Model to support resilient urban growth in a context of climate change

Abstract

In a scenario of growing unplanned urbanization, with a projection of increasing extreme weather events; Iquique - Alto Hospicio is a fragmented and vulnerable conurbation against natural threats, affecting the consolidation and future urban growth of this Metropolitan Area. The objective is to base and improve planning and adaptation for future urban development, in the search for urban sustainability in a context of climate change. Against this, it is important to evaluate the levels of vulnerability and risks of the growth alternatives of the metropolitan system.

The purpose is to guide the planning decisions, based on the construction of a model of the urban system, whose evaluation, allows to indicate potential action axes for its future ordering. A systemic platform is obtained to formulate different future scenarios, a tool that guides the public decision-making process in planning matters.

For this, the surfaces of urban footprints are quantified according to temporary cuts and types of urban fabric, defined by classes of land use analysis, intensity of occupation and level of consolidation; through photointerpretation of aerial photography, measuring historical growth in the period 1982-2017. The need arises to assess vulnerabilities and risks, developing a diagnosis that supports a clear knowledge of the threats and vulnerabilities that affects the future metropolitan system of Iquique - Alto Hospice.

A methodology is developed to evaluate different scenarios; within the framework of an urban planning process and strengthening of public institutions (Metropolitan Government). This, in a context of future growth, in which the threats due to climate change scenarios will increase and therefore will pose challenges for the regional administration with the powers attributed to it by Law 19.175 to reduce vulnerabilities, thus achieving cities resilient and with greater adaptive capacity, based on the participation of the different regional urban public and private actors.

It considers instances of participation of key regional actors with vast knowledge of the territory, for the selection and prioritization of threats, as well as the validation of the results. In addition, a meteorological modeling has been carried out using the WRF model for the 2017 meso-scale year, and the CALMET model, to lower the resolution at local scale incorporating the information of the available surface meteorological stations of Alto Hospicio, and UNAP – Huaiquique

With this background, current and future vulnerabilities of the urban system are quantified from a multidimensional approach (human, physical, functional, economic), through multicriteria and probabilistic analyzes of climatic changes for temperature and wind variables. The weights are obtained from the results of a Participation Workshop, corresponding to the traffic light exercise carried out for the issues of the different dimensions of vulnerability for each threat. The result is urban development scenarios proposed for intelligent growth that considers the reduction of vulnerability due to climate change effects, and thereby minimizing the damage caused by threats.

It concludes in an evaluation of the model used, contributing to the development of a more resilient urban system, reducing vulnerability through better system conditions, in the context of the development of urban planning processes.