日本地球惑星科学連合2018年大会

講演情報

[EE] Eveningポスター発表

セッション記号 H (地球人間圏科学) » H-CG 地球人間圏科学複合領域・一般

[H-CG25] デルタとエスチュアリー:複雑な河口システムの理解を目指して

2018年5月21日(月) 17:15 〜 18:30 ポスター会場 (幕張メッセ国際展示場 7ホール)

コンビーナ:齋藤 文紀(島根大学エスチュアリー研究センター)、堀 和明(名古屋大学環境学研究科地理学講座)、Guan-Hong Lee(共同)、Qing He(State Key Laboratory of Estuarine and Coastal Research, East China Normal University)

[HCG25-P07] Tidal modulation on the extent of saltwater intrusion into the Mekong River, southern Vietnam

*上原 克人1 (1.九州大学)

キーワード:メコンデルタ、潮汐、海陸相互作用、塩水遡上

A three-dimensional numerical simulation using ROM has been undertaken to examine the impact of tides on the extent of salinity intrusion to the Mekong River in the Mekong River Delta, where streamwise gradient of the water-level is extremely low. The model predicted 3-d current speeds and salinity in the Co-Chien distributary of the Mekong River for both dry and wet seasons by specifying boundary values such as temperature, salinity, and hourly water levels which were obtained by referring to CTD data and to water level records at tide-gauge stations. It was found that during the dry season when the river discharge is low and the extent of the salinity intrusion is much more apparent than during the wet season, the location of the salinity front, defined as a section where the salinity of 0.5psu was observed, may shift for more than 10 km in upstream and downstream direction in a tidal cycle. This result indicates the importance of considering such a large and short time-scale temporal variability in the location of the salinity front which has not been considered in previous studies.