Tracking migration and diffusion of red tides in Qinhuangdao coastal water based on FBM method
KUANG Cui-ping1, XIE Hua-lang1, SU Ping2, GU Jie3, MAO Xiao-dan1
1. College of Civil Engineering, Tongji University, Shanghai, 200092, China;
2. Guangxi Communications Planning Surveying and Designing Institute, Nanning, 530029, China;
3. College of Marine Sciences, Shanghai Ocean University, Shanghai 201306, China
Based on the hydrodynamic simulation by Delft3D-FLOW, the model of migration and diffusion of red tides, based on the FBM (Fractional Brownian Motion) particle tracking method, was established and validated. The flow and wind-driven current in Qinhuangdao coastal water were simulated, and the effects of wind-driven current in migration and diffusion of red tides were presented. The characteristics of the FBM method, Lagrange method and the conventional Brown method in simulating migration and diffusion of red tides were compared. The sensitivity of Hurst index in the model was analysed, and its reasonable range in simulation of migration and diffusion of red tides was obtained in Qinhuangdao coastal water. Main conclusions were:1) red tides migrated in Qinhuangdao coastal water with reciprocating tidal currents, resulting in a small net migration distance of red tides during an entire flood and ebb period; 2) the tidal current in Qinhuangdao coastal water was weak in the summer, but the wind-driven current in the northeast direction resulted in the red tide being transported northeastwardly; 3) Hurst index could significantly affect the diffusion range of particle cloud, Hurst index in the range of 0.80±0.03could more accurately simulate migration and diffusion of red tides in Qinhuangdao coastal water; 4) FBM method could simulate the non-Fickian diffusion phenomenon of red tides, which made the diffusion range and shape of the particle clouds closer to the actual situation than those using the Lagrange method and the conventional Brown method.
匡翠萍, 谢华浪, 苏平, 顾杰, 冒小丹. 基于FBM法追踪秦皇岛海域赤潮迁移扩散[J]. 中国环境科学, 2016, 36(8): 2505-2515.
KUANG Cui-ping, XIE Hua-lang, SU Ping, GU Jie, MAO Xiao-dan. Tracking migration and diffusion of red tides in Qinhuangdao coastal water based on FBM method. CHINA ENVIRONMENTAL SCIENCECE, 2016, 36(8): 2505-2515.
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