This thesis looks at the comparison between grain micromorphology of moraines, debris flows and similar accumulations. Moraine samples were taken in the Černé jezero Lake area, Bohemian Forest, in the Velická dolina Valley, High Tatras, and in the Labský důl Valley, Krkonoše Mts. Samples of debris flows and unverified accumulations were taken in the Důl Bílého Labe Valley, Krkonoše Mts., and further samples of accumulations were obtained from the valley of Prudký potok Stream, Králický Sněžník Mts., the valley of Vražedný potok Stream and Velká Kotlina, Hrubý Jeseník Mts. Sediments were examined under electron microscope and their morphological characteristics and influence of the environment were identified and described. Calculated exoscopic moraine standard was used for comparison of examined forms of relief using distance coefficients, statistical analysis were carried out which identified diagnostic characters for distinguishing moraines and debris flows. There was also calculated exoscopic standard for different types of moraines (frontal, lateral, basal). This research highlighted the differences between moraines and debris flows, and between different types of moraines. The study also proved that typical glacial microtextures, that are generally accepted, occur at similar levels on grains...

Several debris flows have affected Åre municipality (Sw. Åre kommun) in the last 20 years. Jämtlandis a declared risk area for landslides and debris flows and there is an even higher probability oflandslides causing great damage around the Åre urban area. Debris flows are fast mass movements inwhich a large volume of saturated soil floats down an incline. Basic conditions are steep inclines,erodible soil and high pore-pressure in the soil. The existing literature on the subject is in agreementthat debris flows pose a considerable risk for Åre town because of the combination of steep slopes,high precipitation, land use and geology. Debris flows are often triggered by heavy precipitation and with the changing climate, precipitationpatterns are expected to change, which will have implications for the risk of debris flows in Jämtland,thus, making this issue more critical. Moreover, climate change could also increase tourism inJämtland in the short term. This could result in an increasing demand for further exploitation, thechange of land use could potentially lead to an increase of the debris flow risk in the area. To furtherunderstand how the planned future development in Åre may affect the consequences of debris flows, acomparison between areas with a risk of debris flows and plans of future development for housing inthe municipality’s current overview plan has been made. This comparison showed five areas ofpotential overlap between future development and risk areas for debris flows. Conclusively, thisindicates that future development could increase the consequences of debris flows if no mitigatingactions are taken. Åre municipality has been criticised for their inaction regarding the lack of mitigation strategies andprotection measures against debris flows in both the media and authority documents. Municipalitiesare responsible for planning future development and therefore, Åre municipality should focus ongaining more knowledge and in addition, establish follow up routines and a network for stakeholders.Regarding climate change, the property owner is liable for implementing the protection measuresneeded which sometimes can be very complex. / Under de senaste 20 åren har Åre kommun drabbats av flertal slamströmmar. Jämtlands län harbedömts som ett riskområde för skred och slamströmmar, där stora skador befaras främst i Åresamhälle. Slamströmmar är snabba massrörelser bestående av vattenmättad jord och kan inträffa därdet finns en brant lutning i terrängen, eroderbara jordmassor samt höga porvattentryck i jorden. Slamströmmar utlöses huvudsakligen av intensiva nederbördsevent vilka förväntas öka i och medklimatförändringarna, detta påverkar i sin tur risken för uppkomsten av slamströmmar i Jämtlandvilket gör ämnet väldigt aktuellt. Syftet med litteraturstudien har varit att undersöka risken för slamströmmar i Åre och hur detta skullekunna förändras i framtiden med hänsyn till klimatförändringar och exploatering. Det är framföralltsvenska myndighetsrapporter och kommunala dokument som studerats men även intervjuer av aktöreri nationella tidningar. Den befintliga litteraturen inom ämnet visar på att slamströmmar utgör en riskför Åre samhälle på grund av kombinationen av den branta terrängen, stora mängden nederbörd,markanvändningen och geologin. Däremot är litteraturen gällande andra delar av Åre kommun mindreomfattande. Klimatförändringar kan dessutom påverka turismen i Jämtland på kort sikt vilket i sin tur ökarefterfrågan på ytterligare exploatering där förändrad markanvändning potentiellt kunnat påverkarisken för slamströmmar i området. En jämförelse mellan riskområden och områden för framtidaexploateringsområden enligt kommunens översiktsplan har gjorts för att vidare kunna förståkommunens utmaningar mer djupgående. Detta resulterade i fem tänkbara överlapp mellan de tvåkategorierna. Sammanfattningsvis tyder det på att framtida exploatering kan påverka risken förslamströmmar om inte åtgärder vidtas. Åre kommun har genom åren blivit kritiserat i media och i myndighetsrapporter för sitt bristfälligaarbete gällande riskhanteringen av slamströmmar. Det finns inget tydligt förhållningssätt för dessatyper av problem vilket påverkar förmågan att sprida samt behålla kunskap och erfarenhet inomorganisationen. I och med att det är kommunens ansvar att planera framtida exploatering så är detviktigt för Åre kommun att framöver erhålla den kunskap som krävs och på liknande sätt ävenredogöra för tydliga uppföljningsrutiner. Vidare har kommunen ansvar för att utvärdera geologiskarisker, exempelvis slamströmmar, inom området i planeringsprocessen. Kommunen kan bli skyldig tillskador som sker upp till tio år efter införskaffandet av planen, därefter faller ansvaret på den enskildefastighetsägaren. Det är däremot fastighetsägaren som ska implementera behövande skyddsåtgärdernär det handlar om klimatförändringar vilket kan bli väldigt komplext.

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[pt] Os fluxos de detritos são perigosos riscos naturais, que afetam países com intensas precipitações e terrenos montanhosos. Tais eventos configuram alto perigo para a vida humana e danificação de infraestrutura, resultando em importantes perdas econômicas. O estudo de fluxos de detritos envolve um mecânismo complexo e suas técnicas de previsão são baseadas na calibração de modelos, que devem ser delimitados por tentativa e erro de eventos anteriores. Tais previsões são ferramentas valiosas para delimitar as potenciais áreas de risco e, dessa forma, projetar medidas de mitigação e convivência. O principal objetivo deste trabalho foi analisar o comportamento de quatro fluxos de detritos deflagrados por precipitações de alta intensidade em regiões tropicais utilizando modelagem numérica em 2D e 3D. Foram analisados os casos de Lajas e Llano de la Piedra na Costa Rica e os casos de Córrego D Antas e Hospital São Lucas no Rio de Janeiro. Os principais parâmetros utilizados, na avaliação do risco deste tipo de movimentos de massa, são: a distância percorrida, a área de impacto, a velocidade e profundidade do fluxo. Os casos foram calibrados utilizando a reologia de Voellmy. A definição dos parametros na calibração é vital, pois oferece a possibilidade de previsões de primeira ordem, feita sobre escorregamentos acontecendo em condições semelhantes. Os resultados da análise dinâmica mostram valores consistentes entre os valores observados e as modelagens numéricas em 2D e 3D para os principais parâmetros avaliados, corroborando o uso destas ferramentas para análises de risco e projeção de medidas de mitigação e convivência. / [en] Debris flows are dangerous natural hazards affecting countries with steep terrains and heavy rainfall. They are associated with serious risks to human lives and infrastructure leading to important economic losses and fatalities. Debris flows involve complex mechanics and prediction techniques that are based on the calibration of models that must be constrained by trial-and-error back-analysis of previous landslides. Such predictions are a valuable tool for outlining potential hazard areas and the development of mitigation strategies and design of protective structures. The main goal of this work was to analyze the behavior of four debris flows triggered by heavy rainfall in tropical regions with numerical modelling. The Voellmy rheology was used to calibrate the cases occurred in Lajas and Llano de la Piedra in Costa Rica, and Córrego D Antas and Hospital São Lucas in Rio de Janeiro. The main parameters used for landslide risk assessment are runout distance, potential impact area, flow velocity and flow depth. The definition of appropriate calibrating parameters is important because it provides the possibility of first order predictions to be made about the motion of future landslides happening under similar conditions. The results of the dynamic analysis showed that consistent values were obtained for the main parameters evaluated in the 2D and 3D runout models, verifying the usefulness of these tools for landslide risk assessment and the project of protection structures.

Flood inundation is a major natural hazard that can have very severe socio-economic consequences. This thesis presents an enhanced numerical model for flood simulation. After setting the context by examining recent large-scale flood events, a literature review is provided on shallow flow numerical models. A new version of the hyperbolic horizontal variable density shallow water equations with source terms in balanced form is used, designed for flows over complicated terrains, suitable for wetting and drying fronts and erodible bed problems. Bed morphodynamics are included in the model by solving a conservation of bed mass equation in conjunction with the variable density shallow water equations. The resulting numerical scheme is based on a Godunov-type finite volume HLLC approximate Riemann solver combined with MUSCL-Hancock time integration and a non-linear slope limiter and is shock-capturing. The model can simulate trans-critical, steep-fronted flows, connecting bodies of water at different elevations. The model is validated for constant density shallow flows using idealised benchmark tests, such as unidirectional and circular dam breaks, damped sloshing in a parabolic tank, dam break flow over a triangular obstacle, and dam break flow over three islands. The simulation results are in excellent agreement with available analytical solutions, alternative numerical predictions, and experimental data. The model is also validated for variable density shallow flows, and a parameter study is undertaken to examine the effects of different density ratios of two adjacent liquids and different hydraulic thrust ratios of species and liquid in mixed flows. The results confirm the ability of the model to simulate shallow water-sediment flows that are of horizontally variable density, while being intensely mixed in the vertical direction. Further validation is undertaken for certain erodible bed cases, including deposition and entrainment of dilute suspended sediment in a flat-bottomed tank with intense mixing, and the results compared against semi-analytical solutions derived by the author. To demonstrate the effectiveness of the model in simulating a complicated variable density shallow flow, the validated numerical model is used to simulate a partial dam-breach flow in an erodible channel. The calibrated model predictions are very similar to experimental data from tests carried out at Tsinghua University. It is believed that the present numerical solver could be useful at describing local horizontal density gradients in sediment laden and debris flows that characterise certain extreme flood events, where sediment deposition is important.

Le modèle de couche mince intégré sur l'épaisseur, Saint-Venant, utilisé classiquement pour simuler la propagation de laves torrentielles et coulées boueuses, repose sur plusieurs approximations concernant la forme des profils de vitesse en zones non-uniformes. Il est pourtant nécessaire d'utiliser ce type de modélisation, comme outil d'aide à la gestion des risques liés aux laves torrentielles. Nous proposons d'éprouver ses hypothèses, en observant une zone fortement non-uniforme, le front de coulées à surface libre et le champ de vitesse à l'intérieur de cette zone.En améliorant notre connaissance de l'évolution de la forme des profils de vitesse (de la dynamique interne) au front de coulées, nous cherchons à améliorer les modèles de couche mince. Cette thèse porte donc sur l'étude de la dynamique interne au front d'écoulements à surface libre de fluides newtoniens et viscoplastiques.Nous avons utilisé le dispositif du canal à fond mobile qui permet de générer des coulées stationnaires dans le référentiel de l'observateur au moyen d'un fond mobile remontant vers l'amont. Nous avons réalisé un travail technique sur ce canal et sur l'analyse des images pour pouvoir mesurer les champs de vitesse à haute résolution spatiale aux fronts de coulées à surface libre de fluides viscoplastiques. L'étude des fluides newtoniens a aussi été réalisée afin de valider les modèles et éprouver le dispositif expérimental.Nous avons comparé les résultats expérimentaux aux solutions théoriques de deux modèles de couche mince adaptés à la rhéologie de Herschel-Bulkley : le modèle classique de la lubrification, à la base du modèle de Saint-Venant et un modèle consistant à l'ordre 1 développé dans cette thèse. Le modèle consistant d'ordre 1 est la somme du modèle à l'ordre 0 (la lubrification) et de termes correctifs qui proviennent des contraintes normales et des termes d'inertie. Dans le cadre de notre configuration du fond mobile remontant vers l'amont, il est possible de déduire la forme du front en cherchant une solution de type onde progressive, sans passer par un modèle intégré dans l'épaisseur.Pour les fluides viscoplastiques, la structure classique du profil de vitesse, avec une zone cisaillée surmontée d'un plug non cisaillé est bien reconnaissable sur nos profils de vitesse en zone uniforme, et en zone faiblement variée. Mais à l'approche du front, cependant, la vitesse de surface augmente, les profils de vitesse expérimentaux deviennent cisaillés sur toute l'épaisseur, conduisant à la disparition du plug à proximité de la ligne de front.Le modèle de lubrification prédit l’existence d'un plug dans le front jusqu'à la ligne de contact, ce qui n'est pas observé expérimentalement. La vitesse de surface du modèle de lubrification augmente à l'approche du front, mais est largement sous-estimée par rapport à la vitesse de surface mesurée. Les vitesses de surface prédites par le modèle d'ordre 1 augmentent plus drastiquement au front, en meilleur accord avec les mesures que le modèle de lubrification. Pour certaines configurations expérimentales l'accord est même très bon. Remarquablement, le cisaillement des profils de vitesse à l'approche du front, observé expérimentalement, est aussi prédit par le modèle d'ordre 1.Les profils de vitesse présentent donc une évolution au front de coulées viscoplastiques en contradiction avec les hypothèses du modèle de Saint-Venant. Le modèle consistant d'ordre 1 permet d'améliorer les prédictions. Un modèle intégré dans l'épaisseur de type Saint-Venant basé sur les développements consistants d'ordre 1 est alors calculé, car il constitue l'étape nécessaire avant d'être intégré dans un outil de simulation opérationnel. / A depth-averaged model based on the thin-layer assumption, called Saint-Venant (Shallow-Water), is classically used to simulate the propagation and the spreading of debris and mud flows. It is based on several approximations concerning the shape of the velocity profile in non-uniform zones. We propose to test these hypotheses, examining a strongly non-uniform zone, the front of free-surface viscoplastic flows and the velocity field within this zone. By improving our knowledge about the internal dynamics in the front zone, we seek to improve the thin-layer models. This thesis therefore focuses on the study of the internal dynamics within the front of viscoplatic free-surface flows.We used the moving conveyor belt to generate stationary flows. We carried out a technical work on this set-up, and specific analysis of images obtained from the high-speed camera, in order to be able to measure velocity fields with a high resolution. The study of a Newtonian fluid was also carried out in order to validate the lubrication model and the experimental device.We compared experimental results to theoretical solutions of two thin-layer models taking into account the Herschel-Bulkley rheology: the classical model of lubrication, which is at the base of Saint-Venant model, and a consistent first-order model specifically developed in this thesis.The first-order model is equal to the zero-order model (lubrication), plus corrective terms derived from the normal stresses and inertia terms.In this study, for the purpose of comparison with our experimental results, we are interested in travelling-wave solutions. We are able to solve the shape of the front without using a depth-averaged model.Far from the front, experimental velocity profiles clearly display the characteristic 2-layer structure predicted by the lubrication solution, with constant values close to the free-surface (plug) and a sheared layer underneath. Closer to surge tip, the shape of experimental longitudinal velocity profilesthen begins to differ from the theoretical prediction. The 2-layer structure tends to disappear, and the profiles display shear across the whole depth ofthe flow. In this tip region, surface velocity also appears to increase faster than its theoretical counterpart. Surface velocity predicted by the first-order model increase more drastically in the tip region, in better agreement with the measurements than the lubrication model. The first-order model predicts a sheared velocity profile when approaching the front, as observed experimentally.The consistent first-order model then provides better predictions about internal dynamics than lubrication model. A depth-integrated model like Saint-Venant, based on consistent first-order developments is then calculated, as a first step before being integrated into an operational simulation tool.

Les crues – telles que les laves torrentielles – engendrées dans les torrents lors de fortes précipitations peuvent mobiliser de grande quantité de sédiments. Lorsqu'elles atteignent les zones urbanisées, elles peuvent mettre en dangers à la fois les personnes et les biens. Les approches visant à réduire le risque torrentiel se basent largement sur des seuils intensité-durée de pluie qui déterminent les conditions minimum de déclenchement d’une lave torrentielle. Pourtant, ces seuils sont sujets à une forte variabilité liée, non seulement aux différences inter-sites, mais aussi à la méthode appliquée lors de leur établissement. De plus, ils peuvent entraîner des fausses prédictions, l’intensité et la durée de l’épisode de pluie n’étant pas les seules variables explicatives. Ce travail de thèse vise (i) à fournir un cadre méthodologique rigoureux pour l’établissement des seuils de pluie afin de limiter les sources de variabilité, et (ii) à améliorer leurs performances en considérant à la fois les facteurs de déclenchement et de prédisposition. Il s’appuie sur les données d’un observatoire des crues torrentielles, mis en place dans les Alpes françaises en 2011 sur les torrents très actifs du Manival et du Réal. Dans un premier temps, les images et mesures hautes-fréquences collectées entre 2011 et 2016 ont été analysées afin de détecter et de caractériser les crues torrentielles. Pour appréhender la diversité des écoulements observés, une classification phénoménologique a été proposée. Dans un second temps, la condition minimum intensité-durée de pluie requise pour déclencher une lave torrentielle a été établie. La sensibilité du seuil à la définition d’un épisode de pluie a été évaluée. Dans un troisième temps, un modèle de régression logistique a été implémenté pour discriminer les épisodes de pluies critiques qui n’ont pas engendré de lave torrentielle. Il a permis de sélectionner les variables explicatives les plus pertinentes. Finalement, des pistes de travail ont été avancées pour (i) passer de conditions critiques établies à une échelle locale vers une échelle régionale, en perspective d’une application au sein d’un système d’alerte dédié aux risques hydrométéorologiques, et (ii) passer des conditions de déclenchement d’une lave torrentielle dans la zone de production sédimentaire aux conditions de propagation jusqu'aux zones à enjeux. / Flows – such as debris flows – caused by heavy rainfalls in torrents can mobilise a huge amount of sediments. When they reach the urbanised areas, they may endanger the people’s safety or cause damages. Approaches aimed at mitigating torrential risk widely rely on rainfall intensity-duration thresholds which determine the minimum debris-flow triggering conditions. However, these thresholds suffer from a high variability related not only to inter-site differences but also to the method applied to design them. In addition, they are likely to cause false prediction because the intensity and the duration of the rainfall event are not the only explanatory variables. This PhD research work aim (i) to provide a rigorous methodological framework for designing rainfall threshold in order to limit the variability sources, and (ii) to improve their performances by including both the triggering and the predisposing factors. It is supported by field observations stemming from high-frequency monitoring stations installed since 2011 on two very active debris flow-prone torrents in the French Alps: the Manival and the Réal. First, the images and data gathered between 2011 and 2016 were analysed in order to detect and characterise the sediment laden-flows. To deal with the variety of recorded flows, a phenomenological classification was performed. Second, the minimum intensity-duration threshold for debris-flow triggering was assessed. The threshold sensitivity to the rainfall event definition was estimated. Third, a logistic regression model was used to discriminate the critical rainfall events which do not lead to a debris flow. It makes it possible to select the most relevant explanatory variables. At last, several avenues of work were proposed (i) to move the knowledge of debris-flow initiation conditions from a local to a regional level, with a view to application in a warning system dedicated to hydrometeorological risks, and (ii) to improve the ability to predict, not the debris-flow triggering in the production zone, but the debris-flow propagation up to the area concerned.

The problem of whether Landsat 7 data could be used to delineate areas prone to mass movement, particularly debris flows and landslides, was examined using three techniques: change detection in NDVI (Normalized Difference Vegetation Index), change detection in band 5, and the tasseled cap transformation. These techniques were applied to areas that had recently experienced mass movement: Layton, Davis County and Alpine, Spanish Fork Canyon and Santaquin, Utah County. No distinctive spectral characteristics were found with any of these techniques with two possible explanations: 1. That despite improved spatial resolution in Landat 7 over its predecessors and improved digital image processing capabilities, the resolution is still too low to detect these characteristics or 2. That the aspects of a slope that make it prone to mass movement are undetectable at any resolution by remote sensing. Change detection in NDVI examined if areas that remained unchanged (defined as < 5% change) between August 14, 1999 and October 17, 1999 correlated to areas that are prone to mass movement. There was no correlation. Change detection in band 5 was examined between August 14, 1999 and October 17, 1999, October 17, 1999 and May 28, 2000, and August 14, 1999 and May 28, 2000. An interesting result is that the Shurtz Lake and Thistle landslides (Spanish Fork Canyon) showed changes of greater than 30% during August 14, 1999 - October 17, 1999 and October 17, 1999 - May 28, 2000. These changes were limited to these landslides and not seen in abundance in surrounding areas. A similar localization of 30% change was seen in the Cedar Bench landslide (Layton) for the same time periods. There were no other correlations. The tasseled cap ransformation shows areas of dominate greenness, soil brightness or wetness. None of these factors had distinctive patterns in the areas studied when compared to surrounding, mass movement-prone areas so no conclusions can be drawn about the utility of the tasseled cap transformation as it relates to areas of potential mass movement.

[pt] A identificação de áreas com predisposição à ocorrência de desastres naturais surge como informação importante, principalmente no contexto urbano. Sendo assim, o objetivo desse estudo foi propor uma metodologia para o mapeamento de áreas de risco de fluxo de detritos, considerado como um dos acidentes naturais que mais provocam mortes e perdas materiais. Para tanto, esse estudo fez a modelagem de estabilidade das encostas diretamente num software GIS, em que foram utilizados o Modelo do Talude Infinito, para o cálculo da estabilidade, e do Método CN, como modelo de infiltração. Na análise de risco, considerou-se que Risco é definido pelo produto da probabilidade de ocorrência de um fluxo de detritos (Perigo), onde é avaliada a influência das características do meio físico e do seu processo deflagrador; com a severidade das suas consequências, medidas em termos de população afetada (Exposição) e suas fragilidades (Vulnerabilidade). Os resultados obtidos foram satisfatórios, indicando que a metodologia foi adequada para atingir os objetivos propostos, qualificando-a como viável e promissora para estudos futuros. Dentre as suas vantagens tem-se: ser facilmente replicada para outras áreas de estudo, possuir uma sequência simples de cálculos possuir dados de entrada de fácil obtenção e apresentar baixo custo computacional. / [en] The identification of areas prone to the occurrence of natural disasters is an important information, especially in urban areas. Therefore, this study aimed to propose a methodology for debris flow risk assessment, considered as one of the natural disasters that most cause deaths and material losses. To this end, this study made the slope stability modeling directly in a GIS software, in which the Infinite Slope Model was used for the slope stability calculation, and the CN Method, as the infiltration model. For the risk assessment, Risk is defined by the product of the probability of the occurrence of a debris flow event (Hazard), where the influence of the environment s physical characteristics and its triggering process are evaluated; with the severity of its consequences, measured in terms of the affected population (Exposure) and its weaknesses (Vulnerability). The results obtained were satisfactory, indicating that the methodology presented was adequate to achieve the proposed objectives, qualifying it as viable and promising for future studies. Among its advantages: being easily replicated to other areas of study; have a simple sequence of calculations; have easily obtainable input data; and present low computational cost.

[pt] Esta tese insere-se no contexto de diversos trabalhos realizados pelo grupo de estudo de Movimentos de Massas formado pelas Instituições PUC-Rio e COPPE-UFRJ, liderado pelos Professores Alberto Sayão e Anna Laura Nunes. O trabalho busca abordar formas de se obter as forças de impacto de fluxos de detritos brasileiros, principalmente advindas da parcela referente aos blocos de rocha (parcela não viscosa) do movimento. O tema ainda necessita de metodologias bem definidas e aplicáveis a casos que, recentemente, apresentam-se como objeto de estudo pelas comunidades técnicas e acadêmicas, no esforço de se mitigar e/ou conviver com movimentos de massa, cada vez mais presentes nas cidades brasileiras. Assim, propõe-se uma metodologia que utiliza ferramentas numéricas como o DAN-3D e o ROCFALL para se obter as forças de impacto dos blocos rochosos em estruturas de contenção estáticas e dinâmicas, levando em consideração parcelas viscosas e forças de atrito, bem como, compara-se a metodologia proposta com as métodos empíricos já existentes. Para obtenção dos resultados buscou-se a aplicação da metodologia em três casos recentes, de importantes fluxos de detritos ocorridos no Brasil, situados na Serra do Mar, mais precisamente nos municípios de Nova Friburgo e Teresópolis no Rio de Janeiro e em São Sebastião em São Paulo. / [en] This thesis is part of the context of several works carried out by the study group of Mass Movements formed by the Institutions PUC-Rio and COPPE-UFRJ, led by Professors Alberto Sayão and Anna Laura Nunes. The work seeks to address ways of obtaining the impact forces of Brazilian debris flows, mainly arising from the portion referring to the rock blocks (non-viscous portion) of the movement. The subject still needs well-defined methodologies applicable to cases that, recently, have become an object of study by the technical and academic communities, in an effort to mitigate and/or coexist with mass movements, increasingly present in Brazilian cities. Thus, a methodology is proposed that uses numerical tools such as DAN-3D and ROCFALL to obtain the impact forces of rock blocks in static and dynamic containment structures, taking into account viscous portions and frictional forces, as well as the proposed methodology is compared with existing empirical methods. To obtain the results, we sought to apply the methodology in three recent cases of important debris flows that occurred in Brazil, located in the Serra do Mar, more precisely in the municipalities of Nova Friburgo and Teresópolis in Rio de Janeiro and in São Sebastião in São Paulo.