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@@ -55,7 +55,8 @@ analysis is based. NULL (nodata) cells are ignored, zero and negative
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values are valid elevation data. Gaps in the elevation map that are
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located within the area of interest must be filled beforehand,
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e.g. with <em><a href="r.fillnulls.html">r.fillnulls</a></em>, to
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-avoid distortions.
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+avoid distortions. The elevation map need not be sink-filled because
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+the module uses a least-cost algorithm.
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<p>
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Map of actual depressions or sinkholes in the landscape that are large
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@@ -113,7 +114,7 @@ their surface runoff and sedimentation yields calculated accurately.
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<p>
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Output <b>tci</b> raster map contains topographic index TCI is
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computed as
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-<tt>ln(α / tan(β))</tt> where α a is the cumulative
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+<tt>ln(α / tan(β))</tt> where α is the cumulative
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upslope area draining through a point per unit contour length and
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<tt>tan(β)</tt> is the local slope angle. The TCI reflects the
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tendency of water to accumulate at any point in the catchment and the
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