Accuracy Improvement of Discharge Measurement with Modification of Distance Made Good Heading

Jongkook Lee,Changsam Jeong,Hongjoon Shin,Jeonghwan Ahn

doi:10.1155/2016/9437401

Jongkook Lee, Changsam Jeong + Show 2 more

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https://doi.org/10.1155/2016/9437401

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Abstract

Remote control boats equipped with an Acoustic Doppler Current Profiler (ADCP) are widely accepted and have been welcomed by many hydrologists for water discharge, velocity profile, and bathymetry measurements. The advantages of this technique include high productivity, fast measurements, operator safety, and high accuracy. However, there are concerns about controlling and operating a remote boat to achieve measurement goals, especially during extreme events such as floods. When performing river discharge measurements, the main error source stems from the boat path. Due to the rapid flow in a flood condition, the boat path is not regular and this can cause errors in discharge measurements. Therefore, improvement of discharge measurements requires modification of boat path. As a result, the measurement errors in flood flow conditions are 12.3–21.8% before the modification of boat path, but 1.2–3.7% after the DMG modification of boat path. And it is considered that the modified discharges are very close to the observed discharge in the flood flow conditions. In this study, through the distance made good (DMG) modification of the boat path, a comprehensive discharge measurement with high accuracy can be achieved.

Highlights

Considering the steadily increasing water demand in Korea, accurate river discharge information is important for sustainable water resources management such as flood control, hydraulic structure design, and hydroenvironment management
Quick and convenient measurement is the advantage of these methods, but there is a drawback that the uncertainty of velocity and cross section area increases due to the unknown flow route when the floating rod does not flow along the assumed straight line
In recent years, the Acoustic Doppler Current Profiler (ADCP), which can probe velocity and bottom changes simultaneously, has been increasingly adopted as an acceptable tool in Korea and is regarded as the preferred method [2]. Because this method measures the change of flow velocity and depth of cross section continuously, this method has an advantage of detailed consideration for the change

Summary

Introduction

Considering the steadily increasing water demand in Korea, accurate river discharge information is important for sustainable water resources management such as flood control, hydraulic structure design, and hydroenvironment management. In recent years, the Acoustic Doppler Current Profiler (ADCP), which can probe velocity and bottom changes simultaneously, has been increasingly adopted as an acceptable tool in Korea and is regarded as the preferred method [2] Because this method measures the change of flow velocity and depth of cross section continuously, this method has an advantage of detailed consideration for the change. The development of a method to reduce this measurement error will enable the river discharge to be measured more accurately and efficiently and we focused on the method to determine an optimal cross section of an arbitrary path due to a remote-controlled operation in a flood condition. The distance made good (DMG) line by the east-north-up (ENU) coordinate system was used to resolve these issues

Background

Measurement and Analysis

Analysis

Conclusion