http://www.ae.ntu.edu.tw/wfc/pdf/A-15.pdf

Second-order Monte Carlo uncertainty/variability analysis using correlated model parameters: application to salmonid embryo survival risk assessment

The deposition of the instantaneously released sediment into a gravel matrix and the hydraulic resistance induced by the rapid siltation are investigated herein. The experimental results reveal that the depositional patterns of the sediment are governed by the gravel-sediment size ratio, the amount of sediment released, and the seepage flowrate. The observations also indicate that the stable stage of sediment deposition is reached shortly after the occurrence of sudden slump. A regression relation is developed to quantify the stable-stage hydraulic resistance with the major governing factors. Given the hydraulic resistance, one can use the siltation equation to evaluate the hydraulic conductivity of the silted porous medium. With such information, planning of the engineering alternatives to meet the seepage flow requirements is made possible.

Hydraulic Resistance Induced by Deposition of Sediment in Porous Medium

This note investigates the deposition of the instantaneously released sediment into a gravel matrix and the hydraulic resistance induced by the rapid siltation. The experimental results reveal that the depositional patterns of the sediment are governed by the gravel-sediment size ratio, the amount of sediment released, and the seepage flowrate. The observations also indicate that the stable stage of sediment deposition is reached shortly after the occurrence of sudden slump. A regression relation is developed to quantify the stable-stage hydraulic resistance with the major governing factors. Given the hydraulic resistance, one can use the siltation equation to evaluate the hydraulic conductivity of the silted porous medium. With such information, planning of the engineering alternatives to meet the seepage flow requirements is made possible.

Hydraulic resistance induced by deposition of sediment in porous medium. technical note

In general the problem in education is that we teach nowadays students the knowledge from five years ago, to be applied in the next 5 to 15 years (I admit, the student of today will have reached his retirement when he will participate in the 50th ICCE, the title is exaggerating reality). When one analyses the developments in the profession, it is clear that teaching present day facts is not very useful. We have to teach approaches, design philosophy, concepts, etc. What the meaning is for education of coastal engineers will be worked out in this paper.

/pdf/education-of-coastal-engineers-for-the-50th-icce-4uf5kt6tpb.pdf

Education of coastal engineers for the 50th ICCE

A stochastic model based on the renewal process was developed and used to analyse the characteristics of floods: the volume exceedence, the duration of the flood and the maximum annual flow. The model contains a method for determination of total annual volume exceedence and total annual duration of floods, as well as a method for calculation of maximum annual exceedence, maximum flood duration and maximum flow. The subset of the flood occurrence number in a given time interval is common for all analysed phenomena (volume exceedence, flood duration, maximum flow). The subset of given exceedences is common for total annual volume exceedence, as well as for maximum annual volume exceedence. The same holds for durations of individual floods. The model was then applied to analyse the floods on the Drina River at the Paunci hydrological station and on the Danube River at the Bezdan station.

Stochastic analysis of flood series

Nous presentons ici des techniques d'approximation au premier ordre pour estimer les parametres stochastiques d'un modele de transport de sediments. Le modele de Poisson, compose non homogene, de Shen-Todorovic eliminant certaines hypotheses idealisees pour decrire le mouvement des sediments dans les ecoulements naturels est une version revisee du modele plus ancien d'Einstein, Hubbell et Sayre. Cependant, sa complexite et les difficultes d'estimation de ses parametres limitent ses applications. Les techniques d'approximation employees utilisent ici des developpements de Taylor au premier ordre, aux differences finies avec des pas de temps et d'espace appropries, pour approcher la fonction de distribution cumulative (CDF) des deplacements des particules. Pour plus de commodite, ils sont rapportes a la CDF originale. Ces schemas simplifies amont-aval sont resolus numeriquement pour evaluer la valeur au point considere. Les parametres non homogenes sont ainsi determines de point en point par reconductions successives de la procedure. Un exemple d'infiltration de sediments dans une colonne de graviers est presentee ici pour illustrer la methode utilisee et verifier les resultats. Les variations spatiales et temporelles des parametres sont egalement commentees.

First-order estimation of stochastic parameters of a sediment transport model

In ihis report, a joint IAHR and UNESCO panel addresses the current developments in hydraulic engineering and their implications for the education of hydraulic engineers. The framework of underlying basic sciences, geosciences and engineering sciences and the large variety of engineering subjects involved must be seen in the broader context of the natural and social environment. In addition to its classical tasks, hydraulic engineering has evolved to deal with water quality, environmental issues and ecology, and it is further broadened by the new challenges posed by the need for sustainable development and by the threat of global changes. New developments in science and technology and computer sciences must be reflected both in contents and methods of teaching. Education must also provide engineering skills and procedures as well as professional preparation including the ability to work in interdisciplinary teams. In view of these developments, continuing education will have a major role to play, ...

/pdf/education-of-hydraulic-engineers-24xtbx5opj.pdf

Education of hydraulic engineers

En este articulo un comite de expertos pertenecientes a las asociaciones AIHR (Asociacion Internacional de Investigaciones Hidraulicas) y UNESCO, con una reflexion comun presentan los recientes desarrollos en Ingenieria Hidraulica y sus aplicaciones para la formacion de ingenieros hidraulicos. Las estructuras de las disciplinas fundamentales subyacentes, geociencias y ciencias de la ingenieria y la gran variedad de asignaturas de ingenieria envueltas deben ser consideradas en el contexto mas general del entorno natural y social. Ademas de los temas tradicionales, la ingenieria hidraulica ha evolucionado para tener en cuenta la calidad del agua, el medio ambiente y la ecologia, rodeados por nuevos cambios caracterizados por la necesidad de un desarrollo sostenido y por el comportamiento de los cambios globales. Los nuevos desarrollos en ciencias y tecnologia, asi como la informatica, deben reflejarse en los contenidos y metodos de ensenanza. La educacion debe ofrecer una especializacion y metodologia asi como una preparacion profesional, incluyendo la facultad para trabajar en equipos interdisciplinarios. A la vista de estos desarrollos, la educacion continua jugara un papel primordial, siendo mayor su importancia en los grandes sistemas y en problemas a escala internacional. Estos avances exigen una adecuada implicacion de la AIHR.

/pdf/la-formacion-del-ingeniero-hidraulico-4z14gtj3ol.pdf

Hsieh Wen Shen

Papers

First-order estimation of stochastic parameters of a sediment transport model

Education of hydraulic engineers

La formación del ingeniero hidráulico