My goal is to calculate the area of mangrove cover (vector layer) per grid cell (vector layer) over time (yearly), to determine land cover change.
I have tried two ways so far. Initially I wanted to Intersect the grid and polygon layers then dissolve by ID and then calculate the area. This has two problems 1) it does not include any grid cells with 0 mangrove polygon intercept, and 2) there are duplicated grid ID values where two polygons intercept the same grid.
I also tried Union. This includes the grid cells with 0 mangrove polygon, but still has the issue with duplication.
Any ideas on how I can avoid this duplication so that I have the same number of grid cells per year so that I can compare between years?