Análisis de la evolución del uso de terreno costero contiguo a zona urbanizada y su influencia en edificaciones: proyecciones a corto, medio y largo plazo en el sur de Chile

Abstract

The thesis addresses the importance of urban development in coastal areas and the need for policies, strategies and adaptation plans due to the climate crisis and changes in relative mean sea level. The evolution of the concept of land use management in coastal cities is analyzed through a review of bibliographic records and a bibliometric analysis. The need to explore adaptive management models to the new climatic reality to reduce long-term flood risk is highlighted. A prototype estuarine system in which to apply this management methodology is the one around the city of Valdivia (Chile), which stands out for its importance in the economic dynamics of the region and its richness in plant and animal species. Within the studies carried out in this thesis, the response of the wetland to projected changes in mean sea level, alterations in suspended sediment concentrations and the effects of local seismic subsidence are determined. The rate of relative sea level rise is expected to directly affect the equilibrium height to which the wetland is subjected and the importance of existing vegetation in controlling this equilibrium height is highlighted. The impact of sea level rise on wetland change in the Valdivia River estuary is also investigated to model land cover changes due to long-term sea level rise over wetlands and coastal areas, to adjust the territorial regulatory plan, noting that the main fluctuations in land use, are present in the irregular flood marshes and in the regular flood marshes, the latter showing the greatest increase in surface area. On the other hand, the importance of urban resilience in climate change adaptation is discussed, focusing on the transformation of political and economic structures to address the social and economic inequalities that make some communities more vulnerable than others. It identifies and develops the characteristics that a dwelling must have in order not to be vulnerable to coastal flooding, using both European and American standards, and highlights flood resilient housing types such as amphibious and stilt houses. In addition, the implementation of vapor barriers that help control interstitial moisture, responsible for causing a number of respiratory diseases in dwellings near wet areas, is considered, using the international standard ISO13788. Finally, the analysis of published works on LUM-CC shows that the risk of flooding due to mean sea level rise is a dominant issue. The Valdivia River Estuary presents annual states called Normal, Extreme, Exceptionally Rainy and Dry. Earthquakes can generate subsidence in the soil, producing direct changes in the height of the wetland. Emphasis is placed on the protection of flood zones and the incorporation of planning measures for the creation of land-use planning programs and Natural Protected Areas. The Chilean government is considering the possibility of developing regulations for the construction of amphibious houses. In addition, the use of non-conventional materials as a vapor barrier, such as Kraft paper, is proposed.