I have a shapefile, clean_intersection, representing a geographic area. I'm trying to add additional columns to the attribute table showing the evapotranspiration (ET) for each element of my map, clean_intersection.
I used the "simplify geometry" tool to simplify clean_intersection enough to handle in Excel, where I created a .csv file to add a couple columns to the attributes table. Then I used "add delimited text layer" to return the .csv file to QGIS now as "clean_simple_data." Clean_simple_data is a shapefile with the data I want but with simplified geometry polygons. I'm now trying to join clean_simple_data with clean_intersection to generate a shapefile with detailed boundaries (like clean_intersection) but with the additional columns from the clean_simple_data attribute table.
The "ICA" value of 6.633 is correctly paired with the ET value of 1.12, but it is assigned to too many rows. Here's a screenshot of the Excel .csv file showing how there should be many different values instead of a few repeated values in the ICA and ET columns.
Originally I had many more columns of data that I was attempting to join but I pared the .csv file down which seemed to help but did not resolve the issue. I have also tried many different variations of the geometric predicates available in the "Join attributes by location" dialogue, to no avail. I am running QGIS 2.18.
Does anyone have any insight?