scholarly journals Hydro-Sedimentary Study of a Tidal River: Case Study of the Arvand River in Iran

2021 ◽  
Vol 11 (1) ◽  
pp. 9-16
Author(s):  
M. Bakhtiari ◽  
A. Ashtari Larki ◽  
A. Samer
Keyword(s):  
Electrical Conductivity ◽  
Field Study ◽  
Water Level ◽  
Neap Tide ◽  
Spring Tide ◽  
Suspended Sediments ◽  
Tidal River ◽  
Deep Distribution ◽  
Suspended Sediments Concentration

Abstract The present field study investigated hydraulic and sediment in tidal conditions. Measurements were made for two stations at neap tide and spring tide for 13-hour periods at no-dimensional depths of 0.2, 0.6 and 0.8 of the water level each time. In these measurements, the parameters of velocity, direction of flow, electrical conductivity, temperature and depth were measured directly, and to determine the amount of suspended sediments per hour, 3 samples of one litre from the mentioned depths were measured by the instantaneous vertical sampler and taken to a laboratory. An examination of the depth charts of the suspended sediments concentration for all stations, and in both the neap tide and the spring tide, showed that, in general the suspended sediments concentration increased with increasing depth. Moreover, the deep distribution of sediments concentration showed that the values obtained in the laboratory corresponded well with the values calculated from the Rouse equation, and as the depth increases, the sediments concentration usually increases.

scholarly journals Modelling Study of Transport Time Scales for a Hyper-Tidal Estuary

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2434
Author(s):  
Guanghai Gao ◽  
Junqiang Xia ◽  
Roger A. Falconer ◽  
Yingying Wang
Keyword(s):  
Numerical Model ◽  
Water Level ◽  
Residence Time ◽  
Exposure Time ◽  
Neap Tide ◽  
Spring Tide ◽  
High Water ◽  
Residence Times ◽  
Severn Estuary ◽  
Release Times

This paper presents a study of two transport timescales (TTS), i.e., the residence time and exposure time, of a hyper-tidal estuary using a widely used numerical model. The numerical model was calibrated against field measured data for various tidal conditions. The model simulated current speeds and directions generally agreed well with the field data. The model was then further developed and applied to study the two transport timescales, namely the exposure time and residence time for the hyper-tidal Severn Estuary. The numerical model predictions showed that the inflow from the River Severn under high flow conditions reduced the residence and exposure times by 1.5 to 3.5% for different tidal ranges and tracer release times. For spring tide conditions, releasing a tracer at high water reduced the residence time and exposure time by 49.0% and 11.9%, respectively, compared to releasing the tracer at low water. For neap tide conditions, releasing at high water reduced the residence time and exposure time by 31.6% and 8.0%, respectively, compared to releasing the tracer at low water level. The return coefficient was found to be vary between 0.75 and 0.88 for the different tidal conditions, which indicates that the returning water effects for different tidal ranges and release times are all relatively high. For all flow and tide conditions, the exposure times were significantly greater than the residence times, which demonstrated that there was a high possibility for water and/or pollutants to re-enter the Severn Estuary after leaving it on an ebb tide. The fractions of water and/or pollutants re-entering the estuary for spring and neap tide conditions were found to be very high, giving 0.75–0.81 for neap tides, and 0.79–0.88 for spring tides. For both the spring and neap tides, the residence and exposure times were lower for high water level release. Spring tide conditions gave significantly lower residence and exposure times. The spatial distribution of exposure and residence times showed that the flow from the River Severn only had a local effect on the upstream part of the estuary, for both the residence and exposure time.

scholarly journals PENDANGKALAN ALUR PELAYARAN DI PELABUHAN PULAU BAAI BENGKULU

2016 ◽  
Vol 1 (3) ◽  
Author(s):  
Lukman Arifin ◽  
Juniar P. Hutagaol ◽  
Mustafa Hanafi
Keyword(s):  
Water Level ◽  
Current Velocity ◽  
Sea Water ◽  
Neap Tide ◽  
Spring Tide ◽  
Current Measurement ◽  
Geophysical Survey ◽  
Measurement Result ◽  
Level Difference ◽  
Sea Current

Alur pelayaran di Pelabuhan Pulau Baai Bengkulu selalu mengalami pendangkalan. Untuk mengetahui penyebab pendangkalan tersebut maka akan diberikan beberapa informasi hasil kajian geofisika kelautan dari beberapa metoda. Metoda tersebut terdiri dari pengukuran kedalaman laut, pengukuran arus dan pasang surut. Hasil pengukuran kedalaman laut memperlihatkan bahwa kedalaman yang paling dalam di bagian kolam pelabuhan adalah sekitar 12 meter dan yang terdalam di daerah alur juga 12 meter. Pengukuran arus laut memperlihatkan bahwa kecepatan arus pada saat pasang tertinggi lebih tinggi daripada kecepatan arus pada saat surut terendah. Pengendapan lebih besar terjadi pada saat air pasang, apalagi ditambah dengan adanya arus sepanjang pantai yang membawa sedimen ke arah alur. Tipe pasang surut laut di pelabuhan ini adalah tipe campuran ganda, artinya pasang dan surut akan terjadi sekali atau dua kali dalam sehari. Adapun perbedaan tinggi muka air pada saat air pasang dan saat air surut adalah 1,53 meter. Shoaling always occurs in the sailing channel of Pulau Baai Bengkulu Harbour. To know the reason of the shoaling, some information based on the result, of the analysis of several methods of marine geophysical survey are therefore presented. The methods are echo-sounding, sea current and tide measurement. Result of sounding shows that the deepest depth in the lagoon area is around 12 metres and the depth in the channel area is also 12 metres. Result of sea current measurement shows that current velocity during the spring tide is higher than the velocity during the neap tide. Sedimentation is higher in the spring tide, moreover it is increased by the existence of long shore current which transport the sediments into the channel. The type of the sea tide in the harbour is a mixed semi diurnal type which means that the spring and the neap will occur once or twice a day. The height of sea water level difference between spring tide and neap tide season is 1.53 metres.

scholarly journals ESTIMATION OF TIDAL EXCURSION LENGTH ALONG THE SHATT AL-ARAB ESTUARY, SOUTHERN IRAQ

2021 ◽  
Vol 59 (1) ◽  
pp. 79
Author(s):  
Ali Lafta
Keyword(s):  
Water Level ◽  
Neap Tide ◽  
Spring Tide ◽  
Field Measurements ◽  
Site Specific ◽  
Estuary Mouth ◽  
Tidal Excursion ◽  
Mathematical Relation ◽  
Southern Iraq

The tidal excursion length along the Shatt Al-Arab estuary was estimated based on the mathematical relation proposed by Parsa and Shahidi (2010). The field measurements of water level, bathymetry, and discharges were conducted to fulfill the objective of the study. The results revealed that the tidal excursion length is site-specific and depends on the characteristics of location which include tidal phases, bathymetry, and geometry. However, the results indicated that there are pronounced differences in tidal excursions lengths between the spring and neap tide phases in all studies stations. The spring tide coincided with the maximum tidal excursion lengths in Shatt Al-Arab estuary with 16.537, 16.187, 11.122, and 9.139 km in the estuary mouth, Faw, Siba, and Abo Flous stations respectively. While the neap tidal excursion lengths were 12.298, 9.254, and 7.269 km in Faw, Siba, and Abo Flous stations respectively.

scholarly journals PERUBAHAN TERJADINYA PUNCAK PASANG SURUT SUNGAI BARITO AKIBAT PEMANASAN GLOBAL

INFO-TEKNIK ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 71
Author(s):  
Holdani Kurdi ◽  
Ulfa Fitriati ◽  
M. Ainun Najib ◽  
Aulia Isramaulana
Keyword(s):  
Global Warming ◽  
Water Level ◽  
Neap Tide ◽  
Spring Tide ◽  
Extreme Conditions ◽  
The Sun ◽  
The Moon ◽  
Gravitational Forces ◽  
The Earth ◽  
The Dead

Regional development engineering in coastal areas, tidal land reclamation, delta area reclamation and port planning, tidal knowledge is very important. Tides mainly occur due to the gravitational forces of the moon, sun, and other planets. The influence of different gravitational forces can be predicted precisely because the rotation and revolutionary movements of the earth, moon, sun, and other planets take place with very high order. The tidal period every day is mainly determined by the rotation of the earth with a 24-hour period. Influence of the sun even though its attraction is only half that of the lunar pull, its influence should not be ignored As understood months around the earth with a period of about 29.5 days. When the position of the moon-earth-sun is in line, the tidal forces of the sun and moon strengthen each other. At that time spring tide occurred. Whereas if the sun-earth forms an angle of 90 degrees, then the minimum tides occur (neap tide). The two conditions are about 7 days old, according to the moon's revolution. Because of the influence of the inertia of the mass of water, the spring and neap tide occur between one and three days after these extreme conditions occur. In short-term studies often researchers take extreme conditions, namely during the tidal peak and peak tide (spring tide), because it does not require a long time compared to researching during a longer tide period. The research approach that will be carried out is whether the tide and peak peaks still occur 1-3 days after the full moon and the dead moon, whether there is a change in the height of the tide and ebb during a certain period due to global warming. As a result of global warming, it is also an effect on the water level of the Barito River. There was a decrease in the maximum water level which previously was around 3 m, now only around 2 m, the minimum water level previously around 2 m was now below 1 m. This will affect the hydrotopographic conditions of tidal swamp land, land that was previously type A can change to type B and so on. The highest tides on the Barito River often occur in the dead months, namely the 1st and 29th of the Hijri.

scholarly journals Small Scales Dynamics Inferred from Tidal Measurements to Mitigate Daily Floodings in the City of Douala: A Case Study of the Besseke's Flood Drain

2020 ◽  
pp. 45-62
Author(s):  
Besack Felix ◽  
Onguene Raphael ◽  
Ebonji Seth Rodrigue ◽  
Oben Mbeng Lawrence ◽  
Kouandji Bekoumb Joseph Betsaleel ◽  
...  
Keyword(s):  
Brackish Water ◽  
Neap Tide ◽  
Spring Tide ◽  
Field Measurements ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Tidal Prism ◽  
Cross Sectional ◽  
Small Scales

The recently constructed Besseke’s flood drain is always filled with water due to individual or combined effect of the tide, urbanization drainage, underground plumes and precipitations runoffs. This study focused on the analysis of small scales dynamics inferred from short term tidal measurements to mitigate the daily flooding in the Besseke’s flood drain. The methodology used is based on field measurements observation. The sampling of water level was conducted during two (02) different tidal regimes in May 2019. The volume of brackish water moving in and out of the Besseke’s flood drain was calculated using the formula of O’Brien. The results showed that Spring conditions had greater amplitudes than Neap tide conditions. During Spring tides, the tidal prism that passed in the midsection of the Besseke’s flood drain (S4) was 3.5 × 101 m3. This means that only a negligible amount of the incoming brackish water reaches the Besseke’s flood drain, amplifies and causes the daily flooding. The unexpected stronger amplitudes and dynamics observed in S4 could be due to its sub estuary nature. Furthermore, the percentage composition of water in this section, showed that the fraction of brackish water changes from 85.7% during Spring tide to 77.8% in the Neap tide conditions. The overall spatial evolution revealed that, the trend in tidal prism (during Spring conditions) was (S0) > (S2) > (S1) > (S3) > (S4) with corresponding values of 2.1 × 104, 1.3 ×104, 1.0 × 104, 2.5 × 102 and 3.5 × 101 m3 respectively. Finally, Tidal prism and Cross-sectional area showed a perfect correlation (r2 = 0.96). The best fitted Cross-sectional area-Tidal prism relationship was obtained in S3 (Market) during Spring tide condition.

PERSIAN GARDENS IN COLD AND DRY CLIMATE: A CASE STUDY OF TABRIZ’S HISTORICAL GARDENS

2016 ◽  
Vol 10 (3) ◽  
pp. 193
Author(s):  
Ahad Nejad Ebrahimi ◽  
Farnaz Nazarzadeh ◽  
Elnaz Nazarzadeh
Keyword(s):  
Comparative Study ◽  
Water Supply ◽  
Field Study ◽  
Cold Climate ◽  
Natural Substrate ◽  
Garden Design ◽  
Climate Conditions ◽  
North West ◽  
Special Expertise

Throughout history, gardens and garden designing has been in the attention of Persian architects who had special expertise in the construction of gardens. The appearance of Islam and allegories of paradise taken from that in Koran and Saints’ sayings gave spirituality to garden construction. Climate conditions have also had an important role in this respect but little research has been done about it and most of the investigations have referred to spiritual aspects and forms of garden. The cold and dry climate that has enveloped parts of West and North West of Iran has many gardens with different forms and functions, which have not been paid much attention to by studies done so far. The aim of this paper is to identify the features and specifications of cold and dry climate gardens with an emphasis on Tabriz’s Gardens.  Due to its natural and strategic situation, Tabriz has always been in the attention of governments throughout history; travellers and tourists have mentioned Tabriz as a city that has beautiful gardens. But, the earthquakes and wars have left no remains of those beautiful gardens. This investigation, by a comparative study of the climates in Iran and the effect of those climates on the formation of gardens and garden design, tries to identify the features and characteristics of gardens in cold and dry climate. The method of study is interpretive-historical on the basis of written documents and historic features and field study of existing gardens in this climate. The results show that, with respect to natural substrate, vegetation, the form of water supply, and the general form of the garden; gardens in dry and cold climate are different from gardens in other climates.

scholarly journals Getting information on suspended sediments in a large river from acoustic backscatter

2018 ◽  
Vol 40 ◽  
pp. 04017
Author(s):  
Adrien Vergne ◽  
Céline Berni ◽  
Jérôme Le Coz
Keyword(s):  
Suspended Sediment Concentration ◽  
Spatial Information ◽  
Suspended Sediments ◽  
Sediment Concentration ◽  
Large River ◽  
Acoustic Backscatter ◽  
Qualitative Information ◽  
Sediment Size ◽  
The Common

There has been a growing interest in the last decade in extracting information on Suspended Sediment Concentration (SSC) from acoustic backscatter in rivers. Quantitative techniques are not yet effective, but acoustic backscatter already provides qualitative information on suspended sediments. In particular, in the common case of a bi-modal sediment size distribution, corrected acoustic backscatter can be used to look for sand particles in suspension and provide spatial information on their distribution throughout a river crosssection. This paper presents a case-study where these techniques have been applied.

scholarly journals Tidal variability of nutrients in a coastal coral reef system influenced by groundwater

2018 ◽  
Vol 15 (4) ◽  
pp. 997-1009 ◽  
Author(s):  
Guizhi Wang ◽  
Shuling Wang ◽  
Zhangyong Wang ◽  
Wenping Jing ◽  
Yi Xu ◽  
...  
Keyword(s):  
Coral Reef ◽  
Water Column ◽  
Water Depth ◽  
Neap Tide ◽  
Groundwater Discharge ◽  
Spring Tide ◽  
Biological Processes ◽  
Reef System ◽  
Nitrite Nitrate ◽  
Coral Reef System

Abstract. To investigate variation in nitrite, nitrate, phosphate, and silicate in a spring–neap tide in a coral reef system influenced by groundwater discharge, we carried out a time-series observation of these nutrients and 228Ra, a tracer of groundwater discharge, in the Luhuitou fringing reef at Sanya Bay in the South China Sea. The maximum 228Ra, 45.3 dpm 100 L−1, appeared at low tide and the minimum, 14.0 dpm 100 L−1, appeared during a flood tide in the spring tide. The activity of 228Ra was significantly correlated with water depth and salinity in the spring–neap tide, reflecting the tidal-pumping feature of groundwater discharge. Concentrations of all nutrients exhibited strong diurnal variation, with a maximum in the amplitude of the diel change for nitrite, nitrate, phosphate, and silicate in the spring tide of 0.46, 1.54, 0.12, and 2.68 µM, respectively. Nitrate and phosphate were negatively correlated with water depth during the spring tide but showed no correlation during the neap tide. Nitrite was positively correlated with water depth in the spring and neap tide due to mixing of nitrite-depleted groundwater and nitrite-rich offshore seawater. They were also significantly correlated with salinity (R2  ≥  0.9 and P < 0.05) at the ebb flow of the spring tide, negative for nitrate and phosphate and positive for nitrite, indicating the mixing of nitrite-depleted, nitrate- and phosphate-rich less saline groundwater and nitrite-rich, nitrate- and phosphate-depleted saline offshore seawater. We quantified variation in oxidized nitrogen (NOx) and phosphate contributed by biological processes based on deviations from mixing lines of these nutrients. During both the spring and neap tide biologically contributed NOx and phosphate were significantly correlated with regression slopes of 4.60 (R2  =  0.16) in the spring tide and 13.4 (R2  =  0.75) in the neap tide, similar to the composition of these nutrients in the water column, 5.43 (R2  =  0.27) and 14.2 (R2  =  0.76), respectively. This similarity indicates that the composition of nutrients in the water column of the reef system was closely related with biological processes during both tidal periods, but the biological influence appeared to be less dominant, as inferred from the less significant correlations (R2  =  0.16) during the spring tide when groundwater discharge was more prominent. Thus, the variability of nutrients in the coral reef system was regulated mainly by biological uptake and release in a spring–neap tide and impacted by mixing of tidally driven groundwater and offshore seawater during spring tide.

Estimating the ratio of pond size to irrigated soybean land in Mississippi: a case study

2016 ◽  
Vol 16 (6) ◽  
pp. 1639-1647 ◽  
Author(s):  
Ying Ouyang ◽  
Gary Feng ◽  
John J. Read ◽  
Theodor D. Leininger ◽  
Johnie N. Jenkins
Keyword(s):  
Water Level ◽  
Groundwater Resources ◽  
Pond Water ◽  
Crop Land ◽  
Experimental Learning ◽  
Storage Pond ◽  
Pond Size ◽  
Stella Model ◽  
On Farm

Although more on-farm storage ponds have been constructed in recent years to mitigate groundwater resources depletion in Mississippi, little effort has been devoted to estimating the ratio of on-farm water storage pond size to irrigated crop land based on pond metrics and its hydrogeological conditions. In this study, two simulation scenarios were chosen to determine such a ratio as well as to investigate pond hydrological processes using a Structural Thinking, Experimental Learning Laboratory with Animation (STELLA) model, one scenario with and the other without using pond water for irrigation for a typical pond that represented the average conditions in East Mississippi. Simulation results showed that pond water level changed moderately for conditions without using its water for irrigation, whereas pond water level changed dramatically for conditions with using its water for irrigation. A reasonable ratio of pond size to irrigated soybeans land was 1:18 if the irrigation rate was 2.54 cm/d (or 1 inch/d) and the low limit of the pond water level was drawn to near zero (0.08 m). For the ratio of 1:18, our simulations further revealed that a 1-ha soybeans land could save about 542 m3 groundwater each year. This study suggests that the STELLA model is a useful tool for estimating the ratio of pond size to irrigated crop land.

Sign in / Sign up

Export Citation Format

Share Document