Uncertainty analysis of HEC-HMS model using the GLUE method for flash flood. CEE Engineering Hydrology HEC-HMS Bare Essentials Tutorial and Example comprehensive or to replace the HEC-HMS documentation; rather it is a. The Hydrologic Modeling System (HEC-HMS) is designed to simulate the complete hydrologic processes of dendritic watershed systems.
|Published (Last):||24 May 2007|
|PDF File Size:||7.8 Mb|
|ePub File Size:||7.84 Mb|
|Price:||Free* [*Free Regsitration Required]|
This is useful for exporting the schematic to other models or programs without loosing the geospatial information. However, if you want to distinguish your points for whatever reason from the default BatchPoint, it is better to just keep them in separate feature class.
You can use this option to trace the flow path the path along which water will flow to the outlet for any point in the tutotial. Stream Link Grid file name: Flow Accumulation Grid This function computes the flow accumulation grid that contains the accumulated number of cells upstream of a cell, for each cell in the input grid.
An alternative to delineate watersheds when you do not want to use the batch mode process a group of points simultaneously to generate the watershed for a single point of interest is the Point Delineation tool. This will add a point for the watershed outlet in the ProjectPoint feature class. Confirm the inputs, and leave the default output name LongestFlowPath unchanged. If cells with higher elevation surround a cell, the water is trapped in that cell and cannot flow.
Adjoint Catchment Polygons file name: Batch Subwatershed Delineation This function delineates subwatersheds for all the points in a selected Point Feature Class.
The output is the Stream Grid named Str, default name that can tutoriall overwritten.
Click OK on the process completion message box. The futorial created up to now have all been stored in a folder named Layers. To create the river centerline in River feature classstart editing, and choose Create New Feature as the Task, and River as the Target as shown below:.
Accept the default 20 map units for Rasterization Cell Size. A point is then created at the location of mouse click, and the following form is displayed:. We will approximate the bridge width to about ft station todeck elevation as 84 ft high chord and 6ft deep low chord as shown below:. On the other hand, watersheds may overlap For example, the two watersheds in the Watershed feature class overlap with each other.
The flowpath lines are used to determine the downstream reach lengths between cross-sections in the main channel and over bank areas.
To create the left and right flow paths in Flowpaths feature classstart editing, and choose Create New Feature as the Task, and Flowpaths as the Target as shown below:. All the cells in water surface grid that result in positive values after subtraction are converted to a polygon, which is the final flood inundation polygon.
Save edits, and stop editing.
HEC-HMS Exercise for CEK at University of Texas at Austin
Click Yes on the message box. This function creates a grid in which each cell carries a value grid code indicating to which catchment the cell belongs. Before you continue, please make sure you have the following datasets in the map document from the previous part. Finally, digitize the lower Baxter reach from junction with the Tule Tributary to the most downstream end of the Baxter River.
We do not have any meteorologic data temperaturerainfall etc at this point. The bms of flood inundation results to create a hydraulically correct output is not covered in this tutorial – this is an iterative process requiring several iterations between GIS and HECRAS.
Step by Step: Flood Hazard Mapping
As a result of this merging, we now have 12 hed and 15 river segments in the project. Fill-in the name and comment as shown below in the form below. Basin Processing The basin processing menu has features such as revising sub-basin delineations, dividing basins, and merging streams. Perform the re-classification of classes.
You will see the reach will get selected, invoking the following window: Save your HMS project. These parameters include SCS curve number, time of concentration, channel routing coefficients, etc.
The function needs as input a raw DEM and a linear feature class like the river network that both have to be present in the map document. The display should look similar to the figure shown below and be zoomed in sufficiently so you can see and click on individual grid cells.
It is then cumbersome to find out which feature classes were used during pre-processing, and which feature classes contain results for visualization.
In the next window, provide the following inputs:. You can also play with the contributing area tool to find out contributing area at different points in the cedar creek stream network.
Terrain Preprocessing – Raster Data. This will create a new folder inside your working folder with the name of the project CedarCreek, and store all the relevant raster, vector and tabular data inside this folder.
Fill in the fields Name and Description – both are string fields. This will help identify any errors in the input data and fix them, and run the simulation again, if necessary. The raster data are stored in a sub folder with the project name Tuutorial inside CedarCreek folder. Obstructions represent blocked flow areas areas with no water and no flow.