FLOOD01888

• County: Statewide
• Title: River Hydraulics
• Date: 10/15/1993
• Prepared By: US Army Corps of Engineers
• Floodplain - Doc Type: Educational/Technical/Reference Information

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. Flow Classification: Open channel, Pressure, or
Both

. Flow Type: Steady - gradually or rapidly
varied Unsteady - gradually or
rapidly varied

. Locations of Controls: Subcritical reaches, supercrit-
ical reaches, transitions, struc-
tures, rating curves

. Boundary type:

Fixed or mobile

f. Other considerations. Once the study objectives,
funds, study time frame, data and personnel availability
are determined, several other important questions and
considerations should be made prior to selecting a partic-
ular numerical or physical model. These may include:

Are the data requirements of the model consistent
with the study Objectives? Personnel costs are
usually more significant than computer costs.

. Capacity of the model and available computer
hardware and software to provide information
required for the study.

. Adequacy of the theoretical basis of the numerical
model.

Degree 10 which the model has been tested and
verified.

Data requirements in relation 10 data availability and
amount of pre-processing required. Also, are the
available data proprietary or public?

Ease of application of the program. Faclors include
model documentation, input structure, diagnostic
capabilities, output structure, flexibility 10 display
output, and support.

Data management capabilities (e.g., ability to pass
information from one module to another).

. Ease of making program modifications, either in-
house or by contract.

Program efficiency in terms of typical run times and
costs.

Program accessibility. Can the program be run on a
computer that is convenient 10 access? Does it

EM 1110-2.1416
15 Oct 93

require a mainframe computer or special
hardware?

. Accessibility of user-support services (i.e.,
consultation with someone who is thoroughly
familiar with the program).

. Quantity, accuracy, and availability of ready-to-
use input data for the study area

g. Summary. The following summary steps are
suggested as a procedure for selecting an appropriate
model for conducting river hydraulics studies.

(I) Defme study objectives and required products.
Identify project time and personnel availability.

(2) Summarize flow classification, state, regime and
type as outlined above and estimate the types of data,
amount of data, and quality of data needed 10 evaluate
the types of flow characteristics identified.

(3) Prepare a list of essential data needs in tabular
form. Data categories may include:

Hydrologic data (flow records, highwater marks, etc.)
Channel and floodplain geometry data
Sediment data
Geomorphologic and historical data
Other information (e.g., previous studies and reports)

(4) Are the data identified above readily available?
Also, are they of the quality and proximity 10 the study
site to be appropriate? Are the data proprietary or pub-
lic? How up-to-date are they? Develop lists of available
and missing data.

(5) Estimate the time and costs associated with the
collection of the missing data.

(6) Examine Tables 3-2, 3-3, and 3-4 and compare
to the results from the estimation of key hydraulic char-
acteristics. Select the most appropriate methods based on
results of this examination.

(7) Consider alternative methods based on results of
subsequent studies made such as the reconnaissance
study. Continually update and improve methods 10 meet
the specific needs of the study.

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