Latest Contributions by SimonClark

Hi all, Please find attached a sample of my data, zipped to *.rar It contains 6 files: - the *.xyz topography - the channel polygon - the channel centreline - original free surface data - free surface data snapped to the centre-line (for both top and bottom banks, separately) Many thanks! ... View more

Not to worry, that's fine. Would you rather me email you or message you on here (if that's possible - looking at the DM it looks like you can only attach links and pictures?) ... View more

Thanks Xander, I've snapped the points to the centre-line, however I'm still at the early stages of learning python (I only recently started a course) so in terms of processing the data I'd be on unsteady ground.  What would I need to write to process the data? ... View more

Thanks for the response, Xander. Re: the free surface graph, you're correct - the x value represents distance along the channel whilst y is free surface elevation on z. For the free surface data, the information constitutes the free surface elevation, as well as distance along the channel on x, y. The data is estimated fro measured discharge, depth, as well as width. The data only has x in Cartesian form, so has information on distance along x but not directly related to the central channel line. Hence, I was thinking of converting the topography to channel-orientated co-ordinates (n,s) to make it easier to position each point. For determining the position of each point, would it be as simple as  creating a layer for placing particular points along the channel using their x,y? When you say process what Arc tools are you thinking of, given that there seems to be a few available.  You're also correct about the banks - the FS points are derived from near-bank locations, as such the channel borders are included. All these points were used to produce the free surface. ... View more

Thanks for the help. I have a raster of the data. My question mostly revolves around using the threshold: is it possible to use a polynomial as the threshold? The free surface varies on a slope. I've attached images of my data  - both the channel topography raster, and the graph of the raw free surface data (the threshold.) The channel topography needs to be below the free surface data.  I'm wondering, perhaps it would be easier to convert the channel away from cartesian to another system. I.e. "straighten" the channel along its centre-line before removing the data. ... View more

Thanks for the reply! Further detail: I have channel topography in *.xyz data. My free surface data has no co-ordinate system attached, however - it's simply a data-plot of surface elevation. I need to use the surface data to create a threshold and then remove any topographic data above (ideally, remove anything above 0.1m below the threshold.) So I imagine I need to convert the data into something digestible  by ArcGIS that will spatially match my topography, then use it to remove topographic data. I'm not familiar Con. I will investigate further. ... View more