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Eprapah Creek
Eprapah Creek (longitude 153.30º East, latitude -27.567º South) is a sub-tropical stream located in Redland City close to Brisbane in South East Queensland, Australia. It rises on the north-eastern slopes of Mount Cotton and flows directly to the Moreton Bay at Victoria Point. It is long with about of estuarine zone. In the latter, the water depth is typically about one to two m mid-stream, the width is about 20 to 30 m and the tides are semi-diurnal with a range of about two m. The catchment (~ 39 km2 area) is mostly urban in the lower reaches and semi rural/rural residential in the upper reaches. The creek includes several conservation areas such as Eprapah hosting endangered species, e.g. koalas, swamp wallabies, sea eagles. Water quality The water quality and ecology have been closely monitored at Eprapah Creek ( Victoria Point, Queensland) over thirty years by Redland Shire Council, Environmental Protection Agency (EPA) and local community groups. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Redland City
Redland City, better known as the Redlands and formerly known as Redland Shire, is a Local government in Australia, local government area and a part of the Brisbane metropolitan area in South East Queensland. With a population of 156,863 in June 2018, the city is spread along the southern coast of Moreton Bay, covering . Its mainland borders the City of Brisbane to the west and north-west, and Logan City to the south-west and south, while its islands are situated north of the City of Gold Coast. Redland attained city status on 15 March 2008, having been a shire since 1949, when it was created by the merger of the former Shire of Tingalpa, Tingalpa and Shire of Cleveland, Cleveland Shires.Queensland State Archives, Search for Agency D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turbulence
In fluid dynamics, turbulence or turbulent flow is fluid motion characterized by chaotic changes in pressure and flow velocity. It is in contrast to a laminar flow, which occurs when a fluid flows in parallel layers, with no disruption between those layers. Turbulence is commonly observed in everyday phenomena such as surf, fast flowing rivers, billowing storm clouds, or smoke from a chimney, and most fluid flows occurring in nature or created in engineering applications are turbulent. Turbulence is caused by excessive kinetic energy in parts of a fluid flow, which overcomes the damping effect of the fluid's viscosity. For this reason turbulence is commonly realized in low viscosity fluids. In general terms, in turbulent flow, unsteady vortices appear of many sizes which interact with each other, consequently drag due to friction effects increases. This increases the energy needed to pump fluid through a pipe. The onset of turbulence can be predicted by the dimensionless Rey ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Rivers Of Australia
This is a list of rivers of Australia. Rivers are ordered alphabetically, by state. The same river may be found in more than one state as many rivers cross state borders. Longest rivers nationally Longest river by state or territory Although the Murray River forms much of the border separating New South Wales and Victoria, it is not Victoria's longest river because the New South Wales border is delineated by the river's southern bank rather than by the middle of the river. The only section of the river formally within Victoria is a stretch of approximately where it separates Victoria and South Australia. At this point, the middle of the river forms the border. Rivers by state or territory The following is a list of rivers located within Australian states and territories. Where a river crosses a state or territory boundary, it is listed in both states and territories. Where a river has a name that includes the word creek, it has been officially designated as a river. Aus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saltwater Intrusion
Saltwater intrusion is the movement of saline water into freshwater aquifers, which can lead to groundwater quality degradation, including drinking water sources, and other consequences. Saltwater intrusion can naturally occur in coastal aquifers, owing to the hydraulic connection between groundwater and seawater. Because saline water has a higher mineral content than freshwater, it is denser and has a higher water pressure. As a result, saltwater can push inland beneath the freshwater. In other topologies, submarine groundwater discharge can push fresh water into saltwater. Certain human activities, especially groundwater pumping from coastal freshwater wells, have increased saltwater intrusion in many coastal areas. Water extraction drops the level of fresh groundwater, reducing its water pressure and allowing saltwater to flow further inland. Other contributors to saltwater intrusion include navigation channels or agricultural and drainage channels, which provide conduits for s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plume (hydrodynamics)
In hydrodynamics, a plume or a column is a vertical body of one fluid moving through another. Several effects control the motion of the fluid, including momentum (inertia), diffusion and buoyancy (density differences). Pure ''jets'' and pure ''plumes'' define flows that are driven entirely by momentum and buoyancy effects, respectively. Flows between these two limits are usually described as forced plumes or buoyant jets. "Buoyancy is defined as being positive" when, in the absence of other forces or initial motion, the entering fluid would tend to rise. Situations where the density of the plume fluid is greater than its surroundings (i.e. in still conditions, its natural tendency would be to sink), but the flow has sufficient initial momentum to carry it some distance vertically, are described as being negatively buoyant. Movement Usually, as a plume moves away from its source, it widens because of entrainment of the surrounding fluid at its edges. Plume shapes can be influ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Advection
In the field of physics, engineering, and earth sciences, advection is the transport of a substance or quantity by bulk motion of a fluid. The properties of that substance are carried with it. Generally the majority of the advected substance is also a fluid. The properties that are carried with the advected substance are conserved properties such as energy. An example of advection is the transport of pollutants or silt in a river by bulk water flow downstream. Another commonly advected quantity is energy or enthalpy. Here the fluid may be any material that contains thermal energy, such as water or air. In general, any substance or conserved, extensive quantity can be advected by a fluid that can hold or contain the quantity or substance. During advection, a fluid transports some conserved quantity or material via bulk motion. The fluid's motion is described mathematically as a vector field, and the transported material is described by a scalar field showing its distribution ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salinity
Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal to ‰). Salinity is an important factor in determining many aspects of the chemistry of natural waters and of biological processes within it, and is a thermodynamic state variable that, along with temperature and pressure, governs physical characteristics like the density and heat capacity of the water. A contour line of constant salinity is called an ''isohaline'', or sometimes ''isohale''. Definitions Salinity in rivers, lakes, and the ocean is conceptually simple, but technically challenging to define and measure precisely. Conceptually the salinity is the quantity of dissolved salt content of the water. Salts are compounds like sodium chloride, magnesium sulfate, potassium nitrate, and sodium bicarbonate which dissolve into ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turbidity
Turbidity is the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air. The measurement of turbidity is a key test of water quality. Fluids can contain suspended solid matter consisting of particles of many different sizes. While some suspended material will be large enough and heavy enough to settle rapidly to the bottom of the container if a liquid sample is left to stand (the settable solids), very small particles will settle only very slowly or not at all if the sample is regularly agitated or the particles are colloidal. These small solid particles cause the liquid to appear turbid. Turbidity (or haze) is also applied to transparent solids such as glass or plastic. In plastic production, haze is defined as the percentage of light that is deflected more than 2.5° from the incoming light direction. Causes and effects Turbidity in open water may be caused by growth of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dissolved Oxygen
Oxygen saturation (symbol SO2) is a relative measure of the concentration of oxygen that is dissolved or carried in a given medium as a proportion of the maximal concentration that can be dissolved in that medium at the given temperature. It can be measured with a dissolved oxygen probe such as an oxygen sensor or an optode in liquid media, usually water. The standard unit of oxygen saturation is percent (%). Oxygen saturation can be measured regionally and noninvasively. Arterial oxygen saturation (SaO2) is commonly measured using pulse oximetry. Tissue saturation at peripheral scale can be measured using NIRS. This technique can be applied on both muscle and brain. In medicine In medicine, oxygen saturation refers to ''oxygenation'', or when oxygen molecules () enter the tissues of the body. In this case blood is oxygenated in the lungs, where oxygen molecules travel from the air into the blood. Oxygen saturation (() sats) measures the percentage of hemoglobin bindin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratification (water)
Stratification is the separation of water in layers. Two main types of stratification of water are uniform and layered stratification. Layered stratification occurs in all ocean basins. Stratified layers act as a barrier to the mixing of water, which impacts the exchange of heat, carbon, oxygen and other nutrients. Due to upwelling and downwelling, which are both wind-driven, mixing of different layers can occur through the rise of cold nutrient-rich and warm water, respectively. Generally, layers are based on water density: heavier, and hence denser, water is below the lighter water, representing a stable stratification. For example, the pycnocline is a layer in the ocean where the change in density is relatively large compared to that of other layers in the ocean. The thickness of the thermocline is not constant everywhere and depends on a variety of variables. Between 1960 and 2018, upper ocean stratification increased between 0.7-1.2% per decade. This means that the differenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mixture Model
In statistics, a mixture model is a probabilistic model for representing the presence of subpopulations within an overall population, without requiring that an observed data set should identify the sub-population to which an individual observation belongs. Formally a mixture model corresponds to the mixture distribution that represents the probability distribution of observations in the overall population. However, while problems associated with "mixture distributions" relate to deriving the properties of the overall population from those of the sub-populations, "mixture models" are used to make statistical inferences about the properties of the sub-populations given only observations on the pooled population, without sub-population identity information. Mixture models should not be confused with models for compositional data, i.e., data whose components are constrained to sum to a constant value (1, 100%, etc.). However, compositional models can be thought of as mixture models ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Quality
Water quality refers to the chemical, physical, and biological characteristics of water based on the standards of its usage. It is most frequently used by reference to a set of standards against which compliance, generally achieved through treatment of the water, can be assessed. The most common standards used to monitor and assess water quality convey the health of ecosystems, safety of human contact, extend of water pollution and condition of drinking water. Water quality has a significant impact on water supply and oftentimes determines supply options. Categories The parameters for water quality are determined by the intended use. Work in the area of water quality tends to be focused on water that is treated for potability, industrial/domestic use, or restoration (of an environment/ecosystem, generally for health of human/aquatic life). Human consumption Contaminants that may be in untreated water include microorganisms such as viruses, protozoa and bacteria ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
