실시간 하천수사용량 계측을 위한 V-ADCP 유속분포법의 적용성 평가

Applicability evaluation of velocity profile method by V-ADCP measuring real-time river water use

Abstract

하천수사용 관리를 적정하게 관리하기 위해서는 객관적인 하천수사용량 자료가 수집되어야 한다. 그러나, 하천수 사용자의 취수여건을 고려하여 유량계 외에 수문조작 등의 간접적인 계측방법을 인정하고 있고, 사용자의 자발적인 보고에 의존함에 따라 자료의 객관화가 어려운 실정이다. 이에 한강홍수통제소에서는 농업용수 사용 비중이 커 하천유량 파악이 어려운 만경강의 고산~봉동 수위관측소 구간에 위치한 어우보 취수로에 V-ADCP를 이용한 계측시설을 설치 및 운영하고 있다. 본 연구에서는 V-ADCP로 측정된 유속을 이용하여 실시간 하천수사용량 산정을 위한 유속분포법의 적용성을 평가하였다. 이를 위해 Chiu의 2차원 유속분포식의 매개변수 민감도를 분석하고, 실측유량 자료에 기초한 최적 매개변수를 산정하였다. 또한 수위-유량관계법, 지표유속법과 비교 평가하여 유속분포법의 특성을 분석하였다.

In order to properly manage the river water use, it is necessary to collect reliable data of river water use. However, It is not easy to get credible river water use data in Korea because there are some difficultites in reporting and measuring river water use data. Thus, Han River Flood Control Office has installed and operated measuring facility using V-ADCP on the EOUBO intake open channel in the Gosan-Bongdong station section of the Mankyung river, where the use of agricultural water is large. In this study, the applicability of the V-ADCP velocity profile method was evaluated for real-time river water use. For this reason, the parameter sensitivity of Chiu's 2D velocity distribution equation was analyzed and the optimal parameters based on actual discharge data were calculated. In addition, the characteristics of the velocity profile method were analyzed by comparative evaluation of the rating curve method and the index velocity method.

Fig. 1. ξ-η Coordinates in open-channel sections (Chiu and Murray, 1992)

Fig. 2. Contour plot of primary velocity with reference values of shape parameters (Cha, 2015)

Fig. 3. Contour plot of primary velocity with  (Cha, 2015)

Fig. 4. Estimate parameter h, versus B/D and mannings n (Chiu and Chiou, 1986)

Fig. 5. Contour plot of primary velocity with β_i (Cha, 2015)

Fig. 6. Estimate parameter β_i, versus B/D and mannings n (Chiu and Chiou, 1986)

Fig. 7. Contour plot of non-dimensional primary velocity with M (Cha, 2015)

Fig. 8. Measuring facility installation location

Fig. 9. Installation of V-ADCP (MOLIT, 2016)

Fig. 10. Measurement of V-ADCP (Principle) (Sontek, 2003)

Fig. 11. Definition of variables in cross-sectional grid

Fig. 12. Range of valid cell to change of water level

Fig. 13. Result of sensitivity analysis for y/B

Fig. 14. Result of sensitivity analysis for h/D

Fig. 15. Result of sensitivity analysis for β_i

Fig. 16. Result of sensitivity analysis for M

Fig. 17. Comparison of result from calculated discharge and measured discharge

Fig. 18. Comparison of relative error between calculated discharge and measured discharge

Fig. 19. Rating curve of EOUGYO

Fig. 20. Index velocity rating of V-ADCP

Fig. 21. Comparison of measurements from VPM, RCM, IVM and manual discharge measurement

Table 1. Result from ADCP, ADV with manual discharge measurements

Table 2. Initial values of parameters applied to sensitivity analysis for y/B and h/D

Table 3. Initial values of parameters applied to sensitivity analysis for β_i

Table 4. Initial values of parameters applied to sensitivity analysis for M

Table 5. Results of parameter sensitivity analysis

Table 6. Result of optimum parameters calculated by trial and error method

Table 7. Index velocity rating of V-ADCP

Table 8. Comparison of result from VPM, RCM, IVM with manual discharge measurements