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<em><b>r.li</b></em> - Landscape structure analysis package overview.
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raster, landscape structure analysis, overview, landscape metrics, landscape pattern, landscape analysis
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The <em>r.li</em> suite is a toolset for multiscale analysis of landscape structure.
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It aims at replacing the <em>r.le</em> suite of modules through a client-server,
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multiprocess implementation. External software for quantitative measures of landscape
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structure is for example FRAGSTATS (McGarigal and Marks 1995).
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The <em>r.li</em> suite offers a set of patch and diversity indices.
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It supports analysis of landscapes composed of a mosaic of
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patches, but, more generally, the modules work with any two-dimensional
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raster map whose cell values are integer (e.g., 1, 2) or floating point
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(e.g., 1.1, 3.2) values. The <em>r.li.setup</em> module has options for
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controlling the shape, size, number, and distribution of sampling
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areas used to collect information about the landscape structure.
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Sampling area shapes can be the entire map or a moving
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window of square, rectangular or with circular shape. The size of
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sampling areas can be changed, so that the landscape can be analyzed
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at a variety of spatial scales simultaneously. Sampling areas may be
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distributed across the landscape in a random, systematic, or
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stratified-random manner, or as a moving window.
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The <em>r.li</em> modules can calculate a number of measures that produce
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single values as output (e.g. mean patch size in the sampling area),
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as well as measures that produce a distribution of values as output
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(e.g. frequency distribution of patch sizes in the sampling area). The
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results are stored as raster maps.
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The general procedure to calculate an index from a raster map is two-fold:
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<li>run <em>r.li.setup</em>: create a configuration file selecting the parts of
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<li>run <em>r.li.'index'</em> (e.g., <em>r.li.patchdensity</em>) for calculate the selected
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index using on the areas selected on configuration file.
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Also the <em>r.li.daemon</em> has a main function and it can be run, but it is only a
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template for development of new indices.
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The function itself has no meaning, it can be used only for debug.
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To calculate a patch density index on a whole 'geology' raster map in the
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Spearfish region, using a 5x5 moving window, follow this procedure:
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<li> CREATE A NEW CONFIGURATION FILE
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<div class="code"><pre>
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<li> The main <em>r.li.setup</em> window is displayed, click on "New"
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<li> Now it is displayed the new configuration window,
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enter the configuration file name (e.g., "my_conf", do not use absolute paths)
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and the name of raster map (e.g., "geology").
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The other fields are not needed for this configuration.
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<li> Click on "Setup sampling frame", select "Whole maplayer" and click "OK"
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<li> Click on "Setup sampling areas", select "Moving window" and click "OK"
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<li> Click on "Use keyboard to enter moving window dimension"
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<li> Select "Rectangle" and enter 5 on "heigth" and "width" fields
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<li> Click on "Save settings"
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<li> Close <em>r.li.setup</em> window
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<li> CALCULATE PATCHDENSITY INDEX
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<li> set region settings to geology raster map:
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<div class="code"><pre>
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g.region rast=geology -p
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<li> run <em>r.li.patchdensity</em>:
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<div class="code"><pre>
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r.li.patchdensity map=geology conf=my_conf out=patchdens
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The resulting patch density is stored in "patchdens" raster map.
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You can verify the result for example with contour lines:
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<div class="code"><pre>
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r.contour in=patchdens out=patchdens step=5
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Note that if you want to run another index with the same area
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configuration, you don't have to create another configuration file.
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You can also use the same area configuration file on another map. The
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program rescale it automatically. For instance if you have selected a
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5x5 sample area on 100x100 raster map, and you use the same
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configuration file on a 200x200 raster map, then the sample area is
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<li> <a href="r.li.daemon.html">r.li.daemon</a>: job launch daemon</li>
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<li> <a href="r.li.setup.html">r.li.setup</a>: Configuration editor for r.li.'index'</li>
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<b>Patch indices</b>:
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<li>Indices based on patch number:
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<li> <a href="r.li.patchdensity.html">r.li.patchdensity</a>: Calculates patch density index on a raster map, using a 4 neighbour algorithm</li>
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<li> <a href="r.li.patchnum.html">r.li.patchnum</a>: Calculates patch number index on a raster map, using a 4 neighbour algorithm</li>
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<li>Indices based on patch dimension:
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<li> <a href="r.li.mps.html">r.li.mps</a>: Calculates mean patch size index on a raster map, using a 4 neighbour algorithm</li>
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<li> <a href="r.li.padcv.html">r.li.padcv</a>: Calculates coefficient of variation of patch area on a raster map</li>
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<li> <a href="r.li.padrange.html">r.li.padrange</a>: Calculates range of patch area size on a raster map</li>
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<li> <a href="r.li.padsd.html">r.li.padsd</a>: Calculates standard deviation of patch area a raster map</li>
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<li>Indices based on patch shape:
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<li> <a href="r.li.shape.html">r.li.shape</a>: Calculates shape index on a raster map</li>
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<li>Indices based on patch edge: <!-- border? -->
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<li> <a href="r.li.edgedensity.html">r.li.edgedensity</a>: Calculates edge density index on a raster map, using a 4 neighbour algorithm</li>
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<li>Indices based on patch attributes:
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<li> <a href="r.li.cwed.html">r.li.cwed</a>: Calculates contrast Weighted Edge Density index on a raster map</li>
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<li> <a href="r.li.mpa.html">r.li.mpa</a>: Calculates mean pixel attribute index on a raster map</li>
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<b>Diversity indices</b>:
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<li> <a href="r.li.dominance.html">r.li.dominance</a>: Calculates dominance's diversity index on a raster map</li>
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<li> <a href="r.li.richness.html">r.li.richness</a>: Calculates dominance's diversity index on a raster map</li>
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<li> <a href="r.li.shannon.html">r.li.shannon</a>: Calculates Shannon's diversity index on a raster map</li>
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<li> <a href="r.li.simpson.html">r.li.simpson</a>: Calculates Simpson's diversity index on a raster map</li>
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<h2>ADDING NEW INDICES</h2>
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New indices can be defined and implemented by any C programmer, without having to
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deal with all basic functions (IO etc.). The computing architecture and the functions
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are clearly separated, thus allowing an easy expandability. Every index is defined
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separately, placed in a directory along with its Makefile for compiling it and a file
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description.html which describes the index including a simple example of use.
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McGarigal, K., and B. J. Marks. 1995. FRAGSTATS: spatial pattern
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analysis program for quantifying landscape structure. USDA For. Serv.
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Gen. Tech. Rep. PNW-351 (<a href="http://www.fs.fed.us/pnw/pubs/gtr_351.pdf">PDF</a>).
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<a href="mailto:porta@cli.di.unipi.it">Claudio Porta</a> and
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<a href="mailto:spano@cli.di.unipi.it">Lucio Davide Spano</a>, students of Computer Science
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University of Pisa (Italy). <br>
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Commission from Faunalia Pontedera (PI)<br>
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<i>Last changed: $Date: 2008-10-29 10:19:46 +0100 (Wed, 29 Oct 2008) $</i>
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