학술논문

A PROPOSED METHOD OF MONITORING FLOW FIELD AND MASS BUDGET IN ESTUARY / 河川感潮域における流量及び物質収支モニタリング手法の提案
Document Type
Journal Article
Source
土木学会論文集B2(海岸工学) / Journal of Japan Society of Civil Engineers, Ser. B2 (Coastal Engineering). 2016, 72(2)1225
Subject
ADCP
H-ADCP
estuary
monitoring
river discharge
upper layer thickness
Language
Japanese
ISSN
1883-8944
1884-2399
Abstract
While recreational waterfront in urban area has been developed, chronical water quality degradation such as red tide and sewage water inflow has been occurred. Monitoring flow field around estuaries is required for appropriate water management. However, it is technically challenging to measure or calculate river discharge in estuaries due to complexity of its flow structure. This study discusses a method of measuring discharge of two-layered flow field by a stationary H-ADCP at Odaibakaihin park. Firstly, in a preliminary survey by an ADCP, a phase shift was observed in tidal velocity components of upper layer and lower layer in the vertical direction, which can be utilized to detect boundary of two layers and to determine thickness of the upper layer. The H-ADCP was settled upward in an angle of 1.5 degrees. Current profiles across the boundary were monitored, and river discharge of two-layered flow field was simultaneously calculated. In addition, a water quality meter combined with two pumping devices was vertically arrayed to observe water properties of multiple layers. Freshwater discharge could be quantified by relating flow rate and salinity of upper layer. This proposed monitoring method enables to monitor discharge of respective water layers and will expand more observatories effectively along analogous estuaries.

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