tailieunhanh - Hydrodynamics Natural Water Bodies Part 7

Tham khảo tài liệu 'hydrodynamics natural water bodies part 7', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Freshwater Dispersion Plume in the Sea Dynamic Description and Case Study 137 A typical summer condition is shown in Fig. 4 the hydrodynamic and dispersion is forced by the freshwater outflow and by the tidal excursion at the offshore boundary. Unfortunately field data are not available for this condition but only for different scenarios commented in the later sections. Fig. 4A presents the results of a simulation carried out in the absence of coastal surface current and wind velocity lower than 1 knot. Simulation conditions are representative of the cycle of freshwater outfall in which tide according with internal basin storage volumes provides outgoing velocity from the channel mouth starting from . and ending 18 hours later at . The physical feature of the presented simulation is characterized by a first low decreasing tidal phase and low outgoing velocity typical of the last summer periods. The tidal excursion at several tidal phases is shown in Fig. 4B. Fig. 4B. Sea water level at the offshore boundary during simulation with results in Fig. 3. Here in the early afternoon variations in salinity and phytoplankton biomass are limited and restricted to the near mouth area and the surface thermoaline profile could be conditioned by wind coastal waves. Evening and nightly scenarios show static conditions for coastal sea with very low current and undefined direction while the most part of freshwater accumulated in the internal basin is outfalled from the mouth according to the maximum tidal decreasing phase. Thermoaline stratification is guaranteed such as in internal harbour section as in the receiver coastal sea. The simulation period shown in Fig. 4 12h-15h-18h covers the main decreasing tidal phase when most freshwater coming from WWTP and confined into the internal channel according with tidal phase is completely discharged through the harbour canal. Evident stratification conditions are represented in coastal sea away from the breakwaters such