Project 2

                                                                    Project 2

Computation  of flood levels for Brahmaputra river or any major river in your area.

Conditions

• Consider minimum of 10km river reach
• Consider all inline and lateral structures
• Use RAS mapper
• For flow calculation use any one method as per syllabus
• Consider both steady and unsteady flow condition
• Compare results with existing flood levels for specific river segment

Tools used:

HEC-RAS

Alos Palsar DEM of 12.5m resolution

Discharge data of chembarambakam reservoir in 2015 over adayar river.

Study area:

Adayar river channel in Chennai district

Procedure:

Step 1:

New project is created to model

 

Step 2:

From the selected river, Using DEM data from ALASKA SATELLITE FACILITY is done.

 

Step 3:

Change the unit system

 

Step 4:

Click on Ras mapper

Add terrain data (Dem of your river)

Click no and locate the DEM data in your storage

 

Click yes to set CRS of DEM

The DEM data gets added in mapper window

 

Step 5:

Open the geometric data view and save geometric data.

 

Step 6:

Add web imagery for referencing the DEM data and create contour intervals

 

Using Ras Mapper, River, Bank lines, Flow paths and cross sections are marked

 

Step 7:

Geometric Data editor in HEC RAS is opened to visualize the data and correction of errors.

 

Step 8:

Data Received from PWD on discharge is added UnSteady Flow data.

 

 

Step 9:

Unsteady flow analysis computations are carried.

 

Step 10:

Add bridge and culvert details.

 

Step 11:

Simulation is computed.

Step 9:

Result

 

Velocity

 

Depth

 

Water surface elevation

Cross section

Profile summary

 

XYZ perspective plot

Hydraulic Plot

 

Also attached the flood summary results