Determination of Discharge by Entropy Concept in Natural River

1. Determination of Discharge by Entropy Concept in Natural River Mehmet Ardiclioglu, Huseyin Bilgin, Onur Genc, Necati Agiralioglu

2. Outline • Introduction • Discharge Calculation • Fields Measurements 4. Result and Discussions 5. Conclusion

3. INTRODUCTION • Water management, • Water resources planning, • Water supply, • Irrigation, • Flood control. • Design of hydraulic structures,

4. Discharge Calculation • Stage discharge rating curve • Empirical formulas • Velocity measurement • Entropy Methods

5. Stage discharge rating curve Q=c(h-a)b Q: Discharge, h: flow depth, c & b: coefficients derived for the relationship corresponding to the station a: Characteristics water level (m) corresponding to Q = 0

6. Manning’s equation Q; stream discharge, n ; Manning’s roughness parameter, A; channel cross-sectional area, R hydraulic radius (cross-sectional area/wetted perimeter) and S ;water slope. n0 ; the value of n for a straight, uniform, smooth channel in natural materials, n1 ; a value added to n0 to correct for the effect of surface irregularities, n2 ; a value for variations in shape and size of the channel cross-section, n3; a value for obstructions, n4 ; a value for vegetation and flow conditions, and m5 ;a correction factor for meandering of the channel.

7. Flow direction z bi V0,2H vj+1 hj aj V0,8H y vj Ai V0,6H Hi x Velocity-Area Method

8. Entropy Equation V; Cross-section mean velocity, vmax ; maximum velocity in the cross section, M ; entropy parameter.

9. Acoustic Doppler Velocimeters (ADV) FlowTracker Handheld ADV produced by SonTek • Velocity range: ±0.001to 4.0m/s • Velocity resolution: 0.0001m/s • Velocity accuracy: ±1% of measured velocity, ±0.25cm/s • Communication protocol: RS-232 • Power supply: 8AA batteries • Operating temperature: -20 to 50ºC

10. TURKEY Population : 67.803.927 - Census 2000Area : 779.452 km²The average altitude :1.132 m

11. Fields Measurements City Centrum SMS, DSI Measured station SIVAS YOZGAT Kizilirmak river Kizilirmak Basin Black Sea Yamula dam Sahsanem KAYSERI TURKEY Sarimsakli stream Mediterranean Sea

12. Velocity measurement at Şahsanem station

13. Topographical Measurements ADV

14. cross-section divided subsections Measuring cross-section

15. bed and water surface slopes measuring

16. Table 1 Flow characteristics

17. Table 2 Discharges and Errors for different methods

18. Figure 4 Relation between V and vmax based on measured data

19. Figure 5 Relative errors for different methods for discharge calculations

20. Conclusion • Velocity-area method, commonly used for discharge determination requires a great amount of time and effort. • Sampling procedure of velocity measurements in a river cross-section during high floods could be difficult and particularly dangerous. • Slope-area methods such as Manning equation includes indefinite parameters such as roughness coefficient n. • The ratio of the mean and maximum velocities of a cross-section, which characterize the flow pattern, approaches a constant. • The mean velocity can be obtained by the constant ratio and the maximum velocity. • The maximum velocity can be determined quickly by measuring only a few velocities from a single vertical axis.

21. Six different measurements shows that, slopes-area method gives relatively high errors (%9,37) for discharge at the measured cross-section on Sarimsakli river. • The two-point and 0,6-depth method produced very sensitive results but, require more measured data along the cross-sections. • Mean relative errors were calculated as %3,31 and %2,90 respectively for these methods. • But application of entropy methods is very easy for known entropy parameter M and this concept gives much closer discharge results compared to integrated ones. • Mean relative error for six different measurements was calculated as %3,23 between integrated discharge and entropy concept.

22. Thanks…