Development and Evaluation of Automatic Discharges Measurement Technology for Small Stream Monitoring

Abstract

Small streams have flood effects on both national and local streams located further downstream. Moreover, damages are increasing in these basins, making the development of adaptive prevention and response measures an urgent necessity. However, the challenge is that small streams remain non-measuring sites. Furthermore, there are about 22,800 small streams, which are too many for the local governments to measure during the flood season. Thus, in this study, a CCTV-based automatic discharge measurement technology was developed to support local governments in monitoring, and minimize the labor required. To evaluate the new technology, discharges were measured in Jungsunfil-chun of Ulju-gun, which is a test bed operated by the National Disaster Management Institute, and compared with the Aquatic Doppler Velocimetry (ADV) based discharges and the weir discharges. The results show that measurements using the new technology are in good agreement with the ADV based discharges. Furthermore, the new technology has the advantage of being able to capture peak flood discharges with short measurement times. Moreover, it is a sustainable measurement method to support flood control by verification of stream flow and situational influences, and provides stable measurements by using a non-contact measurement method. It is expected that the new technology may be used to increase the number of monitoring sites, and the hydraulic data sets collected from various small stream test beds can be used to enhance the design code for estimating flood discharges and the small stream flood warning system to reduce damage in small streams.

Development of Flood Early Warning Frameworks for the Small Streams in Korea

“…The National Disaster Management Institute (NDMI) in Korea developed the Closedcircuit television-based Automatic Discharge Measurement Technology (CADMT) using SIV technology in 2016 and evaluated it through field and hydraulic experiments [6]. The CADMT allows for real-time measurement of flow depth, velocity distribution, and discharge under extreme flow conditions without requiring direct measurement, recording, or data collection and analysis.…”

“…Flood disasters linked to these extreme rainfall events cause the largest socioeconomic losses over the Asian domain [3][4][5]. In Korea, more than 80% of flood disasters occur in river basins [6,7]. As extreme rainfall events occur suddenly and locally, such as in a flash flood, the flood damage caused by extreme rainfall events in small streams is on the rise.…”

“…As extreme rainfall events occur suddenly and locally, such as in a flash flood, the flood damage caused by extreme rainfall events in small streams is on the rise. Disasters in the last 10 years, from 2010 to 2019, show that about 42.3% of the total damage of $68.5 million was caused in the small stream basins [8]. The floods bring more serious impacts on the small stream basin than the large river basin, as the small stream has fast flow characteristics within a one-hour flow duration time with a steep channel slope [6].…”

“…Disasters in the last 10 years, from 2010 to 2019, show that about 42.3% of the total damage of $68.5 million was caused in the small stream basins [8]. The floods bring more serious impacts on the small stream basin than the large river basin, as the small stream has fast flow characteristics within a one-hour flow duration time with a steep channel slope [6]. In particular, more than 60% of casualties have occurred in the small stream Disclaimer/Publisher's Note: The statements, opinions, and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s).…”

Selection of Small Stream Basins and Characteristics Analysis of Closed-circuit Television-based Automated Discharge Measurement Technology

“…따라서 신뢰도 높은 설계홍수량 산정을 위해 다양한 소하천 유역의 관측 홍수량자료가 요구되고 있는 실정이다. Cheong et al (2018)은 표면영상유속계(Surface Image Velocimetry, SIV) 기법을 활용하여 CCTV기반의 자동유량계 측기술을 개발하였으며, 4개 소하천(중선필천, 선장천, 능막천, 운촌천)에 시범 적용하여 홍수량 계측 정확도 검증을 완료하였 다 (NDMI, 2017(NDMI, , 2018. 행정안전부 국립재난안전연구원은 개 발 완료된 자동유량계측기술의 장비 및 설치 표준(안)을 제시함 으로써, 전국 미계측 소하천의 수위, 유량 자료를 자동으로 계측 가능한 기반을 마련하였다 (Joo and Cheong, 2019).…”