The Rapid Development of Settlements in Flood-Prone Areas in Peri-Urban Ulaanbaatar, Mongolia: Monitoring and Spatial Analysis Using VHR Satellite Imageries

Abstract

Mongolia is a mostly arid or semiarid country, so it might seem strange that floods could be one of the disaster threats it faces. However, the low precipitation and high evaporation of surface water are a result of the low absorptive capacity of the soil, and, accordingly, higher than normal precipitation often results in run-offs, which have the potential to become flash floods. In a peripheral area of Ulaanbaatar, the capital municipality of Mongolia, residential areas called ger areas have expanded rapidly in an unplanned manner because of the poor execution of land reform policy, and considerable migration has resulted from a natural hazarddzud. These areas have been encroaching on flash-flood-prone areas, which have resulted in a dozen people losing their lives in 2009. This chapter introduces the background of ger areas expansion and reveals the actual situation of their spatial distribution over fl ash-flood-prone areas using VHR satellite imageries.