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@@ -1,5 +1,12 @@
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<h2>DESCRIPTION</h2>
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+<em>r.spread</em> is part of the wildfire simulation toolset. Preparational
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+steps for the fire simulation are the calculation of the rate of spread (ROS)
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+with <em>r.ros</em>, and the creating of spread map with <em>r.spread</em>.
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+Eventually, the fire path(s) based on starting point(s) are calculated
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+with <em>r.spreadpath</em>.
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+<p>
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+
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Spread phenomena usually show uneven movement over space. Such unevenness
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is due to two reasons:
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@@ -21,7 +28,7 @@ ellipses, and the spread phenomenon moves fastest toward apogees and slowest
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to perigees. The sizes and shapes of spread ellipses may vary cell by cell.
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So the overall spread shape is commonly not an ellipse.
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-<p><I>r.spread </I>simulates elliptically anisotropic spread phenomena,
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+<p><em>r.spread</em>simulates elliptically anisotropic spread phenomena,
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given three raster map layers about ROS (base ROS, maximum ROS and direction
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of the maximum ROS) plus a raster map layer showing the starting sources.
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These ROS layers define unique ellipses for all cell locations in the current
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@@ -30,14 +37,15 @@ For some wildfire spread, these ROS layers can be generated by another
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GRASS raster program r.ros. The actual locations reached by a spread event
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are constrained by the actual spread origins and the elapsed spread time.
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-<p><I>r.spread </I>optionally produces raster maps to contain backlink
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+<p><em>r.spread</em>optionally produces raster maps to contain backlink
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UTM coordinates for each raster cell of the spread time map. The spread
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paths can be accurately traced based on the backlink information by
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<em><a href="r.spreadpath.html">r.spreadpath</a></em> module.
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<p>Part of the spotting function in r.spread is based on Chase (1984)
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-and Rothermel (1983). More information on <I>r.spread</I>, <I><a href="r.ros.html">r.ros</a></I>
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-and <I><a href="r.spreadpath.html">r.spreadpath</a></I> can be found in
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+and Rothermel (1983). More information on <em>r.spread</em>,
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+<em><a href="r.ros.html">r.ros</a></em> and
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+<em><a href="r.spreadpath.html">r.spreadpath</a></em> can be found in
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Xu (1994).
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<p>Options <tt>spot_dist</tt>, <tt>w_speed</tt> and <tt>f_mois</tt> must all
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@@ -97,28 +105,37 @@ accuracy for elliptical simulation significantly, without adding significantly
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extra running time. Further increasing the sample density will not gain
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much accuracy while requiring greatly additional running time.
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-<h2>SEE ALSO</h2>
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-
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-<em><a href="r.cost.html">r.cost</a></em>,
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-<!-- <em><a href="r.mask.html">r.mask</a></em>, -->
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-<em><a href="r.spreadpath.html">r.spreadpath</a></em>,
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-<em><a href="r.ros.html">r.ros</a></em>
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-
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<h2>REFERENCES</h2>
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-Chase, Carolyn, H., 1984, Spotting distance from wind-driven surface fires
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+
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+<ul>
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+<li>Chase, Carolyn, H., 1984, Spotting distance from wind-driven surface fires
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-- extensions of equations for pocket calculators, US Forest Service, Res.
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-Note INT-346, Ogden, Utah.
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+Note INT-346, Ogden, Utah.</li>
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-<p>Rothermel, R. C., 1983, How to predict the spread and intensity
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+<li>Rothermel, R. C., 1983, How to predict the spread and intensity
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of forest and range fires. US Forest Service, Gen. Tech. Rep. INT-143.
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-Ogden, Utah.
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+Ogden, Utah.</li>
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-<p>Xu, Jianping, 1994, Simulating the spread of wildfires using a
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+<li>Xu, Jianping, 1994, Simulating the spread of wildfires using a
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geographic information system and remote sensing, Ph. D. Dissertation,
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-Rutgers University, New Brunswick, New Jersey.
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+Rutgers University, New Brunswick, New Jersey
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+(<a href="https://dl.acm.org/citation.cfm?id=921466">ref</a>).</li>
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+</ul>
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+
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+<h2>SEE ALSO</h2>
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+
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+<em>
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+<a href="r.cost.html">r.cost</a>,
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+<a href="r.mask.html">r.mask</a>,
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+<a href="r.ros.html">r.ros</a>,
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+<a href="r.spreadpath.html">r.spreadpath</a>
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+</em>
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+
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+Sample data download: <a href="http://grass.osgeo.org/download/sample-data/">firedemo.sh</a>
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+(run this script within the "Fire simulation data set" location.
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<h2>AUTHOR</h2>
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Jianping Xu and Richard G. Lathrop, Jr., Center for Remote Sensing and
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Spatial Analysis, Rutgers University.
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-<p><i>Last changed: $Date$</i>
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+<p><em>Last changed: $Date$</em>
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Markus Neteler