scholarly journals DISTRIBUTION CHARACTERISTICS OF SUSPENDED SOLID IN SALT WATER MIXING LAYER OF RIVER MOUTH

2005 ◽  
Vol 49 ◽  
pp. 1423-1428
Author(s):  
Shingo SAKAI ◽  
Akira MANO
Keyword(s):  
Salt Water ◽  
Mixing Layer ◽  
River Mouth ◽  
Suspended Solid ◽  
Distribution Characteristics ◽  
Water Mixing

scholarly journals WATER EXCHANGE IN THE ESTUARY OF THE RAZDOLNAYA RIVER (AMUR BAY, JAPAN SEA) IN THE ICE COVERED PERIOD

2019 ◽  
Vol 196 ◽  
pp. 123-137 ◽  
Author(s):  
P. Yu. Semkin ◽  
P. Ya. Tishchenko ◽  
V. B. Lobanov ◽  
Yu. A. Barabanshchikov ◽  
T. A. Mikhailik ◽  
...  
Keyword(s):  
Water Exchange ◽  
Salt Water ◽  
Groundwater Discharge ◽  
River Mouth ◽  
Japan Sea ◽  
Bottom Layer ◽  
Additional Source ◽  
Flow Through ◽  
Limited Water Exchange ◽  
Annual Discharge

Environmental conditions in the Razdolnaya/Suifen Estuary and adjacent marine area were monitored from 2008 to 2018, by seasons, including winter observations in January 2014 and January 2018. The river discharge in winter was low: 6 m3 /s (mean annual discharge is 73 m3 /s). The estuary was covered by ice. The cline of salt water at the bottom was traced upstream up to 28 km from the river mouth. The currents in the estuary changed in tidal cycle. Increasing of salinity and temperature (> 2о ) at the bottom was observed in the distance 20–24 km from the river bar (this area was distinguished by relatively thin ice, 20 cm, against 40–70 cm in the rest of estuary). Modeling of the water balance in the estuary showed an additional source of salt water in the internal estuary, beyond the direct exchange with the sea over the river bar, that was presumably the water flow through the aquifer. This groundwater discharge was responsible for supporting of the salted bottom layer and for temperature and salinity increasing in the internal estuary during the ebb phase in conditions of limited water exchange by two-layered estuarine circulation because of ice cover at the river mouth.

Movements of Sockeye Salmon (Oncorhynchus nerka) in the Skeena River Estuary as Revealed by Ultrasonic Tracking

1975 ◽  
Vol 32 (2) ◽  
pp. 233-242 ◽  
Author(s):  
C. Groot ◽  
K. Simpson ◽  
I. Todd ◽  
P. D. Murray ◽  
G. A. Buxton
Keyword(s):  
Tidal Cycle ◽  
Sockeye Salmon ◽  
Salt Water ◽  
Oncorhynchus Nerka ◽  
River Estuary ◽  
River Mouth ◽  
Tidal Flows ◽  
Skeena River ◽  
Ultrasonic Tracking ◽  
Passive Movements

Movements of adult sockeye salmon (Oncorhynchus nerka) entering the Skeena River were examined in 1969 and 1970 by ultrasonic tracking methods. Fifteen of 18 sockeye released in the lower river seemed to move passively in and out with flood and ebb streams. Two fish moved upstream independent of tides and one salmon swam against ebb and flood currents. Ground speeds in both years of operation were 1.6 km/h during rising and 2.1 km/h during falling tides, causing the fish to be transported downstream by about 3 km per tidal cycle. Three salmon released outside the river mouth in salt water also seemed to ride the tidal flows passively. Ground speeds during ebb (3.6 km/h) were again greater than during flood (2.0 km/h), indicating a net offshore movement. We conclude that these passive movements are not an artifact but that sockeye salmon normally slow down or pause upon reaching the "home river" and drift for a period in tidal currents in the estuary and river mouth before migrating upstream.

On harbour siltation in the fresh-salt water mixing region

2009 ◽  
Vol 29 (1) ◽  
pp. 175-193 ◽  
Author(s):  
Michel A.J. de Nijs ◽  
Johan C. Winterwerp ◽  
Julie D. Pietrzak
Keyword(s):  
Salt Water ◽  
Water Mixing

scholarly journals The characteristics of the Waiwhetu artesian aquifer beneath Wellington Harbour including the spatial distribution and causes of submarine spring discharge

2021 ◽  
Author(s):  
◽  
Steven James Harding
Keyword(s):  
Salt Water ◽  
River Mouth ◽  
Salt Water Intrusion ◽  
Spring Discharge ◽  
Water Intrusion ◽  
Submarine Springs ◽  
Municipal Water ◽  
Submarine Spring ◽  
Artesian Aquifer ◽  
Artesian Water

<p>This thesis is a study of the sub-harbour Waiwhetu Artesian Aquifer, and in particular the nature and characteristics of artesian leakage from submarine springs. This aquifer is a sheet of gravel and other coarse sediments which continues from the Lower Hutt Valley and extends beneath Wellington Harbour where it varies in thickness from approximately 70m against the Wellington Fault scarp to just over 20m thick against the eastern harbour margin. The water it contains is a valuable resource supplying approximately one third of Wellington's municipal water consumption.  At present, there are plans to utilise this artesian water source to a greater extent in the future, to support a greater burden of the region's water requirements. However concerns over possible salt-water intrusion and contamination of the aquifer led to an interest in developing a better understanding of the characteristics of this artesian system, particularly beneath the harbour floor.  Harbour floor depressions were selected as likely sources of artesian water leakage based on the presumption that they had been formed by the action of leaking artesian water from beneath. Eleven depression 'zones' were investigated by recording the salinity of the water within the depressions using a portable conductivity/temperature meter. SCUBA diver's observations and bathymetric mapping revealed that depressions ranged in width from 53m to 369m (at the harbour floor) and 12m to 69m (at the depression base), with depths ranging from 13.3m to 31.3m below sea level.  Only a few depressions were found to be actively discharging significant amounts of artesian water. SCUBA diver investigations found this leakage to be typically concentrated at a number of small and discrete spring 'vents' located on the base of the active depression. Typical salinities recorded ranged from 28 - 33 ppt within a few centimetres of the discharge vents. Deployment of an S4 current meter in two depressions showed that spring vent discharges vary with the pattern of abstraction from the pumping stations in the Lower Hutt Valley and as a consequence of the tidal cycle. High tides generate a greater load on the underlying aquifer, which in turn compresses the aquifer structure to a greater extent than at low tides, thus 'squeezing' out more water.  Almost all of the recorded leakage was found to occur from a cluster of submarine springs within one of the depression zones, roughly 1100 metres from the Hutt River mouth. One other notable area of leakage was found close to Seaview Wharf. No significant leakage was observed or recorded from the two deep depressions south of Somes Island, which had previously been considered to be the major outlet of artesian leakage in the harbour.  Lower than normal salinity values were also recorded in the harbour entrance. In this region the aquiclude is hypothesised to peter out, allowing artesian water to escape from the aquifer through a large area of the seabed in the form of widespread leakage as opposed to the concentrated, or discrete, form associated with spring vent discharge.  Seismic profiles were used to map the extent of the sub-harbour Waiwhetu Artesian Aquifer and its upper confining aquiclude, the Petone Marine Beds. This work showed that the aquifer gravels extend across the entire harbour area. However, the water-bearing capacity of these deposits was found to be inconsistent. Preferential pathways, present as paleochannels (relic river channels), can be mapped within the aquifer. They concentrate the flow of groundwater through the aquifer and as such supply the submarine spring regions with much higher rates of water flow than the inter-paleochannel areas.  The harbour floor depressions are thought to have formed as a consequence of the deformation of aquifer and aquiclude deposits during intense shaking associated with earthquakes leading to the removal of portions of the confining aquiclude. This typically occurs from a combination of raised piezometric pressures as a result of consolidation of the aquifer material during shaking, and from failure of the aquiclude by liquefaction. This rupture of the aquiclude results in the release of large volumes of artesian water through the aquiclude and to the sea. As this flow of water moves upward through the aquiclude, it erodes and transports away the fine sediment that forms this member. The features left behind are the characteristic harbour floor depressions we associate with submarine spring discharge.  The abstraction of water from the Waiwhetu Artesian Aquifer (for the Wellington municipal water supply) lowers the piezometric pressure within the aquifer close to the abstraction zone. As such, the relocation of the abstraction focus (during 1980) to three kilometres inland from Petone Foreshore has greatly improved the 'health' of the subharbour aquifer and has similarly reduced the threat of salt-water intrusion.  Data gathered during this study implies that while the two deep depressions south of Somes Island are unlikely to be a threat with regard to salt-water intrusion, the cluster of depressions off the Hutt River mouth could be a site of salt-water entry if piezometric pressures in the aquifer beneath them dropped low enough. Spring discharge velocities collected over one spring vent indicate that the presently set minimum piezometric Petone Foreshore level (below which abstraction must cease) needs to be revised.</p>

Biased Monitoring of Fresh Water-Salt Water Mixing Zone in Coastal Aquifers

Ground Water ◽  
2009 ◽  
Vol 47 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Eyal Shalev ◽  
Ariel Lazar ◽  
Stuart Wollman ◽  
Shushanna Kington ◽  
Yoseph Yechieli ◽  
...  
Keyword(s):  
Fresh Water ◽  
Coastal Aquifers ◽  
Salt Water ◽  
Mixing Zone ◽  
Water Mixing ◽  
Water Salt

Seasonal movement and size distribution of three commercially important Australian prawn species (Crustacea : Penaeidae) within an estuarine system

1983 ◽  
Vol 34 (5) ◽  
pp. 727 ◽  
Author(s):  
RG Coles ◽  
JG Greenwood
Keyword(s):  
Life Histories ◽  
Salt Water ◽  
River Mouth ◽  
Distribution Patterns ◽  
Estuarine System ◽  
Rainfall Runoff ◽  
Seasonal Movement ◽  
Southern Half ◽  
Commercially Important ◽  
Abiotic Stimuli

Three penaeid prawn species, Penaeus plebejus Hesse, Metapenaeus bennettae Racek & Dall, and M. macleayi (Haswell), were sampled using a beam trawl, at four sites for 16 months in the Noosa River, Queensland, and data collected are used to provide generalized life histories for the three species and to discuss the composition and timing of the commercial bait prawn fishery. P. plebejus individuals were recruited to the river throughout the year, M. bennettae between March and June, and M. macleayi between April and July. P. plebejus juveniles remained only briefly in the river and were most numerous at sites near the river mouth. There was no distinct period of migration of this species from the river. M. bennettae and M. macleayi individuals remained in the river until December and March, respectively, when, in the absence of obvious abiotic stimuli such as rainfall runoff and reduced salinities, there was a marked egress from the river. While in the river, both of these species could be caught through the zone of salt-water penetration up to 35 km from the sea, and both were most numerous in the southern half of Lake Cootharaba in a zone of approximately 19 × 10-3 mean salinity. Similarity between these and other distribution patterns recorded in topographically different rivers suggests salinity is an important determining factor in the distribution of these prawns.

scholarly journals Response of salinity intrusion to the hydrodynamic conditions and river mouth morphological changes induced by the 2011 tsunami

2020 ◽  
Vol 14 (2) ◽  
pp. 1-16
Author(s):  
Nguyen Xuan Tinh ◽  
Jin Wang ◽  
Hitoshi Tanaka ◽  
Kinuko Ito
Keyword(s):  
Morphological Changes ◽  
Salt Water ◽  
Water Discharge ◽  
River Mouth ◽  
River Channel ◽  
Salt Transport ◽  
Ground Subsidence ◽  
Fishing Ground ◽  
Estuarine System ◽  
Salinity Intrusion

The 2011 Tohoku Earthquake and tsunami were one of the most devastating natural disasters in history. It caused significant ground subsidence and erosion along the Japan coastline. The Natori river mouth which is a habitat for both fishes and bivalves, as an important fishing ground, has been damaged by the tsunami because of the change of the process of salt transport in an estuarine system. In general, salinity intrusion into the river mouth can be affected by many factors such as river water discharge and tidal level, as well as estuarine morphology. In this study, the response of salinity intrusion to the river mouth morphological changes induced by the 2011 Tsunami is investigated. The topographical changes caused by the tsunami are mainly divided into two stages. The first is the direct action of the tsunami, which caused the severe scouring of the coast and the widening of the river. The results have clearly indicated that after tsunami the salt water can intrude much further upstream compare to the condition before the tsunami event. Another changes occurred during the restoration process after the tsunami. The sediment accumulation in the river channel prevented the salt water from entering the river channel, which reduced the salt intrusion degree. However, the effect of the morphology change caused directly by the tsunami is far greater than the sedimentation of the river. Keywords: salinity intrusion; river morphology; tsunami impact; numerical simulation; EFDC model.

scholarly journals HYDROCHEMICAL STUDIES OF THE PARTIZANSKAYA RIVER ESTUARY (NAKHODKA BAY, JAPAN SEA) IN SUMMER SEASON OF LOW WATER DISCHARGE

2018 ◽  
Vol 193 ◽  
pp. 143-152 ◽  
Author(s):  
P. Yu. Semkin ◽  
P. A. Tishchenko ◽  
T. A. Mikhailik ◽  
Yu. A. Barabanshchikov ◽  
G. Yu. Pavlova ◽  
...  
Keyword(s):  
River Water ◽  
Salt Water ◽  
Water Discharge ◽  
Chlorophyll Concentration ◽  
River Estuary ◽  
River Mouth ◽  
Japan Sea ◽  
Bottom Layer ◽  
Autochthonous Organic Matter ◽  
Limited Water Exchange

Chemical water parameters in the Partizanskaya River estuary were measured on July 18–19, 2012 in conditions of low water discharge (20.1 m3 /s). In these conditions, the cline of salt water at the bottom penetrated up to 11 km upstream from the river mouth and the fresh river water passed the estuarine zone of mixing in approximately 2 days. Salt composition of the mixed water in the estuary had conservative dependence on salinity. By dynamical signs, the estuary could be divided into two zones: i) zone of active exchange between the surface freshwater layer and the bottom salted layer on the distance 5.5 km from the river mouth to the first sandy riverbank that the fresh river water passed in 12 hours, and ii) the upper part of the estuary with limited water exchange. The complex of water environments in the estuary, as good water transparency, strong stratification, and high concentrations of terrestrial nutrients, was favorable for phytoplankton blooming, so the chlorophyll concentration in the estuarine waters exceeded 40 μg/L. Destruction of autochthonous organic matter caused anomalies in distribution of carbonate and nutrient parameters and was accompanied by hypoxia in the bottom layer with the dissolved oxygen content lowering to 61 μM/kg.

scholarly journals Experimental and Numerical Study on Dispersion Properties of Salt Water Mixing Zone in a Confined Aquifer

1989 ◽  
Vol 33 ◽  
pp. 193-198
Author(s):  
Tosao HOSOKAWA ◽  
Kazuro MOMII ◽  
Kenji JINNO ◽  
Toshihiko UEDA ◽  
Toshiaki ITOH
Keyword(s):  
Numerical Study ◽  
Salt Water ◽  
Confined Aquifer ◽  
Mixing Zone ◽  
Water Mixing ◽  
Dispersion Properties
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