Hi I am new to model builder in GIS. I have two shapefiles, one is a polygon shapefile of all lightning caused fire in Alaska sine 1939 (~1500 polygons) and the second is a point shapefile with all recorded lightning strike since 1986 in Alaska (~10000 points). What I want to do is create a data/attribute table that outputs the following for varying time scale (1 day through 16 weeks): 1)If the fire had a lightning strike within it on the timescale specified and latitude/longitude of strike 2)If not what is the nearest strike and its distance (point (lightning) to centroid (fire polygon)or point to nearest edge) 3)Polarity of strike 4)Multiplicity of strike The attribute table I have for the lightning data has all strike lat/long, polarity, multiplicity. This is a flow chart of the analysis I want to do:
select lightning and fire that falls in specified time (I have dates of both strikes and fire) --> determine if a strike was in the fire --> if yes then put the specified value from the lightning table into the new table along with fire ID --> If no find the nearest strike to the fire and its distance to the fire --> add specified values for this strike to same table
What would the basic outline for a model that performs this flow look like? Are there any alternate methods to achieve this with such a large data set? I know this is a lot but any help would be greatly appreciated. Thanks
Seems like you just need to run the Intersect tool (or Spatial Join). The output will be a point feature class with all the attributes of the lighting strikes and the attributes of the fire polygons they fall within. You could then run attribute queries on this output.
If a fire polygon doesn't have a lighting strike within it, then the output feature class from Intersect won't contain any features that have that polygon's OBJECTID or attributes. You could then select these "no strikes within" polygons and run Generate Near Table to find the closest strike.