Global terrestrial Human Footprint maps for 1993 and 2009

Abstract

Remotely-sensed and bottom-up survey information were compiled on eight variables measuring the direct and indirect human pressures on the environment globally in 1993 and 2009. This represents not only the most current information of its type, but also the first temporally-consistent set of Human Footprint maps. Data on human pressures were acquired or developed for: 1) built environments, 2) population density, 3) electric infrastructure, 4) crop lands, 5) pasture lands, 6) roads, 7) railways, and 8) navigable waterways. Pressures were then overlaid to create the standardized Human Footprint maps for all non-Antarctic land areas. A validation analysis using scored pressures from 3114×1 km(2) random sample plots revealed strong agreement with the Human Footprint maps. We anticipate that the Human Footprint maps will find a range of uses as proxies for human disturbance of natural systems. The updated maps should provide an increased understanding of the human pressures that drive macro-ecological patterns, as well as for tracking environmental change and informing conservation science and application.

Figure 1. Workflow of the Human Footprint approach to mapping cumulative human pressures on the environment.

Figure 2. The Human Footprint map for 2009, with panels showing regional overlays with the results of the validation plots.

Figure 3. Results from 3114×1 km² validation plots interpreted and scored following Supplementary Appendix 1.

(a) The location and visually interpreted pressure score for plots, and (b) the disagreement between the Human Footprint score and the visual validation score on a normalized 0–1 scale.