New answers tagged spatial-analyst
There is an ArcGIS Spatial Analyst tutorial available which I suggest would make an excellent starting point.
I would use one of the three spatial analyst overlay methods. These include: weighted overlay, weighted sum and fuzzy overlay. Weighted overlay is very intuitive and would likely be a good choice for your analysis. As you can see, the analysis is intuitive and useful (Source ESRI): Additional Resources: Overlay analysis approaches Weighted ...
I believe that your "gaps" are, in fact, NoData. The rule in raster operators is that NoData begets NoData. You can use the raster calculator and a nested statement, without the use of the constant raster, to set NoData to 0. Depending on the version of ArcMap you may need to play with syntax but the basic idea is: Con(IsNull("raster"), 0, "raster") This ...
Find those regions by "region grouping" the cells over 5, then compute zonal statistics of the original grid. Workflow As a running example, here is a small grid in which the darker cells denote higher values: Create an indicator grid of the large-value cells by comparing the original grid to the threshold of 5. RegionGroup this grid into separate ...
If you are wanting to use slope as a factor you will have to use a DTM anyway, https://www.ordnancesurvey.co.uk/opendatadownload/products.html use "OS Terrain 50" and make sure the Supply Format is "ASCII Grid" so you get a raster. the Slope tool is Spatial analyst>Surface >slope. Are the 10 sites on the water feature? As if they are you could just either ...
The documentation states that the column must be an integer (by which it means 32-bit integer). If the table doesn't have a rowid column, adding a field, calculating it to row number, and altering it to be NOT NULL should do the trick (though that last part may not be necessary).
I really do not follow the logic of what you are attempting with "freq". The DEM values should be continuous and using freq just does not make sense to me but, you may have an unstated reason for doing so. I would follow @Thomas advice and use extract. You will then have a list object with a vector of raster values for each sample site. You can use lapply ...
If you mask the raster by raster, you will always get another huge raster. I don't think this is a way to make things faster. What I would do is to try to mask by polygon layer using extract: res <- extract(raster, polygons) Then you will have all the cell values for each polygon and can run freq on them.
ArcGIS fills sinks to the surrounding level and the z_limit won't help you because it effectively does the opposite of what you want. I don't recall any setting for what you need but I can think of a possible work around: Fill all sinks Subtract the original DEM from the filled DEM (makes 'Sinks Only') Reclassify 'Sinks Only' so that all values less than ...
I haven't done anything like this before but my guess is you need to make a Near Table. To do this, I'm thinking you'll need to create points from the raster first. Then make your Near Table and include the optional "Add Location Field". Once you have that table you'll need to figure out the elevation of the points from the road feature that are in the ...
whuber has it right. First, get the euclidean allocation. Second, use the minus operation to get the difference between the two. Can be easily done in python.
In ArcGIS use the zonal statistics tool.
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