floodplain to balance thewater surface elevations of the two reservoirs. The function D-1(Df), which is the inverse
function of the floodplain elevation profile D(Af), describes flooded area, Af, as a function offloodplain water depth, Df (see Figure 4.2c).

345(2) Calculate river discharge (CALC_RIVOUT.F)
In CALC_RIVOUT.F, the river discharge from each cell toward its downstream cell
indicated by the river network map is calculated. The river discharge is calculated with thelocal inertial equation [Bates et al., 2010].
The local inertial equation is derived by neglecting the second term of the St. Venant

350

momentum equation (3.3):

Q   Q 2  gA(h  z ) gn 2Q 2

 4/3  0
t x  A 
x
R A

(3.3)

where Q is the river discharge (m3s-1), A is the flow cross section area (m2), h is the flow
depth (m), z is the bed elevation (m), R is the hydraulic radius (m), g is acceleration due togravity (ms-2], n is the Manning’s friction coefficient (m-1/3s-1). The x and t are the flow

355

distance and time, respectively. The first, second, third, and fourth terms represent the local
acceleration, advection, water slope, and friction slope, respectively. The explicit form of the
he local inertial equation (3.4) is used in the CaMa-Flood model:

16

Q t  

Q t  t gAS t gn 2 Q t 
1 R4/3 A 



.

(3.4)

where S is the water surface slope, Qt is the discharge at the previous time step, and360

Qt+Δt is the river discharge between the time t and t+Δt. The hydraulic radius R isapproximated by flow depth hflw. The Manning’s coefficient is set to n=0.03.
The negative river discharge, which may occur in the calculation by the local inertial
equation and the diffusive wave equation, represents the backward water flow from thedownstream grid cell towards the current grid cell.

365

The flow limiter is introduced in CALC_RIVOUT.F in order to prevent the situation that the
total outflow from a grid exceeds the total water storage of the grid. The amount of the waterleaving each grid cell is calculated, and the modification rate is applied on the riverdischarge calculated by the local inertial equation when the total outflow is larger than the
total storage of the grid.

370(3) Calculate floodplain flow (CALC_FLDOUT.F) *optional, recommended
Floodplain discharge (i.e. high water channel flow) is calculated when floodplain flow
scheme is activated in the shell script (LFLDOUT=.TRUE.). Floodplain discharge is also
calculated by the local inertial equation (Eq. 3.4). The flow area A is calculated by dividing
floodplain storage by channel length. The flow depth h is given by the floodplain depth. The

375

manning’s coefficient for floodplain flow is set to n=0.10.
(4) Calculate bifurcation channel flow (CALC_PTHOUT.F) *optional
Bifurcation channel discharge is calculated when bifurcation flow scheme is activated in
the shell script (LPTHOUT=.TRUE.). Bifurcation channel discharge is also calculated by the
local inertial equation (Eq. 3.4). The flow area A and flow depth h is calculated for

380

aggregated bifurcation channels with same bifurcation channel elevations. The manning’s
coefficient for floodplain flow is set to n=0.03 for river bifurcation and n=0.10 for overland
bifurcation.

17

Discharge in each bifurcation channel is saved as pthflwYYYY.pth (dimension,
npthout*npthlev), while net bifurcation flow at each grid is saved as pthoutYYYY.bin

385(dimension: nx*ny)(5) Calculate storage change (CALC_STONXT.F)
The storage change at each grid cell from the time t to t+Δt is calculated by the massconservation equation (3.5):

Sit t  Sit  k

Upstream390

Qkt t  Qit t  Aci Rit t(3.5),

where Sit and Sit+Δt represent the water storage of grid i at the time t and t+Δt, Qit andrepresents the river (+ floodplain + bifurcation channel) discharge outflow from grid i at time t,
Qkt represents the river (+ floodplain + bifurcation channel) discharge inflow from the
upstream grid k, Aci is the unit-catchment area of grid i, Rit represents the input runoff to thegrid i.

395

18

4. River Network Map
The river network map and its associated sub-grid topographic parameters required for
the CaMa-Flood simulations are stored in the $(CaMa-Flood)/map/ directory. These maps

400

are generated from the fine-resolution global flow direction maps (HydroSHEDS [Lehner etal., 2008]; GDBD [Masutomi et al., 2009] ) and Digital Elevation Models (SRTM3 andSRTM30 [Farr et al., 2007]) by the upscaling algorithm (the FLOW method [Yamazaki et al.,2009]). The errors in the baseline fine-resolution data were removed as much as possible
before applying the FLOW method [e.g. Yamazaki et al., 2012b; Yamazaki et al/. 2014b].

405

The dataset in the map/ directory is prepared in the “plain binary” format, which consistsof the sequence (nx*ny) of 4 byte real data without any header. The data array is from 180W
to 180E and from 90N to 90S in case of global gridded maps. The byte order of the data is“little endian”. For the conversion of the endian, the subroutine endian4.f90 is prepared in
the library/ directory. The description files (*.ctl) to visualize the data on GrADS are

410

included along with the map datasets.

4.1 Global 15 minute river network map (global_15min/)
The three sets of a river network map and topographic parameters are prepared in the
CaMa-Flood v3.2 package. The global_15min/ directory contains the grid-vector-hybrid

415

river network map at the 15’ resolution. The river network map is upscaled from the 3”
HydroSHEDS (between 60N and 60S) and the 1km GDBD (above 60N). Each 15’ grid box
corresponds to one unit-catchment (Figure 4.1a), so that the grid-vector-hybrid river network
map is easy to handle in the analysis and visualization procedure, though the computational
efficiency is about half of the vector-based river network map.

420

19

Figure 4.1: Discretization of unit-catchments in the river network map. The outlet pixel ofeach unit-catchment is marked with a blue circle.

The information of the dimension of the river network map is written in the params.txt.

425

The west and north domain boundary (west, north), the size of the river network map(east-west grid number, nx; north-south grid number, ny), size of the grid box (gsize), thenumber of floodplain layers (nfpl) are listed, as well as the number of the hires databasearea (narea) and the resolution of the hires database (csize).
The river network map (nextxy.bin) prescribes the downstream cell of each grid cell. The

430

records 1 and 2 denote the downstream grid point ix (nextx) and iy (nexty), respectively. A
set of topographic parameters (Figure 4.2a) consists of the unit-catchment area Ac [m2](grarea), base elevation Z [m] (elevtn), channel length L [m] (rivlen), channel depth B [m](rivhgt), channel width W [m] (rivwth), downstream distance X [m] (nxtdst), and floodplain
elevation profile Df=D(Af) [m] (fldhgt). The floodplain elevation profile is the CDF function

435(Figure 4.2b) of the height above the nearest river channel within each unit-catchment(Figure 4.2c), which is used to calculate the flooded area Af [m2] from the flood depth Df [m].
10 values from each 10th percentile of the CDF function are stored in fldhgt.bin. For
example, the record 3 of the fldhgt.bin represents the flood depth [m] of the unit-catchment
when 30% of its area is flooded.

20

440

Channel width and depth parameters (rivwth.bin, rivhgt.bin) are calculated using
empirical equations (see map/s01-channel_params.sh). The satellite-based river width fromGWD-LR [Yamazaki et al., 2014b] is also prepared (width.bin).
The input matrix (lookup table) for interpolating gridded runoff forcing to irregularunit-catchments is also prepared (inpmat-1deg.bin and inpmat-1deg.txt). Each

445

unit-catchment receives input water mass from the input grid boxes which overlap theunit-catchment. The input water mass into the grid cell i is calculated by Equation (4.1):

Fi  N Ai , j R j(4.1)

where Fi is the input water mass into the grid cell i [m3s-1], Ai, j is the overlapped area
between the unit-catchment of the grid cell i and the runoff grid box j [m 2], Rj is the runoff

450

forcing of the runoff grid box j [ms-1]. N is the maximum number of the overlapped runoff gridboxes for one unit-catchment (inpnum) which determines the size of the input matrix(nxin*nyin*inpnum), and it is written in the dimension file (diminfo.txt). Records 1 and 2 of
the input matrix represents the (ixin, iyin) location of the corresponding runoff grid box, andthe record 3 represents the overlapped area Ai,j [m2] (inpa).

455

A file to specify dimensions of simulation (domain, resolution, number of CaMa-Floodgrids and input grids, input matrix filename) is prepared (e.g. diminfo_1deg.txt, for simulation
wit 1 degree runoff input).
Table 4.1: The river network map and topographic parameters
File

Variable

SymbolDescription

params.txt
nextxy.bin

nextx
nexty
grareaelevtnrivlenrivhgtrivwthwidth
nxtdstfldhgt
inpx
inpy
inpa
-

jx
jy
Ac
Z
L
B
W

Map Parameters
Downstream X
Downstream Y
Unit-catchment Area
Base Elevation
Channel Length
Channel Depth
Channel Width
GWD-LR width
Downstream Distance
Floodplain Elevation Profile
Corresponding Input Grid X
Corresponding Input Grid Y
Area of input grid XY
Dimention Info (1deg input)

grarea.bin
elevtn.bin
rivlen.bin
rivhgt.bin
rivwth.bin
width.bin
nxtdst.bin
fldhgt.bin
inpmat-1deg.bin

diminfo_1deg.txt

X
X
Aij
-

Unit
(rec=1)(rec=2)
[m2]
[m]
[m]
[m]
[m]
[m]
[m]
(rec=1~10) [m](rec=1)(rec=2)(rec=3)[m2]

Formattext
integer
real
real
real
real
real
real
real
real
integer
integer
real
text

460
21

Table 4.2: The river network map and topographic parameters
File

Variable

SymbolDescription

Unit

Formatlsmask.binbasin.binbsncol.bin
lonlat.bin

lon
lat
upareaupgrid-Land ID of corresponding hires area
Bain ID
Basin Color Patern for Visualization
Longitude, catchment outlet(rec=1)
Latitude, catchment outlet(rec=2)
Upstream Drainage Area
Upstream Grid Number
GRDC gauge location
LEGOS Envisat station location

deg
deg
[m2]
-

integer
integer
integer
real
real
real
integertxt
txt

uparea.bin
upgrid.bin
grdc_loc.txt
envisat_loc.txt(a) Sub-grid parameters(c) Floodplain Elevation profile

River Channel

L
Sr

Sf
Df

Dr

Z

W
Ac
Af

Sf

B
Ac
Af

Flood water depth [m]Floodplain
160
140

120
100

80
60

40
20

0
0

20

40

60

80

100

Flood area fraction [%]Figure 4.2: (a) Schematic illustration of the sub-grid parameters for the river channel and465

floodplains. (b) Unit-catchment topography. The height above the nearest river channel isshown by the background color. (c) Floodplain elevation profile.

Some additional datasets associated with the river network map are also prepared in thesame directory, and they are listed in Table 4.2. These associated datasets are mainly usedin the analysis and visualization of the simulation results. The locations of the GRDC gauges

470

are listed in the grdc_loc.txt, whose data indicates (from left to right):
GRDC-ID, River, Station, Downstream Info, Longitude, Latitude, Grid (X, Y), Drainage Area.

The downstream info “a” indicates the gauge is allocated most downstream within theriver basin, while “b” indicates there is another gauge in the downstream. The locations of
the Envisat virtual stations (LEGOS: http://www.legos.obs-mip.fr/soa/hydrologie/hydroweb/Page_2.html) are

475

listed in envisat_loc.txt, which represents (from left to right):
ID, Virtual Station Name, Longitude, Latitude, Grid (X, Y), Drainage Area.

Some high-resolution data required for generating input matrix and floodplain depth
downscaling are prepared in map/global_15min/hires/ directory. The high-resolution data is

22

480

divided into 13 continental regions as in “location.txt” file. The regions below 60N (except
na2, eu3, and as4) are based on HydroSHEDS and SRTM3. These hires data is prepared at
Cartesian grid coordination system at the resolution of 0.005 degree. The regions above
60N (na2, eu3, and as4) are based on GDBD and GTOPO30, and prepared in Lambertequal area projection at 1km resolution (following Hydro1k). The parameters of Lambert

485

equal area projection can be found in the code add_lonlat.f90.
The data named $(area).catmxy describes the CaMa-Flood grid (iXX,iYY) of each hires
pixel (ix,iy). The data named $(area).flddif describes the height above the ground elevationof each pixel [m].

4.2 Fully-grid-based Map (within global_15min/)490

Instead of using irregular unit-catchments, the CaMa-Flood model can stably executehydrodynamic simulations with traditional rectangular grid boxes as its computational
elements (fully-grid-based approach). In the fully-grid-based approach, the irregularunit-catchment area is replaced with the area of the rectangular grid box of the 15’ resolution
Cartesian coordinate system, while the river network map of the grid-vector-hybrid approach495

is diverted. The channel length and downstream distance are also replaced with the
distance between the centers of the grid box and its downstream grid box. The topographic
parameters for the fully-grid-based approach are prepared in the same directory of thegrid-vector-hybrid approach.
Table 4.3: The files required in the fully-grid-based approach

500

File

Grid-vector Hybrid

Grid-based

Dimention Information
Unit-catchment Area
Channel Length
Downstream Distance
Input Matrix

diminfo_1deg.bin
grarea.binrivlen.bin
nxtdst.bin
inpmat-1deg.bin

diminfo_1deg_grid.bin
grarea_grid.binrivlen_grid.bin
nxtdst_grid.bin
inpmat-1deg_grid.bin

23

4.4 Channel Cross-section Parameters
The channel cross-section parameters (channel length and channel depth) are estimatedby an empirical function of river discharge climatology, while the other topographic

505

parameters are explicitly derived from the fine-resolution flow direction map and DEM.
Firstly, the climatology of daily river discharge is calculated by the calc_rivout.F program
in $(CaMa-Flood)/map/ directory. The climatology of daily river discharge is written to the
output file rivout.bin. The record 1 is the annual maximum of 30-day moving average of
upstream runoff (m3/s), Rup, while the record 2 represents the annual averaged river

510

discharge (m3/s). Here, the annual maximum of 30-day moving average of upstream runoff,
Rup, is introduced because it is assumed that the size of a channel cross-section isdetermined by flood peak discharge rather than the annual average discharge.
Second, the channel cross-section parameters (channel width (m), W; Channel depth(m), B) are calculated by the program calc_rivwth.F in the $(CaMa-Flood)/map/ directory.

515

The channel width rivwth.bin and channel depth rivhgt.bin are generated. These twoparameters were derived by the following empirical equations:0.75
W  max[ 0.70  Rup,10.0](4.2),

0.40
B  max[ 0.14  Rup,2.00](4.3),

where W is the channel width (m), B is the channel depth (m), and Rup is the520

annual maximum of 30-day moving average of upstream runoff [m3s-1].
Note that the uncertainty in these cross-section parameters is still very high, so extensive
calibration is recommended when you set up a new simulation. The coefficients of Equation(4.2) and (4.3) can be changed in the shell script s01-channel_params.sh.
For generating cross-section parameters, go to the map file directory (e.g.

525map/global_15min/) and execute % ../s01-channel_params.sh .

24

5. Input Runoff Forcing
A set of sample input runoff forcing is prepared at $(CaMa-Flood)/inp/ELSE_GPCC/Roff/

530

directory. The sample input data is prepared for the years 1990 and 1991, from the output of
Ensemble Land State Estimator (ELSE) [Kim et al., 2010]. The sample runoff is calculatedusing the land surface model MATSIRO forced by the climate forcing from the JRA-25
reanalysis with precipitation correction using GPCC. The sample runoff data is at 1 degree
resolution, and prepared in the “plain binary” format. The data array is from 180W to 180E

535

and from 90N to 90S. Note that the byte order of the sample data is “little endian”, so thatendian conversion may be required according to the computer environment.
The naming convention of the input runoff forcing is $(prefix)YYYYMMDD$(suffix). In
case of the sample data, the prefix is “Roff____” and the suffix is “.one”. This setting can bechanged in a shell script in $(CaMa-Flood)/gosh/ directory.

540

The default unit of runoff input is [mm/day] and it’s converted to [m3/s] in simulation.
another unit [water mass / unit area / unit time] can be used by changing the following
parameters in gosh script. DTIN: seconds in one runoff time step (default set to 86400 fordaily runoff), DROFUNIT: runoff unit conversion ratio (set to 1.D-3 in default for conversion
from [mm] to [m])545

If you want the runoff input forcing for the full period other than the sample data period(1990 and 1991), please contact to the CaMa-Flood developer. You can also replace thesample input data with another runoff dataset. Runoff input files in netCDF format can also
be used. Sample netCDF runoff at 0.5 degree is prepared in inp/ELSE_GPCC/runoff_nc/
directory.

550

In case the grid coordinate system of the runoff forcing is different from the sample
dataset, you have to re-calculate the input matrix inpmat-$(resolution).bin for the runoff
interpolation scheme. The input matrix can be generated by editing and executing the shell
script map/s03-generate_inpmat.sh. The default value in map/s03-generate_inpmat.sh can beused to generate the input matrix for the sample 0.5 deg netCDF runoff.

555
25

6. Output Files
The CaMa-Flood has, in a default setting, the 11 output variables listed in Table 7.1.
These output files are in plain binary format at the same grid coordinate system as the river
network map. The output is daily in a default setting. Undefined value (for ocean grids) is set

560

to 1.e20.
Table 6.1 List of output variables
File

Variable Symbol

Description

Unit

FormatrivoutYYYY.bin
rivstoYYYY.bin
rivdphYYYY.bin
rivvelYYYY.bin

rivoutrivstorivdphrivvelQr
Sr
Dr
V

River Discharge
River Wter Storage
River Water Depth
River Flow Velocity[m3/s]
[m3]
[m]
[m/s]

real
real
real
real

fldoutYYYY.bin
fldstoYYYY.bin
flddphYYYY.bin
fldareYYYY.bin
fldfrcYYYY.bin

flddph
fldstoflddphfldarefldfrc

Qf
Sf
Df
Af
Ff

Floodplain Flow
Floodplain Water Storage
Floodplain Water Deoth
Flood Area
Flood Fraction[m3/s]
[m3]
[m]
[m2]
[m2/m2]

real
real
real
real
real

sfcelvYYYY.bin
outflwYYYY.bin
storgeYYYY.bin

sfcelvoutflw
storge

WSE
Qall
Sall

Water Surface Elevation
Total Discharge (Qr + Qf)
Total Storage (Sr + Sf)[m][m3/s]
[m3]

real
real
real

pthoutYYYY.bin
pthflwYYYY.pth

pthoutpthflw

Qp-

Net bifurcation flow from grid (ix,iy)
Flow of bifurcation channel (ipth, ilev)[m3/s][m3/s]

real
real

Flood fraction represents the fraction of the flooded area to the unit-catchment area of
each grid cell. The water surface elevation is calculated as WSE=Z-B+Dr, where Z is base565

elevation, B is channel depth. Flood Fraction is the fraction of flooded area to theunit-catchment area of each grid cell. Note that flooded area and flood fraction is calculated
based on the irregular shaped unit-catchment, so that they are not suitable for a rigorouscomparison against gridded dataset. The river discharge and flow velocity are outputted asdaily average, while the other variables are outputted as the instantaneous value at GMT

570

00:00 of each day.
In the sample executable shell script, the output files are written in the running directory$(CaMa-Flood)/gosh/tmp/$(ExerimentName)/ . After the calculation, it is recommended
to move the running directory to the output directory $(CaMa-Flood)/out/ where someanalysis tools are prepared (such as conv_day2mon.sh, monthly average calculation)

575

26

7. Shell Script to execute simulations
Executable shell scripts to run a CaMa-Flood simulation are prepared in the shell script
directory $(CaMa-Flood)/gosh/. The sample executable shell script is global_15min.sh. In
the executable shell script, the simulation settings are written in the input namelist

580“input_flood.nam”, and then the simulation is executed in the running directory specified in
the shell script.
The setting of the sample executable shell script (global_15min.sh) is as follows.
- BASE Directory: BASE=”$(CaMa-Flood)/” or BASE=`pwd`/../- Experiment name: EXP=“global_15min”

585- The simulation is executed in the running directory RDIR=“${BASE}/out/$EXP”. The
OpenMP parallelization with 4 CPUs.
- Floodplain flow is activated (LFLDOUT=.TRUE.), bifurcation channel scheme isdeactivated(LPTHOUT=.FALSE.).

Storageonlyrestartisdeactivated(LSTOONLY=.FALSE.)

590- River discharge is calculated by the local inertial equation (the local inertial equation forsmall slope areas; the diffusive wave equation for steep areas). Adaptive time step isactivated (LADPSTP=.TRUE.).
- Simulation time is set from 1990 to 1991 (YSTART, YEND). The simulation starts from thezero storage condition (SPINUP=2) and spin-up period is set to 1 years (NSP=1).

595

-

The

river

networkmap

andtopography

parameters

in

the

map

directory

FMAP=”$(CaMa-Flood)/map/global_15min/” are used. Channel width parameter is fromGWD-LR (CRIVWTH=${FMAP}/rivwth_glwlr.bin), channel depth parameter is fromempirical equation (CRIVHGT=${FMAP}/rivhgt.bin).
- Input runoff forcing is interpolated by using the input matrix (LINTERP=.TRUE. ;600

CINPMAT=${FMAP}/inpmat-1deg.bin). Runoff input forcing in the runoff directory
CRUNOFFDIR="${BASE}/inp/ELSE_GPCC/Roff/" is used.

27

- The output is written in the running directory COUTDIR="./" . Total river discharge (outflw),
river water depth (rivdph) and flooded area (fldare), flooded fraction (fldfrc), water surface
elevation (sfcelv), total water storage (storge) are outputted, while the other variables are605

not written (variables which do not have to be output are set to “NONE”). The bifurcation
channel flow output is automatically set to NONE in the simulation when bifurcation channel
scheme is deactivated.

28

8. Simulation Settings
610

The simulation options available in the CaMa-Flood model are explained in this section.
The switches (or variables) to control the simulation setting are stored in “mod_input.F”, andthey can be changed by editing the input namelist “input_flood.nam”.

8.1 Restart Mode
The CaMa-Flood can be run from the zero-storage condition or from the initial condition

615

given by a restart file. For the simulation from the zero-storage condition, set IRESTART=2(default). Spin-up period can be specified by setting NSP=$(spin-up years).
For the simulation from the restart file, set IRSTRT=1, and specify the restart file directory(CRESTDIR) and the restart file name (CRESTSTO). The restart files are outputted at the endof each year as defaults (RESTFREQ=0), but daily restart file can be acquired by setting

620

RESTFREQ=1.
For discharge calculation by local inertial equation, discharge and flood stage of theprevious time step is required for a strict restart. When restart only from water storage ispreferred, please change the setting in gosh script to LSTOONLY=.TRUE.

625

8.2 Simulation Time
Simulation time can be specified at specific dates by editing ISYEAR, ISMON, ISDAY (forthe start date, 00:00am) and IEYEAR, IEMON, IEDAY (for end date, 00:00am).

8.3 Fully-grid-based map
630

Instead of using irregular-shaped unit-catchment, the CaMa-Flood simulation can be
executed with the fully-grid-based river network map with rectangular grid-boxes (for details,see [Yamazaki et al, 2013]). For this purpose, please replace the topographic parameters ina map directory from the one with the irregular unit-catchments (diminfo.txt, grarea.bin,
nxtdst.bin, rivlen.bin, impmat-1deg.bin) to the ones with the rectangular grid-boxes

29

635

(diminfo_grid.txt,

grarea_grid.bin,

nxtdst_grid.bin,rivlen_grid.bin,

impmat-1deg_grid.bin). The sample shell script to execute a simulation with the
fully-grid-based map is prepared in gosh/ directory (test_fullgrid.ksh).

8.4 Runoff Interpolation
640

Runoff forcing can be inputted to unit-catchment by the “nearest point interpolation” or
the “runoff interpolation scheme with mass conservation”. The nearest point interpolation is
activated by setting LINTERP=.FALSE. . The nearest point interpolation is valid only wheneither of the grid-vector-hybrid map or the fully-grid-based map is used. The runoff
interpolation scheme with mass conservation is activated by setting LINTERP=.TRUE. and645

by specifying the input matrix name (CINPMAT).

8.5 Compressed Vector Output
In order to reduce the size of the output files, the compressed vector format which only
writes the values on land grid cells can be activated by setting LOUTVEC=.TRUE. . The

650

compressed vector output can be converted to the normal 2D map by using the script
conv_vec2map.sh in the out/ directory.

8.6 Routing Scheme
Floodplain flow routing can be activated by setting LFLDOUT=.TRUE. .

655

Bifurcation channel scheme can be activated by setting LPTHOUT.TRUE. . Bifurcation
channel parameters must be generated in the map directory by map/s02-set_bifurcation.sh .
The kinematic wave routing can be used by setting LKINE=.TRUE. .
The floodplain inundation scheme can be deactivated by setting LFLD=.FALSE. . Notethat the run without floodplain inundation is not stable with the diffusive wave equation, so

660

the no floodplain option must be used with the kinematic wave equation (LDIFF=.FALSE.).

30

8.7 Adaptive and Constant Time Step Schemes
The adaptive time step scheme is activated by setting LADPSTP=.TRUE. and set the time
step DT=86400 (1 day). Then the adaptive time step routine automatically selects the665

maximum acceptable time step at the initiation of the daily calculation loop in contrplphy.F.
Note that the adaptive time step scheme is valid only when the local inertial equation is used
(LDIFF=.TRUE.).
In order to use the constant time step scheme, deactivate the adaptive time step
(LADPSTP=.FALSE.) and manually set the time step DT=$(timestep_in_sec).

670

8.8 Usage of netCDF
The netCDF I/O commands are supported in the CaMa-Flood model. Please activate theflag DCDF=-DUseCDF in $(CaMa-Flood)/adm/Mkinclude. The netCDF I/O is activated by
the following flags in the namelist: for river network maps (LMAPCDF); for restart data

675

(LRESTCDF), and output data (LOUTCDF). Note that netCDF river network map is mainly
used in ECMWF, and not included in the sample package.

31

References
680

Bates, P. D., M. S. Horrit, and T. J. Fewtrell (2010), A simple inertial formulation of theshallow water equations for efficient two-dimensional flood inundation modeling, J.
Hydrol., 387, 33-45, doi:10.1016/j.jhydrol.2010.03.027.
Biancamaria, S., D. Yamazaki, and V. Pedinotti, 2013, Impact of SWOT orbit subcycles onriver studies, EGU 2013 General Assembly.

685

Cohen, S., Kettner, A.J., and Syvitski, J.P.M., 2013. WBMsed: a distributed global-scaleriverine sediment flux model - model description and validation. Computers andGeosciences, 53, 80-93, doi: 10.1016/j.cageo.2011.08.011.
Farr, T. G., et al. (2007), The Shuttle Radar Topography Mission. Rev. Geophys. 45, RG2004,
doi:10.1029/2005RG000183.

690

Hirabayashi, Y., R. Mahendran, S. Koirala, L. Konoshima, D. Yamazaki, S. Watanabe, H.
Kim, S. Kanae (2013) Global flood risk under climate change, Nature Climate Change,
3, 816-821, doi:10.1038/nclimate1911.
Hunter, N. M., M. S. Horritt, P. D. Bates, W. D. Wilson, and M. G. F. Werner, (2005) An
adaptive time step solution for raster-based storage cell modeling of floodplain
inundation, Advances in Water Resources, 28, 975–991.

695

Lehner, B., K. Verdin, and A. Jarvis (2008), New global hydrography derived fromspaceborne elevation data, EOS Trans. AGU, 89(10), doi:10.1029/2008EO100001.
Masutomi, Y., Y. Inui, K. Takahashi, and U. Matsuoka (2009), Development of highly
accurate global polygonal drainage basin data, Hydrol. Processes, 23, 572-584,
doi:10.1002/hyp.7186.

700

705

Pappenberger, F., E. Dutra, F. Wetterhall, and H. L. Cloke (2012) Deriving global flood
hazard maps of fluvial floods through a physical model cascade, Hydrol. Earth Syst.
Sci., 16, 4143-4156, doi:10.5194/hess-16-4143-2012.
Yamazaki, D., T. Oki., and S. Kanae (2009), Deriving a global river network map and its
sub-grid topographic characteristics from a fine-resolution flow direction map, Hydrol.
Earth Syst. Sci., 13, 2241–2251.
Yamazaki, D., S. Kanae, H. Kim, and T. Oki (2011), A physically-based description offloodplain inundation dynamics in a global river routing model. Water Resour. Res. 47,
W04501, doi:10.1029/2010WR009726.

710

Yamazaki, D., H. Lee, D. E. Alsdorf, E. Dutra, H. Kim, S. Kanae, and T. Oki (2012a),Analysis of the water level dynamics simulated by a global river model: A case study in
the Amazon River, Water Resour. Res., 48, W09508, doi:10.1029/2012WR011869.

32

Yamazaki, D., C. Baugh, P. D. Bates, S. Kanae, D. E. Alsdorf, and T. Oki (2012b),
Adjustment of a spaceborne DEM for use in floodplain hydrodynamic modeling. J.
Hydrol., 436-437, 81-91, doi:10.1016/j.jhydrol.2012.02.045.

715

720

Yamazaki, D., G. A. M. de Almeida, and P. D. Bates (2013), Improving computational
efficiency in global river models by implementing the local inertial flow equation and avector-based river network map, Water Resources Research, published online.
Yamazaki, D., T. Sato, S. Kanae, Y. Hirabayashi, and P. D. Bates (2014a), Regional ﬂ ood
dynamics in a bifurcating mega delta simulated in a global river model, Geophys. Res.
Lett., 41, doi:10.1002/2014GL059744.
Yamazaki, D., F. O ’ Loughlin, M. A. Trigg, Z. F. Miller, T. M. Pavelsky, and P. D. Bates(2014b), Development of the global width database for large rivers, Water Resour. Res.,50, doi:10.1002/2013WR014664.

33

725

Version History
CaMa-Flood Ver 1
The first version developed in U-Tokyo as a part of the master thesis of the developer.
This version was used for the simulations in [Yamazaki et al., 2011, WRR].
CaMa-Flood Ver 2730

The program was improved under the collaboration with ECMWF. Many schemes for
improving the computational efficiency have been implemented to the model, including the
2D-map to 1D-vector conversion and parallelization using OpenMP and MPI. This version
was used for the simulations in [Yamazaki et al., 2012a, WRR].
CaMa-Flood Ver 3735

The routing scheme was finally stabilized in this version by implementing the local inertial
equation developed in U-Bristol.
-

Ver 3.0: Implementation of “the local inertial equation” and “the adaptive time step
scheme”-

740

Ver 3.1: New river network maps in which the elevations of river mouth are corrected
to 0 m.

-Ver 3.2: Implementation of “the vector-based river network map”, and “the runoff
interpolation considering mass conservation”. Many additional changes are included
along with these new schemes.

-745

Ver 3.3.0: The hybrid routing which uses both of the local inertial equation and the
diffusive wave equation. The error of discharge calculation in high slope areas was
fixed. (problem solved in v3.3.1)-

Ver 3.3.1: The stabilized local inertial equation (instead of the hybrid routing). Thisversion is used for the simulation in [Yamazaki et al , 2013]

34

-

750

755

Ver 3.4.0: Floodplain flow is implemented. Minor changes in model structure (e.g.
diagnostic variable, subroutine names at the control level.)-

Ver 3.4.4: Regionalization, Downscaling, Input matrix generation.

-

Ver 3.4.5: Bug fix in elevation map.

-

Ver 3.5: Test Version for Bifurcation Flow (not distributed)-

Ver 3.6.0: Test Version for Global Bifurcation and GDW-LR-

Ver 3.6.1 Distributed Version: Global Bifurcation Flow, GWD-LR, etc.

-

Ver 3.6.2 Bug fix.

35