I ‘ ve been recently (GIS) helping Luis Mata and the Interdisciplinary Conservation Science Research Group of RMIT with the second phase of a very exciting project they are leading. The project is called ‘The little things that run the city’ and seeks to evaluate the diversity of insects that populate the City of Melbourne, the ecological functions and services they provide to society, and to assess the ecological processes that explain where the insects are found. On top of the scientific discoveries, the project seeks to get Melbournians interested in bugs, by showing how wonderful these little creatures are (with the most bizarre shapes and colours) and what important roles they play for us (e.g. pollinating our trees, decomposing organic matter, controlling pests, etc.).
Luís and colleagues have set a wide network of sampling plots (approx. 130 sites) across the green spaces within the city of Melbourne. They have sampled the insects within each of these plots several times over the course of an entire year, stratifying the surveys by habitat type (grassland, lawn, mid-story vegetation and trees). As part of the project we need to generate a shapefile that depicts the sampling plots and that indicate the species found in each sampling plot.
In this post you will learn how to generate a shapefile of sampling plots from point data using ArcGIS. The method I´ll show is not very sophisticated but it works well and it is very intuitive. It will allow you to generate hundreds of sampling points at once (no need to manually draw any polygon ;-o) and in an accurate and easy manner. I am sure this can be quickly done in R (using a very neat and short code, especially for handling the tabular data), as well as in other GIS software. But let´s focus here on how to do it using ArcGIS and a calculus spreadsheet.