Watershed Bounded Network ModelThe Watershed Bounded Network Model WBNM for flood estimation on natural and urban catchment1 Download from: http://www.uow.edu.au/eng/cme/UOW068932.htmlWhich redirect you to http://www.rienco.com.au/index.php?v=Home and on the Our research and Development tab and under Software development you can find WBNM beta and WBMN 2007. Fill in your details as in figure 1 and download iWBNM Beta 01 and WBNM V2007.2- First run (Please use Microsoft office 2003 excel version)Click on options and enable the macros. A pop-up message will appear where you should select enable the content (Figure 1).

Figure 1 Enabling macrosImmediately after, another pop-up box will appear on which you should select Advance option, upon which you will receive a warning file not found message regarding the run files.

Figure 2 Advance optionTo locate the missing files use the tab set-up and click on folders, which will prompt you to a browser utility where you can find the missing files (Figure 3)

Figure 3 Missing filesThe files you require will be in the WBNM 2007 folder as follows: WBNMrun.exe and the sample run files sub folder the WBNM.IFD. Once you browse those files, set-up a directory to save your project and click ok.

Modelling peak discharges with Watershed Bounded Network Model1 Introduction:WBMN requires the following information:Catchment Topology - Catchment surfaces detail - FlowpathsLocal Structures / Outlet structuresStorm events1.1 TopologyThe entire catchment is for the Gundagai is represented in figure 3. In this exercise only the area highlighted will be considered.

Figure 4 Flow path diagram for Gundagai catchment

And the data from the sub-catchment areas and outlet coordinates can be found on figure 4. In flow path considered there is a Dam, so additional information should be inputted concerning the Burrinjuck Dam.

1 - SET-UP TAB In tab set-up click on CLEAR ALL and PROJECTINI, which will prompt you for a list of options (Figure 5).Keep the default options.Write you project details in 1.2 and in 1.3 and 1.4 choose auto-generate option.2 - CATCHMENT TAB 2.1 Catchment details: Insert the catchment area topology information (Figure 6). Inset the information about sub-area, the sub-area the water will be flowing to and the coordinates. Click on ROUTING OPTIONS, maintain the defaults values and Click on SORT SUBAREAS. Here WBNM will sort all subareas according to the catchment topology.2.2 Lag Parameters: C=1.6 and Imp Lag=0.1 (WBNM recommendation). The lag parameters should be introduced for all the areas considered. In order to do that click on POPULATE.

Figure 5 SETUP Tab2.3 Flowpaths: Set for Type=R(Routing) and Value=1 and click on POPULATEGuidelines for the Stream Lag Factor (WBNM, 2007):Natural channel 1.0Gravel bed with rip-rap 0.67Excavated earth 0.5Concrete lined 0.332.4 Rainfall losses: Set IL=1.5 , CRL=2.5, Imp IL=0 and click POPULATE. (Figure 6)

Figure 6 Catchment details3 - Local & Outlet Structures TAb3.1 Structure summary Choose from the pull-down the area where the structure is located, choose a type as HS (Heigh Storage), write brief description. Choose OUTLET option on the LOC/OUT. Take for IWL=1, Surfc.area=the dam surface are in Ha, Stor_Fac=1 (Figure 7). Scroll down to 3.2 and click on build all. On 3.3 input your structure details (Figure 8). Scroll up and click on POPULATES DIRECTED SUBAREAS.

Figure 7 Structures Tab4 RAIN FALL AND STorm TAbHere WBMN allows you choose your elected design storms, ie. ARI=100 with duration=90min.

For that you should define the Rainfall data, as provided in the hand-outs for the gauges located near the catchment, i.e. Cooma, Canberra, This data should be added to the exiting IFD file in the IFD tab (Figure 10 ). In section 4.1 select Internal database and you will be able to select our rainfall gauges in table below (see Figure 9 ). Next. Set the Areal Reduction Factor for design storm as Default 1.00 for Small Catchments. Then back on the storms tab 4.2 click on Populate which will prompt you to a menu where you can choose you storms ARI and period intervals. WBMN will construct the data for you (Figure 9).

Figure 8 Structures Tab

Figure 9 Storm and rainfall Tab

5 RUN tabHere you can run you calculations (Figure 11): Click on iWBNM check, and this will return will the list of mistakes you worksheet might have. Correct any mistake and click on BUILT; choose a output file name and OK. click on RUN this will prompt you to another window where the program will show the calculations steps. Let it finish and return to the excel sheet. WBNM will automatically prompt you to RESULTS 1 tab. 6 RESULTS TABIn RESULTS 1 tab you can see for your selected design storms the peak discharges calculated grouped by sub-area considered (Figure 12).

Figure 10 IFD Tab

Figure 11 RUN Tab

Figure 12 RESULTS 1 TabIn the RESULTS 2 tab you can select a given sub-area a obtain the respective hydrographs: 1 Browse your output file2 Choose from the pull-down menu the subarea, storm and Location.3 Click on extract and the hydrograph will be plotted in the worksheet graph (Figure13).

Figure 13 RESULTS 2 Tab