1. Hydraulic and Sediment Handling Performance Assessment of Rani Jamara Kulariya Irrigation Project (RJKIP) by Conjunctive Use of 1D and 3D Simulation Models
Authors: Aashis Sapkota, Hari P. Pandit, Rajesh Shrestha
Presentation by: Aashis Sapkota
(M.Sc. Water Resources Engineering, B.E.civil Engineering)
3rd Int’l Young Researchers’ Workshop on River Basin Environment & Management
Naresuan University, Thailand
21-22 December, 2015

2. CONTENTS OF THE PRESENTATION
Introduction
Objective of the study
Methodology
Results and discussions
Conclusion and recommendation

3. 1.INTRODUCTION Nepal: Water Main natural resource supporting economy
Agriculture
Contributes about 35% of GDP
Employment for 74% of the work force
Many Glacier fed rivers
Young and Fragile Geology - Steep Catchment area
Sediment handling
Challenge to Irrigation and Hydropower

4. RANI JAMARA KULARIYA IRRIGATION PROJECT:
Permanent side intake at Chisapani, d/s of Karnali bridge
Contd..

5. Capacity 100 m3/s up to Settling basin at 4+950 km
Main canal up to km with capacity 80 m3/s
Free side intake, with no control of river water level

6. 2.OBJECTIVE OF STUDY Objectives
Studying Hydraulic and Sediment handling capacity using Numerical models like HEC RAS and SSIIM
Study limitations in their use
Compare 1D and 3D models
Specific objectives
Check hydraulic capacity and handling of sediment of RJKIP.
Trap efficiency of settling basin.
Study velocity vectors/ flow pattern in the settling basin using 3D model.

7. Introduction to HEC RAS and SSIIM
HEC RAS : Hydraulic Engineering Center – River Analysis System
modeling system to analyze river flow, sediment, and water quality dynamics in 1D
SSIIM : Simulation of Sediment In Intakes with Multi Block Options
Navier-Stokes equations in 3D on a general non - orthogonal grid
For sediment, diffusion/advection equation and a bed load transport formula.

8. 3.METHODOLOGY
1) System including intake, regulator gate, 4800m of canal, 100m transition , 600m settling basin, 110m flush outlet - all modeled into single file in Geometric editor.

9. - a part of open channel and barrel in cross-section editor

10. Settling basin as seen in 3D view of HEC RAS

11. Sediment Data
Sediment concentration of August was used for study purpose as most critical period.
Particle Size Distribution (PSD) during corresponding concentration, was used.

12. 2) Hydraulic and Sediment analysis using SSIIM: Input Parameters
Geometrical data
Sediment concentration and discharge at the inlet and outlet of basin
PSD, fall velocity & sp. Gravity, Channel boundary conditions and shields coefficient
Grid 796x66x13
WaterFlow-3D was executed with convergence 0.001

13. 4.RESULTS AND DISCUSSION
Capacity decrease due to increase in manning’s n and due to undermining of bed level by 50 cm at intake
Initial Capacity (m3/s) for bed level m
Decrease Capacity for bed level m
% decrease in capacity
100 87 13 80 70
12.5
water surface elevation(m)
discharge for n(0.015/0.016)
discharge n(0.020)
% decrease in capacity
193.71 80 71
11.25
193.84
100 88 12

14. Hydraulic study (SSIIM)
The velocity vectors were studied:

15. The horizontal velocity were studied at different locations and compared with that from HEC RAS

16. Comparison between horizontal velocities found from HEC RAS and SSIIM at different sections of Settling Basin
Velocity from
SSIIM
HEC-RAS
Remarks
Min
Max
RS 941
0.2417
1.7513
1.471
End of Barrel
RS 923
0.0796
1.2784
1.013
End of 1st transition
RS 821
0.0651
1.169
0.442
Start of Basin
RS 621
0.164
0.4182
0.382
Center of Basin
RS 221
0.1611
0.5093
0.3
End of Basin

17. Sediment Study (HEC-RAS)
The figure shows deposition of sediment in the settling basin
portion after 20 Hrs of run.

18. Simulation was run was for 40 hours to see sediment behavior of whole system for critical sediment concentration. Intermittent flushing (Original design length of 600m) Trap efficiency for mm - 100% D50 of particles after basin mm Rate of filling m3/hr Time for filling(at this rate) - 9 days and 8 hrs Sediment at intake mg/l At the end of Basin mg/l

19. Sediment Study (SSIIM)
The same case of intermittent flushing was checked in SSIIM.
The same Grain Size distribution was used as for HEC RAS. F 2 RIS was used for Result file of WaterFlow-3D.

20. Sediment concentration
The sediment trap efficiency from SSIIM
particle group
size(mm)
Trap% 1
0.5
100 2
0.4 3
0.3 4
0.2 5
0.15 6
0.1
98.51 7
0.06
82.91 8
0.03
41.45

21. Comparison between HEC RAS and SSIIM, Sediment result
Trap efficiency for mm - 100%
D50 of particles after basin mm
Concentration at end mg/l
SSIIM
Trap efficiency for 0.15 mm - 100%
Trap efficiency for 0.1mm %
Trap efficiency for 0.030mm %
Avg. Concentration at end mg/l

22. Continuous flushing of Basin with 20 m3/s
Trap efficiency for mm %
D50 of particles after basin mm
Rate of filling m3/hr
Time for filling(at this rate) - 6 days 23 hrs
Sediment at intake mg/l
At the end of Basin mg/l

23. Flushing Basin length 400m (without dividing wall)
Complete draw down is required. But still not completely effective, velocity of 1.9 m/s is seen to initiate scouring, which is similar to 1.8m/s in design report.

24. 5. CONCLUSION AND RECOMMENDATION
Results from 1D- HEC RAS and 3D- SSIIM were coherent
400m settling Basin; divide wall; wider flush gates for complete drawdown for this project
This type of study can be really handy to see performance of designed hydraulic structures under different scenario
Sediment concentration data of long term for simulation time series
The results can be highly trusted if parameters are optimized and validated for flow depths and sediment depositions

25. Thank You