Specifications

MIDUSS Version 2
2.25 Revision 465

General

• Metric and Imperial units throughout
• All data saved to a file automatically
• Save Session feature saves exactly where you are in a design
• Use any timestep
• Hover help available for text entry
• Help screens linked to current activity
• Robust error detection and recovery
• Automatic prompts for next step
• Test designs under different storms in Automatic mode
• Design proceeds in logical interactive manner
• Hydrograph details visible during design process
• Drainage network can be of any size (i.e. unlimited nodes)
• Use hydrographs generated with any other software package

Layout

• Full colour plan view of the drainage network is automatically drawn as you design
• Add background image of the land area, lotting fabric using BMP or WMF file formats
• Layout can be set match exact scaling of background
• Set the default drawing size (pixels) for each drainage element
• Option to change the look of the drainage elements
• Hover over drainage elements to view popup data boxes containing design and performanace data
• Move layout elements (or groups or elements) around to match your real world design
• Zoom in and out
• Save layout to file
• Print any portions or the full layout to your local printer

Tools

IDF Curve Fit:

• Compute the ‘a’, ‘b’ and ‘c’ parameters of a Chicago hyetograph that most closely approximates a set of observed rainfall data
• Option to copy parameters to Chicago Storm command
• Compute the IDF curve for user-supplied values of the three coefficients and compare this with observed data
• Metric or U.S.Customary (Imperial) units.

Time of Concentration tool:

• Calculates time of concentration based on flood wave travel time overland flow plus small collector channels plus storm conduits
• Choice of:
  • Friend’s equation
  • Kinematic equation
  • Airport (or FAA) method
  • Bransby-Williams method
• Metric or U.S.Customary (Imperial) units

Roughness Height tool:

• MIDUSS uses Manning 'n'. This tool converts roughness height to Manning ‘n’ and then imports the value into the next design command

Edit Storm tool:

• Build your own Mass Rainfall Distribution curves similar to the various Huff storm quartiles and the SCS hyetographs
• Use your custom MRD curve to create storm events
• Build your curves graphically with mouse actions or using tabular data entry

Swinburne tool (available only to Malaysian users):

• For the approximate determination of the Site Storage that should be provided to compensate for the urbanization of a sub-catchment within an undeveloped watershed.

Make Vortex Valve:

• Design a customized Reg-U-Flo Vortex Valve for any desired throat diameter or flush discharge.

Hydrology

Storm Generation:

• Chicago hyetograph

• 4 Huff quartile design storms

• Mass rainfall distribution curve plus add your own

• Canada Atmospheric Environment Service storms

• User defined Historic storm

• Storms hyetographs can be exported or imported

Infiltration models:

• SCS CN
• Horton
• Green & Ampt
• Runoff coefficient can also be used

Overland flow models:

• Triangular SCS
• Rectagular
• SWMM method
• Linear reservoir

Lag & Route

• Very large catchments can be modelled as single area
• Lag times for hypothetical reservoir and channel used

Base flow

• Add any constant base-flow rate to a hydrograph

IUH Hydrograph

• Lets you define a hydrograph based on a peak flow value and timeto peak applied to an Instantaneous Unit Hydrograph.  The SCS IUH curve is included and you can easily prepare similar files to describe other IUH shapes.

File input / output:

• All design data saved to output file
• Output file can be used for Automatic input
• Junction and diversion hydrographs saved to file
• Runoff and rainfall files can be saved and imported
• Design log created of all your design iterations

Hyetograph / Hydrograph display:

• Quick graphic displays are automatic
• Grids and cross hairs under user control
• Graph colours and styles can be changed.
• Customized graph can include rainfall and runoff and annotations
• Customized graph can be printed, imported or saved as BMP file

Design

The drainage network is designed as a tree network proceeding from the sources to the downstream point of discharge.  Flows from multiple tributaries can be accumulated at confluence points from which the total flow can be recovered for design.  Multiple confluence junctions can exist simultaneously and independently.  Diversion structures can define flows extracted from the main network and which can be subsequently recovered for separate treatment (eg. major - minor flow analysis) see diagram.

Pipes:

• Partial flow analysis for peak hydrograph flow
• Design for a specified flow rate also possible
• Feasible diameter grade values automatically displayed
• Hydraulic gradient reported for surcharged flow
• Pipe roughness defined by Mannings 'n'

Channels:

• General trapezoidal shape defined by a base width and left and right sideslopes.
• Arbitrary corss section defined by up to 50 pairs of coordinates.
• Complex shapes can be drawn and refined by editing
• Save and retreive complex sections to file for easy repeat use
• Table of depth, gradient, velocity values is displayed
• Channel roughness defined by Mannings 'n'
• Variable roughness across complex cross sections

Route:

• Kinematic routing uses modified Muskingham-Cunge method
• Timestep and reach length automitically adjusted
• Numerical stability ensured for nonlinear cases
• Plot

Ponds:

• Automatic storage requirements computed
• Stage-storage computed for standard shapes
• Outflow control device can use multiple orifices and weirs
• Customized vortex valves as outflow control devices
• Timestep adjusted for numerical stability
• Includes parking lot, super-pipe and rooftop storage
• Up to 50 stages
• Display inflow and outflow hydrographs

Exfiltration trench:

• Route inflow into outflow and ground water recharge
• Cross section can include multiple pipes, perforated or solid
• User defined media and soil characteristics
• Profile plot updated continuously
• Display inflow, outflow and recharge hydrographs

Diversion:

• Separates inflow into outflow and diverted hydrographs
• Diverted fraction can be explicit or implied by peak outflow
• Diverted hydrograph saved as file
• Diverted flows can be imported for later design

Culvert:

• Either steady flow or an inflow hydrograph
• Routing shows attenuation caused by ponding upstream
• Routing timestep is user adjustable for numerical stability
• Option to use previous Channel design for upstream storage cross section
• Option to edit or re-define upstream stage-discharge data
• Design a weir over the culvert embankment
• Cross-section of the barrel conduit may be a circular pipe, rectangular box, horizontal or vertical ellipse or a pipe arch
• Multiple barrels may be used - cross-section and other hydraulic parameters are assumed to be the same for all barrels
• Profile and cross section plots updated continuously during design

Cascade:

• Route inflow hydrograph through a short cascade of two storage cells in series
• Cells can be a variety of cross-sectional shapes such as pipes, rectangular boxes, horizontal and vertical elliptical pipes or pipe arch
• Design outflow control from each chamber
• Notification provided if a cell is surcharged

(c) Copyright 1984-2008 Alan A. Smith Inc.
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