Landslide Risk Mapping in an Urban Area of the City of Natal, Brazil

Laddyla Bezerra,Olavo Santos,Slobodan Mickovski,Osvaldo De Freitas Neto

doi:10.3390/su12229601

Laddyla Bezerra, Olavo Santos + Show 2 more

Open Access

https://doi.org/10.3390/su12229601

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Abstract

Landslides are part of the natural processes of Earth’s surface dynamic, which could be accelerated or triggered by anthropic interference. Inadequate occupation of areas highly susceptible to landslide processes is the principal cause of accidents on Brazilian urban slopes, especially those occupied by settlements and slums. In Natal, Rio Grande do Norte state, Brazil, the existence of areas with steep and densely occupied slopes makes the municipality susceptible to landslides. In this context, the present study aimed to map the risk of landslides in an urban area located in the city of Natal. Using the quali-quantitative model proposed by Faria (2011), adapted for the conditions of the study area, which applies a multicriteria analytical hierarchy process (AHP) to a Geographic Information System (GIS), 11 risk indicators were submitted to pairwise comparisons by 10 risk management specialists in order to determine the relative importance (weighting) for each of these factors as a function of their contribution to the risk. The weightings obtained were combined to produce the final risk map of the study area, using a map algebra framework. The results show the existence of a critical risk for the resident population, primarily related to the possibility of a landslide, with potentially negative economic, environmental, and mainly social impacts.

Highlights

There has been a considerable increase in the frequency, intensity, and impacts generated by socioenvironmental disasters worldwide [1]
Field inspections sought to identify information that can indicate the occurrence or the possibility of developing landslides in the area or the possibility of their occurring at the site, such as the existence of cracks in the floor and/or masonry, the inclination of rigid structures, such as Sustainability 2020, 12, 9601
Field inspections sought to identify information that can indicate the occurrence or the possibility of developing landslides in the area or the possibility of their occurring at the site, such as the existence of cracks in the floor and/or masonry, the inclination of rigid structures, such as retaining walls, large trees, fences, posts, and the facade of residences and subsidence of the residential floor, among other problems

Summary

Introduction

There has been a considerable increase in the frequency, intensity, and impacts generated by socioenvironmental disasters worldwide [1]. According to [3], this significant increase in the number of landslides on Brazilian slopes is caused primarily by the lack of urban planning and infrastructure The latter fact has led the most underprivileged individuals to occupy naturally unsuitable areas or those that are highly susceptible to unstable slopes, mostly as a result of the low real estate value of the land. The methodology used to achieve this aim was a multicriteria decision-making technique (AHP) and Geographic Information System (GIS) system for application at the local level This approach includes the use of a limited number of key risk indicators and allows the delineation and mapping of risk zones with different associated risk levels which can help engineers and land planners to design and assess infrastructure and evaluate its effects on the surrounding environment

Materials and Methods

Water emergence on slope profile

Results and Discussion

Risk Mapping

Hazard Map

Vulnerability Map