Landscape Expansion Index

Introduction

The Landscape Expansion Index classifies new landcover into three classes: infill, expansion, and leapfrog. This classification is performed on gridded maps of built area; the code and examples in this repository are based on the Global Human Settlement Layer, but any built area dataset with at least two time periods could be used. The classification works by identify new urban features (contiguous cells of new built area) and buffering by a consistent distance (default 300m). This buffer creates a donut around the feature of interest, which is then compared to the original built area. LEI is calculated as the ratio of the area of the buffer to the area of the old built area within the buffer note that the percent threholds are customizeable:

• Infill: Greater than 80% of the donut is covered by the old city
• leapfrog: less than 20% of the donut is covered by the old city
• expansion: the area of the old city within the donut is between 20% and 80%

References

A new landscape index for quantifying urban expansion using multi-temporal remotely sensed data