Session B.pdf - Clarkson University

The given above example characterizes the modern approach to the solution of the
floods problem resulted from ice jams and mixing phenomena. For building a detailed
and correct (valid) model of the processes taking place in this region it appears desirable
to have a combination of several program products. Such a scheme will allow to
decrease a possibility of logical and program mistakes, to compare results and what is
especially important to use special packages in difficult cases.
DEVELOPMENT OF MATHEMATICAL MODELS
The current programs make it possible to produce modeling of the most different
processes occurring in waterways (reservoirs) and fulfil calculations with a rather high
degree of adequacy. From the whole program diversity there was accepted a graphicanalytical
package HEC-RAS as the technically closest one for solving problems of ice
jams and mixing phenomena on the Amur river. This product has been developed with
the assistance of the USA Corps of military engineers in West Point which can to a
great extent guarantee its high quality and excellent adequacy. HEC-RAS is an
integrated program package of hydraulic calculations in which the user interacts with
the system through the graphic interface of the user GUI – Graphical User Interface).
The system is capable to fulfill calculations of curves of a free surface at steady or
unsteady movements, some calculations on designing hydrotechnical structures, bridges
availability of the ice cover in its different conditions.
The main purpose of the model development in the given electronic environment is a
possibility of creating a connected picture of processes capable to change in time on the
river Amur in a region of the Khabarovsk agglomeration of processes. At the same time
there is both a possibility of forecasting possible ice difficulties and issuing correct
hydrologic prognosis of development of events taking the influence on man’s activity
into consideration.
The input process of the environment data HEC-RAS is fulfilled at several separate
stages, each of which is little dependent from the rest but is substantially necessary.
There are the following basic technical stages of creation: inputting of the geometric
data, inputting of the flow and boundary conditions data, fulfillment of hydraulic
estimations.
Materials of the geometric data are put into the geometric data block providing
communication of the data system of hydrotechnical structures (bridges, tubular
structures, weirs) with the flow (scheme of the river system), data of the cross section
etc.
In our case it was necessary to geometrically determine a section from the beginning of
the Amur river branching to the arbitrary known cross section downstream from the
bridge. A number of factors make this task difficult: heavy branching of the Amur river
channel upstream above Khabarovsk, instability of geometric forms of waterways
resulted from heavy treatment of the channel during floods passing and ice jams and
mixing on the level rise, lack of cartographic materials and measuring data of depths in
the river.
Possible ways of the problem solution can be considered as either purchasing of the
commercial cartographic material which is connected with significant costs and does
not fully guarantee the correctness of geometrical data even of the last year or usage of
materials of the related industries. As for accuracy, frequency of innovations and
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