Hi
I have two polygon layers of grid and population density. I want to determine average population density around each grid within a specified radius, and I used the geoprocessing Buffer, Intersect and Dissolve tools for this. I created a buffer with the specified radius for the grid layer first, and then I intersected the grid buffer layer with the population density layer. In order to obtain the average population density around each grid, I dissolved the intersected grid buffer-population density layer based on the FID of the grid buffer layer. Logically after dissolving the grid buffer FID field, sum of the intersected feature areas (i.e, grid buffer and population density polygons) in each dissolved grid buffer must be equal to the associated area of the dissolved grid buffer, but it doesn’t in some circumstances. The sum of the intersected feature areas in the dissolved grid buffer is larger than the associated dissolved grid buffer area. This error generally occurs when the number of the population density polygons is very large or when the number of the intersected features in the dissolved grid buffer is very large (more than 200 features). However sometimes even with having more than 400 intersected features in the associated dissolved grid buffer this error does not occur!.
I want to know the reasons of having this error and the possible ways for fixing it.
Best Regards
Chro,
I have two polygon layers of grid and population density. I want to determine average population density around each grid within a specified radius, and I used the geoprocessing Buffer, Intersect and Dissolve tools for this. I created a buffer with the specified radius for the grid layer first, and then I intersected the grid buffer layer with the population density layer. In order to obtain the average population density around each grid, I dissolved the intersected grid buffer-population density layer based on the FID of the grid buffer layer. Logically after dissolving the grid buffer FID field, sum of the intersected feature areas (i.e, grid buffer and population density polygons) in each dissolved grid buffer must be equal to the associated area of the dissolved grid buffer, but it doesn’t in some circumstances. The sum of the intersected feature areas in the dissolved grid buffer is larger than the associated dissolved grid buffer area. This error generally occurs when the number of the population density polygons is very large or when the number of the intersected features in the dissolved grid buffer is very large (more than 200 features). However sometimes even with having more than 400 intersected features in the associated dissolved grid buffer this error does not occur!.
I want to know the reasons of having this error and the possible ways for fixing it.
Best Regards
Chro,