Project 2

• Select a river. Here I choose narmada river.
• Consider minimum of 10km river reach.
• Start a new project in HEC-RAS software.
• Open cross section data editor and give the necessory values.
• 
• 
• Click Options -> Add cross section data.
• Change river station to a value and change the necessory data required.
• Similarly,add all data of cross section of each station and then click on 'apply data' option to get a graph plotted on the right side of that window.
• Click on plot -> plot profile to view that.
• Now add bridges and culvert datas.
• Now, click on Bridge/Culvert option in the left side of this window.
• 
• A new window will appear like this.
• Click on option menu -> add a bridge and/or culvert option. Then a box will appear like this. 
• Add each station for a new station for the new bridge or culvert and enter all its details.
• (add high chord and low chord also)
• 
• Similarly, continue this process for all new station.
• Then click on Apply Data option. then a window will appear like this.
• Similarly, all graph can be obtained for the entered value.
• Other structural details can be obtained from google earth pro.
• Then click on file menu -> save geometry data as option.
• Then save the cross section data in appropriate folder.
• Now we can move to the section of catchment area calculation.
• Open Google Chrome (or any other browser)
• Search for "SOI Nakshe".
• Select the link which direct to the site "https://onlinemaps.surveyofindia.gov.in/"
• A home page will appear then.
• Click on Sign In.
• Then a box will appear for signing in.
• If its a first ttime user, then click on "Register Here" option. Then register with an email id and enter a password. 
• Then an OTP will come at your registered email id. 
• After reading all the terms and condition, do the needful.
• Else Enter Mobile Number, Password and Captcha.
• Then click Sign In.
• After successful login a new screen will appear with online toposheet series.
• 
• Enter the toposheet number and click download button.
• Then a pdf will get download.
• Convert it into .jpg format in order to insert this image into the Autocad Software.
• 
• Then open it in Autocad.
• 
• Click start Drawing option.
• Click File -> Import -> PDF (or .jpg).
• The image will appear on screen.
• Considering it as a background image, draw the necessary data needed in an another layer.
• Then sketch the layout of river using the polyline toolwhich is under draw option in home tab.
• Click Area
• Then click on the boundary upto which area is to be known.
• Then area will be shown there.
• 
• Like that any area can be calculated here accuratly.
• 
• Each river can again be selected clicking on the line itself. And deselect by pressing esc key on the keyboard.
• 
• To get isopluvial map go to website https://www.mapsofindia.com/maps/india/annualrainfall.htm
• 
• Collect the isopluvial map for flood after 25 year from wesite.

• Also collect the isopluvial map for flood after 100 year from wesites.

• Plot these data obtained in a table.

• 1	Catchment Area			A =	216.49	Sq. Kms
  2	Length of Stream from origin To Site			Ls =	41.15	Kms
  3	Length of Stream from   I   on centroid  to site			Lc =	25.68	Kms
  4	R.L. at extreme length ( At Origin of Stream )				500.00	m
  5	River Bed R.L. at  Site				90.00	m

• Sr.No.	Reduced distance from point of study (KM)	Reduced level of river bed in m	Length of each segment in Km (Li)	Height above datum in m
  1	0	90	0.00	0.00
  2	2.33	100	2.33	10.00
  3	19.80	180	17.47	90.00
  4	32.42	260	12.62	170.00
  5	34.71	300	2.29	210.00
  6	37.31	340	2.60	250.00
  7	38.30	360	0.99	270.00
  8	38.90	400	0.60	310.00
  9	41.15	500	2.25	410.00

• Find Equivalent stream slope (S) using analytical method.
• Add 2 more column [(Di-1)+Di] and [Li *((Di-1)+Di)] for that.  $S=\Sigma (L_i\cdot \frac{(D_i-1)+D_i}{L^2})$
• 
• Find the synthetic unit hydrograph datas using equations.
• 
• Now calculate rainfall of 25 years.
• 
• Calculate the time distribution of cumulative Hourly Rainfall (i.e. 25 year rainfall excess)
• 
• Then compute 25 years of peak flood.
• 
• Similarly calculate the rainfall calculations for 100 years.
• 
• Calculate the time distribution of cumulative Hourly Rainfall (i.e. 100 year rainfall excess)
• 
• Then compute 100 years of peak flood.
• 
• Then plot a graph with the following datas

  Time (Hours)	Discharge (Cumecs)
  0	0
  1	12
  2	36
  3	80
  4	161
  5	110
  6	63
  7	44
  8	32
  9	23
  10	16
  11	11
  12	6
  13	3
  14	0
  ∑	597

• Graph is plotted time in x axis and discharge in y axis.
• Maximum Discharge is 161 cumecs 
• A check can also be done to know whether the obtained result is right or not using the equation, $\frac{\Sigma Q\cdot 3600\cdot 100}{C\cdot /(A\cdot {\mathrm{10^}}^{\mathrm{6)}}}$
• Now we have to obtain the DEM datas of the selected river.
• Open any browser and search for 'bhuven dem download'
• 
• Then click on the first option opening in the window.
• A page will open like this.
• Navigate to open archieve.
• Click on login.
• 
• Fill Cartosat-1 and its product.
• 
• Click on tile tab -> start button. Select the tile needed.
• Click download.
• Now downloading of DEM data is done.
• Now open QGIS software which we have already installed.
• 
• Click layer panel -> add layer -> add raster layer.
• 
• Now, Open HEC RAS software
• Open a project
• Click on the RAS Mapper option from that window 
• 
• A new window will appear.
• 
• Click File menu -> Open -> Select from our library.
• 
• Click on tools -> Add new layers -> Select the layer from your library. (If layers are already prepared in autocad software) 
• 
• Now after identifying the river give the cross section data if there is any change.
• Add profile line by clicking '+' symbol in the profile line tab.
• 
• Now enter cross sectional data as we had done earlier.
• 
• Now we can move on to the unsteady flow analysis section.
• Click Edit menu -> Unsteady flow data.
• A new window will appear like this.
• 
• Click on the initial condition tab of that window. Then the window will be like this.
• 
• Enter the initial flow limit, say 0.1 & 0.2.
• Then again go back to boundary condition tab and select the boundary condition type for each flow.
• On selecting Normal Depth a window appear like this. And enter the frictional Slope.
• 
• Also add flow hydrograph data.
• 
• A window will appear like this and give the adequate data required.
• I have changed the time interval to 6 hrs and entered the data.
• 
• Click on Plot data to see the graph plotted.
• 
• Now save the unsteady flow data.
• Click file menu -> Save unsteady flow data.
• Now we have to analysis on this part.
• Click run menu -> unstaedy flow analysis from main window.
• A window will appear like this.
• 
• Click compute.
• 
• Now click view menu -> Detailed Output table.
• A table showing all the data will appear then.
• From this data flood data analysis can be done.
• Now we can move on to the steady flow analysis section.
• Click on 'Perform a Steady flow simulation' on the main window for steady flow analysis.
• This component of the modeling system is intended for calculating water surface profiles for steady gradually varied flow. The system can handle a full network of channels, a dendritic system, or a single river reach. The steady flow component is capable of modeling subcritical, supercritical, and mixed flow regimes water surface profiles.
  
  The basic computational procedure is based on the solution of the one-dimensional energy equation. Energy losses are evaluated by friction (Manning's equation) and contraction/expansion (coefficient multiplied by the change in velocity head). The momentum equation may be used in situations where the water surface profile is rapidly varied. These situations include mixed flow regime calculations (i.e., hydraulic jumps), hydraulics of bridges, and evaluating profiles at river confluences (stream junctions).
• (By clicking on compute, we can see if there is any errors. If so a pop up window will appear showing what are the absent values for the correct processing of data.)
• Then click on set locations for flow distribution option for entering various datas.
• 
• Click on plot profile data to obtain all data in a table 
• Also click on Add Flow Change Location button and Add Multiple button when necessory.
• Click file menu -> Save to save the entire steady flow calculations.
• Then the main window will be like this,
• Now enter steady flow data.
• 
• Then click on reach boundary condition to give boundary conditions. 
• 
• Choose downsream and downstream type.
• 
• Give adequate values.
• Do bank Station and flow path corrections.
• 
• Click Compute.
• You will get the required datas.

Result

• The final result of cross section can be checked in X-Y-Z Perspective Plot option of HEC-RAS software.
• 
• Flood estimation for 25 years and 100 years are calculated using UH method. And analysis is done and graph is plotted and check is done.
• Run model of different profiles are plotted.
• Steady flow analysis also done.
• Unsteady flow analysis also done.
• A hydraulic model with RAS Mapper is developed successfully after analysis.
• Profile Plot Table is also plotted.

Ref: 

1. https://www.hec.usace.army.mil/confluence/rasdocs/rasum/latest/introduction-to-hec-ras
2. https://civiltoday.com/construction/bridge/114-difference-between-bridge-and-culvert
3. https://www.quora.com/What-is-the-red-line-and-blue-line-normally-used-to-mark-the-boundary-of-a-river-bank
4. https://www.hec.usace.army.mil/confluence/rasdocs/rasum/latest/working-with-hec-ras