Land use trajectories as text data
Channel: csvconf
Date: 31/05/2023

Presented by: Germán Rosati

How does land use change over time? Can agrarian frontier expansion and deforestation be detected in high resolution images over a long period of time? This question has implications in both environmental and socio-economic dimensions. Since the publication of large government databases derived from processed satellite images, new analytical and methodological approaches have emerged
Problems of this kind are usually addressed by aggregating information at higher levels (municipalities, departments, administrative areas). For this talk we propose another approach: to work at the pixel level. We will represent each land use pixel sequence over time as if it were a word. This makes it possible to use the so-called “edit distances” (which measure the number of operations necessary to transform one sequence into another) and to generate a matrix that allows clustering land use trajectories using simple techniques. 
We will present an illustration of this procedure covering the 1992-2020 period in Argentina (excluding Patagonia region), using information from the European Space Agency and Dynamic World. Our main goal is to obtain a map with the highest possible resolution that shows the following situations: 1) areas of recent expansion of the agrarian frontier; 2) areas of “consolidated” agriculture and 3) areas of recent urban expansion. We will present some cool visualizations of these trajectories and their spatial distributions.