Resumen La carretera Puyo-Tena es propensa a deslizamientos de tierra debido a la geodinámica, geomorfología y materiales geológicos de la zona (afloramientos y estratos inestables). En los últimos años, este problema ha provocado de forma persistente la inutilización parcial o total de la carretera en numerosas ocasiones. El objetivo de la investigación fue generar un modelo cartográfico de susceptibilidad a deslizamientos a partir de variables como la pendiente, las formaciones geológicas, la cobertura y uso de la tierra, así como las distancias a fallas, carretera y ríos. El grado de incidencia de deslizamientos se estimó como la combinación lineal de las variables ponderadas mediante el proceso de jerarquía analítica. La importancia de este método semicuantitativo radica en su capacidad para desagregar un problema de decisión complejo en un modelo de decisión más simple y coherente. El modelo cartográfico resultante se reclasificó en cinco categorías de susceptibilidad: muy baja, baja, moderada, alta y muy alta. Los resultados mostraron que 17 km de los 80 km de la carretera Puyo-Tena tienen una alta probabilidad a deslizamientos, lo que equivale a 21,25% de la carretera. Además, dentro de este porcentaje, se determinó que existen quince regiones con alta probabilidad de deslizamientos debido a su ubicación en zonas con fuertes pendientes, litología porosa y permeable, gran cantidad de ríos y suelos agrícolas. Para la verificación del modelo se utilizó el área bajo la curva (en inglés AUC) de la característica operativa del receptor (en inglés ROC). Los resultados de la verificación mostraron que el modelo cartográfico para el área de estudio tiene un valor de precisión de 83,7%. El modelo cartográfico de susceptibilidad a deslizamientos permitirá tomar las decisiones pertinentes para mitigar eventos potenciales que puedan poner en peligro a transportistas, bienes materiales y residentes de la zona.

Abstract The Puyo-Tena roadway is prone to landslides due to the geodynamics, geomorphology, and geological materials of the area (unstable outcrops and strata). In recent years, this problem has persistently caused the road to be partially or completely disabled on numerous occasions. The objective of the research was to generate a cartographic model of landslides susceptibility based on variables such as slope, geological formations, land cover and land use, as well as distances to faults, road, and rivers. The degree of landslides incidence was estimated as the linear combination of the weighted variables using the analytic hierarchy process. The importance of this semi-quantitative method lies in its ability to break down a complex decision problem into a simpler and more coherent decision model. The resulting cartographic model was classified into five susceptibility categories: very low, low, moderate, high, and very high. The results showed that 17 km out of the 80 km of the Puyo-Tena roadway have a high probability of landslides, which is equivalent to 21.25% of the road. Furthermore, within this percentage, it was determined that there are fifteen regions with a high probability of landslides due to their location in areas with steep slopes, porous and permeable lithology, a large number of rivers, and agricultural soils. The area under the curve (AUC) of the receiver operating characteristic (ROC) was used for model verification. The verification results showed that the cartographic model for the study area has an accuracy value of 83.7%. The cartographic model of landslide susceptibility will enable relevant decisions to be made to mitigate potential hazards that may endanger transporters, material goods, and residents of the area.

This article addresses the problem of practical definitions of disasters. Theoretically and methodologically supported by pragmatically oriented sociological approaches, its considerations are based on the analysis of political discursive action about landslides associated with pluvial events set between 2010 and 2022 in the Legislative Assembly of the State of Rio de Janeiro. The main finding is the relevance of the idea of tragedy to interpret disasters, something that follows two primary paths of discursive construction: naming and narrative. The article also engages in a critical theoretical dialogue within pragmatic sociology. disasters approaches 201 202 Janeiro construction narrative sociology 20 2

Este artigo endereça o problema das definições práticas sobre desastres. Apoiado teórica e metodologicamente em linhagens sociológicas orientadas pelo pragmatismo, suas considerações se baseiam na análise da ação discursiva política produzida entre 2010 e 2022 na Assembleia Legislativa do Estado do Rio de Janeiro sobre deslizamentos de terra associados a eventos pluviais. O principal resultado encontrado é a relevância da ideia de tragédia como forma de interpretação dos desastres, algo que segue duas vias principais de construção discursiva: a nomeação e a narrativa. O artigo também se engaja em um diálogo teórico crítico com a sociologia pragmática. desastres pragmatismo 201 202 pluviais narrativa pragmática 20 2

Abstract Small-scale physical models of geotechnical problems are thought-provoking didactic tools that motivate students by arousing their curiosity and facilitating the understanding of physical phenomena and theoretical concepts. This work presents the development of an educational video about slope stability failures and its contributing factors. It shows several small-scale models built in a glass wall tank measuring 150 x 50 x 10 cm. Layers of fine gravel were placed on a sloping surface of polystyrene to represent a slope with a layer of residual soil on rock. Toy houses and cars were used to represent anthropogenic agents, and water with dye represents the groundwater flow. Each model depicts a different scenario of shallow slope failure. The objective of the video is to show that most slope failures in urban areas result from natural and anthropogenic factors. Several influence factors are shown: porewater level rise, excavation, surcharge application, and solid urban waste deposition. The 6-minute video has had more than 130,000 views on YouTube. Thanks to its simple and concise language, the video is shown in basic education and science museum, as well as in graduate and undergraduate courses. A questionnaire survey was carried out with undergraduate students to assess how helpful the video was for the learning process. This article explains the construction of the model, the video script, and the strategies for its use, as well as its reception. It was found that the video promoted motivational and learning benefits of providing context, establishing relevance, and teaching inductively. Smallscale Small scale thoughtprovoking thought provoking concepts smallscale small 15 5 1 cm rock agents flow failure rise excavation application deposition 6minute minute 6 130000 130 000 130,00 YouTube language museum courses process script use reception context relevance inductively 13000 13 00 130,0 1300 0 130,

Abstract The residual tropical soils and their unsaturated condition add more complexity to the study of slope stability, introducing the suction variable to the stress state analysis. Due to the complexity of the pedological processes involved in their formation, tropical soils present variability in their parameters. This results in uncertainties regarding its behaviour in geotechnical structures. The most common promotion agent for deformation and loss of strength in residual soils in an unsaturated condition is the advancing of the wetting front due to rainfalls. A tropical climate with high levels of rainfall makes landslides a constant and dangerous phenomenon, leading to loss of human life and material. Thus, it is essential to verify the influence of precipitation on slope behaviour in residual conditions. This study analyzes the behaviour of a slope formed by a residual soil by determining the soil properties followed by a numerical analysis. Laboratory tests were performed to characterize the soil and determine the strength, hydraulic, and unsaturated condition parameters. In the numerical analysis, it was intended to visualize the influence of rainfall and hydraulic parameters on the pore pressure distribution inside the slope and in its stability. After the numerical step, it was found that the different rainfall characteristics (intensity and duration) increased the pore pressures and decreased the strength of the material. However, it was insufficient to trigger any failure mechanisms. The hydraulic parameters’ critical roles at seepage through the soil and how this is reflected in the calculations of safety factors were verified. stability analysis formation structures rainfalls phenomenon material Thus conditions step intensity duration However mechanisms verified

Resumen: El riesgo de desastres es el resultado de un largo proceso de vulnerabilidad de las comunidades expuestas a fenómenos hidrológicos y/o geológicos. El contexto socioeconómico y las desigualdades raciales y de género agravan esta condición, generando impactos diferenciales en determinados grupos. Dado que este es un escenario crónico en Brasil, es necesario investigar la construcción sociohistórica y la condición de las áreas de riesgo en las ciudades con recurrencia de eventos como corrimentos de tierras e inundaciones. Por lo tanto, buscamos aquí analizar las condiciones sociales y materiales de vulnerabilidad de las mujeres que viven en áreas con riesgo de deslizamientos en Santos, São Paulo. Con base en una metodología cuali-cuantitativa, con métodos estadísticos y cartográficos, las discusiones aportan elementos para comprender cómo y por qué las mujeres, principalmente las no blancas, son más afectadas por el desastre. Resumen yo o geológicos grupos Brasil inundaciones tanto Santos Paulo cualicuantitativa, cualicuantitativa cuali cuantitativa, cuantitativa cuali-cuantitativa cartográficos blancas desastre

Abstract: Disaster risk results of a vulnerability long process of communities exposed to hydrological and/or geological phenomena. The socioeconomic context and gender and racial inequalities aggravate this condition, generating differential impacts on certain groups. Since this is a chronic scenario in Brazil, it is necessary to investigate the socio-historical construction and the condition of risk areas in cities with recurrence of events such as mass movements and floods. Therefore, this article aims to analyze the social and material vulnerability conditions of women living in areas at risk of landslides in Santos, São Paulo. Based on a quali-quantitative methodology, with statistical and cartographic methods, the discussions bring elements to understand how and why women, mainly non-white women, are more affected by the disaster. Abstract andor or phenomena groups Brazil sociohistorical socio historical floods Therefore Santos Paulo qualiquantitative quali quantitative methodology methods nonwhite non white disaster

Resumo: O risco a desastres é resultado de um longo processo de vulnerabilização das comunidades expostas aos fenômenos hidrológicos e/ou geológicos. O contexto socioeconômico e as desigualdades de gênero e raça agravam esta condição, gerando impactos diferenciais em determinados grupos. Sendo este um cenário crônico no Brasil, faz-se necessário investigar a construção sócio-histórica e a condição das áreas de risco nas cidades com recorrência de eventos como movimentos de massa e inundações. Para tanto, busca-se aqui analisar as condições sociais e materiais de vulnerabilidade de mulheres residentes nas áreas de risco a escorregamentos em Santos, São Paulo. A partir de uma metodologia qualiquantitativa, com métodos estatísticos e de cartografia, as discussões trazem elementos para compreender como e por que as mulheres, principalmente as não brancas, são mais afetadas pelos desastres. Resumo eou ou geológicos grupos Brasil fazse faz se sóciohistórica sócio histórica inundações tanto buscase busca Santos Paulo qualiquantitativa cartografia brancas

Abstract In Mexico, natural disasters related to sediments, such as landslides, landslides and alluviums, are generally induced by anthropogenic activities such as road construction, which modify the vegetation cover, soil characteristics, root density and soil stability. slopes. The objective of this research was to evaluate the mechanical and chemical characteristics of roots of tree forest species (J. deppeana, Q. sideroxyla, P. durangensis y P. cooperi) present in slope cuts of the main road that connects the urban area with the rural area of the municipality of Pueblo Nuevo, Durango. 30 root samples per species were collected and divided into three diameter categories (CD) (CD I = 0.1-3.0 mm, CD II = 3.1-6.0 mm and CD III = 6.1-10 mm). The mechanical properties (maximum breaking force [Fmax], tensile strength [Ts] and elastic modulus [Eroot]) were analyzed with an Instron SATEC universal machine at a constant speed of 10 mm/min. The amount of cellulose, lignin and hemicellulose was determined using the Van-Soest method. The results showed significant differences between species for all the properties analyzed. Particularly J. deppeana presented higher values of Fmax, Ts and Eroot of 402.80 N, 34.06 N mm2, 1283.45 N mm2, as well as the contents of cellulose (40.29%), hemicellulose (12.57%) and lignin (37.63%). The mechanical and chemical characterization of the roots of the evaluated forest species provides important information that can be considered in slope maintenance and rehabilitation activities.

Resumen En México los desastres naturales relacionados con sedimentos, como los desprendimientos, deslizamientos y aluviones, generalmente son inducidos por actividades antropogénicas como la construcción de caminos, que modifican, la cubierta vegetal, características del suelo, la densidad de las raíces y la estabilidad de los taludes. El objetivo de esta investigación fue evaluar las características mecánicas y químicas de raíces de especies forestales arbóreas (J. deppeana, Q. sideroxyla, P. durangensis y P. cooperi) presentes en cortes de talud de la carretera principal que conecta la zona urbana con la zona rural del municipio de Pueblo Nuevo, Durango. Se colectaron 30 muestras de raíces por especie y fueron divididas en tres categorías diamétricas (CD) (CD I = 0.1-3.0 mm, CD II = 3.1-6.0 mm y CD III = 6.1-10 mm). Las propiedades mecánicas (fuerza máxima de quiebre [Fmax], fuerza de tensión [Ts] y módulo de elasticidad [Eroot]) se analizaron con una maquina universal Instron SATEC a una velocidad constante de 10 mm/min. La cantidad de celulosa, lignina y hemicelulosa se determinó por medio del método de Van-Soest. Los resultados mostraron diferencias significativas entre especies para todas las propiedades analizadas. Particularmente J. deppeana presentó valores más altos de Fmax, Ts y Eroot de 402.80 N, 34.06 N mm2, 1283.45N mm2, así como de los contenidos de celulosa (40.29%), hemicelulosa (12.57%) y lignina (37.63%). La caracterización mecánica y química de las raíces de las especies forestales evaluadas provee información importante que puede ser considerada en actividades de mantenimiento y rehabilitación de taludes.

Resumen Se presenta la caracterización regional del contexto de inestabilidad de laderas y taludes a lo largo de la Ruta Nacional de montaña 613 ubicada en Coto Brus, Costa Rica, disparada por precipitaciones intensas durante el paso del huracán Eta entre el 1 y 6 de noviembre de 2020. Estableciendo el contexto geológico, geomorfológico e hidroclimático, además de observaciones de campo, mapas inventario de deslizamientos y depurado de insumos geoespaciales, se brinda una propuesta de zonificación a priori del corredor montañoso en tramos estables y propensos ante deslizamientos (presencia deslizamientos, pendiente, altura taludes y laderas). A partir de mapas inventario de deslizamientos, estudio por subcuencas hidrológicas, interpretación geológica y predominancia de suelos MH derivados de materiales volcaniclásticos, se determina moderada a alta disección en gran parte de la zona de influencia del corredor, determinándose que al menos 24 % de la ruta es susceptible a procesos de remoción en masa, con influencia de controles geológico-estructurales. Además, los moduladores hidroclimáticos e hidrometeorológicos (larga y corta estancia, respectivamente), que favorecen con cada época lluviosa los eventos extremos de precipitación en el Pacífico sur, podrían disparar a futuro inestabilidad de laderas en el corredor; sin excluir escenarios de sismos superficiales generados en alguna de las cinco fallas geológicas por las cuales atraviesa el corredor. Este estudio contribuye a la definición posterior del peligro y riesgo, como estudio base que establece las condiciones ambientales del corredor vial.

Abstract In this regional investigation, it is characterized the slope instability along the 613 National Road corridor located in Coto Brus county in Costa Rica, triggered by intense precipitation rates between November the 1st and the 6th related to Eta's hurricane pathway. By stablishing the geological, geomorphological and hydroclimatic context, besides field annotations, landslides map inventory and geospatial terrain inputs, it is proposed a priori road zonation in stable and landslide prone sections of the mountain corridor (considering landslide occurrence, slope, and slope height). From landslides map inventory, hydrological sub-basin analysis, geological setting and MH soil-type predominance derived from volcaniclastic deposits allows to determine moderate to high terrain dissection and at least 24 % of the road corridor is prone to slope instability with a clear influence of geological tectonic features. In addition, there are hydroclimatic and hydrometeorological features (long and short period modulators, respectively) that could trigger hillslope instability along the road corridor in the near future, by the development of extreme precipitation events every rainy season on Costa Rica's southern Pacific, without excluding possible superficial seismic rupture scenarios at one of the five active fault traces that crosses the road corridor. This study contributes to future geological hazard and risk assessments, as a base study of the environmental conditions that moderate geodynamic processes at the road corridor.

Resumen Se presenta la caracterización regional del contexto de inestabilidad de laderas y taludes a lo largo de la Ruta Nacional de montaña 613 ubicada en Coto Brus, Costa Rica, disparada por precipitaciones intensas durante el paso del huracán Eta entre el 1 y 6 de noviembre de 2020. Estableciendo el contexto geológico, geomorfológico e hidroclimático, además de observaciones de campo, mapas inventario de deslizamientos y depurado de insumos geoespaciales, se brinda una propuesta de zonificación a priori del corredor montañoso en tramos estables y propensos ante deslizamientos (presencia deslizamientos, pendiente, altura taludes y laderas). A partir de mapas inventario de deslizamientos, estudio por subcuencas hidrológicas, interpretación geológica y predominancia de suelos MH derivados de materiales volcaniclásticos, se determina moderada a alta disección en gran parte de la zona de influencia del corredor, determinándose que al menos 24 % de la ruta es susceptible a procesos de remoción en masa, con influencia de controles geológico-estructurales. Además, los moduladores hidroclimáticos e hidrometeorológicos (larga y corta estancia, respectivamente), que favorecen con cada época lluviosa los eventos extremos de precipitación en el Pacífico sur, podrían disparar a futuro inestabilidad de laderas en el corredor; sin excluir escenarios de sismos superficiales generados en alguna de las cinco fallas geológicas por las cuales atraviesa el corredor. Este estudio contribuye a la definición posterior del peligro y riesgo, como estudio base que establece las condiciones ambientales del corredor vial.

Abstract In this regional investigation, it is characterized the slope instability along the 613 National Road corridor located in Coto Brus county in Costa Rica, triggered by intense precipitation rates between November the 1st and the 6th related to Eta’s hurricane pathway. By stablishing the geological, geomorphological and hydroclimatic context, besides field annotations, landslides map inventory and geospatial terrain inputs, it is proposed a priori road zonation in stable and landslide prone sections of the mountain corridor (considering landslide occurrence, slope, and slope height). From landslides map inventory, hydrological sub-basin analysis, geological setting and MH soil-type predominance derived from volcaniclastic deposits allows to determine moderate to high terrain dissection and at least 24 % of the road corridor is prone to slope instability with a clear influence of geological tectonic features. In addition, there are hydroclimatic and hydrometeorological features (long and short period modulators, respectively) that could trigger hillslope instability along the road corridor in the near future, by the development of extreme precipitation events every rainy season on Costa Rica’s southern Pacific, without excluding possible superficial seismic rupture scenarios at one of the five active fault traces that crosses the road corridor. This study contributes to future geological hazard and risk assessments, as a base study of the environmental conditions that moderate geodynamic processes at the road corridor.

Abstract This research employed empirical methods that relate rainfall to debris flow movements, which consist of series of accumulated rainfall that trigger these movements. Additionally, statistical thresholds were established using power law in linear coordinates (logarithmic relationship) and non-parametric statistics. Consequently, critical thresholds for triggering accumulated rainfall (LA) and antecedent accumulated rainfall (LAA) were established. Furthermore, this empirical-statistical model incorporates the local conditions of the study area, including certain physical parameters and soil moisture conditions, and combines them with the hazard conditions specific to the region for which they were defined.

Resumen Esta investigación utilizó métodos empíricos que relacionan la lluvia con los movimientos de flujo de detritos; los cuales, consisten en series de lluvia acumulada que detonan estos movimientos. Además, se procedió a establecer los umbrales estadísticos mediante la ley de la potencia en coordenadas lineales (relación logarítmica) y la estadística no paramétrica. En consecuencia, se establecieron los umbrales críticos de lluvia acumulada detonante (LA) y lluvia acumulada antecedente (LAA). Asimismo, a este modelo empírico-estadístico, se añade las condiciones locales de la zona de estudio; es decir, algunos parámetros físicos y la condición húmeda del suelo, así como combinarlos con las condiciones de amenaza de la región para la cual fueron definidos.

ABSTRACT An evaluation of the areas susceptible to the occurrence of landslides in the coastal zone and representative hydrographic basins of the Guamá municipality was carried out. The Mora-Vahrson method was used through a Geographic Information System, with modifications to the original proposal according to the characteristics of the area. The susceptibility map was obtained, categorized into four levels: Low, Moderate, High and Very High. As a result of the zoning, it was obtained that high susceptibility is the most representative (52%); Towns such as El Macho, La Plata, Uvero, Montompolo and El Francés are located there. The result constitutes an update of the danger for the Guamá municipality and creates the bases for the development of local strategies for management and mitigation of impacts.

RESUMEN Se realizó una evaluación de las áreas susceptibles a la ocurrencia de deslizamientos en la zona costera y cuencas hidrográficas representativas del municipio Guamá. Se empleó, a través de un Sistema de Información Geográfica, el método Mora-Vahrson, con modificaciones de la propuesta original de acuerdo con las características del área. Se obtuvo el mapa de susceptibilidad, categorizado en: Baja, Moderada, Alta y Muy Alta. Como resultado de la zonificación se obtuvo que la susceptibilidad alta es la de mayor representatividad (52%); en ella se ubican localidades como El Macho, La Plata, Uvero, Montompolo y El Francés. El resultado constituye una actualización del peligro para el municipio Guamá y crea las bases para el desarrollo de estrategias locales de gestión y mitigación de los impactos.

Resumen El municipio de Autlán presenta problemas de cambio de uso de suelo y erosión que favorecen los deslizamientos de tierra. La identificación espacial de este fenómeno (5 clases de riesgo) muestra que 3 localidades se ubican en riesgos altos y muy altos (Autlán, Ahuacapán y Mezquitán), debido principalmente a la influencia de los suelos Regosol, precipitación anual y máxima en 24 horas con una relación estadísticamente significativa de P < 0.05, R2 = 0.99, 0.66 y 0.86. El deslizamiento presenta un riesgo para la infraestructura y la población encontrando una relación significativa (α = 0.001) entre el número de viviendas y densidad de población por localidad solo para amenaza regular a alto al deslizamiento de tierra. Al no existir una planeación de uso de suelo por parte del municipio se plantea realizar actividades de atención y remediación principalmente en zonas urba-nas ubicadas en estructuras sensibles al deslizamiento tomando en cuenta los resultados obtenidos.

Resumo O município de Autlán apresenta problemas de mudança de uso da terra e erosão que favorecem os deslizamentos de terra. A identificação espacial deste fenômeno (5 tipos de risco) mostra que 3 localidades estão localizadas em risco alto e muito alto (Autlán, Ahuacapán e Mezquitán), princi-palmente devido à influência dos solos Regosol, precipitação anual e máxima em 24 horas com uma relação significativa de P < 0,05, R2 = 0,99, 0,66 e 0,86. O deslizamento apresenta risco para a infraestrutura e para a população, encontrando uma relação significativa (α = 0,001) entre o número de casas e a densidade populacional por localidade apenas para ameaça de deslizamento regular a alta. Como não há planejamento de uso do solo por parte do município, propõe-se a realização de atividades de atenção e remediação principalmente em áreas urbanas localizadas em estruturas sensíveis a deslizamentos, levando em consideração os resultados obtidos.

Abstract The municipality of Autlán presents problems of land use change and erosion that favor landslides. Spatial identification of these phenomena (5 risk classes) shows that 3 localities are located in high and very high risks areas (Autlán, Ahuacapán and Mezquitán), mainly due to the influence of Regosol soils, annual and maximum precipitation in 24 hours with a statistically significant relationship of P < 0.05, R2 = 0.99, 0.66 and 0.86. Landslides represent a risk for infrastructure and the population, finding a significant relationship (α = 0.001) between the number of houses and population density per locality only for regular to high threat to landslide. In the absence of land use planning by the municipality, attention and remediation activities are proposed, mainly in urban areas located in landslide-sensitive structures, taking into account the results obtained.

Resumen Este documento tiene el propósito de exponer la deducción de una ley para predecir la velocidad de deslizamiento superficial de laderas conformadas por aluviones afectados por un elevado nivel freático y erosión hídrica (socavación lateral) partiendo de dos variables predictivas: La precipitación media y el caudal medio fluvial que causa socavación lateral en la base. La metodología consistió en la toma semanal a quincenal de coordenadas topográficas de puntos en el terreno llamados mojoneras, a partir de las cuales se calcularon el desplazamiento y la velocidad. El modelo geológico ha sido determinado a partir de estudios de geofísica y ensayos de suelos. Para elaborar el modelo matemático se ha utilizado el Teorema Pi Π de Buckingham, relacionando la velocidad observada como desplazamiento de la masa en un lapso determinado de tiempo y las características del suelo con las variables predictivas mediante la combinación de parámetros adimensionales. El modelo matemático obtenido ha dado resultados muy cercanos frente a valores observados de velocidad. Su aplicación más importante es identificar umbrales de precipitación y caudal que producirían un aumento en la actividad en laderas de aluviones, a partir de modelos de evaluación de riesgo.

Abstract This document has the purpose of presenting the deduction of a law to predict the velocity of surface landslides on slopes made up of alluvium, affected by a high water table level and water erosion (lateral scour), based on two predictive variables: average precipitation and mean fluvial flow that causes lateral scour at the base. The methodology consisted of taking weekly to fortnightly topographic coordinates of points on the ground called landmarks, from which displacement and speed were calculated. The geological model has been determined from geophysical studies and soil tests. To develop the mathematical model, Buckingham's Pi Π Theorem has been used, relating the velocity observed as displacement of the mass in a given period of time and the characteristics of the soil with the predictive variables through the combination of dimensionless parameters. The mathematical model obtained has given very close results compared to observed values of speed. Its most important application is to identify precipitation and flow thresholds that would produce an increase in activity on alluvial slopes, based on risk assessment models.

RESUMEN Malasia es uno de los países donde cada año se presentan deslizamientos de tierra debido a eventos naturales y actividades humanas. La isla de Penang es el segundo estado más desarrollado de Malasia y el más poblado. Es un estado propenso a deslizamientos de tierra con impactos ambientales devastadores. Por consiguiente, es necesario caracterizar las condiciones roca-suelo cerca de la superficie. Este estudio utiliza información de teledetección a través de técnicas de Radio Frecuencia (FR, del inglés Frequency Ratio) para identificar las áreas propensas a deslizamientos con base en diferentes categorías de factores causales de deslizamientos. Para entender mejor las condiciones y los perfiles hidrodinámicos suelo-roca que causan los deslizamientos de tierra se realizaron tomografías de resistividad eléctrica y de refracción sísmica en una zona del área de estudio que se presume es propensa a estos movimientos. Además, se realizó el modelamiento satelital de la anomalía gravitacional de Bouguer para identificar las variadas anomalías de la gravedad asociadas con los factores que desencadenan los deslizamientos en las unidades litológicas. Los modelos multigeofísicos ofrecen resultados fuertemente correlacionados con los mapas causales teledetectados y el mapa del índice de susceptibilidad de deslizamientos de tierra (LSI, del inglés Landslide Susceptibility Index). La probabilidad de ocurrencia de deslizamientos, de acuerdo con lo sugerido por la curva de información LSI en el área, establece una alta efectividad de predicción de 83.47 %. Con esto, la perspectiva de deslizamientos fue mayor en las secciones elevadas y montañosas, mientras que las secciones menos susceptibles se identificaron en las planicies. Los deslizamientos también podrían desencadenarse, en algunas instancias, en secciones empinadas con cuerpos variados de suelos contractivos y estructuras superficiales. Lo más destacado es que el aprovechamiento del mapa LSI ayudaría a las agencias a prevenir o mitigar los futuros deslizamientos de tierra en el área.

ABSTRACT Malaysia is one of the countries in the world that experiences landslides yearly due to natural events and human activities. Penang Island is Malaysia's second most developed state and the largest by population. It is prone to landslides with devastating environmental impacts. Hence, the need to characterize its near-surface soil-rock conditions. This study uses remotely sensed data, with frequency ratio (FR) analysis, to identify landslide-prone areas based on different categories of landslide causative factors. To further understand the conditions and hydrodynamics of the soil-rock profiles causing landslides, electrical resistivity tomography and seismic refraction tomography were carried out at a landslide-suspected section in the study area. Also, satellite-derived Bouguer gravity anomaly modeling was performed to map the varied gravity anomalies associated with landslide-triggering factors in lithologic units. The multi-geophysical models offer strongly correlated results with the remote sensing causative factor maps and the landslide susceptibility index (LSI) map. The likelihood of landslides occurring in the area, as suggested by the area under curve modeling of LSI data, yielded a high predicted success rate of 83.47%. Hence, prospective landslides were identified in the hilly and elevated sections, while the less susceptible sections were identified on flat reliefs. Landslides may also be triggered, for instance, at steep sections with varied contractive soil bodies and shallow structures. Most importantly, leveraging the LSI map would help the necessary agencies forestall and mitigate future landslide occurrences in the area.

Abstract Mass movements naturally occurring along slopes, especially after heavy rains, cause heavy losses of materials and life and affect highways, pipelines, and bridges, among other structures. Among the most common mass movements, landslides and subsequent mass flows especially stand out. Remote sensing and geoprocessing techniques are useful tools for geological and geotechnical analysis, here applied to characterization of mass movements from the analysis of the influence of slopes, lineaments or fractures, and geological-geotechnical at the junction of the Curral homocline and the Moeda syncline, Quadrilátero Ferrífero, Southeast Brazil. The area consists of Archean granitic-gneissic basement and the greenstone belt sequence of the Rio das Velhas Supergroup with Proterozoic metasedimentary rocks of the Minas Supergroup covering these two older successions. Based on satellite images, a preliminary map of lineaments was created, and fractures were grouped according to their direction before being rasterized. Each lineament group was associated with a previously known geological and/or structural feature. Geological units mapped in the area were numerically classified according to their mass movement susceptibility and related geotechnical units. Using a Shuttle Radar Topography Mission (SRTM) image, a terrain slope raster was generated. The objective was to obtain a raster indicating low and high probabilities of mass movements. Four sets of lineaments were identified: the first set associated with the northeast strike stratification of the rocks of the Moeda Formation; the second set related to eastward-trending warp axis lineations; the third set related to the southeast trend of stretch lineaments or mafic dykes directions; and the fourth set evidently associated with the watershed pattern of the Curral Range crest, perpendicular to the strike of the rocks in the area. Simulations with different combinations of parameters produced eight scenarios were generated were constructed to classify the area as to its susceptibility to rupture through changes in slope, lithotype, and lineament density; the first four (1 to 4) were classified by using the slope percentage raster without interval reclassification, so its values in the cartographic algebra were not grouped. The last for (5 to 8), consider the slope percentage classified. This methodology successfully combines mathematical models for predicting mass movements and determining areas in the urban landscape most susceptible to these phenomena. As such, it comprises a useful tool for government planning of preventative actions for areas of high risk. slopes rains highways pipelines bridges structures out geologicalgeotechnical syncline Ferrífero Brazil graniticgneissic granitic gneissic successions images created rasterized andor feature SRTM (SRTM image identified Formation eastwardtrending eastward trending lineations directions crest lithotype density 1 ( 4 reclassification 5 8, 8 , 8) phenomena such risk

Resumen En 2003, ante los escenarios de desastre asociados a deslizamientos e inundaciones, el Gobierno Federal de Brasil inició un programa para incentivar el desarrollo de Planes Municipales de Reducción de Riesgos (PMRRs). Dada la novedad de la acción y la variedad de instituciones responsables de su ejecución, que involucran diferentes recursos materiales y humanos, es importante dar a conocer cómo los PMRR se han construido para, posiblemente, buscar su mejoría. El presente trabajo investigó los documentos de los 33 PMRR disponibles en el sitio web del Ministerio de Desarrollo Regional, enfocándose en los siguientes ítems: composición del equipo técnico involucrado, participación popular, mapeo de riesgos, tipologías y costos de las acciones estructurales propuestas, y acciones no-estructurales. Entre las conclusiones, se destaca la observación de una excesiva asimetría en el abordaje de los PMRR a favor de los aspectos físicos del problema en detrimento de los sociales, influyendo en el método de estimación del riesgo y las medidas mitigadoras propuesta. 2003 inundaciones PMRRs. PMRRs . (PMRRs) ejecución humanos posiblemente mejoría 3 Regional ítems involucrado popular riesgos propuestas noestructurales. noestructurales no estructurales. no-estructurales conclusiones sociales propuesta 200 (PMRRs 20 2

Abstract The disasters associated with landslides and floods forced the Brazilian Federal Government to launch, in 2003, a program aimed at encouraging the development of Local Disaster Risk Reduction and Management Plans (PMRRs - Planos Municipais de Redução de Riscos). Given the uniqueness of this action and the variety of institutions accounting for executing these plans, which involve different material and human resources, it is important explaining how PMRRs have been built in order to, likely, improve them. The aim of the current study is to gather information about all 33 PMRRs available on the website of the Ministry of Regional Development by focusing on the following items: composition of the technical team involved in them, popular participation, risk mapping, typologies and costs of proposed structural and non-structural actions. Among the herein reached conclusions, it is worth emphasizing the excessive asymmetry observed in PMRRs’ approach to physical aspects of this issue to the detriment of its social aspects, a fact that affects both the risk estimation method and the proposed mitigating measures. launch 2003 Riscos. Riscos . Riscos) plans resources likely them 3 items participation mapping nonstructural non actions conclusions measures 200 20 2

Resumo Em 2003, mediante o cenário de desastres associados a deslizamentos e inundações, o Governo Federal Brasileiro iniciou um programa de incentivo à elaboração de Planos Municipais de Redução de Riscos (PMRRs). Diante do ineditismo da ação e da variedade de instituições responsáveis pela sua execução, envolvendo diferentes recursos materiais e humanos, é importante dar-se a conhecer como os PMRRs vêm sendo construídos para, possivelmente, se buscar seu aperfeiçoamento. O presente trabalho realizou o levantamento de informações sobre os 33 PMRRs disponibilizados no site do Ministério do Desenvolvimento Regional, focando-se nos seguintes itens: composição da equipe técnica envolvida; participação popular; mapeamento de risco; tipologias e custos de ações estruturais propostas; ações não estruturais. Dentre as conclusões, destaca-se a observação de uma excessiva assimetria de abordagem dos PMRRs a favor dos aspectos físicos do problema em detrimento dos sociais, influenciando o método de estimativa do risco e as medidas mitigadoras propostas. 2003 inundações PMRRs. . (PMRRs) execução humanos darse dar para possivelmente aperfeiçoamento 3 Regional focandose focando itens envolvida popular propostas conclusões destacase destaca sociais 200 (PMRRs 20 2