Geografic-Information-System/raster/r.topmodel/r.topmodel.html

<h2>DESCRIPTION</h2>

<b><em>r.topmodel</em></b> simulates TOPMODEL which is a physically based
hydrologic model.

<h3>Selected Parameters:</h3>

<dl>
<dt><b>parameters</b></dt>
<dd>
This file contains TOPMODEL parameters that describe the study area. Any lines
starting with a # sign or empty lines are ignored.
<div class="code"><pre>
# Subcatchment name
Subcatchment 1

################################################################################
# A [m^2]: Total subcatchment area
3.31697E+07

################################################################################
# qs0 [m/h]:	Initial subsurface flow per unit area
#		  "The first streamflow input is assumed to represent
#		  only the subsurface flow contribution in the watershed."
#								- Liaw (1988)
# lnTe [ln(m^2/h)]: Areal average of ln(T0) = ln(Te)
# m [m]:	Scaling parameter
# Sr0 [m]:	Initial root zone storage deficit
# Srmax [m]:	Maximum root zone storage deficit
# td [h]:	Unsaturated zone time delay per unit storage deficit
#		  if greater than 0.
#  OR
# -alpha:	Effective vertical hydraulic gradient if not greater than 0.
#		  For example, -10 means alpha = 10.
# vch [m/h]:	Main channel routing velocity
# vr [m/h]:	Internal subcatchment routing velocity

#     qs0      lnTe         m       Sr0     Srmax  td/alpha       vch        vr
 0.000075        4.    0.0125    0.0025     0.041       60.    20000.    10000.

################################################################################
# infex:	Calculate infiltration excess if not zero (integer)
# K0 [m/h]:	Surface hydraulic conductivity
# psi [m]:	Wetting front suction
# dtheta:	Water content change across the wetting front

#   infex         K       psi    dtheta
        0        2.       0.1       0.1

################################################################################
# d [m]:	Distance from catchment
#		  The first value should be the mainstream distance from
#		  the subcatchment outlet to the catchment outlet.
# Ad_r:		Cumulative area ratio of subcatchment (0.0 to 1.0)
#		  The first and last values should be 0 and 1, respectively.

#   d  Ad_r
    0   0.0
 1000   0.2
 2000   0.4
 3000   0.6
 4000   0.8
 5000   1.0
</pre></div>
</dd>

<dt><b>input</b><dt>
<dd>
This file contains observed weather data.
<div class="code"><pre>
# ntimesteps:   Number of time steps
# dt [h]:       Time increment per time step

# ntimesteps   dt
365            24

################################################################################
# R [m/dt]:     Rainfall
# Ep [m/dt]:    Potential evapotranspiration

# R             Ep
0.000033        0.000000
0.000053        0.011938
0.004821        0.000000
.
.
.
</pre></div>
</dd>

<dt><b>obsflow</b></dt>
<dd>
Compare simulated flows with observed flows and calculate the model
efficiency. This file contains observed flow data and the number of records
should match the number of time steps (ntimesteps in the input file).
<div class="code"><pre>
# Qobs [m^3/dt]: Observed flow per time step
2568918.24
1668573.562
1039800.24
.
.
.
</pre></div>
</dd>

<dt><b>timestep</b></dt>
<dd>
If a time step is specified, output will be generated for the specific time
step in addition to the summary and total flows at the outlet. This parameter
can be combined with topidxclass to specify a time step and topographic index
class at the same time. If no topidxclass is given, output will be generated
for all the topographic index classes.
</dd>

<dt><b>topidxclass</b></dt>
<dd>
If a topographic index class is specified, output will be generated for the
given topographic index class. This parameter can be combined with timestep. If
no timestep is given, output will be generated for all the time steps.
</dd>

<dt><b>topidx</b>, <b>ntopidxclasses</b>, <b>outtopidxstats</b></dt>
<dd>
The <b>topidx</b> map can optionally be used for creating a new topographic
index statistics file. This map has to be already clipped to the catchment
boundary. The entire range of topographic index values will be divided into
<b>ntopidxclasses</b> and the number of cells in each class will be reported in
the <b>outtopidxstats</b> file using the following command:
<div class="code"><pre>
r.stats -Anc input=[topidx] output=[outtopidxstats] nsteps=[ntopidxclasses]
</pre></div>
These three parameters can be omitted unless a new topidxstats file needs to be
created.
</dd>
</dl>


<h2>REFERENCES</h2>

Cho, H., 2000. GIS Hydrological Modeling System by Using Programming Interface
of GRASS. Master's Thesis, Department of Civil Engineering, Kyungpook National
University, Korea.
<p>
Beven K., R. Lamb, P. Quinn, R. Romanowicz, and J. Freer, 1995. TOPMODEL, in
V.P. Singh (Ed.). Computer Models of Watershed Hydrology. Water Resources
Publications.
<p>
Liaw, S.C., 1988. Streamflow Simulation Using a Physically Based Hydrologic
Model in Humid Forested Watersheds. Dissertation, Colorado State University,
CO. p163.


<h2>SEE ALSO</h2>
<em>
<a href="r.fill.dir.html">r.fill.dir</a>,
<a href="r.mapcalc.html">r.mapcalc</a>,
<a href="r.topidx.html">r.topidx</a>
</em>
<br>
<a href="http://idea.isnew.info/grass_gis/r.topmodel">How to run r.topmodel</a>


<h2>AUTHORS</h2>

<a href="mailto:grass4u@gmail com">Huidae Cho</a><br>
Hydro Laboratory, Kyungpook National University, South Korea
<p>
Based on TMOD9502.FOR by Keith Beven.

<p><i>Last changed: $Date$</i>