Mark the area in the figure where you have to enter the parameters for the individual
calculation methods.
Select the area in which the program displays notes and error messages
What is the marked area used for in the program?
→ Graphical display of the basin model
• The basin map is used to develop a basin model.
• Hydrologic elements (subbasin, reach, reservoir etc.) are added from the toolbar and connected to represent the physical drainage network of the study area.
• Background maps can be imported to help visualize the watershed.
Which of the components do you need at
least to be able to run a simulation?
Mark these components.
• Basin Model Manager
• Meteorologic Model Manager
• Control Specifications Manager
• Time-Series Data Manager
A catchment area has been defined in the program.
Explain which calculation methods have been defined for this catchment area.
No canopy –> Interception
No surface –> Depression storage of impervious areas;
Initial and constant –>soil moisture storage
No transform –> runoff specifications, no transformation between two systems
No baseflow –> streamflow, that is not runoff, groudnwater
On the left you see the individual components to be modeled in a watershed; on the right
you see the hydrological model concept.
Connect the individual elements from the hydrological model representation to the
elements in the catchment area of HEC-HMS.
What is the role of the meteorological model in the
system?
Briefly describe what it is used for.
→ specifies the precipitation input required by a subbasin element
—> links the Rainfall of the Time-Series Data with the Subbasin
At what point do you start a
simulation run?
Mark the points in the program
interface.
EXTRA
Explain the difference between a controlled and uncontrolled flood control reservoir. What is the use of a controlled flood control reservoir?
• Control or uncontrolled flood control reservoir regards the outlet of water in a reservoir, e.g. a dam
• uncontrolled flood control: outlet of water without regulating the flow, e.g. overflow spillway
• controlled flood control: outlet of water with regulating the flow, e.g. a gate or valve → for example control over quantity and (sometimes?) flow velocity
What is a controlled flood detention basin? How to add one in HEC-HMS?
Controlled flood reservoir: outlet of water with regulating the flow, e.g. a gate or valve. A controlled flood detention basin can be used to model reservoirs, lakes, and ponds and is designed to represent a simple storage-outflow relationship.
1) Creating Reservoir
2) Implementing Data
3) Connect “reach”, “subbasin”, etc. to Reservoir per Downstream
4) Select Initial Elevation[M]
5) Select Discharge Gage
What does HEC stand for and what is its functionality?
• Hydrological Modeling System
• Modeling tool for mapping water management systems
• available as open source program and can be downloaded for free on the internet
• developed by the American Corps of Engineers
• Functionality:
Calculation of the basin-related runoff in response to precipitation events
Calculation of runoff generation on the basis of different approaches
Implementation of different unit hydrograph methods and the Kinematic Wave methods
Runoff concentration with different calculation methods
What is the minimum information you need to store in the model in order to run a simulation?
• Basin
• time series data (start and end of rainfall event)
• description of the subbasin (total area, imperverious area, calculation methods, flow directions etc.)
• simulation time (start and end time) (Control Specification)
• meteorological model (precipitation data)
• connection to downstram area or component
Which loss methods were used here?
Which components are available to you in HEC-HMS to simulate a natural catchment area?
• Terrain Data Manager
• Grid Region Manager
• Basin Model Manager → converts atmospheric conditions into runoff at specific locations in the catchment area
Subbasin creation tool
Reach creation tool
Reservoir creation tool
Junction creation tool
Diversion creation tool
Source creation tool
Sink creation tool
• Meterological Models → determines the precipitation input required by a subbasin element; includes snowmelt & evapotranspiration
• Control specifications → controls the beginning and end of a simulation; specifies which time-interval is used for the simulation
• Time series data manager → input of for example precipitation gages or discharge gages
• Paired data manager → input of Storage-Discharge Functions or Elevation-Storage Functions
• Grid Data Manager
What are the differences (in terms of the runoff) when using the two runoff balancing methods?
Initial and constant
Direct runoff
Does not show real conditions
Peak discharge is much higher than the peak discharge of the soil moisture accounting
Peak discharge is later
Soil moisture accounting
Direct runoff, interflow, groundwater flow
Peak discharge is much lower
Peak discharge is much earlier
Requires more information
Explain the difference between Green&Ampt, Soil Moisture Accounting and Initial & Constant. Draw a hydrograph for each example.
How can the max. discharge (2 [m³/s]) and max. damming height in HRB be specified?
• Select Method [Specified Release]
• Max discharge can be entered in Max Release [M3/S]
• Max Capacity can be entered in Max Capacity [1000 M3]
Last changed10 months ago
