The course provides an introduction to the Hydrologic Modeling System, HEC-HMS, focusing both on using the program and performing watershed studies. The course starts with a summary and overview of the program and the mechanics of constructing watershed models. Then, components of the software are studied in detail. Major modules include GIS tools, data entry, historic precipitation approaches, computing infiltration and excess surface runoff, transforming excess precipitation to runoff, baseflow, and channel routing. Parameter estimation techniques are taught throughout with instruction about model calibration. Instruction material is supported with workshops that illustrate the basic steps of building a model for project applications. A final project is included that ties together topics to create a calibrated model from scratch.
The following table provides links to YouTube videos for all lectures. Links are provided to the workshop pages located in the HEC-HMS Tutorials and Guides space. All workshop files can be downloaded from the workshops pages as well. Finally, all PowerPoint files are included below and can be downloaded for reference. You will need HEC-HMS version 4.10 or newer to open the workshop files. You can download the software from https://www.hec.usace.army.mil/software/hec-hms/downloads.aspx.
An archived copy of all the workshop instructions (HMS Workshop Instructions.zip) and workshop files (HMS Workshop Files.zip) can be downloaded from here.
|Lectures and Workshops||Videos and Links||PowerPoint Files|
Lecture 0: Overview of Hydrologic Modeling for Studies
This lecture details common purposes and applications of rainfall-runoff modeling within the U.S. Army Corps of Engineers. Study goals and commonly-utilized rainfall-runoff processes are related to the overall task of model development with consideration given to the intended use of the model.
|Overview of Hydrologic Modeling for Studies|
Lecture 1: Introduction to HEC-HMS
Lecture and workshop 1 show the basic components of the HEC-HMS software and how to configure the components to create a simulation and visualize results. Steps to create a model are discussed as well.
Workshop 1: Creating a Simple Model
Lecture 2: HEC-HMS GIS Delineation Tools
Lecture and workshop 2 describe the GIS delineation tools available in HEC-HMS. You can import GIS elements or delineate subbasin and stream elements using terrain data. The delineation tools allow you to customize the hydrologic element network.
Workshop 2: Creating a Georeferenced Model using HEC-HMS GIS Tools
Lecture 3: GIS Parameter Estimation Tools
Lecture and workshop 3 describe GIS tools that can be used to compute physical characteristics for subbasins and reach elements. The lesson also discusses the parameter calculator and how it can be used to process GIS data for estimating model parameters.
Workshop 3: Applying HEC-HMS GIS Parameter Estimation Tools
Lecture 4: Shared Data Components
Lecture and workshop 4 describe three types of data that can be shared throughout the model: paired data, time-series data, and grid data. The lesson discusses methods for entering or importing the data, managing existing data, and connecting the data to model components.
b) Paired Data
c) Gridded Data
Workshop 4: Introduction to Shared Component Data
Lecture 5: Meteorologic Models - Historic Precipitation
Lecture and workshop 5 provide an introduction to developing meteorologic models for precipitation events that have occurred in the past. This includes an overview of the role of the meteorological model in a simulation and details on precipitation modeling methods in HEC-HMS. Two precipitation methods are highlighted: gage weights and gridded precipitation. Evapotranspiration and snow modeling included too.
c) Gage Weights
Workshop 5: Meteorologic Models for Historical Precipitation
Lecture 6: Loss Rate Methods
Lecture and workshop 6 introduce canopy, surface, and infiltration methods within HEC-HMS. Multiple infiltration methods are detailed including: Initial Constant, Green and Ampt, and Deficit and Constant. Strengths and weaknesses of each method are presented in addition to common parameter estimation techniques.
Workshop 6: Applying Loss Methods in HEC-HMS
Lecture 7: Transform Methods
Lecture and workshop 7 introduce the various surface transform methods available in HEC-HMS. The lesson goes into detail on deriving a unit hydrograph from observed flow as well as discussing 3 popular synthetic unit hydrograph methods: Clark Unit Hydropgraph, Snyder’s Unit Hydrograph, and SCS Dimensionless Unit Hydrograph.
Workshop 7: Estimating Clark Unit Hydrograph Parameters
Lecture 8: Baseflow Simulation
Lecture and workshop 8 introduce baseflow methods available in HEC-HMS. The baseflow methods can be used to model the interflow and/or slower responding groundwater flow components of subsurface flow. The linear reservoir and recession baseflow methods will be discussed.
Workshop 8: Applying Baseflow Methods in HEC-HMS
Lecture 9: Channel Routing Techniques
Lecture and workshop 9 introduce open channel flow processes within HEC-HMS. Several available channel routing methods are detailed including: Lag, Muskingum, and Muskingum-Cunge. Strengths and weaknesses of each method are presented in addition to common parameter estimation techniques. Multiple considerations that can be used to select appropriate channel routing techniques are also exhibited.
b) Lag Method
Workshop 9: Applying Reach Routing Methods within HEC-HMS
Lecture 10: Model Calibration
Lecture and workshop 10 discuss the importance of calibrating a hydrologic model, and provide strategies and guidance for performing model calibration. A detailed look at the impact of several hydrologic parameters on the calibration process and advice for adjusting them in a real world model is included.
Workshop 10: Calibrating a Simple HEC-HMS Model:
Project: Develop a Calibrated Model from Scratch
This final workshop combines information from all lessons and gives you another chance to build an HEC-HMS model application. You will create a model from scratch, estimate model parameters, and then calibrate the model to a flood event.