Written report and Web Site.
The present work developed for this Web Site, as complement of a written report, corresponds to a part of the graduation project to apply to the Specialist's Degree in Hydraulic Resources and Environment by the Engineer Gregorio Marín Uribe in the Colombian School of Engineering, under the direction of the Engineer Héctor Alfonso Rodríguez Díaz, professor of the same University. This work will deal in the first part generalities on fluvial hydraulics. In the second section, it has specifically been possible to gather and present in an appropriate way, according to the available bibliography, different formulas for the calculation of the transportation of sediments in alluvial rivers.
To fulfill the previously proposed objectives, it has fundamentally taken as reference the structure of the subject ‘Fluvial Hydraulics’ and their corresponding class’ notes prepared by the Engineer Héctor Alfonso Rodríguez Díaz. This course is dictated in the Hydraulic Resources and Environment Specialization of the Colombian School of Engineering. I especially thank Dr. Rodríguez for the opportunity in using their excellent class’ notes that he gave to us during his course.
In the first part of this document, in summary we can say, that notions of fluvial hydraulics are presented, which are the concepts and the general equations that evaluate the calculation of the transportation of sediments in alluvial rivers. All this consider the origin of the material (sediments) and the way as this material is transported. Besides, some generalities are also presented about the transportation of sediments in the water currents, with the purpose of facilitating the application of technical comparisons, measurements and available mathematical formulations for the estimation of the solid flow transported by the alluvial rivers. Such proposed estimates are useful to facilitate the application of qualitative analysis, construction of physical and mathematical models, in field measurements and the elaboration of different studies like: modification of beds, modification of natural channels and the variation of the volume of the deposit of sediments in a reservoir, among many others. In this knowledge area basically exist, two schools: a deterministic that tries to express by means of equations the physical phenomenon of the sediments’ transportation; the other one is the empiric that tries to obtain relationships directly among the measured variables through obtained data and in field measured. To the first school of thinking belong the researchers DuBoys, Einstein, Kennedy, Vanoni, Brooks, etc. To the second, Blench, Conti, Colby, etc.
In the second part of this work general and theoretical concepts are analyzed for the calculation of the transportation of sediments in accordance with the origin of the material and their type of transportation. It follows presenting the most common formulas reported by the available bibliography and their selection will be made in agreement with the consistency of its measurement units.
Note: The measurement and estimation of the solid flow will be right if it is possible to determine with accuracy the origin and the type of transportation of the material that it is carried by the river. In this way is possible to obtain a good approximation of the value of the transported solid flow. Such estimation of this physical phenomenon of great complexity, is carried out by means of the appropriate calibration of the different empiric, theoretical and technical measurement formulas. This is possible starting from a careful control process and taking of field data (in situ) for the different presented situations. It is relevant to note that the hydraulic and geo-morphological processes for each river in particular depend on different variables that make the modeling of the transportation of sediments a particular situation for each case. (1)
1. For example, the Einstein-Brown semi-theoretical equation, obtained in United States by the son of the celebrated German physic; the anecdote (apocryphal?) says that the father tried to persuade his son against his will to leave such a complex matter as the mechanics of the transport of sediments, due to the quantity and random nature of the variables that involves this phenomenon.