96-752: The Kalgan River is a river in the Great Southern region of Western Australia . The river is 140 kilometres (87 mi) long and, along with the King River , drains into Oyster Harbour . The lower 9 km of the river take the form of a drowned river valley with steep hillsides of forest and farmland, and the occasional outcrop of granite. The river's source is west of the Stirling Ranges . It rises north-west of Kendenup and flows generally southwards until it reaches Oyster Harbour about 10 km north-east of Albany . The Kalgan River
192-582: A lake , an ocean , or another river. A stream refers to water that flows in a natural channel , a geographic feature that can contain flowing water. A stream may also be referred to as a watercourse. The study of the movement of water as it occurs on Earth is called hydrology , and their effect on the landscape is covered by geomorphology . Rivers are part of the water cycle , the continuous processes by which water moves about Earth. This means that all water that flows in rivers must ultimately come from precipitation . The sides of rivers have land that
288-547: A trip hammer , and grind grains with a millstone . In the Middle Ages , water mills began to automate many aspects of manual labor , and spread rapidly. By 1300, there were at least 10,000 mills in England alone. A medieval watermill could do the work of 30–60 human workers. Water mills were often used in conjunction with dams to focus and increase the speed of the water. Water wheels continued to be used up to and through
384-500: A 33 centimetres (13 in) females ay lay 200,000 eggs in a spawning season. The eggs, larvae and juveniles are planktonic and drift southwards along the western coast of Australia and eastward along its south coast by the prevailing winds and currents, the Leeuwin Current being particularly important in this. At 30–60 millimetres (1.2–2.4 in) length the juveniles settle in the winter and spring using nursery sites along
480-740: A boat along certain stretches. In these religions, such as that of the Altai in Russia , the river is considered a living being that must be afforded respect. Rivers are some of the most sacred places in Hinduism. There is archeological evidence that mass ritual bathing in rivers at least 5,000 years ago in the Indus river valley . While most rivers in India are revered, the Ganges is most sacred. The river has
576-515: A central role in various Hindu myths, and its water is said to have properties of healing as well as absolution from sins. Hindus believe that when the cremated remains of a person is released into the Ganges, their soul is released from the mortal world. Freshwater fish make up 40% of the world's fish species, but 20% of these species are known to have gone extinct in recent years. Human uses of rivers make these species especially vulnerable. Dams and other engineered changes to rivers can block
672-408: A continuous flow of water throughout the year. This may be because an arid climate is too dry depending on the season to support a stream, or because a river is seasonally frozen in the winter (such as in an area with substantial permafrost ), or in the headwaters of rivers in mountains, where snowmelt is required to fuel the river. These rivers can appear in a variety of climates, and still provide
768-564: A habitat for aquatic life and perform other ecological functions. Subterranean rivers may flow underground through flooded caves. This can happen in karst systems, where rock dissolves to form caves. These rivers provide a habitat for diverse microorganisms and have become an important target of study by microbiologists . Other rivers and streams have been covered over or converted to run in tunnels due to human development. These rivers do not typically host any life, and are often used only for stormwater or flood control. One such example
864-495: A large scale. This has been attributed to unusually large floods destroying infrastructure; however, there is evidence that permanent changes to climate causing higher aridity and lower river flow may have been the determining factor in what river civilizations succeeded or dissolved. Water wheels began to be used at least 2,000 years ago to harness the energy of rivers. Water wheels turn an axle that can supply rotational energy to move water into aqueducts , work metal using
960-424: A narrow band of small, pointed teeth on each jaw. It has an almost straight lateral line . The whole of the head and body, except for the lower jaw, snout and over the eyes is covered in small, finely ctenoid scales. The long dorsal fin has a small notch between the higher spiny and the soft rayed parts, They have a small anal fin which is around half the length of the soft part of the dorsal fin. The caudal fin
1056-556: A peak in the 1970s, when between two or three dams were completed every day, and has since begun to decline. New dam projects are primarily focused in China , India , and other areas in Asia . The first civilizations of Earth were born on floodplains between 5,500 and 3,500 years ago. The freshwater, fertile soil, and transportation provided by rivers helped create the conditions for complex societies to emerge. Three such civilizations were
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#17327728943551152-891: A ritualistic sense has been compared to the Christian ritual of baptism , famously the Baptism of Jesus in the Jordan River . Floods also appear in Norse mythology , where the world is said to emerge from a void that eleven rivers flowed into. Aboriginal Australian religion and Mesoamerican mythology also have stories of floods, some of which contain no survivors, unlike the Abrahamic flood. Along with mythological rivers, religions have also cared for specific rivers as sacred rivers. The Ancient Celtic religion saw rivers as goddesses. The Nile had many gods attached to it. The tears of
1248-425: A river can take several forms. Tidal rivers (often part of an estuary ) have their levels rise and fall with the tide . Since the levels of these rivers are often already at or near sea level, the flow of alluvium and the brackish water that flows in these rivers may be either upriver or downriver depending on the time of day. Rivers that are not tidal may form deltas that continuously deposit alluvium into
1344-460: A section of the river behind them into a lake or reservoir. This can provide nearby cities with a predictable supply of drinking water. Hydroelectricity is desirable as a form of renewable energy that does not require any inputs beyond the river itself. Dams are very common worldwide, with at least 75,000 higher than 6 feet (1.8 m) in the U.S. Globally, reservoirs created by dams cover 193,500 square miles (501,000 km ). Dam-building reached
1440-530: A small clearing and can be readily landed upon. A smaller island, Willie Island, is a little downstream of the Upper Kalgan bridge. The Kalgan River is a place of great significance to the local Noongar people. A Dreaming story tells of a husband and wife who lived in the Porongurup Range . The husband beat his wife terribly but she escaped from him by stumbling through the thick bushland. As
1536-438: A water body is that body's riparian zone . Plants in the riparian zone of a river help stabilize its banks to prevent erosion and filter alluvium deposited by the river on the shore, including processing the nitrogen and other nutrients it contains. Forests in a riparian zone also provide important animal habitats . River ecosystems have also been categorized based on the variety of aquatic life they can sustain, also known as
1632-605: A water cycle that involved precipitation. The term flumen , in planetary geology , refers to channels on Saturn 's moon Titan that may carry liquid. Titan's rivers flow with liquid methane and ethane . There are river valleys that exhibit wave erosion , seas, and oceans. Scientists hope to study these systems to see how coasts erode without the influence of human activity, something that isn't possible when studying terrestrial rivers. Australian herring Centropristes georgianus Valenciennes, 1831 The Australian herring ( Arripis georgianus ), also known as
1728-445: Is a tributary , and the place they meet is a confluence . Rivers must flow to lower altitudes due to gravity . The bed of a river is typically within a river valley between hills or mountains . Rivers flowing through an impermeable section of land such as rocks will erode the slopes on the sides of the river. When a river carves a plateau or a similar high-elevation area, a canyon can form, with cliffs on either side of
1824-519: Is a natural freshwater stream that flows on land or inside caves towards another body of water at a lower elevation , such as an ocean , lake , or another river. A river may run dry before reaching the end of its course if it runs out of water, or only flow during certain seasons. Rivers are regulated by the water cycle , the processes by which water moves around the Earth. Water first enters rivers through precipitation , whether from rainfall,
1920-478: Is a species which is considered to be a desirable recreational fish. However, in Western Australia it is regarded as a commercially important species for fisheries and has been caught using lines, gill nets and seine nets . They were fished for using 'G' trap nets but following scientific advice on the health of the stock this was banned in 2015. It has a soft, slightly oily flesh and is thought of as
2016-504: Is also important for the lumber industry , as logs can be shipped via river. Countries with dense forests and networks of rivers like Sweden have historically benefited the most from this method of trade. The rise of highways and the automobile has made this practice less common. One of the first large canals was the Canal du Midi , connecting rivers within France to create a path from
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#17327728943552112-564: Is an ancient dam built on the Nile 4,500 years ago. The Ancient Roman civilization used aqueducts to transport water to urban areas . Spanish Muslims used mills and water wheels beginning in the seventh century. Between 130 and 1492, larger dams were built in Japan, Afghanistan, and India, including 20 dams higher than 15 metres (49 ft). Canals began to be cut in Egypt as early as 3000 BC, and
2208-448: Is at a higher elevation than the river itself, and in these areas, water flows downhill into the river. The headwaters of a river are the smaller streams that feed a river, and make up the river's source. These streams may be small and flow rapidly down the sides of mountains . All of the land uphill of a river that feeds it with water in this way is in that river's drainage basin or watershed. A ridge of higher elevation land
2304-405: Is because any natural impediment to the flow of the river may cause the current to deflect in a different direction. When this happens, the alluvium carried by the river can build up against this impediment, redirecting the course of the river. The flow is then directed against the opposite bank of the river, which will erode into a more concave shape to accommodate the flow. The bank will still block
2400-453: Is correlated with and thus can be used to predict certain data points related to rivers, such as the size of the drainage basin (drainage area), and the length of the channel. The ecosystem of a river includes the life that lives in its water, on its banks, and in the surrounding land. The width of the channel of a river, its velocity, and how shaded it is by nearby trees. Creatures in a river ecosystem may be divided into many roles based on
2496-455: Is deeply forked, the pectoral fins are small and the pelvic fins are moderately sized, having their origin underneath the centre of the pectoral fin base and extending midway to the anus. Australian herring are similar to the juveniles of the congeneric Australian salmon and differ from that species by their comparatively larger yellow and black eye and rounder head. This species is silver in colour with black tips on tail and gold spots along
2592-497: Is in part because of a projected loss of snowpack in mountains, meaning that melting snow can't replenish rivers during warm summer months, leading to lower water levels. Lower-level rivers also have warmer temperatures, threatening species like salmon that prefer colder upstream temperatures. Attempts have been made to regulate the exploitation of rivers to preserve their ecological functions. Many wetland areas have become protected from development. Water restrictions can prevent
2688-402: Is part of permafrost ice caps, or trace amounts of water vapor in the atmosphere. However, there is evidence that rivers flowed on Mars for at least 100,000 years. The Hellas Planitia is a crater left behind by an impact from an asteroid. It has sedimentary rock that was formed 3.7 billion years ago, and lava fields that are 3.3 billion years old. High resolution images of the surface of
2784-633: Is rarely static, the exact location of a river border may be called into question by countries. The Rio Grande between the United States and Mexico is regulated by the International Boundary and Water Commission to manage the right to fresh water from the river, as well as mark the exact location of the border. Up to 60% of fresh water used by countries comes from rivers that cross international borders. This can cause disputes between countries that live upstream and downstream of
2880-701: Is that of the Mississippi River , whose drainage basin covers 40% of the contiguous United States . The river was then used for shipping crops from the American Midwest and cotton from the American South to other states as well as the Atlantic Ocean. The role of urban rivers has evolved from when they were a center of trade, food, and transportation to modern times when these uses are less necessary. Rivers remain central to
2976-553: Is the Sunswick Creek in New York City, which was covered in the 1800s and now exists only as a sewer-like pipe. While rivers may flow into lakes or man-made features such as reservoirs , the water they contain will always tend to flow down toward the ocean . However, if human activity siphons too much water away from a river for other uses, the riverbed may run dry before reaching the sea. The outlets mouth of
Kalgan River - Misplaced Pages Continue
3072-452: Is the global fisheries name used by the Food and Agriculture Organization . The Australian herring has a streamlined, moderately deep and slightly elongate body which is somewhat compressed and has a relatively thin caudal peduncle. It has a quite small head with rather large eyes and a moderately large oblique mouth with the maxillae extending as far as the level of the centre of eyes. It has
3168-572: Is the region’s fourth largest river in terms of average annual flow (53,400 megalitres), and has the third largest catchment area (2,562 km). The upper reaches of the Kalgan River lie within the National Park. These tributaries are marginally saline to brackish, suggesting the levels of salinity are natural. The loss of catchment vegetation (66% of the catchment is cleared) has increased salinity levels downstream. The lower section of
3264-842: Is what typically separates drainage basins; water on one side of a ridge will flow into one set of rivers, and water on the other side will flow into another. One example of this is the Continental Divide of the Americas in the Rocky Mountains . Water on the western side of the divide flows into the Pacific Ocean , whereas water on the other side flows into the Atlantic Ocean . Not all precipitation flows directly into rivers; some water seeps into underground aquifers . These, in turn, can still feed rivers via
3360-599: The 2024 Summer Olympics . Another example is the restoration of the Isar in Munich from being a fully canalized channel with hard embankments to being wider with naturally sloped banks and vegetation. This has improved wildlife habitat in the Isar, and provided more opportunities for recreation in the river. As a natural barrier , rivers are often used as a border between countries , cities, and other territories . For example,
3456-678: The Albany Fish Traps have been situated here for at least the last 7,500 years. The fringing vegetation of the estuarine portion of the Kalgan River is dominated by the saltwater paperbark trees surrounded by dense stands of coastal saw sedge and shore rushes . The downstream freshwater parts of the river have a much greater variety of species, with a fringing forest that includes swamp paperbark , marri , jarrah , wattle and Western Australian peppermint trees . Further inland, species such as swamp yate , flooded gum and varieties of Banksia and Hakea are found. Parts of
3552-487: The Atlantic Ocean to the Mediterranean Sea . The nineteenth century saw canal-building become more common, with the U.S. building 4,400 miles (7,100 km) of canals by 1830. Rivers began to be used by cargo ships at a larger scale, and these canals were used in conjunction with river engineering projects like dredging and straightening to ensure the efficient flow of goods. One of the largest such projects
3648-501: The Industrial Revolution as a source of power for textile mills and other factories, but were eventually supplanted by steam power . Rivers became more industrialized with the growth of technology and the human population . As fish and water could be brought from elsewhere, and goods and people could be transported via railways , pre-industrial river uses diminished in favor of more complex uses. This meant that
3744-791: The Lamari River in New Guinea separates the Angu and the Fore people in New Guinea. The two cultures speak different languages and rarely mix. 23% of international borders are large rivers (defined as those over 30 meters wide). The traditional northern border of the Roman Empire was the Danube , a river that today forms the border of Hungary and Slovakia . Since the flow of a river
3840-525: The Nile and the Ganges . The Quran describes these four rivers as flowing with water, milk, wine, and honey, respectively. The book of Genesis also contains a story of a great flood . Similar myths are present in the Epic of Gilgamesh , Sumerian mythology, and in other cultures. In Genesis, the flood's role was to cleanse Earth of the wrongdoing of humanity. The act of water working to cleanse humans in
3936-568: The River Continuum Concept . "Shredders" are organisms that consume this organic material. The role of a "grazer" or "scraper" organism is to feed on the algae that collects on rocks and plants. "Collectors" consume the detritus of dead organisms. Lastly, predators feed on living things to survive. The river can then be modeled by the availability of resources for each creature's role. A shady area with deciduous trees might experience frequent deposits of organic matter in
Kalgan River - Misplaced Pages Continue
4032-627: The River Lethe to forget their previous life. Rivers also appear in descriptions of paradise in Abrahamic religions , beginning with the story of Genesis . A river beginning in the Garden of Eden waters the garden and then splits into four rivers that flow to provide water to the world. These rivers include the Tigris and Euphrates , and two rivers that are possibly apocryphal but may refer to
4128-787: The Sumerians in the Tigris–Euphrates river system , the Ancient Egyptian civilization in the Nile, and the Indus Valley Civilization on the Indus River . The desert climates of the surrounding areas made these societies especially reliant on rivers for survival, leading to people clustering in these areas to form the first cities . It is also thought that these civilizations were the first to organize
4224-485: The climate . The alluvium carried by rivers, laden with minerals, is deposited into the floodplain when the banks spill over, providing new nutrients to the soil, allowing them to support human activity like farming as well as a host of plant and animal life. Deposited sediment from rivers can form temporary or long-lasting fluvial islands . These islands exist in almost every river. About half of all waterways on Earth are intermittent rivers , which do not always have
4320-685: The cultural identity of cities and nations. Famous examples include the River Thames 's relationship to London , the Seine to Paris , and the Hudson River to New York City . The restoration of water quality and recreation to urban rivers has been a goal of modern administrations. For example, swimming was banned in the Seine for over 100 years due to concerns about pollution and the spread of E. coli , until cleanup efforts to allow its use in
4416-484: The discharge of a river, the amount of water passing through it at a particular time. The flow of a river can act as a means of transportation for plant and animal species, as well as a barrier. For example, the Amazon River is so wide in parts that the variety of species on either side of its basin are distinct. Some fish may swim upstream to spawn as part of a seasonal migration . Species that travel from
4512-465: The extinction of some species, and lowered the amount of alluvium flowing through rivers. Decreased snowfall from climate change has resulted in less water available for rivers during the summer. Regulation of pollution, dam removal , and sewage treatment have helped to improve water quality and restore river habitats. A river is a natural flow of freshwater that flows on or through land towards another body of water downhill. This flow can be into
4608-613: The mud minnow ( Galaxiella munda ), Balston's pygmy perch ( Nannatherina balston ), nightfish ( Bostockia porosa ) and the western pygmy perch ( Edelia vittata ). The river is home to a large population of birds. In the estuarine part of the river, species such as the Australian pelican , little black cormorant , pied cormorant , pied oystercatcher , black-winged stilt , common sandpiper , Australian white ibis , straw-necked ibis , yellow-billed spoonbill , Pacific gull and Caspian tern can often be seen. The freshwater parts of
4704-575: The ruff , tommy ruff , or Australian ruff , is one of four Australasian fish species within the genus Arripis . It closely resembles its sister species, the Australian salmon , although it grows to a smaller size. Like the other members of its genus, it is found in cooler waters around the southern coast of Australia . It is not biologically related to the herring family Clupeidae . In Australia, additional vernacular names used for this fish include bull herring, herring, rough, ruffies, sea herring, tommy, tommy rough and South Australian roughy. Ruff
4800-402: The runoff of water down a slope, the melting of glaciers or snow , or seepage from aquifers beneath the surface of the Earth. Rivers flow in channeled watercourses and merge in confluences to form drainage basins , areas where surface water eventually flows to a common outlet. Rivers have a great effect on the landscape around them. They may regularly overflow their banks and flood
4896-436: The sea . The sediment yield of a river is the quantity of sand per unit area within a watershed that is removed over a period of time. The monitoring of the sediment yield of a river is important for ecologists to understand the health of its ecosystems, the rate of erosion of the river's environment, and the effects of human activity. Rivers rarely run in a straight direction, instead preferring to bend or meander . This
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#17327728943554992-521: The water table , the groundwater beneath the surface of the land stored in the soil . Water flows into rivers in places where the river's elevation is lower than that of the water table. This phenomenon is why rivers can still flow even during times of drought . Rivers are also fed by the melting of snow glaciers present in higher elevation regions. In summer months, higher temperatures melt snow and ice, causing additional water to flow into rivers. Glacier melt can supplement snow melt in times like
5088-444: The Kalgan River is good fishing for many species including black bream , with a few skippy, herring , mulloway and whiting . The Kalgan River is renowned as being an excellent place to fish for bream and some of the state's largest bream have been caught in the river. Smaller freshwater species that can be found in the Kalgan River include the western galaxias ( Galaxias occidentalis ), the common jollytail ( Galaxias maculatus ),
5184-558: The Kalgan River is tidal; a rockbar at the Upper Kalgan bridge separates the upper section from the tidal lower section. The tributaries of the Kalgan River include Napier Creek, Boonawarrup Creek, Young River, Stony Creek and Gaalgegup Creek. The river flows through two pools of note: Meriwarbelup Pool and Noorubup Pool. The Kalgan River was named the "Riviere des Francais" by the French Scientific Expedition in 1803, captained by French explorer Nicolas Baudin , in
5280-534: The Lower King Bridge site. The jetty was also later used as a landing point for tourist vessels that travelled upriver from Albany. It is now in a state of disrepair. The Kalgan River contains many small islands, particularly in the section below the Upper Kalgan bridge. The largest is Honeymoon Island (also called Elbow Island), which is slightly upstream of the Lower Kalgan bridge. This island has
5376-695: The bodies of humans and animals worldwide, as well as in the soil, with potentially negative health effects. Research into how to remove it from the environment, and how harmful exposure is, is ongoing. Fertilizer from farms can lead to a proliferation of algae on the surface of rivers and oceans, which prevents oxygen and light from dissolving into water, making it impossible for underwater life to survive in these so-called dead zones . Urban rivers are typically surrounded by impermeable surfaces like stone, asphalt , and concrete. Cities often have storm drains that direct this water to rivers. This can cause flooding risk as large amounts of water are directed into
5472-405: The complete draining of rivers. Limits on the construction of dams, as well as dam removal , can restore the natural habitats of river species. Regulators can also ensure regular releases of water from dams to keep animal habitats supplied with water. Limits on pollutants like pesticides can help improve water quality. Today, the surface of Mars does not have liquid water. All water on Mars
5568-436: The effect of normalizing the effects of rivers; the greatest floods are smaller and more predictable, and larger sections are open for navigation by boats and other watercraft. A major effect of river engineering has been a reduced sediment output of large rivers. For example, the Mississippi River produced 400 million tons of sediment per year. Due to the construction of reservoirs , sediment buildup in man-made levees , and
5664-826: The first human civilizations . The organisms that live around or in a river such as fish , aquatic plants , and insects have different roles, including processing organic matter and predation . Rivers have produced abundant resources for humans, including food , transportation , drinking water , and recreation. Humans have engineered rivers to prevent flooding, irrigate crops, perform work with water wheels , and produce hydroelectricity from dams. People associate rivers with life and fertility and have strong religious, political, social, and mythological attachments to them. Rivers and river ecosystems are threatened by water pollution , climate change , and human activity. The construction of dams, canals , levees , and other engineered structures has eliminated habitats, has caused
5760-451: The fish zonation concept. Smaller rivers can only sustain smaller fish that can comfortably fit in its waters, whereas larger rivers can contain both small fish and large fish. This means that larger rivers can host a larger variety of species. This is analogous to the species-area relationship , the concept of larger habitats being host to more species. In this case, it is known as the species-discharge relationship, referring specifically to
5856-673: The floating of wood on rivers to transport it, was especially important. Rivers also were an important source of drinking water . For civilizations built around rivers, fish were an important part of the diet of humans. Some rivers supported fishing activities, but were ill-suited to farming, such as those in the Pacific Northwest . Other animals that live in or near rivers like frogs , mussels , and beavers could provide food and valuable goods such as fur . Humans have been building infrastructure to use rivers for thousands of years. The Sadd el-Kafara dam near Cairo , Egypt,
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#17327728943555952-412: The flow of the river beneath its surface. These help rivers flow straighter by increasing the speed of the water at the middle of the channel, helping to control floods. Levees are also used for this purpose. They can be thought of as dams constructed on the sides of rivers, meant to hold back water from flooding the surrounding area during periods of high rainfall. They are often constructed by building up
6048-399: The flow, causing it to reflect in the other direction. Thus, a bend in the river is created. Rivers may run through low, flat regions on their way to the sea. These places may have floodplains that are periodically flooded when there is a high level of water running through the river. These events may be referred to as "wet seasons' and "dry seasons" when the flooding is predictable due to
6144-650: The form of leaves. In this type of ecosystem, collectors and shredders will be most active. As the river becomes deeper and wider, it may move slower and receive more sunlight . This supports invertebrates and a variety of fish , as well as scrapers feeding on algae. Further downstream, the river may get most of its energy from organic matter that was already processed upstream by collectors and shredders. Predators may be more active here, including fish that feed on plants, plankton , and other fish. The flood pulse concept focuses on habitats that flood seasonally, including lakes and marshes . The land that interfaces with
6240-508: The goddess Isis were said to be the cause of the river's yearly flooding, itself personified by the goddess Hapi . Many African religions regard certain rivers as the originator of life. In Yoruba religion , Yemọja rules over the Ogun River in modern-day Nigeria and is responsible for creating all children and fish. Some sacred rivers have religious prohibitions attached to them, such as not being allowed to drink from them or ride in
6336-428: The irrigation of desert environments for growing food. Growing food at scale allowed people to specialize in other roles, form hierarchies, and organize themselves in new ways, leading to the birth of civilization. In pre-industrial society , rivers were a source of transportation and abundant resources. Many civilizations depended on what resources were local to them to survive. Shipping of commodities, especially
6432-434: The late summer, when there may be less snow left to melt, helping to ensure that the rivers downstream of the glaciers have a continuous supply of water. Rivers flow downhill, with their direction determined by gravity . A common misconception holds that all or most rivers flow from North to South, but this is not true. As rivers flow downstream, they eventually merge to form larger rivers. A river that feeds into another
6528-474: The level of river branching in a drainage basin. Several systems of stream order exist, one of which is the Strahler number . In this system, the first tributaries of a river are 1st order rivers. When two 1st order rivers merge, the resulting river is 2nd order. If a river of a higher order and a lower order merge, the order is incremented from whichever of the previous rivers had the higher order. Stream order
6624-561: The local ecosystems of rivers needed less protection as humans became less reliant on them for their continued flourishing. River engineering began to develop projects that enabled industrial hydropower , canals for the more efficient movement of goods, as well as projects for flood prevention . River transportation has historically been significantly cheaper and faster than transportation by land. Rivers helped fuel urbanization as goods such as grain and fuel could be floated downriver to supply cities with resources. River transportation
6720-407: The mechanical shadoof began to be used to raise the elevation of water. Drought years harmed crop yields, and leaders of society were incentivized to ensure regular water and food availability to remain in power. Engineering projects like the shadoof and canals could help prevent these crises. Despite this, there is evidence that floodplain-based civilizations may have been abandoned occasionally at
6816-400: The migration routes of fish and destroy habitats. Rivers that flow freely from headwaters to the sea have better water quality, and also retain their ability to transport nutrient-rich alluvium and other organic material downstream, keeping the ecosystem healthy. The creation of a lake changes the habitat of that portion of water, and blocks the transportation of sediment, as well as preventing
6912-399: The natural meandering of the river. Dams block the migration of fish such as salmon for which fish ladder and other bypass systems have been attempted, but these are not always effective. Pollution from factories and urban areas can also damage water quality. " Per- and polyfluoroalkyl substances (PFAS) is a widely used chemical that breaks down at a slow rate. It has been found in
7008-429: The natural terrain with soil or clay. Some levees are supplemented with floodways, channels used to redirect floodwater away from farms and populated areas. Dams restrict the flow of water through a river. They can be built for navigational purposes, providing a higher level of water upstream for boats to travel in. They may also be used for hydroelectricity , or power generation from rivers. Dams typically transform
7104-425: The plain show evidence of a river network, and even river deltas. These images reveal channels formed in the rock, recognized by geologists who study rivers on Earth as being formed by rivers, as well as "bench and slope" landforms, outcroppings of rock that show evidence of river erosion. Not only do these formations suggest that rivers once existed, but that they flowed for extensive time periods, and were part of
7200-448: The removal of natural banks replaced with revetments , this sediment output has been reduced by 60%. The most basic river projects involve the clearing of obstructions like fallen trees. This can scale up to dredging , the excavation of sediment buildup in a channel, to provide a deeper area for navigation. These activities require regular maintenance as the location of the river banks changes over time, floods bring foreign objects into
7296-536: The reverse, death and destruction, especially through floods . This power has caused rivers to have a central role in religion , ritual , and mythology . In Greek mythology , the underworld is bordered by several rivers. Ancient Greeks believed that the souls of those who perished had to be borne across the River Styx on a boat by Charon in exchange for money. Souls that were judged to be good were admitted to Elysium and permitted to drink water from
7392-477: The river also support an enormous variety of birds including nankeen kestrel , Australian hobby , wedge-tailed eagle , short-billed black cockatoo , long-billed black cockatoo , galah , little corella , purple-crowned lorikeet , red-capped parrot , laughing kookaburra , willie wagtail , white-breasted robin , splendid fairywren , New Holland honeyeater , red wattlebird and red-eared firetail . Amphibious species that can be commonly be found in and around
7488-478: The river are frogs, such as the western banjo and moaning frogs . Reptiles frequently found in the area include tiger snakes and dugites . The southern end of the Kalgan River has two bridges of note: the Upper Kalgan bridge and the Lower Kalgan Bridge. The Lower Kalgan Bridge was built from 1906 and opened in 1908. At 900 feet (274 m) in length, it was the longest of its kind over water in
7584-468: The river, and natural sediment buildup continues. Artificial channels are often constructed to "cut off" winding sections of a river with a shorter path, or to direct the flow of a river in a straighter direction. This effect, known as channelization, has made the distance required to traverse the Missouri River in 116 kilometres (72 mi) shorter. Dikes are channels built perpendicular to
7680-552: The river. Areas of a river with softer rock weather faster than areas with harder rock, causing a difference in elevation between two points of a river. This can cause the formation of a waterfall as the river's flow falls down a vertical drop. A river in a permeable area does not exhibit this behavior and may even have raised banks due to sediment. Rivers also change their landscape through their transportation of sediment , often known as alluvium when applied specifically to rivers. This debris comes from erosion performed by
7776-625: The river. A country that is downstream of another may object to the upstream country diverting too much water for agricultural uses, pollution, as well as the creation of dams that change the river's flow characteristics. For example, Egypt has an agreement with Sudan requiring a specific minimum volume of water to pass into the Nile yearly over the Aswan Dam , to maintain both countries access to water. The importance of rivers throughout human history has given them an association with life and fertility . They have also become associated with
7872-796: The riverbank that have been cleared support a variety of introduced weeds that are shallow rooted. In areas in which the native deep-rooted species have been lost, erosion of the river bank has become a problem. Many wild flowers can be found along the Luke Pen Walk, a trail that follows the river for 9 km before it reaches Oyster Harbour. Some of the varieties include Hovea trisperma (common hovea), Hovea pungens (devil’s pins), Hovea elliptica (tree hovea), Adenanthos obovatus (basket flower), Lysinema ciliatum (curry flower), Leucopogeon pulchelus (beard heath), Banksia sessilis (parrot bush), Banksia squarrosa (pringle) and Acacia extensa (wiry wattle). The estuarine end of
7968-457: The rivers themselves, debris swept into rivers by rainfall, as well as erosion caused by the slow movement of glaciers. The sand in deserts and the sediment that forms bar islands is from rivers. The particle size of the debris is gradually sorted by the river, with heavier particles like rocks sinking to the bottom, and finer particles like sand or silt carried further downriver . This sediment may be deposited in river valleys or carried to
8064-412: The rivers. Due to these impermeable surfaces, these rivers often have very little alluvium carried in them, causing more erosion once the river exits the impermeable area. It has historically been common for sewage to be directed directly to rivers via sewer systems without being treated, along with pollution from industry. This has resulted in a loss of animal and plant life in urban rivers, as well as
8160-409: The sea from their mouths. Depending on the activity of waves, the strength of the river, and the strength of the tidal current, the sediment can accumulate to form new land. When viewed from above, a delta can appear to take the form of several triangular shapes as the river mouth appears to fan out from the original coastline . In hydrology , a stream order is a positive integer used to describe
8256-414: The sea to breed in freshwater rivers are anadromous. Salmon are an anadromous fish that may die in the river after spawning, contributing nutrients back to the river ecosystem. Modern river engineering involves a large-scale collection of independent river engineering structures that have the goal of flood control , improved navigation, recreation, and ecosystem management. Many of these projects have
8352-548: The ship Géographe , which anchored in what is now known as Frenchmans Bay, and was subsequently known as the "French River" by early settlers. The explorer Alexander Collie recorded the river as "Kal-gan-up" in April 1831. The name Kalganup is believed to be the Noongar word for "place of many waters". Kalganup is also thought to mean "place of fishes" and there are still the remains of Aboriginal fish traps. The traps, known as
8448-402: The south coast and along the east coast as far north as Forster, New South Wales . It is also found around Tasmania. Australian herring form large schools in sea-grass meadows, off beaches, over reefs, in coastal bays and in estuaries. They are normally found near the surface, going no deeper than a few metres. They are predators feeding on smaller fishes and some invertebrates which live among
8544-480: The south coast. Some remain close to where the spawning grounds are along the southern part of the western coast of Western Australia. Geographe Bay appears to be a very important source of recruitment for the west coast population. Once they have spawned, the adult fish remain off the west coast of Western Australia and do not return to the south coast. They disperse along the coast, they move into estuaries and go as far north as Shark Bay . In most of Australia this
8640-519: The spread of waterborne diseases such as cholera . In modern times, sewage treatment and controls on pollution from factories have improved the water quality of urban rivers. Climate change can change the flooding cycles and water supply available to rivers. Floods can be larger and more destructive than expected, causing damage to the surrounding areas. Floods can also wash unhealthy chemicals and sediment into rivers. Droughts can be deeper and longer, causing rivers to run dangerously low. This
8736-467: The state at the time. At this time, the bridge had a special navigation span, 40 feet (12 m) wide at the deepest part of the river. The original bridge remained in place until 1958, when it was replaced, but the navigation span trusses were removed for preservation and are now on display in the park at the western end of the bridge. The Government Jetty was also built in 1906 so that timber and other construction materials could be delivered adjacent to
8832-485: The surrounding area, spreading nutrients to the surrounding area. Sediment or alluvium carried by rivers shapes the landscape around it, forming deltas and islands where the flow slows down. Rivers rarely run in a straight line, instead, they bend or meander ; the locations of a river's banks can change frequently. Rivers get their alluvium from erosion , which carves rock into canyons and valleys . Rivers have sustained human and animal life for millennia, including
8928-553: The upper body. The juveniles have dark golden bars on their flanks. The dorsal fin contains 9 spines and 16 soft rays and the anal fin has 3 spines and 10 soft rays. The maximum fork length recorded is 41 centimetres (16 in) but they are commonly 25–30 centimetres (9.8–11.8 in). The Australian herring is endemic to the temperate seas of southern Australia from the Swan River in Western Australia along
9024-485: The weed beds and sea grass meadows. These fish reach sexual maturity at around 2–3 years of age and once mature they move westwards along the Australian coast to an area of the southwestern coast where they spawn alongside adults resident in that area. The spawning takes place in April to June. The fertility of the females depends on their size, a 20 centimetres (7.9 in) long individual may lay 50,000 eggs while
9120-475: The wife ran through the bush, her digging stick trailed over the Earth and cut open the soil behind her forming the path of the Kalgan river. The Luke Pen Walk is a track that follows the Kalgan River; it was constructed in 1997. The walk is described as easy with the terrain being generally flat and even. With a total length of 9 kilometres (6 mi) it can take about 4 hours to complete the round trip. The walk
9216-637: Was named after Dr Luke Pen , a local scientist, who made significant contributions to the local community with his preservation work. The walk was named in 2002 following Pen's death. The northern end of the walk is near the Upper Kalgan Bridge and is on the eastern bank of the river, the southern end of the walk is located at the end of East Bank road about 3 kilometres (2 mi) north of the lower Kalgan bridge. 34°57′03″S 117°58′41″E / 34.95083°S 117.97806°E / -34.95083; 117.97806 River A river
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