Volume XLI-B8
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLI-B8, 733-737, 2016
https://doi.org/10.5194/isprs-archives-XLI-B8-733-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLI-B8, 733-737, 2016
https://doi.org/10.5194/isprs-archives-XLI-B8-733-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.

  23 Jun 2016

23 Jun 2016

ASSESING GEOGRAPHIC ISOLATION OF THE GALAPAGOS ISLANDS

D. Orellana1,2 and F. Smith2,3 D. Orellana and F. Smith
  • 1Faculty of Agronomic Sciences, Universidad of Cuenca, Av. 12 de Abril, Cuenca, Ecuador -
  • 2Charles Darwin Foundation, Puerto Ayora, Ecuador
  • 3c Department of Ecology & Evolutionary Biology, Brown University, Providence, Rhode Island, USA

Keywords: Galapagos, accessibility, geographical isolation, human impact, mobility, island ecosystems

Abstract. The Galapagos Archipelago is one of the most important ecological spots in the planet due its unique biodiversity, active geology, and relatively well-preserved ecosystems. These characteristics are strongly based on the geographical isolation of the islands. On the one hand this isolation allowed the evolution processes that gave the islands their international fame and on the other hand it kept them from major human impacts that affected the vast majority of the Earth’s surface. Galapagos’ geographical isolation is therefore of mayor value, but it is rapidly diminishing due to the increase of marine and air transportation among islands and with the rest of the world. This increased accessibility implies enhanced risks for the ecological dynamics on the archipelago (e.g. increased risk of biological invasions, uncontrolled tourism growth, more water and energy consumption). Here, we introduce a general accessibility model to assess geographical isolation of the Galapagos Islands. The model aims to characterize accessibility in terms of human mobility by evaluating travel time to each point of the archipelago using all available transportation modalities. Using a multi criteria cost surface for marine and land areas, we estimated travel time for each surface unit using the fastest route and mode of transportation available while considering several friction factors such as surface type, slope, infrastructure, transfer points, legal restrictions, and physical barriers. We created maps to evaluate the isolation of different islands and places, highlighting the potential risks for several habitats and ecosystems. The model can be used for research and decision-making regarding island conservation, such as estimating spreading paths for invasive species, informing decisions on tourism management, and monitoring isolation changes of sensitive ecosystems.