Assessing population exposure for landslide risk analysis using dasymetric cartography

作者：Garcia Ricardo A C; Oliveira Sergio C; Zezere Jose L

来源：Natural Hazards and Earth System Sciences, 2016, 16(12): 2769-2782.

DOI：10.5194/nhess-16-2769-2016

<jats:p>Assessing how many people are exposed and where are they located is a crucial step in landslide risk management and emergency planning. Frequently the available population statistical data have no sufficient detail to an accurate assessment of the potential exposed people to a hazardous phenomenon, mainly if it occurs at the local scale, like landslides. The present study aims to apply the dasymetric cartography technic to improve population spatial resolution and to assess potential exposed population. An additionally objective is to compare the obtained results with a more common approach that uses basic census units in its better spatial resolution (BCU) as spatial units. Considering the Portuguese census data and a layer of residential building limits, whose area was used as ancillary information, the number of exposed inhabitants significantly differs between two approaches. Using BCU approach and considering the three highest landslide susceptible classes, people inhabitants are overestimated in 132 % (2539 inhabitants). Despite the associated uncertainties in a general cost-benefit analysis the presented methodology seems to be a reliable approach as first approximation to a more detailed estimation of exposed people. The approach based on dasymetric cartography allows an increasing of the spatial resolution of population over large areas and enable the use of detailed landslide susceptibility maps and thus improving the population assessment.</jats:p>

• 出版日期2016-12-19