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Drainage is essential to ensure the useful life of roads. Not only water circulates through the sewers, but also sediment that is carried by the flow, either as bottom drag or in suspension. Therefore, the sustainable design of culverts must allow the sediment transport associated with natural river systems. In the present work, 6 culverts located on a mountain road in the Andes of southern Ecuador were studied. The hydraulic capacity of each culvert was evaluated evacuating a peak flow with a 25-year return period using specialized software. Additionally, the criterion of the beginning of the movement of the sediments was applied to analyze the self-cleaning capacity of the culverts. After the evaluation, it was found that only three of the culverts studied had sufficient capacity to transport the evaluated flow and that all culverts had the necessary conditions to avoid the deposition of sediment., El drenaje es fundamental para asegurar la vida útil de las carreteras. A través de las alcantarillas no solo circula agua, sino también el sedimento que es arrastrado por la corriente, sea como arrastre de fondo o en suspensión, por lo que el diseño sostenible de alcantarillas debe permitir el transporte natural de sedimentos asociados con los sistemas fluviales. En el presente artículo se estudian seis alcantarillas ubicadas en una carretera montañosa de los Andes del sur del Ecuador. Se evaluó la capacidad hidráulica de cada una para evacuar un caudal de crecida con 25 años de periodo de retorno empleando un software especializado y se aplicó el criterio del inicio del movimiento de los sedimentos para analizar la capacidad de autolimpieza de la alcantarilla. Luego de la evaluación, se pudo comprobar que solo tres de las alcantarillas tienen la capacidad suficiente para transportar el caudal de evaluación. Todas las alcantarillas cumplen con las condiciones necesarias para evitar depósito de material de arrastre.

Mass movements are responsible for large human and material losses. The main action for the prevention of hillside movements is the creation of susceptibility maps, which can be carried out quickly and economically through the application of multi-criteria evaluation techniques. These are based on the identification of conditioning and triggers factors that cause the instability of the slopes, which are weighted according to their influence for the occurrence of the phenomenon under study. In the present work, multi-criteria evaluation techniques were applied to define the susceptibility to landslides in a mountainous road located in the south of Ecuador. Variables that have a direct influence on the occurrence of mass movements were selected and related to different events observed in the field to define a thematic categorization of each variable and to determine weighting factors. Susceptibility was defined by linear weighting. Medium and high levels of susceptibility were identified in the road understudy with the presence of rotational and translational landslides., Los movimientos en masa son los responsables de cuantiosas pérdidas humanas y materiales. La principal medida para prevenir los movimientos de ladera es la elaboración de mapas de susceptibilidad, de manera rápida y económica, mediante la aplicación de técnicas de evaluación que se basan en identificar factores condicionantes y desencadenantes que provocan la inestabilidad de las laderas, ponderados según su influencia para la ocurrencia del fenómeno en estudio. En el presente artículo, se usaron técnicas de evaluación multicriterio para definir la susceptibilidad a deslizamientos que presenta una carretera montañosa ubicada al sur de Ecuador. Se seleccionaron variables que tienen influencia directa en la ocurrencia de los movimientos en masa y se relacionaron con diferentes eventos observados en campo para definir una categorización temática de cada variable y determinar los factores de ponderación. La susceptibilidad fue se definió mediante una ponderación lineal. Se identificaron niveles de susceptibilidad medio y alto en la vía en estudio con la presencia de deslizamientos rotacionales y traslacionales.

Artificial neural networks (ANN) are applied in this research for the analysis of variables that could influence the occurrence of traffic accidents on mountain roads. The model was developed through Artificial Neural Networks (RNA), and its efficiency was evaluated for the prediction of traffic accidents considering variables as radio of curvature and track slopes. RNA performance was evaluated by applying the Nash-Sutcliffe efficiency and the mean quadratic mistake. The results of the research showed a low performance of the RNA in the prediction of accidents according to the selected variables, which suggests that accidents do not appear to be due to track geometry, but to other elements such as speeding or driver’s sleight of hand. However, the research provides several alternatives for modeling the Network to achieve a more accurate prediction., En esta investigación se aplican redes neuronales artificiales para el análisis de variables que podrían tener influencia en la ocurrencia de accidentes de tránsito en carreteras de montaña. El modelo se desarrolló utilizando Redes Neuronales Artificiales (RNA) y se evaluó su eficiencia para la predicción de accidentes de tránsito considerando variables como radios de curvatura y pendientes de la vía. El desempeño de las Redes Neuronales Artificiales se evaluó aplicando la eficiencia de Nash- Sutcliffe y en el error cuadrático medio. Los resultados de la investigación mostraron un bajo desempeño de las Redes Neuronales Artificiales en el pronóstico de accidentes en función de las variables seleccionadas, lo que sugiere que los accidentes aparentemente no se deben a la geometría de la vía, o topografía, geografía del terreno, sino a otros elementos tales como el exceso de velocidad o la impericia del conductor. Sin embargo, la investigación muestra varias alternativas de modelamientos de la Red para intentar tener una mejor predicción.

The prediction of river discharge using hydrological models (HMs) is of utmost importance, especially in basins that provide drinking water or serve as recreation areas, to mitigate damage to civil structures and to prevent the loss of human lives. Therefore, different HMs must be tested to determine their accuracy and usefulness as early warning tools, especially for extreme precipitation events. This study simulated the river discharge in an Andean watershed, for which the distributed HM Runoff Prediction Model (RPM) and the semi-distributed HM Hydrologic Modelling System (HEC-HMS) were applied. As precipitation input data for the RPM model, high-resolution radar observations were used, whereas the HEC-HMS model used the available meteorological station data. The obtained simulations were compared to measured discharges at the outlet of the watershed. The results highlighted the advantages of distributed HM (RPM) in combination with high-resolution radar images, which estimated accurately the discharges in magnitude and time. The statistical analysis showed good to very good accordance between observed and simulated discharge for the RPM model (R2: 0.85-0.92; NSE: 0.77-0.82), whereas for the HEC-HMS model accuracies were lower (R2: 0.68-0.86; NSE: 0.26-0.78). This was not only due to the application of means values for the watershed (HEC-HMS), but also to limited rain gauge information. Generally, station network density in tropical mountain regions is poor, for which reason the high spatiotemporal precipitation variability cannot be detected. For hydrological simulation and forecasting flash floods, as well as for environmental investigations and water resource management, meteorological radars are the better choice. The greater availability of cost-effective systems at the present time also reduces implementation and maintenance costs of dense meteorological station networks.