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Actually I am new to GIS, so I don't know much about technical terminology.

I have extracted a river network but now have a problem in distinguishing the branch order of stream (from order 1 to 2, 2 to 3; side branches, not the main ones [say 1 to 1, 2 to 2]) according to the Strahler scheme. It is displaying only one column of stream order. Can anybody tell me how can I extract a separate column for side branch streams as I mentioned above?

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Here is a Strahler ordering scheme. In the strahler order method, all links with no tributaries are assigned an order of one and are referred to as first order. When two first-order links intersect, the downslope link is assigned an order of two. When two second-order links intersect, the downslope link is assigned an order of three, and so on. When two links of a different order (say 1 to 2) intersect, the downslope link is assigned the order of the maximum of these two. My query is, can we make a separate field for the same order branch (1 to 1, 2 to 2) and different order branch (1 to 2, 2 to 3)?

I have added two tables. In first table we can see that all stream orders (Grid_code) are given in one column. I want to know how many streams of 1st order are joining with other 1st order, 2nd order, 3rd order, etc. Similarly, how many streams of 2nd order are joining with 2nd order, 3rd order, etc.

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For example, in this table there are 12 '1st' order streams. I have to know that out of 12, how many are joining with another 1st order (1 to 1)? How many are joining with a 2nd order (1 to 2)? How many are joining with a 3rd order (1 to 3)? And so on.

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Chris W
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    I'm not sure I follow. Stream order is a property of all segments/branches. Common properties are stored in a single field ("column"). It doesn't matter if a 2 meets a 3 at the end or in the middle, it's still a 2. If you want a new attribute that distinguishes those two kinds of 2s, you'd have to create a new field and calculate the values after doing some selections. Can you provide a screenshot of what you're after? – Chris W Jul 17 '15 at 22:16
  • I'm fairly sure that ArcHydro will generate Strahler stream order http://gis.stackexchange.com/questions/138530/generate-strahler-number, Arc Hydro tools are free to download from Esri http://resources.arcgis.com/en/communities/hydro/01vn00000010000000.htm As @ChrisW said please provide a picture of what you're after from what you have. – Michael Stimson Jul 17 '15 at 22:18
  • @MichaelMiles-Stimson I don't think there is any need to download the ArcHydro tool-set as most of the ArcHydro feature have been incorporated into ArcGis 10+ under the name "Hydrology toolset". As long as you have the Spatial Analyst extension, you should be good to go. – TsvGis Jul 18 '15 at 02:08
  • Thanks @TsvGis, I haven't done much with hydo since 9.3, at least on the creation side. I get the impression the OP already has stream order and it trying to do something with it; I mentioned the tools as I can't discern if they are saying the stream orders are incorrect or they don't know what to do with them... it's not very clear. I should go through the exercise of creating ordered streams from a DEM to get across the current toolset but just can't find the time. – Michael Stimson Jul 18 '15 at 02:30
  • In addition to @ChrisW's comment, there is FROM-TO aspect of this segment representation. Assume there is a segment of stream order 2 which is connected to two segments FROM the start point (upstream), whose orders are 3 and 2 (as to my knowledge, waterway poly-lines with stream order information should be planar), further, this example segment connects TO another segment at the end point which is stream order 1 (this also assumes there is another connection with stream order 2 to make the next segment 1). How could you define all of these connectivity information at once (i.e., in one field)? – fatih_dur Jul 18 '15 at 02:45
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    While you've explained the Strahler order well, I think most of us watching this particular question are familiar with it. I'm still not clear what you're wanting the attribute table to look like (what this new attribute would show) - perhaps you can provide a mock-up example table that corresponds to the diagram you have above? You have no 1 to 1 that are not also 1 to 2 (and so on). Are you looking for some kind of flag attribute that says a particular segment has only lower order segments feeding it? – Chris W Jul 18 '15 at 17:46
  • In my previous comment I mixed stream order hierarchy, sorry about that. In your EDIT, how are you planning attribute the second 2 from the left since it has 2 to 2, 1 to 2 and 2 to 3? Or am I missing something here altogether? – fatih_dur Jul 19 '15 at 03:34
  • In 100% agreement with @ChrisW, you need to upload an picture of the attribute table you wish to build as it's not at all clear what you want. – Hornbydd Jul 20 '15 at 09:05
  • The chart you've added there, the second one, isn't an attribute table. It's an analysis result or summary table. In an attribute table, every feature (segment in this case) has one value for any given attribute. "2" is the value of the attribute "order" for a particular segment. It applies only to that segment, and no other. You're talking about a chart that summarizes how many 1s touch another 1, how many touch a 2, etc. And your example throws out higher order matches (meaning you only care about 2 touches 3, not 3 touches 2). This isn't a matter of creating a column, it's a whole analysis. – Chris W Jul 22 '15 at 00:00
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    I'm not familiar with hydrology tools or network analysis, so there may be one or a name for the analysis you want to do out there. But I can think of a brute force method to get the summary you want. First you'd need to split your file up by stream order. All ones into a feature class, all twos into another, and so on. Then you'd start at your highest order and select them all, following by selecting all from the next lowest order that intersect them. Repeat. It'd be easier to do this with start/end extractions as points, but I can't give a full outline to that process right now. – Chris W Jul 22 '15 at 00:05
  • This link has a solution for working out from nodes and to nodes. Once that is done, you should be able to do the calculations that you are after. – TsvGis Jul 22 '15 at 02:53

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