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.
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Raw DEM file name: You can also open the.
HEC-HMS Exercise for CEK at University of Texas at Austin
This creates a new polyline feature class showing the flowpath for each centroid point along longest flow path. This is where ArcHydro will store its grid results. Watershed and stream network delineation using ArcHydro Tools.
The output file CedarCreek. Cross-section cutlines are used to extract the elevation data from the terrain to create a ground profile across channel flow. These lines are used to compute distances between cross-sections in the over bank areas.
If you want to split the river segment at the selected point, you can just right click on the point inside the dockable window and split the river. You will have to look at the inundation map and the underlying terrain to correct errors in the flood inundation polygon. Subwatersheds delineated from a set of points are therefore by definition non overlapping because the watershed draining to a point that is within another watershed is excluded from the subwatershed of the downstream point.
Also you need to make sure the name and description match with each other. Just ignore this message and continue. If you need to pan, click the pan tool, pan through the map and then continue by clicking the sketch tool do not double-click until you reach the junction.
The flow conditions defined in the above window are upstream conditions. As centroid locations look reasonable, we will accept the center of gravity method results, and proceed.
Center of Gravity Method computes the centroid as the center of gravity of the sub basin if it is located within the sub basin. Choose the lookup parameter as Curve Number which is default in the next window, Click OK, and then select the inputs for the next window as shown below:.
Now open the attribute table of River featureclass, and you will see that the information you just provided on river and reach names is entered as feature attributes as shown below: To perform a batch watershed delineation: For example, we will use one bridge location in this exercise tutoril downstream of the junction with tributary as shown below bridge location is shown in red:.
However, if you are interested, you can explore these functions because you have all the necessary data for their execution. For example, we will use one bridge location in this exercise just downstream of the junction with tributary as shown below bridge location is shown in red: Finally, verify the tables and Click OK.
Save the ArcMap document. Upon successful completion of the process, the Catchment grid Cat is added to the map. Management of models through ProjectPoint and ProjectArea let users see areas for which HMS basin models are already created, and also allow users to re-create models with different stream network threshold. In the layer setup for post-processing, first select the New Bms option, and name the new analysis as Steady Flow. You can open the attribute table of subbasin feature class to see that the subbasin methods are added to LossMet, TransMet, and BaseMet fields, respectively.
Before creating an import file, make sure we are exporting the right layers. You can check it is PolylineZ by opening its attribute table.
Add wshslopepct percent slope for watershed grid to the map document. Confirm the layers in the next window, and click OK.
The new watershed is stored in the Watershed feature class and another feature class named WatershedPoint is also added to the map. Terrain Preprocessing – Raster Data.
Step by Step: Flood Hazard Mapping
This function generates the aggregated upstream catchments from the Catchment feature class. To create the left and right flow paths in Flowpaths tutogial classstart editing, and choose Create New Feature as the Task, and Flowpaths as the Target as shown below:. Therefore, creating adequate number of cross-sections to produce a good representation of channel bed and floodplain is critical. After the computations tuotrial complete, open the attribute table of Centroid to examine the Elevation field.
Another main task that we want to do is to edit data related to structures. You are done exporting the GIS data! You can write some metadata if you wish,and finally choose the outside MainView Geodatabase for Project Data Location, and browse to your working directory where cedar.
Open the attributes of the IneffectivePositions table shown below to understand how this information is stored. You have already downloaded the three required zip files cf. The output is the Flow Direction Grid, named by default Fdr. Before you continue, please make sure you have the following datasets in the map document from the hef part. Save the flow data give whatever title you likeand close the Steady Flow editor. The River Auto Name function assigns names to river segments.
Also note that there are still some unpopulated attributes in the River feature class FromNode, ToNode, etc. Similar to previous tables, the data are organized as the feature identifier XS2DIDits relative station number and the corresponding n value as shown below:. In the next window, choose English units default from the drop-down menu, and click OK. The next step is to enter flow data. Creating bank lines is similar to creating the channel centerline, but there are no specific guidelines with regard to line orientation and connectivity – they can be digitized either along the flow direction or against the flow direction, or may be continuous or broken.
Step by Step: Flood Hazard Mapping | UN-SPIDER Knowledge Portal
Confirm the input River name, and click OK. Click on the Tracing icon in the ArcHydro toolbar to activate the tool. Tutoriql cross-sections data, make sure all Import Data boxes are checked for crosssections, and click OK accept default values for matching tolerance, round places, etc.
Creating Bridges and Culverts After creating cross-sections, the next step is to define bridges, culverts and other structure along the river.