Landslide–Anthropogenic Interactions in Urban Areas: A Multidisciplinary Case Study from Taounate, Morocco
摘要
Taounate city experienced rapid urban expansion due to population increase and rural exodus episodes, as shown by the General Census of Population and Housing data covering the period of 1971–2014. This expansion led to the construction of peri-urban neighborhoods, often built on potentially hazardous areas. This trend evolved overtime into a reciprocal interaction between slope instability and urbanization (anthropogenic effect). As such, the main objective of this study is to investigate this interaction using a multidisciplinary approach that combines explanatory statistics, probability theory, damage classification, landslide inventory mapping, slope instability simulation, as well as geotechnical, geophysical tests and slope stability analyses. The results indicate that the majority of landslides in Taounate territory are old. Active processes are mainly located within the borders of the anthropogenic areas. Additionally, the damage inventory analysis reveals that 67% of cracked buildings are found in landslide and/or swellable marl zones, confirmed by laboratory and insitu geotechnical tests. Geostatistical and frequency-area distribution analyses show that the factors controlling landslides spatial distribution are also those influencing their size. These investigations also suggest that the urban fabric is built over large-scale relict landslides. The latter remain active not only due to natural factors but also because of non-regulated urbanization, as further demonstrated by geophysical data and limit equilibrium analyses. Finally, this study proposes a new approach for validating landslide susceptibility in an urban setting, which uses damaged building inventories as validation dataset. It also provides more relevant insight into the long-term stability of such buildings in a landslides-prone area.