# Mapping overlapping density estimates

I need a map that can represent density estimates. The estimates are tied to points, but are for 1 hectare (100m*100m) areas of which the point is the centre. Each point has at least one, but usually 3 or 4 other points that fall within its 1 ha area. I would like all of the overlapping areas to show up as means of the relevant estimates.

In other words I would like the density estimate tied to the point to be applied across 1 ha, and for the estimate to be averaged anywhere that it intersects the area of another estimate.

Is this possible?

Preferably I would be able to do this in QGIS, but am also open to instruction in ArcGIS.

So far, I have tried a point density map, and a kernal density map in arcgis, but the values were not averages of the estimated densities tied to each point.

I also tried converting the points to square polygons using the buffer tool and then the feature envelope to polygon tool in ArcGIS, which allowed me to make the points into 1 ha boxes. I was unsure what to do after that.

My question is also somewhat similar to this one from two years ago, which never received an answer: http://gis.stackexchange.com/questions/87429/how-to-simulate-venn-diagram-of-buffers-using-qgis

• Kernel density is wrong tool, study interpolation techniques. docs.qgis.org/2.2/en/docs/gentle_gis_introduction/…, qgistutorials.com/en/docs/interpolating_point_data.html etc. Apr 7, 2016 at 0:47
• Thanks. I'd already read both of those sites. Kernal density was suggested to me by someone with more experience so I tried it out. I don't think TIN or IDW are right for me either, though maybe I'm just doing something wrong. Apr 7, 2016 at 17:56
• Very hard to answer because I do not quite understand what kind of data you have. I thought that your points have an attribute that gives a measure for density like animals/hectare but perhaps I guessed wrong. Apr 7, 2016 at 20:31
• Thank you. You were right. I have density per hectare measure as an attribute (trees per hectare). The measure is already an estimate, so I want to increase the accuracy of the estimate by averaging each estimate with any other that fall within 1 ha, and applying that averaged estimate to the area of overlap. Not unlike this problem, gis.stackexchange.com/questions/94358/… except I want each point to be treated as the centre of a hectare. I don't want to average the values that happen to fall into a 1ha grid. Apr 7, 2016 at 20:51