I need to assign a point value in raster format to a raster stream segment, which contains the point. See bellow:
The expected result is a segment, whose value is the point value. How could I?
1 Answer
One method is to use the segments as zones and request zonal statistics for the point values. Provided there is at most one point per segment, many statistics will work, including max, mean, sum, and min. When there is more than one point per segment, you will need to decide how to combine the point values, but zonal stats is still a good candidate for a solution method.
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I've tried zonal statistics but it resulted a stream point feature rather than line. I don't know why...– Werisk_Commented Sep 18, 2012 at 17:41
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1Exactly how did you "try" the zonal stats? What command did you use? (Indeed, what software are you using?) Depending on the software and the command, you will get either a new raster for the results or a table: it's not possible to get a point feature layer as an output using zonal stats.– whuberCommented Sep 18, 2012 at 18:21
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First of all thank you for your attention. I'm using the ArcGIS 10 and the command Zonal Statistics. I don't know why but it returned a lot of points in the same shape of the stream network. =/– Werisk_Commented Sep 18, 2012 at 21:51
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1OK, that's mysterious. Exactly how do you represent the stream network? Based on your illustration I assumed each segment is identified by a unique (integral) value. That's an important prerequisite for using zonal statistics. Is that the case with your grid?– whuberCommented Sep 18, 2012 at 22:38
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For any reason I could use Zonal correctly and result is fine right now...go figure! Thank you guy!– Werisk_Commented Sep 18, 2012 at 22:52