Urban Land Policies for Landslide Risk Reduction: Conditions and Potentials in the Andes

Background and aim
The Andes is one of the regions that concentrates landslide-prone areas the most in the world with considerable fatalities. This condition is exacerbating, considering the regional unfavorable geodynamics, and increasing extreme climatic events, while tendencies of urban population–growth, densification, environmental degradation, uncontrolled development, institutional weakness, and the ignorance of local vulnerabilities prevail.
This PhD thesis studies the conditions and potentials that land policies have in Andean cities to reduce extensive landslide risk. It addresses the mismatch between conventional land use planning and the reality of urban peripheries households settled on challenging topographies. To this end, naturalistic approaches are complemented with constructivist ones to have a comprehensive picture. The representative case study for analysis is Quito, the capital of Ecuador.
Contents and methods
This work departs from a conceptual framework encompassing environmental, economic, socio-cultural and policy dimensions supported by a semi-systematic literature review. More importantly, the multiple, constant, and reciprocal relations between these dimensions are highlighted. This first conceptual part emphasizes on the dichotomy between land use planning and urban management (implementation) in Latin America, which needs better articulation to effectively reduce landslide risk.
An intermediate part presents Quito at the macro level. First, by describing the city profile with the urban systems that shaped it and the tendential scenarios. This includes the focus on the local risk management policy and its evolution, in parallel to the land use policy. Furthermore, it identifies the landslide risk areas within the city by combining landslide susceptibility with social vulnerability maps by means of different methodologies, including Logistic Regression, Sensitivity Analysis, Principal Component Analysis, and the Comparative Environmental Risk Index.
The last part downscales the topic at the neighborhood scale by performing a multiple-case study in eight landslide-prone sites in the Quito periphery. Survey and systematic observation of buildings vulnerability allow a comparative analysis across sites and a global descriptive statistic. A complement with qualitative research techniques, such as semi-structured interviews, focus groups, experts’ forum, desk research and site observation provided the base to characterize the conditions and potentials of the peripheral landslide-prone neighborhoods to implement landslide risk reduction policies.
Key Findings
Results suggest on the potential of informality to complement formality and the use of socio-technical approaches to fulfill landslide risk reduction through urban policies. In this sense, diverse trans-dimensional local configurations of landslide risk would need specific risk-reduction strategies. In this regard, the multiple-case study in Quito provided three archetypes, based on a center-periphery notion, with nuanced complexities and adaptative degrees. Regardless the potentials and ongoing planning systems reforms in the region towards a more proactive urban management for landslide risk reduction, land policies are still found difficult to overcome the maladaptation to local specificities, inequities as root causes of risk, raised urbanization on rugged topographies, extreme climatic events, and a strong patronizing ethos, based on the so-called patrimonialist vision of land.
Quito, as the representative Andean case, has had to face this landslide risk production problem because of the late 20th century internal migration boost and the urbanization of the peripheries. This was followed by an urban sprawl that created an inefficient and unbalanced metropolitan area in terms of services delivery, highly dependent on the city “hypercenter” as economic engine, and depleting land with former agricultural and ecological vocations.
Regarding the specific landslide risk zoning policy, Quito has anyhow articulated disaster management and land policies in the last two decades, with a cross-sectoral policy and focusing better on prevention and reduction. In this matter, this study offers a suitable input–susceptible of enhancement–to identify the degree of landslide risk at the block scale by combining landslide susceptibility and social vulnerability mapping. This landslide risk map helps to locate households at the most critical condition–probably in need of relocation–corresponding to 0.1% of the population, which is a manageable number for action and a criterion for policy segmentation. Landslide susceptibility mapping highlighted urban factors as important drivers of landslide danger production, highlighting road and population densities; and identified the highest susceptibilities in the peripheries, and a few inner areas. In complement, social vulnerability analysis provided a clear picture portraying a clear vulnerable southern Quito, scattered vulnerabilities in the north ends and a wealthy and safe axial territory running from the center-north of the main city towards the central-eastern valley. In this city, social vulnerability is mainly driven by low-skilled occupational groups with limited access to insurance and new ICT technologies. This social input for land use planning has been often claimed in participatory processes and this study aims to deliver it for discussion and eventually to strengthen policy design.
Finally, the multiple-case study unveiled knowledge from the neighborhood scales. Survey results confirmed some literature review findings, including the preference for housing betterments over relocation or other hard measures, the underestimation of risk in self-assessments, or the preference of on-site relocation. However, results also suggested that relocation was negotiable for households, based on intuitive cost-benefit analyses. In complement, the qualitative study highlighted the patronizing attitude of dwellers and authorities, the use of housing cooperatives as a semi-legal mean to access land and many community problems that hinder governance around landslide risk reduction. Among these problems are the rise of pseudo-leaders who deceived and manipulated reckless migrant dwellers, profiting from illegal subdivisions, and supported on informal networks across community organizations and public institutions. The latter neglected planning, control, and public works execution from former times. All in a set contributed to produce current landslide risk in a history of more than four decades in this Andean city.