Flood Hydrograph and Link-Node Modeling


Hydrologic Process

Comment (text file of 3 lines)
Subarea Runoff Hydrograph
a. Standard Unit Hydrograph Analysis
b. Small Area Unit Hydrograph (1-min. computation interval only)
Flow-by Basin Analysis
a. Hydrograph Separation based on a Constant Q
b. Hydrograph Separation based on a Qinflow vs. Qoutflow Relationship
Flow-Through Basin Analysis
a. Modified Puls Method using 5-min. Computation Interval
b. Modified Puls Method using 1-min. Computation Interval
c. Finite Difference Method using 1-min. Computation Interval

(allows decrease in Q vs. Depth)

Pipe Flow Routing (Kinematic Wave Analog)
Open Channel Routing Methods
a. Translation Method
b. Convex Routing Method
c. Muskingum Routing Method
Set a Stream to Zero
Add Stream to Another Stream
Split Hydrograph by Proportioning
Advance Hydrograph in Time
Runoff Hydrograph Memory Function
a. User-Defined Runoff Hydrograph
b. Write Stream Hydrograph to a DNA File
c. Read DNA File and add to a Stream
View Stream Hydrograph
Other Options

Detailed Output
Summary Output
Graphical Hydrograph Plots
1-minute Computation Interval
Multiple Day Storm Patterns (5 day)
a. Flow-by Storm Pattern
b. Flow-Through Storm Pattern User-Defined 24-hour Rainfall Pattern
Global Editor
a. Globally Change the Basin Factor
b. Globally Change Depth-Area Factors via User Specified Values
c. Globally Change Depth-Area Factors via Total Catchment Area
Convert AES FLOOD File to LAPRE1/HEC1 File
a. Transfer Unit Hydrograph Data
b. Transfer AES Flood Runoff Hydrograph
c. Convert all Convex Routing Links to Muskingum-Cunge Links, or Muskingum Links
d. Metric (Transfer AES Flood Runoff Hydrographs)
Flood Routing and Unit Hydrograph Applications

FLOODSCx: Flood Routing Applications

This application incorporates the Unit Hydrograph System Program (UNITHxx) into a high-speed, completely user-interactive watershed simulation computer program. Analogous to the Rational Method Hydrology Program (RATxx), the watershed is split into several subareas by the designer. The watershed can also be divided into streams which are analyzed independently. The study proceeds in a sequential manner (for each stream) in the downstream direction. The designer selects from a menu of possible hydrologic and hydraulic processes to describe the watershed characteristics. With these several submodels, a watershed can be modeled as a link-node system composed of large subareas contributing runoff at nodal points which are linked together by channel or pipe routing submodels. The program also includes several submodels which approximate the important effects of detention basin storage for both flow-through and flowby detention basin processes. These storage approximations allow the runoff hydrograph modeling approach to be used for most complex urban watershed flood control systems, and enables the designer to optimize the necessary flood control benefit to cost ratio.

Key Features

– Automatically converts FLOOD data file to LAPRE-1/HEC-1 data file format. HEC-1 can then be used to generate output file.
– Subarea runoff hydrograph development (see Unit Hydrograph program description)
– Pipe routing: Flows stored in excess of pipe capacity
– Set a stream to zero for reuse
– Add contents of a stream to another
– Runoff: User enters hydrograph values
– View: Plot stream hydrograph and volumes
– Flowby basin routing: Hydrograph separation
– Flow-through basin routing: Modified Puls method
– Open channel flow routing: Translation method; Convex routing method; Muskingum method
– Transfer portion of a stream to another
– Advance stream hydrograph in time
– Infiltration algorithm for channel and detention basin routing models
– Comments: Three lines of text can be entered to describe the following hydrologic/hydraulic process.

Please contact AES for current software prices.

UNITH: Unit Hydrograph Applications

This application provides a high-speed computer solution to a runoff hydrograph problem. A base 24-hour synthetic critical storm is used which nests the peak 5 minutes of recorded rainfall thorough the peak 24-hours of recorded rainfall. The peak 5 minutes, 30 minutes, 1-hour, 3-hour, 6-hour, and 24-hours of rainfall are adjusted by depth-area curves used by the well-known NOAA Atlas II (or user specified) values. Runoff time distribution patterns are determined from US Army Corps of Engineers "S" curves developed for southern California watersheds, or the standard SCS Unit Hydrograph. This highly cost-effective study tool can be tailored to incorporate specific critical storm patterns or specific "S" curve patterns. Special versions of this program are available for the southern California counties of Orange, San Diego, San Bernardino, Riverside, Kern, and San Joaquin.

Key Features

– Complete user-interaction with computer. All necessary information is prompted by the computer and checked to be within suitable limits. Changes for parameter selection are provided by the computer for the user’s convenience.
– Computerized runoff hydrograph and total volume graphs.
– Computer output ready for inclusion into drainage study reports.
– The unit hydrograph modules are internal of the FLOOD program and provides additional computational features to the designer,including:
-Multiple hydrograph confluencing
-Global depth-area adjustments
-Multiple basin hydrograph generation
– Internal computer tutor text which reviews for the hydrologist or novice pertinent first-course hydrology information.
– User specified soil-loss and baseflow models.
– Weighted "S" curve model which enables the user to develop a specific "S" curve within the computer based on user specified proportions of base "S" curves.
– Internal computation of unit hydrograph, effective rainfall storm pattern, soil losses, runoff hydrograph, and rainfall depth-area duration reduction factors.
– Internal computation of watershed "Lag", total soil-loss, total effective rainfall, and total runoff volume.

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