View source for Arc Export Raster to asc

=Introduction=
TUFLOW can directly read elevation data from a Digital Elevation Model (DEM).  The format recognised by TUFLOW is ESRI ASCII Grid (.asc),  this is an open text format that is recognised by a wide range of software including ArcGIS, MapInfo and Quantum GIS.  The instructions below outline the process for exporting from a raster layer in ArcMap to a ESRI ASCII grid.<br>
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TUFLOW can also read .asc format data for setting a number of model parameters including, initial water level (Read GRID IWL == ), Soil Type (Read Grid Soil == ), roughness (Read Grid CnM == ), storage reduction factor (Read Grid SRF == ).
=Method=
<ol>
<li>Open the raster layer that you wish to convert.</li>
<li>In the Arc Toolbox menu, select '''Conversion Tools >> From Raster >> Raster to ASCII'''</li>
[[File:Arc raster to asc.jpg]]
<li>In the dialogue, select the desired input raster and set the output filename.  Note, there is no set extension for this file type, both .asc and .txt are widely used.

[[File:Arc raster to asc 2.jpg]]
<li>The DEM file is ready for reading into TUFLOW.</li>
</ol>
=Tips=
To convert between the .asc and .flt format the TUFLOW utility "asc_to_asc" can be used.
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