Carotid atherosclerosis, one of the leading causes of ischemic stroke worldwide, can induce severe narrowing or even occlusion of the vessel, restricting blood flow to the brain and resulting in perfusion deficits. The plaque that has a high probability of undergoing rapid progression or future ruptures is defined as “vulnerable plaque”. Identifying vulnerable plaque is of great importance in clinical carotid atherosclerosis imaging. To date, a multi-contrast magnitude-based MR approach with blood suppression technique has been widely used to detect vulnerable plaque features. However, due to the limitations of magnitude-based methods, developing new MR techniques that have better sensitivity to hemorrhage and calcification is of great interest. Quantitative Susceptibility Mapping (QSM) is a technique that utilizes the MR phase information and has been widely used for quantifying the tissue susceptibility in the brain. The susceptibility contrast is extremely sensitive to hemorrhage and calcium which makes QSM a potential tool for carotid plaque imaging to identify intraplaque hemorrhage (IPH) and calcification. However, existing QSM methods have not been successfully implemented in the neck due to several challenges. The presence of air/tissue interface, plaque that has high susceptibility, and fat surrounding the carotid arteries can cause severe phase aliasing and other problems that will induce errors in the resultant susceptibility maps. To overcome these challenges and thus, develop a robust method for carotid QSM, a protocol that includes both data acquisition strategy and post-processing methods is proposed. For data acquisition, four echoes including two water/fat in-phase echoes and two water/fat out-of-phase echoes were collected. For data post-processing, temporal domain algorithm Catalytic Multiecho Phase Unwrapping Scheme (CAMPUS) was used to unwrap the phase images and local QSM was proposed. This protocol is able to properly unwrap the phase images even with the presence of high susceptibility plaque and eliminate the water/fat chemical shift effect in QSM reconstructions which will generate reliable susceptibility maps. From our results, the proposed QSM protocol has demonstrated the ability to generate reliable susceptibility maps and excellent sensitivity to IPH and calcification. Combining QSM with existing magnitude-based methods will lead to a major improvement in the diagnosis of carotid atherosclerosis. / Thesis / Master of Applied Science (MASc)

The purpose of this study is to evaluate and to compare the results of bivariate statistical analysis conducted with three different data sets in Geographical Information Systems (GIS) based landslide susceptibility mapping applied to the Devrek region. The data sets are created from the seed cells of crowns and flanks, only crowns, and only flanks of the landslides by using 10 different parameters of the study area. To increase the data dependency of the analysis, all parameter maps are classified into equal frequency classes based directly on the percentile divisions of each seed cells data set. The resultant maps of the landslide susceptibility analysis indicate that all data sets produce acceptable results. In each seed cell data set analysis, elevation, lithology, slope, aspect and drainage density parameters are found to be the most contributing factors in landslide occurrences. The results of the three data sets are compared by Seed Cell Area Index (SCAI). This comparison shows that the crowns data set produces the most accurate and successful landslide susceptibility map of the study area.

The Saint Lawrence Lowlands in eastern Canada contain extensive deposits of marine soils deposited in post-glacial seas during and following the retreat of the most recent continental glacier. These marine soils include silt and clay deposits known collectively as Champlain clay. When the pore fluid in these marine deposits has changed over time to a lower salinity, the clay can become very sensitive, or demonstrate substantial strength loss after reaching the peak strength with sufficient strain under undrained load conditions. Sensitive clay soils are subject to a peculiar type of very large landslide that typically involves great extents of nearly horizontal ground, usually occurring suddenly and without warning. These landslides tend to be described as “retrogressive” in the literature and practice, implying that they develop as a series of successive small failures that advance rearward until a final stable position is reached. The work of this thesis is organized into four different themes, with an overall objective of understanding the hazard and risk associated with large landslides in sensitive clay to linear infrastructure such as railways. The first theme, documented in Chapter 2, develops a number of spatial relationships between specific physiographic and geologic features and landslide occurrence or absence, as determined through air photo analysis and a review of the literature. The second theme, documented in Chapter 3, presents the construction of a digital database of large landslides in sensitive clay in eastern Canada, for the purposes of studying landslide susceptibility, hazard and risk. The third theme, documented in Chapters 4 and 5, presents and defends a novel mechanical model for development of these large landslides. This model suggests the landslides develop progressively, rather than retrogressively, and the science of fracture mechanics is employed to substantiate the model. The fourth theme, documented in Chapters 6 and 7, synthesizes the findings of the earlier themes and presents a methodology for estimating landslide susceptibility in Champlain clay. That approach is then extended to develop an understanding of the hazard. The concluding chapter extends that work to present an initial appreciation of landslide risk to railways. / Thesis (Ph.D, Geological Sciences & Geological Engineering) -- Queen's University, 2009-04-23 13:22:19.53

Magnetic Resonance Imaging (MRI) is a widely used, non-invasive imaging technique that provides a means to reveal structural and functional information of different body tissues in detail. Susceptibility Weighted Imaging (SWI) is a field in MRI that utilizes the information from the magnetic susceptibility property of different tissues using the gradient echo phase information. Although longer echo times (TEs) have been widely used in applications involving SWI, there are a few problems related with the long TE data, such as the strong blooming effect and phase aliasing even at macroscopic levels. In this thesis, the use of very short TEs is proposed to study susceptibility mapping. The short TEs can be used to study structures with susceptibilities an order of magnitude larger (such as air and bones in and around the brain sinuses, skull and teeth) than those within soft tissue. Using a new iterative susceptibility mapping technique that we recently developed, it becomes possible to map the geometry of such structures, which to date has proven difficult due to the lack of water content (for sinuses) or due to very short T2* (for bones). The method of phase replacement inside the sinuses proposed in this thesis provides more accurate phase information for the inversion than assuming zero or some arbitrary constant inside these structures. The first and second iterations were responsible for most of the changes in mapping out the susceptibility values. The mean susceptibility value in the sphenoid sinus is calculated as +9.3 ± 1.1ppm, close to the expected value of +9.4ppm for air. The reconstruction of the teeth in the in-vivo data provides a mean Δχ(teeth-tissue)=–3.3ppm, thanks to the preserved phase inside the jaw. The mean susceptibility inside a relatively homogeneous region of the skull bone was measured to be Δχ(bone-tissue)=–2.1ppm. Finally, these susceptibilities can be used to help remove the unwanted background fields prior to applying either SHARP or HPF. In addition, the effects of the background field gradient on flow compensation are studied. Due to the presence of these background gradients, an unwanted phase term is induced by the blood flow inside the vessels. Using a 3D numerical model and in vivo data, the background gradients were estimated to be as large as 1.5mT/m close to the air-tissue interfaces and 0.7mT/m inside the brain (leading to a potential signal loss of up to 15%). The quantitative susceptibility mapping (QSM) results were improved in the entire image after removing the confounding arterial phase thanks to the reduced ringing artifacts. Lastly, a novel approach to improve the susceptibility mapping results was introduced and utilized to monitor the changes in venous oxygen saturation levels as well as the changes in oxygen extraction fraction instigated by the vasodynamic agents, caffeine and acetazolamide. The internal streaking artifacts in the susceptibility maps were reduced by giving an initial susceptibility value uniformly to the structure-of-interest, based on the a priori information. For veins, the iterative results, when the initial value of 0.45 ppm was used, were the best in terms of the highest accuracy in the mean susceptibility value (0.453 ppm) and the lowest standard deviation (0.013 ppm). Using this technique, the venous oxygen saturation levels (inside the internal cerebral veins (ICVs)) for normal physiological conditions, post-caffeine and post-Diamox for the first volunteer were calculated as (mean ± standard deviation): Y_Normal = 69.1 ± 3.3 %, Y_Caffeine = 60.5 ± 2.8 % and Y_Diamox = 79.1 ± 4.0%. For the caffeine challenge, the percentage change in oxygen extraction fraction (OEF) for pre and post caffeine results was calculated as +27.0 ± 3.8%; and for the Diamox challenge, the percentage change in OEF was calculated as −32.6 ± 2.1 % for the ICVs. These vascular effects of Diamox and caffeine were large enough to be easily measured with susceptibility mapping and can serve as a sensitive biomarker for measuring reductions in cerebro-vascular reserve through abnormal vascular response, an increase in oxygen consumption during reperfusion hyperoxia or locally varying oxygen saturation levels in regions surrounding damaged tissue. In conclusion, our new approach to QSM offers a means to monitor venous oxygen saturation reasonably accurately and may provide a new means to study neurovascular diseases where there are changes in perfusion that affect the oxygen extraction fraction. / Thesis / Doctor of Philosophy (PhD) / Magnetic Resonance Imaging (MRI) is a widely used, non-invasive imaging technique that provides a means to reveal structural and functional information of different body tissues in detail. Susceptibility Weighted Imaging (SWI) is a field in MRI that utilizes the information from the magnetic susceptibility property of different tissues using the gradient echo phase information. Firstly, we demonstrate that using our phase replacement technique, it becomes possible to map the geometry of structures with almost no MR signal, which to date has proven difficult due to the lack of water content (for sinuses) or due to very short T2* (for bones). Secondly, the effects of the background field gradient on flow compensation were studied. Due to the presence of these background gradients, an unwanted phase term is induced by the blood flow inside the vessels. And, lastly, we present our new approach utilizing SWI data, offering a means to monitor venous oxygen saturation reasonably accurately and, potentially, a new means to study neurovascular diseases where there are changes in perfusion that affect the oxygen extraction fraction.

Each year in the United States, approximately 1.35 million people are a ected by mTBI (aka concussion) and subsequent cognitive impairment. Approximately 33% of mTBI cases results in persistent long-term cognitive de cits despite no abnormalities appearing on conventional neuroimaging scans. Therefore, an accurate and reliable imaging method is needed to determine injury location and extent of healing. The goal of this study was to characterize and quantify mTBI through DTI, an advanced MRI technique that encodes voxel-wise tissue water microstructural di usivity as a tensor, as well as QSM, which measures iron deposition within tissues. We hypothesized that personalizing the analysis of DTI and QSM will provide a better understanding of trauma-induced microstructural damage leading to improved diagnosis and prognosis accuracy. Through regression analysis, a preliminary comparison between DTI data to QSM measurements was performed to determine potential correlations between the two MRI techniques. Further, a large database of healthy pediatric brain DTI data was downloaded and each was warped into a standardized brain template to ultimately use for voxel-wise z-score analysis of individual mTBI patients (n=26). This allowed localization and quantitation of abnormal regions on a per-patient basis. Signi cant abnormalities were commonly observed in a number of regions including the longitudinal fasciculus, fronto-occipital fasciculus, and corticospinal tract, while unique abnormalities were localized in a host of other areas (due to the individuality of each childs injury). Further, through group-based Bonferroni corrected T-test analysis, the mTBI group was signi cantly di erent from controls in approximately 65% of regions analyzed. These results show that DTI is sensitive to the detection of microstructural changes caused by mTBI and has potential to be a useful tool for improving mTBI diagnosis accuracy / Thesis / Master of Applied Science (MASc) / Concussions affect over one million people in the United States each year. In a number of cases, these individuals must cope with persistent long-term cognitive impairment resulting from the injury. A current, significant problem is that concussion cannot be reliably diagnosed using conventional CT and MR imaging methods. Therefore, an accurate and reliable imaging method is needed to determine both injury location and severity, as well as to monitor healing. The goal of this study was to quantify concussion through MR imaging techniques known as Di ffusion Tensor Imaging and Quantitative Susceptibility Mapping, which accurately model the brain's mi- crostructure. Analysis utilizing these MRI methods found signifi cant abnormalities in a number of brain regions of concussed subjects relative to healthy individuals. These results suggest that DTI, in particular, is sensitive to microstructural changes caused by concussions and has the potential to be a useful tool for improving diagnosis accuracy.

<p>Quantitatively measuring oxygen saturation is important to characterize the physiological or pathological state of tissue function. In this thesis, we demonstrate the possibility of using susceptibility mapping to noninvasively estimate the venous blood oxygen saturation level. Accurate susceptibility quantification is the key to oxygen saturation quantification. Two approaches are presented in this thesis to generate accurate and artifact free susceptibility maps (SM): a regularized inverse filter and a k-space iterative method. Using the regularized inverse filter, with sufficient resolution, major veins in the brain can be visualized. We found that different sized vessels show a different level of contrast depending on their partial volume effects; larger vessels show a bias toward a reduced susceptibility approaching 90% of the expected value. Also, streaking artifacts associated with high susceptibility structures such as veins are obvious in the reconstructed SM. To further improve susceptibility quantification and reduce the streaking artifacts in the SMs, we proposed a threshold-based k-space iterative approach that used geometric information from the SM itself as a constraint to overcome the ill-posed nature of the inverse filter. Both simulations and in vivo results show that most streaking artifacts inside the SM were suppressed by the iterative approach. In simulated data, the bias toward lower mean susceptibility values inside vessels has been shown to decrease from around 10% to 2% when choosing an appropriate threshold value for the proposed iterative method, which brings us one step closer to a practical means to map out oxygen saturation in the brain.</p> / Doctor of Philosophy (PhD)

Changes in climatic regimes and land use have led to increases in wildfire activities around the world. Wildfires are now happening more frequently, at higher altitudes, and higher severities. Adverse impacts of wildfires can last years after the fire has been contained through post-fire geohazards, such as shallow landslides. Post-wildfire shallow landslides are often mobilized by rainfall and due to fire-induced changes in soil and land cover properties and near-surface processes. This study aims to develop a physics-based framework to evaluate the stability of burned hillslopes against rainfall-triggered shallow landslides. A coupled hydromechanical infiltration model is developed by employing a closed-form solution of the Richards equation. The model is integrated into an infinite slope stability analysis to capture the effect of temporal changes in the pressure head profile of an unsaturated vegetated slope on its stability. The proposed model considers the antecedent condition of soil and vegetation cover, the time-varying nature of rainfall intensity, and wildfire-induced changes in soil properties, root reinforcement, transpiration rate, and canopy interception. The efficacy of the proposed framework is illustrated through modeling a case study in the Las Lomas watershed in California, USA. The watershed was a part of a larger area that was burned in the San Gabriel Complex Fire (consisting of two separate fires, the Fish Fire and the Reservoir Fire) in 2016. Three years later, during a heavy rainstorm in January 2019, the affected area, including the Las Lomas watershed, experienced widespread landslides. The proposed framework is then integrated into a geographic information system (GIS) to generate a susceptibility map of post-wildfire rainfall-triggered shallow landslides. The applicability of the proposed framework at a regional scale is tested for the entire area affected by the San Gabriel Complex Fire to model the observed shallow landslides within the boundaries of the Fish Fire and the Reservoir Fire. The findings of this study can be used to warn the community of post-wildfire shallow landslides activities.

<p>Magnetic resonance imaging is a research and clinical tool that has been applied in a wide variety of sciences. One area of magnetic resonance imaging that has exhibited terrific promise and growth in the past decade is magnetic susceptibility imaging. Imaging tissue susceptibility provides insight into the microstructural organization and chemical properties of biological tissues, but this image contrast is not well understood. The purpose of this work is to develop effective approaches to image, assess, and model the mechanisms that generate both isotropic and anisotropic magnetic susceptibility contrast in biological tissues, including myocardium and central nervous system white matter. </p><p>This document contains the first report of MRI-measured susceptibility anisotropy in myocardium. Intact mouse heart specimens were scanned using MRI at 9.4 T to ascertain both the magnetic susceptibility and myofiber orientation of the tissue. The susceptibility anisotropy of myocardium was observed and measured by relating the apparent tissue susceptibility as a function of the myofiber angle with respect to the applied magnetic field. A multi-filament model of myocardial tissue revealed that the diamagnetically anisotropy α-helix peptide bonds in myofilament proteins are capable of producing bulk susceptibility anisotropy on a scale measurable by MRI, and are potentially the chief sources of the experimentally observed anisotropy.</p><p>The growing use of paramagnetic contrast agents in magnetic susceptibility imaging motivated a series of investigations regarding the effect of these exogenous agents on susceptibility imaging in the brain, heart, and kidney. In each of these organs, gadolinium increases susceptibility contrast and anisotropy, though the enhancements depend on the tissue type, compartmentalization of contrast agent, and complex multi-pool relaxation. In the brain, the introduction of paramagnetic contrast agents actually makes white matter tissue regions appear more diamagnetic relative to the reference susceptibility. Gadolinium-enhanced MRI yields tensor-valued susceptibility images with eigenvectors that more accurately reflect the underlying tissue orientation.</p><p>Despite the boost gadolinium provides, tensor-valued susceptibility image reconstruction is prone to image artifacts. A novel algorithm was developed to mitigate these artifacts by incorporating orientation-dependent tissue relaxation information into susceptibility tensor estimation. The technique was verified using a numerical phantom simulation, and improves susceptibility-based tractography in the brain, kidney, and heart. This work represents the first successful application of susceptibility-based tractography to a whole, intact heart.</p><p>The knowledge and tools developed throughout the course of this research were then applied to studying mouse models of Alzheimer’s disease in vivo, and studying hypertrophic human myocardium specimens ex vivo. Though a preliminary study using contrast-enhanced quantitative susceptibility mapping has revealed diamagnetic amyloid plaques associated with Alzheimer’s disease in the mouse brain ex vivo, non-contrast susceptibility imaging was unable to precisely identify these plaques in vivo. Susceptibility tensor imaging of human myocardium specimens at 9.4 T shows that susceptibility anisotropy is larger and mean susceptibility is more diamagnetic in hypertrophic tissue than in normal tissue. These findings support the hypothesis that myofilament proteins are a source of susceptibility contrast and anisotropy in myocardium. This collection of preclinical studies provides new tools and context for analyzing tissue structure, chemistry, and health in a variety of organs throughout the body.</p> / Dissertation

Os movimentos de massa são fenômenos naturais que fazem parte dos processos de dinâmica superficial que modelam a superfície terrestre. Quando ocorrem em áreas ocupadas, podem provocar perdas econômicas, impactos sociais e, em casos extremos, perda de vidas humanas. O estabelecimento de medidas preventivas para mitigar estes danos demanda a identificação das áreas mais propensas a esses fenômenos. Partindo deste contexto, o objetivo desta dissertação foi desenvolver uma proposta metodológica para mapear a suscetibilidade a escorregamentos no município de Porto Alegre-RS, com o emprego de ferramentas de geoprocessamento. As variáveis utilizadas foram: declividade, geologia, distância de lineamentos, acúmulo de fluxo, uso do solo e cobertura vegetal, as quais foram processadas no software Idrisi. Após a padronização das variáveis por meio da aplicação de funções fuzzy e pela atribuição direta de notas, definiu-se a importância de cada uma na predisposição do terreno a escorregamentos com base na consulta a especialistas, com o apoio da técnica denominada processo analítico hierárquico. A integração das variáveis foi realizada por meio de combinação linear ponderada, estabelecendo-se dois cenários de suscetibilidade a escorregamentos: o primeiro com a suscetibilidade natural e o segundo com a suscetibilidade induzida. Os resultados indicam que as áreas mais suscetíveis a escorregamentos situam-se, principalmente, nos morros da Crista de Porto Alegre e nos morros isolados no sul do município. O restante do município apresenta, de maneira geral, baixa suscetibilidade. A validação dos resultados obteve uma exatidão geral de 95% e 94% respectivamente para os Cenários 1 e 2. As áreas abaixo da curva ROC (Receiver Operating Characteristic) foram respectivamente de 0,960 e 0,966, o que indica que as variáveis e os pesos foram adequados e que ambos os cenários são robustos. Assim, constata-se que as ferramentas de geoprocessamento são úteis no mapeamento da suscetibilidade a escorregamentos, pois tornam ágil o mapeamento e sua atualização, e dão mais clareza e transparência ao processo de avaliação da suscetibilidade. Além disso, o método proposto permite reduzir os esforços nas etapas iniciais da gestão de riscos, possibilitando ao gestor priorizar os mapeamentos mais detalhados nas áreas com maior suscetibilidade. Isso demonstra que as rotinas de apoio à decisão, como as utilizadas neste trabalho, podem ser incorporadas em estudos de suscetibilidade, provendo importantes informações para o planejamento urbano dos municípios. / Mass movements are natural phenomena that are part of the surface dynamic processes that shape the Earth’s surface. When they occur in urban areas, can cause economic losses, social impacts and, in extreme cases, losses of human lives. The implementation of preventive measures to mitigate those damages requires the identification of the areas prone to these events. Therefore, the aim of this dissertation was to develop a methodological approach to map landslide susceptibility at the municipality of Porto Alegre-RS, with the use of geoprocessing tools. The variables used were: slope, geology, distance from lineaments, flow accumulation and land use, which were processed in the Idrisi software. After the standardization of the variables through the application of fuzzy functions and the direct assignment of notes, the importance of each one on the predisposition of landslides was defined, based on the opinion of experts, with the support of the technique entitled analytic hierarchy process (AHP). The integration of the variables was based on weighted linear combination, resulting in two scenarios: the first with the natural susceptibility and the second with the induced susceptibility. The results indicate that the most susceptible areas to landslide are located in the hills of the Crista de Porto Alegre and in the isolated hills located at the south of the municipality. The remaining area has, in general, low susceptibility. The validation of the results obtained an overall accuracy of 95% and 94%, respectively for Scenarios 1 and 2. The areas under the ROC (Receiver Operating Characteristic) curve were respectively 0.960 and 0.966, indicating that the variables and weights were adequate and both scenarios are robust. Thus, it is noted that geoprocessing tools are useful to map the landslide susceptibility, since they make the mapping process and its updates agile, and give more clarity and transparency to the susceptibility assessment process. In addition, the proposed method reduces efforts in the early stages of risk management, enabling the manager to prioritize the most susceptible areas for detailed mappings. This demonstrates that decision support routines, such as those used in this dissertation, can be incorporated into susceptibility studies, providing important information for the urban planning.

Os movimentos de massa são fenômenos naturais que fazem parte dos processos de dinâmica superficial que modelam a superfície terrestre. Quando ocorrem em áreas ocupadas, podem provocar perdas econômicas, impactos sociais e, em casos extremos, perda de vidas humanas. O estabelecimento de medidas preventivas para mitigar estes danos demanda a identificação das áreas mais propensas a esses fenômenos. Partindo deste contexto, o objetivo desta dissertação foi desenvolver uma proposta metodológica para mapear a suscetibilidade a escorregamentos no município de Porto Alegre-RS, com o emprego de ferramentas de geoprocessamento. As variáveis utilizadas foram: declividade, geologia, distância de lineamentos, acúmulo de fluxo, uso do solo e cobertura vegetal, as quais foram processadas no software Idrisi. Após a padronização das variáveis por meio da aplicação de funções fuzzy e pela atribuição direta de notas, definiu-se a importância de cada uma na predisposição do terreno a escorregamentos com base na consulta a especialistas, com o apoio da técnica denominada processo analítico hierárquico. A integração das variáveis foi realizada por meio de combinação linear ponderada, estabelecendo-se dois cenários de suscetibilidade a escorregamentos: o primeiro com a suscetibilidade natural e o segundo com a suscetibilidade induzida. Os resultados indicam que as áreas mais suscetíveis a escorregamentos situam-se, principalmente, nos morros da Crista de Porto Alegre e nos morros isolados no sul do município. O restante do município apresenta, de maneira geral, baixa suscetibilidade. A validação dos resultados obteve uma exatidão geral de 95% e 94% respectivamente para os Cenários 1 e 2. As áreas abaixo da curva ROC (Receiver Operating Characteristic) foram respectivamente de 0,960 e 0,966, o que indica que as variáveis e os pesos foram adequados e que ambos os cenários são robustos. Assim, constata-se que as ferramentas de geoprocessamento são úteis no mapeamento da suscetibilidade a escorregamentos, pois tornam ágil o mapeamento e sua atualização, e dão mais clareza e transparência ao processo de avaliação da suscetibilidade. Além disso, o método proposto permite reduzir os esforços nas etapas iniciais da gestão de riscos, possibilitando ao gestor priorizar os mapeamentos mais detalhados nas áreas com maior suscetibilidade. Isso demonstra que as rotinas de apoio à decisão, como as utilizadas neste trabalho, podem ser incorporadas em estudos de suscetibilidade, provendo importantes informações para o planejamento urbano dos municípios. / Mass movements are natural phenomena that are part of the surface dynamic processes that shape the Earth’s surface. When they occur in urban areas, can cause economic losses, social impacts and, in extreme cases, losses of human lives. The implementation of preventive measures to mitigate those damages requires the identification of the areas prone to these events. Therefore, the aim of this dissertation was to develop a methodological approach to map landslide susceptibility at the municipality of Porto Alegre-RS, with the use of geoprocessing tools. The variables used were: slope, geology, distance from lineaments, flow accumulation and land use, which were processed in the Idrisi software. After the standardization of the variables through the application of fuzzy functions and the direct assignment of notes, the importance of each one on the predisposition of landslides was defined, based on the opinion of experts, with the support of the technique entitled analytic hierarchy process (AHP). The integration of the variables was based on weighted linear combination, resulting in two scenarios: the first with the natural susceptibility and the second with the induced susceptibility. The results indicate that the most susceptible areas to landslide are located in the hills of the Crista de Porto Alegre and in the isolated hills located at the south of the municipality. The remaining area has, in general, low susceptibility. The validation of the results obtained an overall accuracy of 95% and 94%, respectively for Scenarios 1 and 2. The areas under the ROC (Receiver Operating Characteristic) curve were respectively 0.960 and 0.966, indicating that the variables and weights were adequate and both scenarios are robust. Thus, it is noted that geoprocessing tools are useful to map the landslide susceptibility, since they make the mapping process and its updates agile, and give more clarity and transparency to the susceptibility assessment process. In addition, the proposed method reduces efforts in the early stages of risk management, enabling the manager to prioritize the most susceptible areas for detailed mappings. This demonstrates that decision support routines, such as those used in this dissertation, can be incorporated into susceptibility studies, providing important information for the urban planning.