https://community.esri.com/t5/arcgis-pro-questions/finding-nearest-wind-data-point-for-given-location/m-p/1034388#M38291 <P>Did you look at the suggestion then?</P> Tue, 09 Mar 2021 10:56:21 GMT DanPatterson 2021-03-09T10:56:21Z https://community.esri.com/t5/arcgis-pro-questions/finding-nearest-wind-data-point-for-given-location/m-p/1034326#M38282 <P>Hi,</P><P>I am using ArcGIS Pro to work out which areas of terrain are exposed to prevailing winds. I have a 20 m DEM (with which I have created an aspect raster) but my wind data (in degrees, direction only) is approximately 2 km resolution and in netcdf format. I have successfully added the netcdf wind data to my map and converted it to point data. (which I think is the correct step). I need to find the wind direction at every DEM point, but rather than interpolate the wind data to the high res DEM, I want to know the wind direction at the nearest wind data point to any given point.</P><P>&nbsp;Is there a straightforward way to do this?</P> Tue, 09 Mar 2021 05:18:44 GMT https://community.esri.com/t5/arcgis-pro-questions/finding-nearest-wind-data-point-for-given-location/m-p/1034326#M38282 RachelBadlan 2021-03-09T05:18:44Z https://community.esri.com/t5/arcgis-pro-questions/finding-nearest-wind-data-point-for-given-location/m-p/1034330#M38284 <P>It almost sounds like</P><P><A href="https://pro.arcgis.com/en/pro-app/latest/tool-reference/spatial-analyst/distance-allocation.htm" target="_blank">Distance Allocation (Spatial Analyst)—ArcGIS Pro | Documentation</A></P><P>but what variant you use and whether it is appropriate would depend on your data.&nbsp;&nbsp;</P><P>What do you think the interplay is between your topography and wind direction? and where was wind direction being measured?&nbsp; Fuzzy questions perhaps, but you want to be careful about allocating anything anywhere unless there is a sound reason</P> Tue, 09 Mar 2021 05:32:03 GMT https://community.esri.com/t5/arcgis-pro-questions/finding-nearest-wind-data-point-for-given-location/m-p/1034330#M38284 DanPatterson 2021-03-09T05:32:03Z https://community.esri.com/t5/arcgis-pro-questions/finding-nearest-wind-data-point-for-given-location/m-p/1034331#M38285 <P>The reason I am lookig at wind and topography is to identify areas of terrain that have increased fire risk given certain conditions. The wind data is gridded ad we really want to identify the general direction of flow in a given area (i.e. to get an idea of blocking due to terrain).&nbsp; The wind doesn't have to be exact or high resolution, as the algorithm we use to identify areas of risk has a fairly large uncertainty built in and will allow fairly large variations in very local wind conditions. We just want to be able to assume the given wind direction at any wind data point to be associated with the terrain around it. Therefore given a regular grid of wind points ( 2km x 2 km - delta x and delta y), a 2 km x 2 km area of the DEM would be associated with each gridpoint (with the wind data in the centre of that square area).</P><P>&nbsp;</P><P>Hopefully this makes sense!</P> Tue, 09 Mar 2021 05:53:16 GMT https://community.esri.com/t5/arcgis-pro-questions/finding-nearest-wind-data-point-for-given-location/m-p/1034331#M38285 RachelBadlan 2021-03-09T05:53:16Z https://community.esri.com/t5/arcgis-pro-questions/finding-nearest-wind-data-point-for-given-location/m-p/1034388#M38291 <P>Did you look at the suggestion then?</P> Tue, 09 Mar 2021 10:56:21 GMT https://community.esri.com/t5/arcgis-pro-questions/finding-nearest-wind-data-point-for-given-location/m-p/1034388#M38291 DanPatterson 2021-03-09T10:56:21Z