Hydrologic Modeling using HEC-HMS
Prepared by
害羞草图片Venkatesh Merwade
School of Civil Engineering, Purdue University
vmerwade@purdue.edu
April 2007
Introduction
The intent of this exerci is to introduce you to the structure and some of the functions of the HEC-Hydrologic Modeling System (HEC-HMS), by simulating the runoff hydrographs resulting from a design storm on Waller Creek in Austin, Texas. This exerci involves the study of extreme discharges on Waller Creek using rainfall-runoff analysis. The physical parameters describing the watershed were developed previously using a GIS program (PrePro) available at
ceprofs.tamu.edu/folivera/GISTools/PrePro2002/PrePro2002.htm. A GIS pre-processing tool called HEC-GeoHMS, available from U.S. Army Corps of Engineers can also be ud for this task. HEC-GeoHMS is available at:
www.hec.usace.army.mil/software/hec-geohms/
A tutorial on how to u the newer version of HEC-GeoHMS that works with the latest version of ArcGIS is available at: web.ics.purdue.edu/~vmerwade/tutorial.html Computer Requirements
You must have a computer with the latest windows operating system, and HEC-HMS 3.1.0 installed.
HEC 3.1.0 for windows is available for free from the Hydrologic Engineering Center's home page at: www.hec.usace.army.mil/software/hec-hms/download.html. A ur's manual is also available at this location. (Purdue Students: The program is loaded on computers in ITaP’s JNSN B012 lab)
Data Requirements
To run HEC-HMS model, a basin file is needed to specify the physical parameters of the watershed, and a map file to give the outline of the drainage areas and creeks. The files for Waller creek (zipped as waller.zip) can be downloaded from the following link: web.ics.purdue.edu/~vmerwa
吸引人de/education/waller.zip
Make a working directory on your computer and download waller.zip, and unzip its contents. .
Getting Started
Start HEC-HMS by clicking on the HEC-HMS icon by going to
StartÆProgramsÆHEC-HMSÆHEC-HMS 3.1.0 (Purdue students doing this tutorial in an ITap Lab may have to first run the t-up file by going to StartÆProgramsÆCour SoftwareÆEngineeringÆHEC-HMSÆHEC-HMS 3.1.0)羊肉炖豆腐
After a few conds, the following should appear:
Henceforth, this window will be referred to as HMS Interface. The HEC-HMS interface consists of a menu bar, tool bar, and four panes. The panes are referred to as the Watershed Explorer, the Component Editor, the Message Log and the Desktop. More description on the panes, menus and tools is provided when they are ud later in the exerci.
Creating a new HEC-HMS project
The first step is to create a new HEC-HMS project by lecting FileÆNew in the menu bar. Enter the project name and description as shown below, and specify your working directory (where waller.zip is downloaded).
Click Create to create the Waller project.
HMS Model Components
固态硬盘拆解
HMS has four main model components (you can e the by lecting components on the menu bar): basin model, meteorologic model, control specifications and input data (time ries, paired data and gridded data). The Basin Model, for instance, contains information relevant to the physical attributes of the model, such as basin areas, river reach connectivity, or rervoir data. Likewi, the Meteorologic Model holds rainfall data. The Control Specifications ction contains information pertinent to the timing of the model such as when a storm occurred and what type of time interval you want to u in the model, etc. Finally, the input data component stores parameters or boundary conditions for basin and meteorologic models. Each of the ctions is explored below individually
Importing a Basin Model
The first of the Components we will consider is the Basin Model. To create a hydrologic model of Waller Creek, you need to import the basin file that you just downloaded. In HMS interface, u FileÆImportÆBasin Model…Brow to Waller_Ck.basin in the working directory, and click Select to add it to the HMS project. To e the Waller Creek basin model in the Desktop window, expand (by clicking on the + sign) the folders in the Waller folder until you get to Waller_Ck as shown below.
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If you expand Waller_Ck, you will e different hydrologic elements in the basin in the watershed explorer. Before we get into the details of the basin, go ahead and add the basin map which is stored in the Hms.map file.
In the HMS interface, lect ViewÆBackground Maps. This will prompt a Background Maps window. In the Background Maps window, click on Add…Brow to the
Hms.map file in the working folder (make sure you change the Files of type to HMS Map
File (*.map) as shown below), and lect it.
This will add Hms.map in the Background Maps window. Click OK to add it to the HMS
You should then e a schematic of Waller Creek showing the watershed and stream map and an overlay of the hydrologic elements. You will notice that the whole map of the basin does not fit in the
Desktop window. You can change the Desktop ttings by lecting ViewÆMaximum Extents in the Menu bar. Select the display method as Union
of All Maps and Elements with an element buffer of 40 % or more as shown below:
Now you should e the whole basin in the desktop window. Save the project. Navigating the HMS Desktop
用一和便造句
You can u the following four tools in the tool bar to navigate through the HMS desktop:
The arrow tool lets you lect any hydrologic element in the basin. You can u the
zoom-in tool to zoom-in to a smaller area in the desktop, and zoom-out tool to zoom out to e a larger area. The pan tool can be ud to move the display in the desktop. Go ahead and experiment with the buttons to understand better how each works.
Now lets explore the basin information.
Hydrologic Elements
The Waller_Ck basin contains different hydrologic elements. The following description gives brief information on each symbol that is ud to reprent individual hydrologic element.毛笔种类
Subbasin – Ud for rainfall-runoff computation on a watershed.
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