
Dear list,
 
I am an entomologist and have basic statistics knowledge, but spatial aspect is new to me. Currently reading heavily to better understand spatial statistics. Let me explain the issues I am experiencing with my insect counts. I have a dataset of an insect count for two consequent years, for about 80x40km region. Data was sampled on agricultural fields basis (100 samples from each field) and averaged then this average value was attached to related point, in GIS. This repeated for the following year, but this time, some of fields are not sampled, instead, some samples were taken from nearby fields.
 
I want to create hotspot maps for each year. My problem is these different points. The good thing is, over 70% of points are same fields for both years. I am trying to find a way whether the difference among these close points are statistically important or not. If not, I can include them too, for hotspot tests.
 
When I create hotspot maps for each individual year with all points belonging to this year (point numbers are different, say, 100 points for first year, 120 points for the next), hotspots are still appearing in same or similar locations (with same bandwidth for each year), do not know how to indicate these datasets/points are statistically and/or spatially not different.
 
To summarize, I do not want to waste samplings for points that not appear in both years, so I need to find a way, whether two or more datasets randomly sampled from same region are statistically different or not, by means of geographical locations and collected data.
 
To obtain a uniformity, a solution may be creating a grid, (eg, as quarters of utm rectangles, 5x5km) and averaging points of corresponding year falling into each cell, then running hotspot analysis on this polygons, for each year. But this time, finding out the most appropriate grid cell size/bandwidth becomes a problem..
 
I appreciate if you may direct me on possible solutions.
 
I did my best to simplify the problem above, but may further explain if needed. If I can handle this point selection stage, want to apply GWR to the data.
 
Regards,
 
Alper
 
 		 	   		  
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