Overflow Water Research Articles

A conceptual model for talik dynamics and icing formation in a river floodplain in the continuous permafrost zone at Salluit, Nunavik (Quebec), Canada

AbstractIcing occurs each winter along the floodplain of the Kuuguluk River in the continuous permafrost zone at Salluit in Nunavik (Quebec), Canada. The source of successive water overflows which thicken and enlarge this ice cover over time is suprapermafrost groundwater discharging from a talik below the riverbed. Electrical resistivity tomography was used to delineate the talik, while water level and temperature dataloggers were used to assess the thermo‐hydraulic conditions of the riverbed. The mean annual riverbed temperature was 1.8°C in 2016 while the mean annual air temperature was −6.0°C. Hydraulic heads below the ice cover as high as 2.8 m and events of abrupt decreases in hydraulic head due to suprapermafrost groundwater overflow through cracks in the ice cover were monitored. An analytical solution based on beam mechanics theory was used to assess the water pressure‐induced stresses which are sufficient to fracture the ice cover. A detailed conceptual model of the talik and icing dynamics is proposed to explain the cryo‐hydrogeological processes taking place in this complex groundwater–river system. The groundwater pressure buildup in the talik during the winter is due to constricted flow of suprapermafrost groundwater in the talik. These results have implications for understanding the dynamics of river taliks and their use as potential water supplies in northern communities.

VRBagged-Net: Ensemble Based Deep Learning Model for Disaster Event Classification

A flood is an overflow of water that swamps dry land. The gravest effects of flooding are the loss of human life and economic losses. An early warning of these events can be very effective in minimizing the losses. Social media websites such as Twitter and Facebook are quite effective in the efficient dissemination of information pertinent to any emergency. Users on these social networking sites share both textual and rich content images and videos. The Multimedia Evaluation Benchmark (MediaEval) offers challenges in the form of shared tasks to develop and evaluate new algorithms, approaches and technologies for explorations and exploitations of multimedia in decision making for real time problems. Since 2015, the MediaEval has been running a shared task of predicting several aspects of flooding and through these shared tasks, many improvements have been observed. In this paper, the classification framework VRBagged-Net is proposed and implemented for flood classification. The framework utilizes the deep learning models Visual Geometry Group (VGG) and Residual Network (ResNet), along with the technique of Bootstrap aggregating (Bagging). Various disaster-based datasets were selected for the validation of the VRBagged-Net framework. All the datasets belong to the MediaEval Benchmark Workshop, this includes Disaster Image Retrieval from Social Media (DIRSM), Flood Classification for Social Multimedia (FCSM) and Image based News Topic Disambiguation (INTD). VRBagged-Net performed encouraging well in all these datasets with slightly different but relevant tasks. It produces Mean Average Precision at different levels of 98.12, and Average Precision at 480 of 93.64 on DIRSM. On the FCSM dataset, it produces an F1 score of 90.58. Moreover, the framework has been applied on the dataset of Image-Based News Topic Disambiguation (INTD), and exceeds the previous best result by producing an F1 evaluation of 93.76. The VRBagged-Net with a slight modification also ranked first in the flood-related Multimedia Task at the MediaEval Workshop 2020.

A Study on Protection Measure for Water Level Fluctuation and Overflow Conditions in Earth-filled Embankment by Centrifuge Model Tests

A Study on Protection Measure for Water Level Fluctuation and Overflow Conditions in Earth-filled Embankment by Centrifuge Model Tests

Paleolimnological approach for management sustainable use of tropical lakes

Tropical aquatic resources provide ecosystem services, which are affected by human activities. Human-induced environmental change in Indonesian lakes has considerably increased since the new order in 1970. In general, many Indonesian lakes had deteriorated due to sedimentation and eutrophication, which induced the blooming of aquatic plants, mostly by water hyacinth. Water security becomes a problem, particularly in the dry seasons, but water overflow and flooding occur in many places during wet seasons. Landscape and climate changes, pollution, species diversity, preserved in lake sediment, provide long-term proof of environmental changes. This paper will discuss a paleolimnological approach to reconstruct past environmental changes. Paleolimnology is learning about stratigraphy sediment of the lakes where fossils are well preserved in the sediment and provide information about the past conditions of the catchment area. Lakes’ sediment records the changes in condition of the catchment area, like a diary book. Paleolimnology had been studied for Rawapening Lake and Telaga Warna Lake, Dieng. Reconstruction of the past environmental condition is required to predict future conditions. Reconstruction is an activity recreate past conditions by pointing the organism stored in layers of sediment, therefore, reflecting the environmental conditions based on organisms deposited, to develop the best sustainable water resources management, as in alignment with the concept of water – energy – food nexus.

Assessing Eddying (1/12°) Ocean Reanalysis GLORYS12 Using the 14‐yr Instrumental Record From 59.5°N Section in the Atlantic

AbstractThe eddy‐resolving (1/12°) global ocean reanalysis GLORYS12 is assessed against 14 years (2002–2015) of independent hydrographic observations collected at 59.5°N in the North Atlantic. Two multi‐observations statistical analyses, ISAS‐15 and ARMOR‐3D, and an eddy‐permitting (1/4°) reanalysis, GLORYS025, also contribute to this comparison. The mean thermohaline structure along the 59.5°N section revealed by the observations is well‐reproduced by GLORYS12, except for the overflow waters. A good agreement with observations is found for linear trends over the whole period, exhibiting a dipole‐like pattern with a cooling/freshening in the main thermocline and a warming/salinization below. However, localized discrepancies with observations suggest the need for improvement in the reanalysis system (especially in the overflows representation and the consistency between the forcing and data assimilation system) and the deep observational array. The reanalysis reliably represents the ocean heat content in the upper 700‐m layer but shows significant differences with observations between 700 and 2,000 m. The meridional volume and heat transports across the 59.5°N section are compared for years when ADCP observations were available. The reanalysis does not reproduce the variability observed in the western boundary current but agrees well with observed transports in the other parts of the section. The reanalysis reproduces the major mesoscale eddy features that contribute to the meridional transport and provides the large‐scale context of their location. The analysis of time correlation at all measurement points demonstrated that GLORYS12 is the most accurate among the analyzed datasets used in this study to represent and explain the observed ocean characteristics and variability along that section.

Quantitative evaluation of water injection composition in high injection-production ratio blocks - Taking Chao 5 well block as an example

The injection-production ratio of the oilfields in the periphery of the Changyuan Placanticline is high. The cumulative injection-production ratio of the main oilfields in the Putaohua oil layer is between 1.29-2.46, and the cumulative injection-production ratio of the main oilfields in the Fuyang oil layer is between 1.98-2.65. At present, the viewpoints of high cumulative injection-production ratio and large ineffective water injection are generally concentrated on unmarked reservoir sandstone sections, water absorption by shale, overflow along faults and fracture systems, measurement errors, and pipeline leakage. In response to the above problems, this paper takes the Chao 5 well block as an example, establishes a block-wide numerical simulation model, carries out a quantitative evaluation of the water injection composition of a high injection-production ratio block, and analyzes the main controlling factors of different types of water injection. The research results show that the water absorption of the reservoirs in the North Chao 5-Chao 5 block accounts for 55%, the unmarked reservoir section absorbs 28%, and the mud shale absorbs 8%; the overflow of water drops to 12%. The research content of this article has a certain guiding significance for improving the level of oilfield water injection development and ensuring the efficient and sustainable development of oilfields.

Cyclonic eddies in the West Greenland Boundary Current System

AbstractThe boundary current system in the Labrador Sea plays an integral role in modulating convection in the interior basin. Four years of mooring data from the eastern Labrador Sea reveal persistent mesoscale variability in the West Greenland boundary current. Between 2014 and 2018, 197 mid-depth intensified cyclones were identified that passed the array near the 2000 m isobath. In this study, we quantify these features and show that they are the downstream manifestation of Denmark Strait Overflow Water (DSOW) cyclones. A composite cyclone is constructed revealing an average radius of 9 km, maximum azimuthal speed of 24 cm/s, and a core propagation velocity of 27 cm/s. The core propagation velocity is significantly smaller than upstream near Denmark Strait, allowing them to trap more water. The cyclones transport a 200-m thick lens of dense water at the bottom of the water column, and increase the transport of DSOW in the West Greenland boundary current by 17% relative to the background flow. Only a portion of the features generated at Denmark Strait make it to the Labrador Sea, implying that the remainder are shed into the interior Irminger Sea, are retroflected at Cape Farewell, or dissipate. A synoptic shipboard survey east of Cape Farewell, conducted in summer 2020, captured two of these features which shed further light on their structure and timing. This is the first time DSOW cyclones have been observed in the Labrador Sea—a discovery that could have important implications for interior stratification.

Differentiating Enterococcus lineages in combined sewer overflow and potable water combating to hospital acquired high-level β-lactam resistance

Understanding the sewage borne transmission pathway of hospital-associated enterococci can provide an insight for developing effective strategies to reduce the spread of nosocomial pathogens and illnesses in low- and middle-income countries. This research investigated the hospital borne enterococcal lineages in combined sewage overflowed (CSO) onto the streets and contaminating the freshwater, considered as an environmental challenge. The Enterococcus faecium and E. faecalis were heavily resistant to multiple β-lactams including, amino penicillins, cephalosporins (1st to 4th generation), carbapenems and aminoglycoside. Enterococcus species obtained from CSO exhibits resistance plasticity, which is correlated with varied ampicillin MICs (64 to ≥ 2048 μg ml−1), polymorphism in php4 and pbp5 genes and repetitive BOX-DNA. The quantified enterococcal densities in drinking water (i.e. 1.5 × 106 CFUs ml−1) were far beyond to the permissible limit defined by world health organization, and European food safety authority. The CSO and clinical species harbored IS16 element, clyA, esp, efaAfm, efaAfs, ace, and conjugative plasmids readily differentiated with waterborne and commensal strains might have been developed during niche adoption and broad spectral antibacterial activities. The bacteriocinogenic enterococcal groups in combined sewage were avirulent, susceptible to ampicillin and produced multiple enterocins (entA, entB, entP, entL, entL50, ent1071, ent1097, entSEK4). The enterocinogenic E. faecium showed natural abundance in CSO restrained the growth of six Enterococcus species (ATCC), β-lactam resistant enterococci of clinical and sewage origin, Listeria monocytogenes ATCC 13932, and Micrococcus leuteus ATCC 10240. Furthermore, enterocinogenic activities led to in-vitro dysbiosis of human microbiota. In conclusion, constant monitoring of sewage spills near residential areas essentially involved the enterococci (fecal and resistome indicator) and proper disposal of hospital waste prior to draining into community sewage and wastewater treatment plants is highly recommended.

Cold-water corals in the Subpolar North Atlantic Ocean exposed to aragonite undersaturation if the 2 °C global warming target is not met

The net uptake of carbon dioxide (CO 2 ) from the atmosphere is changing the ocean's chemical state. Such changes, commonly known as ocean acidification, include a reduction in pH and the carbonate ion concentration ([CO 3 2− ]), which in turn lowers oceanic saturation states (Ω) for calcium carbonate (CaCO 3 ) minerals. The Ω values for aragonite (Ω aragonite ; one of the main CaCO 3 minerals formed by marine calcifying organisms) influence the calcification rate and geographic distribution of cold-water corals (CWCs), important for biodiversity. Here, high-quality measurements, collected on thirteen cruises along the same track during 1991–2018, are used to determine the long-term changes in Ω aragonite in the Irminger and Iceland Basins of the North Atlantic Ocean, providing the first trends of Ω aragonite in the deep waters of these basins. The entire water column of both basins showed significant negative Ω aragonite trends between −0.0014 ± 0.0002 and −0.0052 ± 0.0007 per year. The decrease in Ω aragonite in the intermediate waters, where nearly half of the CWC reefs of the study region are located, caused the Ω aragonite isolines to rapidly migrate upwards at a rate between 6 and 34 m per year. The main driver of the decline in Ω aragonite in the Irminger and Iceland Basins was the increase in anthropogenic CO 2 . But this was partially offset by increases in salinity (in Subpolar Mode Water), enhanced ventilation (in upper Labrador Sea Water), and increases in alkalinity (in classical Labrador Sea Water, cLSW; and overflow waters). We also found that water mass aging reinforced the Ω aragonite decrease in cLSW. Based on these Ω aragonite trends over the last three decades, we project that the entire water column of the Irminger and Iceland Basins will likely be undersaturated for aragonite when in equilibrium with an atmospheric mole fraction of CO 2 (xCO 2 ) of ~880 ppmv, corresponding to climate model projections for the end of the century based on the highest CO 2 emission scenarios. However, intermediate waters will likely be aragonite undersaturated when in equilibrium with an atmospheric xCO 2 exceeding ~630 ppmv, an xCO 2 level slightly above that corresponding to 2 °C global warming, thus exposing CWCs inhabiting the intermediate waters to undersaturation for aragonite. • Aragonite saturation state significantly decreased for 1991–2018. • Anthropogenic CO 2 uptake is the main driver for the observed decrease. • At cold-water corals (CWC) depths, the aragonite isolines shoaled at 6–34 m yr −1 . • Projection of future change in aragonite saturation state based on observed change. • CWC reefs exposed to undersaturation at atmospheric CO 2 levels causing 2 °C warming.

Flood Plain Modelling of Krishna Lower Basin Using Arcgis, Hec-Georas And Hec-Ras

A flood is an overflow of water that submerges land which is usually dry. Floods can also occur in rivers when the flow rate exceeds the capacity of the river channel, particularly at bends or meanders in the waterway. This results in causing damage to human and property if they are in the natural flood plains of rivers or settled on the banks of rivers. To facilitate the appropriate measures for effective flood mitigation in advance, there is a need to model the flood plain which facilitates to locate the flood plain and its extent for effective flood mitigation measures. By understanding the extent of flooding and floodwater inundation, decision makers are able to make choices about how to best allocate resources to prepare for emergencies and to generally improve the quality of life. This research presents a straightforward approach for processing output of the HEC-RAS hydraulic model, to enable two and three dimensional floodplain mapping and analysis in the ArcView geographic information system. The methodology is applied to a stretch of river Krishna from downstream of Nagarjuna Sagar project to Kummaripalem which is located on upstream of Prakasam Barrage. The flood plain maps are developed for the flows corresponding to 2, 10, 25, 50 and 100 year return periods. The resulting surface model provides a good representation of the general landscape and contains additional detail within the stream channel. Overall, the results of the research indicate that GIS is an effective environment for floodplain mapping and analysis.

Transports and Accumulations of Greenland Sea Intermediate Waters in the Norwegian Sea

AbstractThe Greenland Sea intermediate waters transported via the Jan Mayen Channel (JMCh) are a significant source for the Iceland‐Scotland Overflow Water. Based on hydrographic data collected by a Norway‐China survey in 2015 and Argo floats, we classify the water masses of the Greenland Sea outflow and then reveal their distributions in the Norwegian Sea. The Atlantic‐origin water produced by density increase during winter in the northern Greenland Sea was an important component of the intermediate waters exported to the Norwegian Sea, accounting for about 30% of the total volume in 2015. The hydrographic data revealed that the major passage of outflow from the Greenland Sea was located in the southern Mohn Ridge in 2015, rather than in the JMCh, as generally recognized. The transport of intermediate waters from the Greenland Sea via the southern Mohn Ridge in the summer of 2015 is estimated to be about 0.8–1.7 Sv. This transport pattern provides a perspective that there exists a multi‐passage system of outflow in the JMCh and Mohn Ridge, promoting a stable supply of intermediate waters to the Norwegian Sea.

Momordica Charantia'nın Sıçan Ayak İltihabı ve Davranışı Üzerine Etkilerinin İncelenmesi; deneysel Model.

Background: Pain is one of the common experiences which is unpleasant feeling that originates from any part of the body, is associated with real or possible tissue damage and linked to human past experiences. Momordica Charantia (MC) or bitter melon mainly is used all around the world for the treatment of diabetes, cancer and inflammation- associated conditions due to the existence of many bioactive ingredients which have vigorous biologic effect. The aim of our study is to investigate how low and high doses of MC plant affect foot inflammation and animal's behavior.
 Materials and Methods: Sixteen male rats randomly divided into 4 experimental groups. Formaldehyde was (hind-paw formalin injection) administered for inducing pain model. After 24 hours MC (50 mg/kg, 200 mg/kg) was administered every day for five days. During the experiment, the pain thresholds, motor cortex measurements and inflamed foot volume, Locomotor Activity Test and Water Overflow Method in sequence.
 Results: According to our result, when we consider the foot volume, pain threshold and motor cortex data of our control group, there is no significant difference between the beginning and the last day, while On the 7th day, the pain threshold continues to decrease as the foot volume of our animals in our positive control group does not decrease. 200 mg concentration of MC has provided a great treatment by reducing the increasing foot volume at the same time pain threshold and motor activity was in highest level at 4th day.
 Conclusion: Our experiment shows that MC (200 mg/ml MC ) has high analgesic activity provides significant pain reduction and improvement in symptoms

Evaluating the impact of Mediterranean overflow on the large-scale Atlantic Ocean circulation using neodymium isotopic composition

Palaeo-oceanographical archives in the Mediterranean Sea indicate the occurrence of Sapropel depositions, which are characteristic of anoxic bottom conditions and of a stratified sea. The impact of such drastic changes in the thermohaline circulation of the Mediterranean Sea on the large-scale circulations in the North Atlantic basin is not fully understood. Here we evaluate the impact of a direct perturbation of the Mediterranean Sea circulation through different idealized simulations with freshwater release rates of 20, 50, 100, and 200 mSv (1 mSv = 103 m3/s), using a the IPSL-CM5A-LR global coupled atmosphere-ocean model, with simulations up to 1000 years long. The simulations are compared to available data for the Mediterranean Sea and the North Atlantic. The Neodymium isotopic composition (εNd) anomalies in the North Atlantic are clearly dependent on the rate of fresh water release in the Mediterranean Sea, and subsequent modification of Atlantic meridional overturning circulation (AMOC) intensity and subpolar gyre (SPG) extension. Based on comparison with seawater εNd records from Rockall Trough, we suggest that a limited release of freshwater around 50 mSv may be more representative of hydrological conditions of the Mediterranean Sea during the Sapropel S1 deposition. Our results indicate that a decrease in Mediterranean overflow was clearly a factor in the intensification of upper AMOC following the Early Holocene period, when a large eastward expansion of the subpolar gyre is simulated. Also, eastward expansion of the subpolar gyre due to freshwater release in the Mediterranean (e.g. Sapropel-like events) and its impact on the εNd signature highlight the fact that the modification of ocean circulation in the North Atlantic basin might be more complex than a straightforward change in the AMOC, since there may also be a large impact on barotropic circulation. The simulations also produce a significant decrease in the εNd values of the Iceland-Scotland Overflow Water (between −3.5 and − 1.3 εNd unit), which is consistent with changes observed during the S1 event in the reconstructions. Thus the 3-dimensional changes in baroclinic and barotropic circulations of the ocean, as reconstructed in some εNd records, are broadly consistent with the sensitivity simulations performed, and might thus be partly related to changes in Mediterranean overflow, which would have contributed to modification of the Atlantic Ocean circulation following a complex 3-dimensional pattern that is detailed in the paper.

Numerical Study on the Hydrologic Characteristic of Permeable Friction Course Pavement

The hydrologic characteristic of a permeable friction course (PFC) pavement is dependent on the rainfall intensity, pavement geometric design, and porous asphalt properties. Herein, the hydrologic characteristic of PFC pavements of various lengths and slopes was determined via numerical analysis. A series of analyses was conducted using length values of 10, 15, 20, and 30 m and slope values of 0.5%, 2%, 4%, 6%, and 8% for the equivalent water flow path. The PFC pavements were simulated for various values of rainfall intensity, which ranged from 10 to 120 mm/h, to determine the time taken for water to flow over the PFC pavement surface. The results show that the time for water overflow decreased when the pavement length or rainfall intensity increased, and it increased when the slope increased. Finally, a series of design charts was developed to determine the time taken for water to flow over the PFC pavement surface for given rainfall intensities. Since this study was conducted based on numerical analysis, further studies are recommended to verify experimentally the results presented.

Water masses in the Atlantic Ocean: characteristics and distributions

Abstract. A large number of water masses are presented in the Atlantic Ocean, and knowledge of their distributions and properties is important for understanding and monitoring of a range of oceanographic phenomena. The characteristics and distributions of water masses in biogeochemical space are useful for, in particular, chemical and biological oceanography to understand the origin and mixing history of water samples. Here, we define the characteristics of the major water masses in the Atlantic Ocean as source water types (SWTs) from their formation areas, and map out their distributions. The SWTs are described by six properties taken from the biased-adjusted Global Ocean Data Analysis Project version 2 (GLODAPv2) data product, including both conservative (conservative temperature and absolute salinity) and non-conservative (oxygen, silicate, phosphate and nitrate) properties. The distributions of these water masses are investigated with the use of the optimum multi-parameter (OMP) method and mapped out. The Atlantic Ocean is divided into four vertical layers by distinct neutral densities and four zonal layers to guide the identification and characterization. The water masses in the upper layer originate from wintertime subduction and are defined as central waters. Below the upper layer, the intermediate layer consists of three main water masses: Antarctic Intermediate Water (AAIW), Subarctic Intermediate Water (SAIW) and Mediterranean Water (MW). The North Atlantic Deep Water (NADW, divided into its upper and lower components) is the dominating water mass in the deep and overflow layer. The origin of both the upper and lower NADW is the Labrador Sea Water (LSW), the Iceland–Scotland Overflow Water (ISOW) and the Denmark Strait Overflow Water (DSOW). The Antarctic Bottom Water (AABW) is the only natural water mass in the bottom layer, and this water mass is redefined as Northeast Atlantic Bottom Water (NEABW) in the north of the Equator due to the change of key properties, especially silicate. Similar with NADW, two additional water masses, Circumpolar Deep Water (CDW) and Weddell Sea Bottom Water (WSBW), are defined in the Weddell Sea region in order to understand the origin of AABW.

Synthesis of a copolymeric system and its flocculation performance for iron ore tailings

The medium grade iron ores contain high ultrafine fractions of soft slime which result in poor dewatering characteristics. Herein, a detailed study was conducted to assess the settling behaviour of iron slimes or tailings using a novel starch-based binary graft copolymeric flocculant (St-g-(pAAm-co-pSS)) and the performance was compared with four commercial reagents. The copolymer has been synthesized by grafting of acrylamide and sodium p-styrene sulfonate on starch using free radical polymerization. The polymer demonstrated outstanding settling behaviour with respect to settling speed and capacity to remove turbidity during iron-ore tailings flocculation as compared to other commercial reagents. An optimal dosage of synthesized reagent has been recommended based on the mud-level index and settling rate, for single-step and multi-step addition to the iron tailings slurry. The synthesized reagent has been assessed upon its capacity to produce clear overflow water and compaction of the solids.

A Conceptual Model of Polar Overturning Circulations

AbstractThe global ocean overturning circulation carries warm, salty water to high latitudes, both in the Arctic and Antarctic. Interaction with the atmosphere transforms this inflow into three distinct products: sea ice, surface Polar Water, and deep Overflow Water. The Polar Water and Overflow Water form estuarine and thermal overturning cells, stratified by salinity and temperature, respectively. A conceptual model specifies the characteristics of these water masses and cells given the inflow and air–sea–land fluxes of heat and freshwater. The model includes budgets of mass, salt, and heat, and parameterizations of Polar Water and Overflow Water formation, which include exchange with continental shelves. Model solutions are mainly controlled by a linear combination of air–sea–ice heat and freshwater fluxes and inflow heat flux that approximates the meteoric freshwater flux plus the sea ice export flux. The model shows that for the Arctic, the thermal overturning is likely robust, but the estuarine cell appears vulnerable to collapse via a so-called heat crisis that violates the budget equations. The system is pushed toward this crisis by increasing Atlantic Water inflow heat flux, increasing meteoric freshwater flux, and/or decreasing heat loss to the atmosphere. The Antarctic appears close to a so-called Overflow Water emergency with weak constraints on the strengths of the estuarine and thermal cells, uncertain sensitivity to parameters, and possibility of collapse of the thermal cell.

Iot Automatic Water Conservation System

Water the word plays a vital role in our life. It is the most important factor for the survival of every living organisms.The mankind facing the water scarcity problem in wordwide for the past decade.The water demand is the most challenging factor in India too. So there should be some technology to Conservand manage the water resource available in nature. In this proposed work, with the concept of IoT we have designed a water monitoring and control system with real time data bases. It is really useful in many areas like apartments, colleges, hostels, shopping malls etc.The concept is to intimate the user about the excess flow of waterthrough mail and control the overflow of water using solenoid valve.Therefore the water conservation and management can be done simultaneously.With the help of Proteus Software, simulationof the monitoring and controlling system can be done.

Effect of Height and Surface Roughness of a Broad Crested Weir on the Discharge Coefficient: Experimental Study

Weir is usually incorporated as control or regulation devices in hydraulic systems, with flow measurement as their secondary. It is normally intended for use in the field and thus to regulate broad discharges. Broad-Crested weir is among the oldest common weir types. In this paper, the effect of height and surface roughness for different Board Crested weirs models were studied on discharge coefficient (Cd) in a horizontal open channel. In the crest of the weir, certain materials may be combined with concrete (e.g., boulders) or may be used as cladding to minimize the effect of water overflow (e.g. stone). The weir surface should not be considered smooth in this case, and the discharge coefficient (Cd) must be re-estimated. For these purposes, laboratory flume was used to study the effect of height and surface roughness on the discharge coefficients with four of the different weir models dimensions of the concrete blocks. In this study, the flow conditions were considered to be free water flow and the viscosity effect was neglected. In all cases, the weir height effect was directly proportional to the discharge coefficient while the surface roughness effect was found to be inversely proportional to the coefficient Cd of the case study.

Unusual male size vs sperm count relationships in a coastal marine amphipod indicate reproductive impairment by unknown toxicants

Sperm quantity/quality are significant reproductive endpoints with clear links to population level dynamics. Amphipods are important model organisms in environmental toxicology. Despite this, field monitoring of male fertility in invertebrates has rarely been used in monitoring programs. The aim of this study was to compare sperm quality/quantity in an amphipod collected at six UK locations with differing water quality. Due to low sperm counts and an observed lack of relationship between sperm count and weight in amphipods collected from a nationally protected conservation area (Langstone Harbour, England), we also compared datasets from this site over a decade to determine the temporal significance of this finding. One collection to evaluate a female reproductive endpoint was also performed at this site. Interestingly, this harbour consistently presented some of the lowest sperm counts comparable to highly industrial sites and low eggs number from females. Amphipods collected from all the sites, except from Langstone Harbour, presented strong positive correlations between sperm count and weight. Given Langstone Harbour has several international and national protected statutes primarily for marine life and birds, our results indicate that E. marinus, one important food component for wading birds, might be impacted by unknown reproductive stressors. These unknown stressors maybe related to agricultural runoff, leachate from historical landfills and effluent from storm water overflows. This study highlights the importance of exploring new reproductive endpoints such as sperm quantity/quality in marine monitoring programs.