A markedly intense rain fell on southeastern Mexico during the period of 29 October–1 November 2007. As a result, the state of Tabasco recorded the gravest flood in the last 50 years. A reconstruction of the event is presented, including the identification of the factors that aggravated the sequels, and a discussion of the actions that were carried out to evaluate the flooding. The phenomenon consisted of a succession of rains in the region, including 3 days of continuous rain with over 403 mm d⁻¹. The operation of a system of dams, the saturation of the soil, and runoff times below 16 h were the factors that generated the catastrophe, in synergy with the meteorological phenomenon. The analysis presented here will aid in understanding the development of the phenomenon in an integral way, and in establishing the minimum procedures to be followed to evaluate similar events in other regions where, as in Mexico, one does not have timely access to information. In the case of this disaster, for example, different versions of the causes of the flood continued to circulate 6 months after it took place, some lacking technical bases and some access-restricted. However, the information generated provided the academic community and state officials with a reference on which to evaluate the event. This analysis also makes a contribution by placing emphasis on the need to establish non-structural mitigation measures such as future urban growth and regulation plans and future early warning systems against flooding, monitoring the variables that were analysed and generating products useful to the decision-makers involved in civil protection systems and in carrying out preventive measures to mitigate the effects of extreme events.

Observed longitudinal water-surface profiles are commonly used to calibrate river hydrodynamic models, relying on assumptions of lateral uniformity in water surface elevation and velocity distribution. While suitable for 1D models, this approach has limitations in regard to 2D model calibration. When 2D flow measurements are available, a more robust quantitative evaluation is necessary to assess model accuracy. This study introduces a novel methodology to improve 2D model calibration and evaluate performance. High-resolution bathymetric and hydrodynamic data collected with a multibeam echosounder (MBES) and acoustic Doppler current profiler (ADCP) were aligned to compare observed and simulated flow velocities at matching spatial locations. Statistical metrics, including relative mean absolute error and root-mean-square error, were employed to assess hydrodynamic modeling. The methodology was tested using MBES and ADCP measurements alongside TELEMAC-2D simulations of a dynamic neck cutoff on the White River, Arkansas, USA. This approach provides a 2D calibration process, enhancing model accuracy and informing parameter selection, such as channel boundary roughness and downstream boundary water surface elevation.

En la actualidad las conchas de ostión «Crassostrea virginica», explotadas comercialmente en Tabasco, representan un problema de contaminación. Debido a que las personas después de consumir la parte comestible del ostión, desechan en las calles o en lugares públicos e incluso en los rellenos sanitarios las conchas, provocando mal aspecto al lugar, mala higiene y propagación de plagas. Por lo anterior, mediante esta investigación se pretende dar una solución a este problema de contaminación y reciclar este desecho para obtener un material con fines ambientales para la construcción. Las conchas fueron recolectadas y seleccionadas en diversos tamaños y sometidas a tratamientos de molienda en grueso con fracturación manual y molienda en seco en un molino de bolas. Posteriormente, estas conchas de ostión fueron tratadas térmicamente para calcinar a 500, 700, 800, 900 y 1000°c. Los polvos obtenidos con los dos tratamientos fueron separados con una mesa vibratoria para realizar el análisis granulométrico. Y mediante el análisis por difracción de rayos x (DRX), se encontró que los polvos están compuestos de CAO, CAOH y CACO3. Mediante estos resultados, se propone la factibilidad de la utilización de este desecho de conchas de ostión como un material aglomerante para fabricación de mortero utilizado en la construcción.

When modelling flow and/or sediment transport in streams and rivers, one must frequently use the computer software of differing levels of complexity. The level of sophistication, accuracy, and quality of results are the parameters by which models can be classified as being 1D, 2D, or 3D; it seems certain that in the future, there will also be 4D and 5D models. However, the results obtained from very sophisticated models are frequently questionable, and designers in the field of hydraulic structures must have considerable experience distinguishing important information from irrelevant information. Thus, this paper aims to investigate the effect of the selected boulder block ramp hydraulic structure at Poniczanka stream on the bed-load transport. We evaluated sediment transport using the CCHE2D numerical model. We analysed several scenarios depending on the river bed type (erodible, non-erodible, rocky) and examined the rock blocks used for hydraulic structure construction. The obtained results were compared with the Hjulström and the Shields graph, which are a classic approach for identifying fluvial processes in river channels. In addition to these two methods, numerical modelling using the 1D HEC-RAS (Hydrologic Engineering Center’s River Analysis System) modelling were conducted, which included the determination of horizontal and vertical changes to the river bed morphology of the examined section of river reach as well as providing the basic hydrodynamics parameters which, from the practical point of view, designers involved in the process of designing ramps could use.