scholarly journals Investigation of saltwater intrusion in thach han river system by mike hydro river package

2021 ◽  
Vol 72 (1) ◽  
pp. 46-57
Author(s):  
Chi Vuong Tai ◽  
Linh Nguyen Khanh ◽  
Ngan Vu Huong ◽  
Quang Dinh Nhat ◽  
Anh Truong Van
Keyword(s):  
Saltwater Intrusion ◽  
River Flow ◽  
River System ◽  
Future Scenarios ◽  
Han River ◽  
Negative Impacts ◽  
Hydrological Droughts ◽  
Structural Solutions ◽  
Large Discharge ◽  
Coast Region

Saltwater intrusion is one of the most severe problems for worldwide coastal regions, leading to negative impacts on both human and aquatic inhabitant communities. Quang Tri province, located in the Central Coast region of Vietnam, faces consequences of saltwater intrusion because of its dense river network and El Nino phenomena’s influences. To analyse hydrological, hydraulic processes as well as investigate saltwater intrusion’s situation in this province, the authors adopted MIKE HYDRO River package and obtained results with good agreements with measured data from survey campaigns. The present conditions scenario shows that saltwater intrudes Thach Han and Cam Lo rivers with a distance of 25.35 km and 15.04 km respectively, where the salt concentration is under 0.75‰ and water can be drunk and irrigated. The large discharge of 30 m3/s can only push saltwater only 1.85 km to the sea, which is insignificant in comparison with the value of seawater wedge length, saltwater intrusion in Thach Han river system can only be mitigated slightly. Since the authors only consider hydrological droughts, future scenarios in 2030 and 2050 have slight differences with the present, where topography and river flow remain unchanged. Based on the above results, non-structural measurements are not recommended to deal with saltwater intrusion for both present and future scenarios, and local authorities should consider structural solutions, e.g. constructions of anti-salt dams, during the decision-making process.

Morphotectonic Analysis of Tanjung Bungo Area Based on Geological Structure Control, Central Sumatera Basin

2020 ◽  
Author(s):  
D., A., L., A. Putri
Keyword(s):  
Natural Resources ◽  
River Flow ◽  
Measurement Data ◽  
River System ◽  
Flow Patterns ◽  
Source Rocks ◽  
Aerial Photographs ◽  
Morphological Data ◽  
Tectonic Activity ◽  
Geological Structures

Tectonic activity in an area could result in various impacts such as changes in elevation, level of slope percentages, river flow patterns and systems, and the formation of geological structures both locally and regionally, which will form a new landscape. The tectonic activity also affects the stratigraphic sequences of the area. Therefore, it is necessary to study morphotectonic or landscape forms that are influenced by active tectonic activities, both those occur recently and in the past. These geological results help provide information of the potential of natural resources in and around Tanjung Bungo area. Morphological data are based on three main aspects including morphogenesis, morphometry, and morphography. The data are collected in two ways, the first is field survey by directly observing and taking field data such as measuring geological structures, rock positions, and outcrop profiles. The second way is to interpret them through Digital Elevation Model (DEM) and aerial photographs by analyzing river flow patterns and lineament analysis. The field measurement data are processed using WinTensor, Dips, and SedLog Software. The supporting data such as Topographic Maps, Morphological Elevation Maps, Slope Maps, Flow Pattern Maps, and Lineament Maps are based on DEM data and are processed using ArcGis Software 10.6.1 and PCI Geomatica. Morphotectonically, the Tanjung Bungo area is at a moderate to high-class level of tectonic activity taken place actively resulted in several joints, faults, and folds. The formation of geological structures has affected the morphological conditions of the area as seen from the development of steep slopes, structural flow patterns such as radial, rectangular, and dendritic, as well as illustrated by rough surface relief in Tanjung Bungo area. This area has the potential for oil and gas resources as indicated by the Telisa Formation, consisting of calcareous silts rich in planktonic and benthonic fossils, which may be source rocks and its contact with the Menggala Formation which is braided river system deposits that could be good reservoirs. Further research needs to be done since current research is only an interpretation of surface data. Current natural resources being exploited in Tanjung Bungo region are coals. The coals have thicknesses of 5-7 cm and are classified as bituminous coals.

scholarly journals The occurrence and distribution of antibiotics in the Karst river system in Kaiyang, Southwest China

2018 ◽  
Vol 18 (6) ◽  
pp. 2044-2052 ◽  
Author(s):  
Shengzhang Zou ◽  
Fuyang Huang ◽  
Liang Chen ◽  
Fei Liu
Keyword(s):  
Southwest China ◽  
River Flow ◽  
Wastewater Treatment Plants ◽  
River System ◽  
Contamination Source ◽  
Antibiotic Concentration ◽  
Detection Frequency ◽  
Karst River ◽  
Flow Quantity ◽  
Total Concentrations

Abstract To our knowledge, this was the first study to investigate the occurrence and distribution of antibiotics in the Karst river system in Kaiyang, Southwest China. Ten water samples were collected from the Karst river in Kaiyang, Southwest China. Thirty-five antibiotics, including nine sulfonamides, four tetracyclines, five macrolides, sixteen quinolones and chloramphenicol, were analyzed. The results suggest that antibiotics are widely prevalent in the Karst river, with macrolides and quinolones being the most dominant and occupying 47% and 43% of total antibiotic concentration, respectively. The maximum total concentrations of sulfonamides, tetracyclines, macrolides, and quinolones were 30.4, 421, 884, and 1,807 ng/L, respectively. Lincomycin, roxithromycin, nalidixic acid, ofloxacin, and norfloxacin were detected in all samples with a detection frequency of 100%. The main sources of antibiotics were wastewater treatment plants (WWTPs) and rural dumps that did not contain sanitary treatment, which accounted for 33% and 40% of the total antibiotics present in the Karst river. Due to an increase in river flow quantity, the presence of WWTPs and rural dumps did not affect the concentration and distribution of antibiotics in the Karst river; however, the mass flux of antibiotics were significantly affected by the contamination source and the poor natural attenuation.

Effects of hydrological change and the cessation of stocking on a stream population of Salmo trutta L

1988 ◽  
Vol 39 (3) ◽  
pp. 337 ◽  
Author(s):  
PE Davies ◽  
RD Sloane ◽  
J Andrew
Keyword(s):  
Brown Trout ◽  
Salmo Trutta ◽  
River Flow ◽  
River System ◽  
Riparian Habitat ◽  
Mean Flow ◽  
Age Composition ◽  
The North ◽  
Trout Population ◽  
Class Strength

The North Esk-St Patricks river system, northern Tasmania, was electrofished at 27 sites in 1985, 30 years after the same sites had been electrofished in a previous study on the survival of released brown trout. All sites were dominated by brown trout, Salmo trutta L. Before 1955, stocking of brown trout fry and yearlings had been heavy. Stocking ceased after 1956 and few releases were made to 1985. At all but 4 sites, the number and total biomass of brown trout were higher in 1985 than in 1955. The estimated total population of brown trout had increased by 63%, accompanied by a 55% increase in the number of fish of legal size (>22 cm). Previously described 'nursery streams' still maintained high densities of 0+ fish, despite considerable changes in the age composition at other sites. Little or no change had occurred in riparian habitat at 23 of 27 sites. Change in year-class strength was highly correlated with change in total annual river flow in the natal year. This is explained in terms of mortality in 'nursery streams' during periods of low river flow. At 19 sites out of 21, changes in age composition were related to relative changes in year-class strength due to interannual variability in river flow. Four sites where major changes in riparian habitat occurred exhibited decreased brown trout biomass but still showed changes in age structure due to variation in annual flow. Mean annual river flow had increased by three times since the 1950s and this was attributed to a doubling in the proportion of cleared land in the catchments. Effects of changes in river hydrology on the trout population are discussed. Growth of S. trutta was essentially independent of density. The number of anglers, total effort and the total harvest in 1985/86-1986/87 were significantly higher than in 1945/46-1953/54. A shift toward higher catch per season per angler was observed in 1985/86-1986/87 compared to the 1945/46- 1953/54 seasons, but catch per day had not changed. Total annual mortality remained at 70%. The effects of increased mean flow and interannual flow variability on the brown trout population of the North Esk river system are discussed.

Experimental infection of the endangered bonytail chub (Gila elegans) with the Asian fish tapeworm (Bothriocephalus acheilognathi): impacts on survival, growth, and condition

2006 ◽  
Vol 84 (10) ◽  
pp. 1383-1394 ◽  
Author(s):  
S.P. Hansen ◽  
A. Choudhury ◽  
D.M. Heisey ◽  
J.A. Ahumada ◽  
T.L. Hoffnagle ◽  
...  
Keyword(s):  
Synergistic Effects ◽  
Grand Canyon ◽  
River System ◽  
Health Condition ◽  
Infected Fish ◽  
Control Fish ◽  
Potential Threat ◽  
Humpback Chub ◽  
Bothriocephalus Acheilognathi ◽  
Negative Impacts

Bothriocephalus acheilognathi Yamaguti, 1934, a tapeworm known to be pathogenic to some fish species, has become established in the endangered humpback chub ( Gila cypha Miller, 1964) in Grand Canyon, USA, following the tapeworm’s introduction into the Colorado River system. The potential impact of this tapeworm on humpback chub was studied by exposing the closely related bonytail chub ( Gila elegans Baird and Girard, 1853) to the parasite under a range of conditions that included potential stressors of humpback chub in their natal waters, such as abrupt temperature change and a limited food base. Survival of infected fish under low food rations was considerably lower than that of control fish, and mortality of infected fish began 20 days earlier. Growth of infected fish was significantly reduced, and negative changes in health condition indices were found. No significant negative impacts were revealed from the synergistic effects between temperature shock and infection. Bothriocephalus acheilognathi does present a potential threat to humpback chub in Grand Canyon and should be considered, along with conventional concerns involving altered flow regimes and predation, when management decisions are made concerning conservation of this endangered species.

Challenge and response in the Indus Basin

Water Policy ◽  
2014 ◽  
Vol 16 (S1) ◽  
pp. 58-86 ◽  
Author(s):  
Madison Condon ◽  
Don Kriens ◽  
Anjali Lohani ◽  
Erum Sattar
Keyword(s):  
River Flow ◽  
Environmental Flows ◽  
Irrigation System ◽  
River System ◽  
Indus Basin ◽  
Implementation Challenges ◽  
History Of ◽  
Basin Irrigation ◽  
Indus Waters Treaty ◽  
Institutional Architecture

The authors examine the complex history of the development of the Indus Basin and the challenges faced by Pakistan during the evolution of the Indus Basin Irrigation System and the country's responses to date. The Indus river system must meet the multiple needs of agriculture, energy and flood security. Pakistan's constitutional structure, in which the federation shares overall responsibility for the operation of the Indus with the provinces, poses unique management and implementation challenges. What are the institutional arrangements Pakistan needs to address the challenges to the Indus Waters Treaty it signed with India in 1960? How is the country going to regulate the use of over-abstraction in the basin with the increased reliance on groundwater to maintain agricultural productivity? What are the institutional mechanisms in place to manage increased river flow variations from glacial melt as a result of climate change and for coping with devastating floods? At the same time, is the country maintaining adequate environmental flows to its delta? Provincial mistrust and a lack of institutional capacity underpins the history of the Indus in Pakistan with the Interprovincial Water Accord 1991 serving as a ray of hope on which to build a new institutional architecture of cooperation.

A multiple-reach model describing the migratory behavior of Snake River yearling chinook salmon (Oncorhynchus tshawytscha)

1998 ◽  
Vol 55 (3) ◽  
pp. 658-667 ◽  
Author(s):  
Richard W Zabel ◽  
James J Anderson ◽  
Pamela A Shaw
Keyword(s):  
Chinook Salmon ◽  
Migration Rate ◽  
River Flow ◽  
Oncorhynchus Tshawytscha ◽  
Nonlinear Models ◽  
Columbia River ◽  
River System ◽  
Snake River ◽  
Migration Route ◽  
Time Step

A multiple-reach model was developed to describe the downstream migration of juvenile salmonids in the Columbia River system. Migration rate for cohorts of fish was allowed to vary by reach and time step. A nested sequence of linear and nonlinear models related the variation in migration rates to river flow, date in season, and experience in the river. By comparing predicted with observed travel times at multiple observation sites along the migration route, the relative performance of the migration rate models was assessed. The analysis was applied to cohorts of yearling chinook salmon (Oncorhynchus tshawytscha) captured at the Snake River Trap near Lewiston, Idaho, and fitted with passive integrated transponder (PIT) tags over the 8-year period 1989-1996. The fish were observed at Lower Granite and Little Goose dams on the Snake River and McNary Dam on the Columbia River covering a migration distance of 277 km. The data supported a model containing two behavioral components: a flow term related to season where fish spend more time in regions of higher river velocity later in the season and a flow-independent experience effect where the fish migrate faster the longer they have been in the river.

scholarly journals Long-chain diols in rivers: distribution and potential biological sources

2018 ◽  
Vol 15 (13) ◽  
pp. 4147-4161 ◽  
Author(s):  
Julie Lattaud ◽  
Frédérique Kirkels ◽  
Francien Peterse ◽  
Chantal V. Freymond ◽  
Timothy I. Eglinton ◽  
...  
Keyword(s):  
River Flow ◽  
River System ◽  
18S Rrna Gene ◽  
Rrna Gene ◽  
River Systems ◽  
Eukaryotic Diversity ◽  
Fractional Abundance ◽  
Biological Sources ◽  
Rrna Gene Sequencing ◽  
Long Chain

Abstract. Long-chain diols (LCDs) occur widespread in marine environments and also in lakes and rivers. Transport of LCDs from rivers may impact the distribution of LCDs in coastal environments, however relatively little is known about the distribution and biological sources of LCDs in river systems. In this study, we investigated the distribution of LCDs in suspended particulate matter (SPM) of three river systems (Godavari, Danube, and Rhine) in relation with precipitation, temperature, and source catchments. The dominant long-chain diol is the C32 1,15-diol followed by the C30 1,15-diol in all studied river systems. In regions influenced by marine waters, such as delta systems, the fractional abundance of the C30 1,15-diol is substantially higher than in the river itself, suggesting different LCD producers in marine and freshwater environments. A change in the LCD distribution along the downstream transects of the rivers studied was not observed. However, an effect of river flow is observed; i.e., the concentration of the C32 1,15-diol is higher in stagnant waters such as reservoirs and during seasons with river low stands. A seasonal change in the LCD distribution was observed in the Rhine, likely due to a change in the producers. Eukaryotic diversity analysis by 18S rRNA gene sequencing of SPM from the Rhine showed extremely low abundances of sequences (i.e., < 0.32 % of total reads) related to known algal LCD producers. Furthermore, incubation of the river water with 13C-labeled bicarbonate did not result in 13C incorporation into LCDs. This indicates that the LCDs present are mainly of fossil origin in the fast-flowing part of the Rhine. Overall, our results suggest that the LCD producers in rivers predominantly reside in lakes or side ponds that are part of the river system.

scholarly journals Optical and molecular-level characterization of fluvial organic matter biodegradation in a highly urbanized river system

2017 ◽  
Author(s):  
Most Shirina Begum ◽  
Hyojin Jin ◽  
Inae Jang ◽  
Jung-Min Lee ◽  
Han Bin Oh ◽  
...  
Keyword(s):  
Water Pollution ◽  
Organic Matter ◽  
Optical Properties ◽  
Co2 Emission ◽  
Molecular Level ◽  
River System ◽  
Agricultural Runoff ◽  
Han River ◽  
Ft Icr Ms ◽  
Ft Icr

Abstract. Rapid urbanization worldwide is changing both the transport of organic matter (OM) and CO2 emission in urban streams and rivers, yet little is known as to how the altered quality of riverine OM affects biodegradation and CO2 emission. The relationships between the chemical properties and biodegradation of riverine OM, including dissolved and particulate OM (DOM and POM), were examined against the level of anthropogenic perturbation along the Han River, a river system in South Korea that has been highly modified by dams and urban water pollution. DOM optical properties and biodegradable dissolved organic carbon (BDOC), together with in situ measurements of the partial pressure of CO2 (pCO2) using a membrane-enclosed sensor, were compared between the up-, mid-, and downstream reaches of the Han River and three urban tributaries in a basin-scale field campaign combined with a 7 day incubation of both filtered and unfiltered samples. Another 5 day incubation was conducted with unfiltered water samples from a downstream river site and an urban tributary, in isolation and mixed (1 : 1), to measure changes in dissolved CO2 concentrations at 10-min intervals and BDOC and optical properties at intervals of 1–2 days. Fourier transform-ion cyclotron resonance-mass spectrometry (FT-ICR-MS) was used to detect molecular-level changes in DOM composition between the initial and post-incubation samples. The average BDOC concentration in the urban tributaries was 4–12 times higher than those of three mainstem reaches, while BDOC was highly variable at three downstream sites and tended to be higher at the mainstem sites affected by agricultural runoff or dams than at the forested headwater stream. Longitudinal increases in protein-like and microbial humic-like fluorescence, fluorescence index (FI), and biological index (BIX) reflected increasing inputs of anthropogenic DOM along the downstream reach and urban tributaries. These optical indices, along with pCO2, were significantly correlated with BDOC concentrations measured at 12 sites. The cumulative CO2 production measured in the second incubation was greatest in the mixture, followed by the urban tributary and mainstem samples in the descending order. The amount of CO2 produced in the mixture was greater than the BDOC measured in the same sample or the average of CO2 produced in the separate samples, indicating a mixing-enhanced biodegradation of DOM including the fraction transformed from soluble components of POM. FT-ICR-MS analysis revealed a much larger number of molecules consumed (3984) than those produced (771) during the incubation of the mainstem sample in contrast to the produced molecules (2789) exceeding the consumed molecules (1479) in the tributary sample, indicating a high rate of OM processing in the urban tributary that might be limited in the availability of immediately consumable organic materials. Overall results suggest that water pollution, along with impoundment effects of dams, can alter the optical properties and biodegradability of both DOM and POM in highly urbanized watersheds to such a degree that can induce a priming effect on OM biodegradation and CO2 emission.

scholarly journals Environmental Flow Assessment of a Tropical River System Using Hydrological Index Methods

Water ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 2477
Author(s):  
Mohammad Haroon Hairan ◽  
Nor Rohaizah Jamil ◽  
Mohammad Noor Amal Azmai ◽  
Ley Juen Looi ◽  
Moriken Camara
Keyword(s):  
River Flow ◽  
Maximum Flow ◽  
River System ◽  
Environmental Flow ◽  
Low Flow ◽  
Index Method ◽  
Flood Pulses ◽  
Post Impact ◽  
High Flood ◽  
High Level

Tropical rivers and wetlands are recognized as one of the greatest and most abundant ecosystems in terms of ecological and social benefits. However, climate change, damming, overfishing, water pollution, and the introduction of exotic species threaten these ecosystems, which puts about 65% of river flow and aquatic ecosystems under a moderate to high level of threat. This paper aims to assess the environmental flow of the Selangor River based on the hydrological index method using the Global Environmental Flow Calculator (GEFC) and Indicators of Hydrological Alterations (IHA) software. The daily flow data collected by the Department of Irrigation and Drainage (DID), Malaysia, over a 60-year period (1960–2020) was used in this study to assess the Selangor River flow alterations. As per the results, the river flow has had two distinct periods over the last 60 years. In the first period, the river flows without any alteration and has a natural flow with high flood pulses and low flow pulses. While in the second, or post-impact, period, the flow of the river has a steady condition throughout the year with very little fluctuations between the dry and wet seasons of the year. From the overall comparison of the pre- and post-impact periods, it can be concluded that the minimum flow in the dry seasons of the year has increased, while the maximum flow has decreased in the monsoon seasons during the post-impact period. As a result, the Flow Duration Curve (FDC) and Environmental Management Class (EMC) analysis of the river flow recommends that the Selangor River be managed under EMC “C” to provide sufficient water for both human use and ecosystem conservation, which would also help to avoid a water level drop in the reservoirs. However, further holistic studies are suggested for a detailed analysis of the effects of the dams on aquatic biodiversity and ecosystem services in the Selangor River Basin.

scholarly journals A New Method for Extracting Elevation Information of River System from Contours

2019 ◽  
Vol 2 ◽  
pp. 1-7
Author(s):  
Guifang He ◽  
Minshi Liu
Keyword(s):  
River Flow ◽  
Spatial Relationship ◽  
River System ◽  
New Method ◽  
River Section ◽  
Trend Surface ◽  
Existing Problems ◽  
Logical Error ◽  
Conventional Methods ◽  
Low Efficiency

<p><strong>Abstract.</strong> Considering the existing problems in methods of extracting elevation in river system, such as low efficiency, low accuracy, elevation logic errors and other issues, this paper proposes a new method of elevation extraction based on contours. Firstly, the spatial relationship between river system and contours is constructed to improve the intersection efficiency. Secondly, the accuracy of river system elevation can be improved and river flow logical error can be avoided by using the method of interpolation of trend surface of the river section. And then, the river tree is established to avoid the logical error of river system. Many comparison experiments about efficiency, elevation accuracy and elevation logical error between this method and other two conventional methods have been carried out, and the results show that both accuracy and efficiency can be improved and there is no logical error of elevation by this method.</p>

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