Simulation of tidal river dynamics

Since 1932, Limboto Lake has been experiencing siltation, in 2006 it was measured that about 4.000 hectare of lake was covered. It was predicted by many that in 2031 Lake Limboto would disappear. The ‘Lake Limboto Revitalization’ has been conducted since 2017 by conducting many activities, including sabo plan implementation (also known as sabo technology). This study was originally conducted to review sabo plan in Limboto Lake, however this particular report was conducted to measure potential of erosion and sedimentation using WaTEM/SEDEM Model. Among 12 upstream rivers/Sub-DAS flowing into Limboto Lake, here were rivers with most potential to bring erosion and sedimentation into the lake to the least: Batulayar 193.662 m3, Biyonga Boluta 123.095 m3, Alo1 120.273m3, Alo 115.204 m3, Molamahu 73.058 m3, Marisa 57.075 m3, Pulubala 53.445 m3, Pone 40.254 m3, Molamahu1 39.585 m3, Pilolalenga 32.306 m3, Talumelito 32.247 m3, Pulubala2 31.267 m3, Tuladengi 28.908 m3, Pone1 27.306 m3, Payunga 26.746 m3, Biyonga Boluta1 25.895 m3, Pilolalenga1 21.841 m3, Tabongo 20.151 m3, Pulubala1 17.741 m3, and Tabongo1 11.031 m3. Considering the river dynamics as well as absence of secondary data about rivers, it was crucial to review sabo plan and to measure sedimentation potential per year.

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Effect of Salinity on Reaeration Coefficient of Receiving Waters

Water Science & Technology ◽

10.2166/wst.1984.0127 ◽

1984 ◽

Vol 16 (5-7) ◽

pp. 139-154 ◽

Cited By ~ 1

Author(s):

Ching-Gung Wen ◽

Jao-Fuan Kao ◽

Lawrence K Wang ◽

Chii Cherng Liaw

Keyword(s):

Saline Water ◽

Chloride Concentration ◽

Practical Method ◽

Tidal River ◽

Quality Analysis ◽

Flow Conditions ◽

Water Quality Analysis ◽

Design Engineers ◽

Reaeration Coefficient ◽

Receiving Waters

A practical method of determining reaeration coefficients would greatly aid design engineers in determining the degree of wastewater treatment required for a proposed effluent discharge. Many previous tidal river and estuary studies emphasized mainly the effects of flow conditions (such as velocity, water depth, turbulent intensity, hydraulic gradient, etc.) and temperature on stream aeration, and the effect of salts was not seriously considered. In this research a new mathematical model of reaeration coefficient considering the effect of salts has been developed for water quality analysis in tidal rivers and estuaries. The reaeration coefficient in saline water, k2s(day−1, base e) at any chloride concentration C(g/l) and at 20°C, can be expressed byin which k2f is the reaeration coefficient in fresh water at 20°C. The correlation coefficient of k2s/k2f and C is 0.88.

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Comparison of Cell Culture and a Poliovirus Gene Probe Assay for the Detection of Enteroviruses in Environmental Water Samples

Water Science & Technology ◽

10.2166/wst.1993.0366 ◽

1993 ◽

Vol 27 (3-4) ◽

pp. 311-314 ◽

Cited By ~ 7

Author(s):

Aaron B. Margolin ◽

Charles P. Gerba ◽

Kenneth J. Richardson ◽

Jaime E. Naranjo

Keyword(s):

Cell Culture ◽

Activated Sludge ◽

Water Samples ◽

Cdna Probe ◽

Culture Method ◽

Tidal River ◽

Nucleic Acid Hybridization ◽

Treated Wastewater ◽

Gene Probe ◽

Naturally Occurring

Nucleic acid hybridization provides a rapid non-cell culture method for the detection of enteric viruses in water. The purpose of this work was to compare the detection of naturally occurring enteroviruses by cell culture with their detection by a poliovirus gene probe in various types of water samples. Samples of activated sludge effluent, tertiary treated wastewater (activated sludge, filtration and passage through reverse osmosis), ground water, surface water and tidal river water were processed through 1 MDS Virozorb filters to concentrate any naturally occurring virus. Viruses were eluted from the filters with pH 9.5 beef extract and reduced in volume by flocculation to 20-30 ml. These concentrates were then assayed in the BGM cell line by the cytopathogenic effects (CPE) method and by a poliovirus cDNA probe (base pairs 115-7440) labeled with 32P. A total of 233 samples were assayed in this manner. In slightly more than 93% of the samples gene probe and cell culture yielded the same results. Of these samples 36 were positive by gene probe and 28 by cell culture assay. Positive samples for gene probe were confirmed by treatment with NaOH or RNAse and then reprobed. Samples demonstrating CPE upon primary passage were confirmed positive by subsequent passage of cell lysate on a new monolayer of BGM cells. Ten samples were positive by gene probe and negative by cell culture, and 4 samples were negative by gene probe and positive by cell culture.

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Physical and bacterial processes affecting suspended particulate matter in a tidal river

Water Science & Technology ◽

10.2166/wst.1998.0268 ◽

1998 ◽

Vol 38 (6) ◽

pp. 327-335

Author(s):

Yasunori Kozuki ◽

Yoshihiko Hosoi ◽

Hitoshi Murakami ◽

Katuhiro Kawamoto

Keyword(s):

Particle Size ◽

Particulate Matter ◽

Suspended Particulate Matter ◽

River Mouth ◽

Tidal River ◽

Natural Soil ◽

Size Change ◽

Run Off ◽

Suspended Particulate ◽

And Behavior

In order to clarify the origin and behavior of suspended particulate matter (SPM) in a tidal river, variation of SPM in a tidal river was investigated with regard to its size and constituents. SPM was separated into three groups according to size. Change of contents of titanium and organic substances of each group of SPM was examined. SPM which was discharged by run-off was transported with decomposition and sedimentation in a tidal river. Concentration of SPM with a particle size greater than 0.45 μm increased due to resuspension in a tidal river. Origin of SPM with a size of less than 0.45 μm at upstream areas was from natural soil and most of such SPM which had been transported settled near a river mouth. It was determined from examination of the CN ratio and the ratio of the number of attached bacteria to free bacteria that SPM with a size greater than 1.0 μm at upstream areas was decomposing intensively. At the downstream areas, SPM with a size of less than 0.45 μm came from the sea. SPM with particle size greater than 1.0 μm consisted of plankton and substances which were decomposed sufficiently while flowing.

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Crocodylus johnstoni and C. porosus Coexisting in a Tidal River

Wildlife Research ◽

10.1071/wr9830639 ◽

1983 ◽

Vol 10 (3) ◽

pp. 639 ◽

Cited By ~ 27

Author(s):

GJW Webb ◽

SC Manolis ◽

GC .Sack

Keyword(s):

Competitive Exclusion ◽

Dry Season ◽

Tidal River ◽

Main Stream ◽

Wet Season ◽

Seasonal Movements ◽

Crocodylus Johnstoni ◽

Seasonal Factors

A 52.5-km section of the Adelaide River, N.T. (12�13'S., 131�13'E.). was spotlight-surveyed 20 times between June 1979 and September 1981. C, johnstoni (15.3 � 9.2 sighted per survey) were less abundant than C. porosus (137.6 � 36.5 sighted per survey), and were mainly in the upstream 20 km of the survey route (96% of C. johnstoni sightings); here considered a zone of syntopy within the survey route. C. johnstoni congregate in the main stream during the dry season and disperse from it during the wet season, which parallels similar seasonal movements to and from dry-season refuges in non-tidal areas lacking C. porosus. As the dry season progresses, C. johnstoni are located further and further upstream, and this movement (or loss ofanimals) appears unrelated to changes in salinity. Numbers of C.johnstoni within the zone of syntopy are negatively correlated with numbers of C. porosus (r*2 = 0.50, P=0.005). and competitive exclusion may be occurring. Independent of seasonal factors, numbers of C. johnstoni within the zone of syntopy declined with consecutive month (1979-81: r*2=0.47, P= O.004), whereas numbers ofthe more recently protected C, porosus increased (r2 = 0.48, P= 0,006). The location of the syntopic zone was unchanged.

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