Title |
Analyzing Flow Variation and Stratification of Paldang Reservoir Using High-frequency Water Temperature Data |
Authors |
류인구 ( Ryu In-gu ) ; 이보미 ( Lee Bo-mi ) ; 조용철 ( Cho Yong-chul ) ; 최황정 ( Choi Hwang-jeong ) ; 신동석 ( Shin Dong-seok ) ; 김상훈 ( Kim Sang-hun ) ; 유순주 ( Yu Soon-ju ) |
DOI |
https://doi.org/10.15681/KSWE.2020.36.5.392 |
Keywords |
Density currents; High-frequency monitoring; Paldang Reservoir; rLakeAnalyzer; Thermal stratification |
Abstract |
The focus of this study was to quantify the thermal stratification and analyze the relationship between the stratification structure and the tributaries to understand flow variations in the Paldang Reservoir. The vertical distribution of the temperature and density gradients, and the depth and thickness of the thermocline were quantitatively calculated using a lake physics tool (rLakeAnalyzer) and high-frequency monitoring data. Based on a density gradient of 0.2 kg/m3/m, the thermocline was formed from mid-May to early-September 2019 and the other periods were weakly stratified or mixed. The thickness of the thermocline was developed until 4.7 m and the depth of the thermocline was formed at a depth of 3 - 6 m at the front of the Paldang Reservoir. During the formation of the thermocline, the Namhangang and Gyeongancheon tributaries with relatively high water temperature (low-density) flowed into the upper layer of the reservoir, and the Bukhangang tributary with low water temperature (high-density) mainly affected the lower layer of the reservoir. This is because the density currents were formed due to the difference in the water temperature of the tributaries. The findings of this study may be used for constructing high-frequency monitoring and quantitative data analyses of reservoirs. |