103-654: The Bonnet Carré Spillway / ˈ b ɒ n iː ˈ k ɛr iː / is a flood control operation in the Lower Mississippi Valley . Located in St. Charles Parish, Louisiana , about 12 miles (19 km) west of New Orleans , it allows floodwaters from the Mississippi River to flow into Lake Pontchartrain and thence into the Gulf of Mexico . The spillway was constructed between 1929 and 1931, following
206-449: A dam , landslide, or glacier . In one instance, a flash flood killed eight people enjoying the water on a Sunday afternoon at a popular waterfall in a narrow canyon. Without any observed rainfall, the flow rate increased from about 50 to 1,500 cubic feet per second (1.4 to 42 m /s) in just one minute. Two larger floods occurred at the same site within a week, but no one was at the waterfall on those days. The deadly flood resulted from
309-646: A flash flood . Flash floods usually result from intense rainfall over a relatively small area, or if the area was already saturated from previous precipitation. The amount, location, and timing of water reaching a drainage channel from natural precipitation and controlled or uncontrolled reservoir releases determines the flow at downstream locations. Some precipitation evaporates, some slowly percolates through soil, some may be temporarily sequestered as snow or ice, and some may produce rapid runoff from surfaces including rock, pavement, roofs, and saturated or frozen ground. The fraction of incident precipitation promptly reaching
412-515: A landslide , earthquake or volcanic eruption . Examples include outburst floods and lahars . Tsunamis can cause catastrophic coastal flooding , most commonly resulting from undersea earthquakes. The primary effects of flooding include loss of life and damage to buildings and other structures, including bridges, sewerage systems, roadways, and canals. The economic impacts caused by flooding can be severe. Every year flooding causes countries billions of dollars worth of damage that threatens
515-401: A terminal mouth , ctenoid scales, and a lateral line that is arched upward anteriorly. The bluegill typically ranges in size from about 4 to 12 inches (100–300 mm), and reaches a maximum size just over 16 inches (410 mm). The largest bluegill ever caught was 4 lb 12 oz (2.2 kg) in 1950. The bluegill is most closely related to the orangespotted sunfish and
618-484: A tropical cyclone or an extratropical cyclone , falls within this category. A storm surge is "an additional rise of water generated by a storm, over and above the predicted astronomical tides". Due to the effects of climate change (e.g. sea level rise and an increase in extreme weather events) and an increase in the population living in coastal areas, the damage caused by coastal flood events has intensified and more people are being affected. Flooding in estuaries
721-411: A balance between food abundance and predator abundance. Bluegill use gill rakers and bands of small teeth to ingest their food. During summer months, bluegills generally consume 3.2 percent of their body weight each day. To capture prey, bluegills use a suction system in which they accelerate water into their mouth. Prey comes in with this water. Only a limited amount of water is able to be suctioned, so
824-410: A command center for the escape response and respond quickly once the neural pathway has been activated by an initial stimulus. The cells trigger a contraction of muscle that bends the fish body into a 'C' to then aid in the propulsion away from a predator. The C-start trajectory is highly variable, allowing the fish to alter its escape response each time. Because of this high variability, predators have
927-468: A country can be lost in extreme flood circumstances. Some tree species may not survive prolonged flooding of their root systems. Flooding in areas where people live also has significant economic implications for affected neighborhoods. In the United States , industry experts estimate that wet basements can lower property values by 10–25 percent and are cited among the top reasons for not purchasing
1030-538: A drainage channel has been observed from nil for light rain on dry, level ground to as high as 170 percent for warm rain on accumulated snow. Most precipitation records are based on a measured depth of water received within a fixed time interval. Frequency of a precipitation threshold of interest may be determined from the number of measurements exceeding that threshold value within the total time period for which observations are available. Individual data points are converted to intensity by dividing each measured depth by
1133-627: A few minutes for roof and parking lot drainage structures, while cumulative rainfall over several days would be critical for river basins. Water flowing downhill ultimately encounters downstream conditions slowing movement. The final limitation in coastal flooding lands is often the ocean or some coastal flooding bars which form natural lakes . In flooding low lands, elevation changes such as tidal fluctuations are significant determinants of coastal and estuarine flooding. Less predictable events like tsunamis and storm surges may also cause elevation changes in large bodies of water. Elevation of flowing water
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#17327722721791236-605: A few. Gastrointestinal disease and diarrheal diseases are very common due to a lack of clean water during a flood. Most of clean water supplies are contaminated when flooding occurs. Hepatitis A and E are common because of the lack of sanitation in the water and in living quarters depending on where the flood is and how prepared the community is for a flood. When floods hit, people lose nearly all their crops, livestock, and food reserves and face starvation. Floods also frequently damage power transmission and sometimes power generation , which then has knock-on effects caused by
1339-728: A home. According to the U.S. Federal Emergency Management Agency (FEMA), almost 40 percent of small businesses never reopen their doors following a flooding disaster. In the United States, insurance is available against flood damage to both homes and businesses. Economic hardship due to a temporary decline in tourism, rebuilding costs, or food shortages leading to price increases is a common after-effect of severe flooding. The impact on those affected may cause psychological damage to those affected, in particular where deaths, serious injuries and loss of property occur. Fatalities connected directly to floods are usually caused by drowning ;
1442-431: A key role within the food chain of its freshwater ecosystem . A popular panfish among anglers , bluegill usually hide around and inside old tree stumps in swamps and other underwater structures (e.g. snags ), and can live in either deep or very shallow water. Bluegills also like to find shelter among aquatic plants and in the shade of trees along banks , and will often move from one cover to another depending on
1545-404: A lower chance of learning a successful predation technique to capture the fish. The C-start escape response produces other advantages, including the ability to move quickly and unpredictably to capture prey. Hydrodynamically, the bluegill exhibits specific flow patterns that accompany its C-start escape response. The caudal (tail) fin is a main source of momentum in typical kinematic models of
1648-518: A major source of sand and clay that is used in construction projects throughout the area. But in the post- Katrina era, clay extracted from the spillway will be crucial to raising the levees in St. Charles Parish and east Jefferson Parish . The several openings of the spillway have had a significant effect on marine fisheries in the Mississippi Sound , which resulted in a federal award of damages in 2011 and ongoing federal litigation over
1751-486: A more distant point controls at higher water levels. Effective flood channel geometry may be changed by growth of vegetation, accumulation of ice or debris, or construction of bridges, buildings, or levees within the flood channel. Periodic floods occur on many rivers, forming a surrounding region known as the flood plain . Even when rainfall is relatively light, the shorelines of lakes and bays can be flooded by severe winds—such as during hurricanes —that blow water into
1854-413: A thunderstorm over part of the drainage basin, where steep, bare rock slopes are common and the thin soil was already saturated. Flash floods are the most common flood type in normally-dry channels in arid zones, known as arroyos in the southwest United States and many other names elsewhere. In that setting, the first flood water to arrive is depleted as it wets the sandy stream bed. The leading edge of
1957-493: A tombstone and casket were discovered. In 1986, the corps ordered a historical study of the spillway and discovered a second cemetery. The two cemeteries were placed on the National Register of Historic Places in 1987. The artifacts discovered during the 1986 study included coffin furniture, coffins, grave markers, cultural remains, and human remains. The Kenner and Kugler Cemeteries Archeological District consists of
2060-520: A type of hybrid river/areal flooding can occur, known locally as "overland flooding". This is different from "overland flow" defined as "surface runoff". The Red River Valley is a former glacial lakebed, created by Lake Agassiz , and over a length of 550 mi (890 km), the river course drops only 236 ft (72 m), for an average slope of about 5 inches per mile (or 8.2 cm per kilometer). In this very large area, spring snowmelt happens at different rates in different places, and if winter snowfall
2163-483: A very distinctive coloring, with deep blue and purple on the face and gill cover, dark olive-colored bands down the side, and a fiery orange to yellow belly. They are omnivorous and will consume anything they can fit in their mouth, but mostly feed on small aquatic insects and baitfishes . The fish are important prey for bass , other larger sunfish , northern pike and muskellunge , walleye , trout , herons , kingfishers , snapping turtles and otters , and play
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#17327722721792266-543: Is also occasionally used as bait for larger game fish species, such as blue catfish , flathead catfish and largemouth bass . Fishermen are sometimes able to use polarized sunglasses to see through water and find bluegills' spawning beds. Bluegill have a rather bold character; many have no fear of humans, eating food directly dropped into the water, and a population in Canada 's Lake Scugog will even allow themselves to be stroked by human observers. Because of their size and
2369-405: Is also the intentional flooding of land that would otherwise remain dry. This may take place for agricultural, military, or river-management purposes. For example, agricultural flooding may occur in preparing paddy fields for the growing of semi-aquatic rice in many countries. Flooding may occur as an overflow of water from water bodies, such as a river , lake , sea or ocean. In these cases,
2472-659: Is an overflow of water ( or rarely other fluids ) that submerges land that is usually dry. In the sense of "flowing water", the word may also be applied to the inflow of the tide . Floods are of significant concern in agriculture , civil engineering and public health . Human changes to the environment often increase the intensity and frequency of flooding. Examples for human changes are land use changes such as deforestation and removal of wetlands , changes in waterway course or flood controls such as with levees . Global environmental issues also influence causes of floods, namely climate change which causes an intensification of
2575-698: Is common in Texas , "copper nose", is a species of North American freshwater fish , native to and commonly found in streams, rivers, lakes, ponds and wetlands east of the Rocky Mountains . It is the type species of the genus Lepomis (true sunfish), from the family Centrarchidae (sunfishes, crappies and black basses ) in the order Perciformes ( perch -like fish). Bluegills can grow up to 16 in (41 cm) long and about 4 + 1 ⁄ 2 lb (2.0 kg). While their color can vary from population to population, they typically have
2678-419: Is common when heavy flows move uprooted woody vegetation and flood-damaged structures and vehicles, including boats and railway equipment. Recent field measurements during the 2010–11 Queensland floods showed that any criterion solely based upon the flow velocity, water depth or specific momentum cannot account for the hazards caused by velocity and water depth fluctuations. These considerations ignore further
2781-493: Is commonly caused by a combination of storm surges caused by winds and low barometric pressure and large waves meeting high upstream river flows. The intentional flooding of land that would otherwise remain dry may take place for agricultural, military or river-management purposes. This is a form of hydraulic engineering . Agricultural flooding may occur in preparing paddy fields for the growing of semi-aquatic rice in many countries. Flooding for river management may occur in
2884-400: Is controlled by the geometry of the flow channel and, especially, by depth of channel, speed of flow and amount of sediments in it Flow channel restrictions like bridges and canyons tend to control water elevation above the restriction. The actual control point for any given reach of the drainage may change with changing water elevation, so a closer point may control for lower water levels until
2987-544: Is crossed by U.S. 61 and Interstate 10 . The spillway's secondary function is as a recreational area. It is used for off-road vehicles, biking, boating, hiking, hunting, and fishing. It is designated a protected wildlife management area by the Louisiana Department of Wildlife and Fisheries . To enhance fishing in the spillway, the clay extraction pits were filled with water and stocked with bluegill , largemouth bass , and other fish . The floodgate inlet
3090-584: Is divided between the main river and the diversion channel, with the surcharge bypassing the New Orleans metropolitan area, resulting in the Mississippi being lower (through that area) than it could have been and reducing the stress on the area's levees that line the river. Confined by guide levees, the floodway stretches nearly six miles (9.7 km) to Lake Pontchartrain, with a design capacity of 250,000 cu ft/s (7,100 m/s). The spillway
3193-461: Is more significant to flooding within small drainage basins. The most important upslope factor in determining flood magnitude is the land area of the watershed upstream of the area of interest. Rainfall intensity is the second most important factor for watersheds of less than approximately 30 square miles or 80 square kilometres. The main channel slope is the second most important factor for larger watersheds. Channel slope and rainfall intensity become
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3296-532: Is not just the reversal of forward swimming. The fish utilizes its pectoral fins to provide a rhythmic beat while the dorsal and anal fins produce momentum to drive the fish backwards. The pectoral fins' rhythmic beat is asymmetric and aids the fish's balance in its slow, backward movement. The bluegill, amongst a wide array of other fishes, exhibits the C-start escape response , which is generated by large neurons called Mauthner cells . Mauthner cells operate as
3399-516: Is offset into the Mississippi River bank, at a location that had seen natural flooding for at least two centuries. The concrete structure has been designed to reduce settling into the riverbank. The opening and closing of the spillway is done by lifting out up to 7000 wooden ' needles ' (8" x 12" wooden beams) arranged in 350 linear bays. This is done by two rail-mounted gantry cranes atop the spillway. The number of needles removed determines
3502-424: Is scarce, bluegill will also feed on aquatic vegetation and algae , and if scarce enough, will even feed on their own eggs or offspring. As bluegill spend a great deal of time near the surface of water, they can also feed on surface bugs. Most bluegills feed during daylight hours, with a feeding peak being observed in the morning and evening (with the major peak occurring in the evening). Feeding location tends to be
3605-721: Is the state fish of Illinois . At Lake St. Helen , Michigan, an annual "Blue Gill Festival" is held in July. Bluegills are popular panfish , caught with live bait such as worms, crickets, grasshoppers, flies , minnows, maggots or small frogs, as well as small shrimp bits, processed bait, bread, corn, other table scraps, small crankbaits, spinners, fake worms, or even a bare hook. They mostly bite on vibrant colors like orange, yellow, green, or red, chiefly at dawn and dusk. They are noted for seeking out underwater vegetation for cover; their natural diet consists largely of crickets, water bugs, larvae , and very small fish. The bluegill itself
3708-535: Is unknown. The sites adjoin 19th- and early 20th-century sugar plantations in St. Charles Parish. According to oral histories and as confirmed by GIS analysis, both cemeteries were located in the midst of the cane fields of their respective plantations. The Kenner Cemetery, located on the former Roseland Plantation, was reported to be marked by iron and wooden crosses during its period of use. No such markers were confirmed archaeologically, but one granite US veteran headstone
3811-534: Is very rapid in the first three years, but slows considerably once the fish reaches maturity. Many fish reach five to eight years old, and in extreme cases, can live 11 years. Occasionally a bluegill may spawn with another member of its genus, though this is rare. This tends to happen in bodies of water that are fairly isolated and have a decent population of bluegill in close proximity to another, smaller, population of lepomid species such as green sunfish . Limited nesting grounds can also factor in hybridization causing
3914-836: The Chesapeake Bay , indicating they can tolerate up to 1.8% salinity. In some locations where they have been transplanted, they are considered pests: trade in the species is prohibited in Germany and Japan . In the case of Japan, bluegills were presented to the then-crown prince, Akihito , in 1960 as a gift by Richard J. Daley , mayor of Chicago . The prince, in turn, donated the fish to fishery research agencies in Japan, from which they escaped and became an invasive species that wreaked havoc with native species, especially in Lake Biwa . Akihito has since apologized. Bluegill live in
4017-627: The Great Mississippi Flood of 1927 , and has been designated as a National Historic Civil Engineering Landmark by the American Society of Civil Engineers . The Bonnet Carré Crevasse was one of several levee breaches in the Bonnet Carré area in 1871. Local drainage systems were unable to contain the floodwater and strong winds caused the water to enter Lake Pontchartrain and surrounding urban areas. The river levee
4120-562: The Second World War ). Floods are caused by many factors or a combination of any of these generally prolonged heavy rainfall (locally concentrated or throughout a catchment area), highly accelerated snowmelt , severe winds over water, unusual high tides, tsunamis , or failure of dams, levees , retention ponds , or other structures that retained the water. Flooding can be exacerbated by increased amounts of impervious surface or by other natural hazards such as wildfires, which reduce
4223-503: The alluvial valley between Cape Girardeau, Missouri . and the mouth of the river near Venice , Louisiana. Because of the wide expanse of the project and the complex problems involved, the plan contains an array of features. The MR&T Project provides for levees to contain flood flows, floodways such as the Bonnet Carré to redirect excess flows away from the Mississippi, and other aspects such as channel improvement and river bank stabilization, for efficient navigation and protection of
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4326-400: The larvae are able to hatch and swim away on their own. The bluegill generally begins its spawning career at one year of age, but has been found to spawn as early as four months of age under favorable conditions. Anglers find spawning season to be a very successful time to fish for bluegills, as they aggressively attack anything, including a hook, that comes near. The growth of the bluegill
4429-566: The redear sunfish , but different in a distinct spot at or near the base of the soft dorsal fin. The bluegill occurs naturally in the United States east of the Rocky Mountains from coastal Virginia to Florida , west to Texas and northern Mexico , and north to western Minnesota , New York and southeastern Ontario . They have been introduced widely in North America and Europe , South Africa , Zimbabwe , Asia , South America , and Oceania . Bluegills have also been found in
4532-562: The water table is shallow, such as a floodplain , or from intense rain from one or a series of storms . Infiltration also is slow to negligible through frozen ground, rock, concrete , paving, or roofs. Areal flooding begins in flat areas like floodplains and in local depressions not connected to a stream channel, because the velocity of overland flow depends on the surface slope. Endorheic basins may experience areal flooding during periods when precipitation exceeds evaporation. Floods occur in all types of river and stream channels, from
4635-528: The C-start escape response but the bluegill draws a majority of its momentum from the body bending associated with the response, as well as its dorsal and anal fins. The dorsal and anal fins' roles as propulsors during escape response suggest that the size of the fins could lead to an evolutionary advantage when escaping predators. Spawning season for bluegills starts late in May and extends into August. The peak of
4738-501: The Davis Pond Freshwater Diversions, especially concerning wetlands maintenance more than wetlands building, has led to studies for more fresh water diversion projects. Caernarvon and Davis Pond diversions have limits, because of laws governing their operation, aimed at limiting the flow of freshwater to minimize damage to oysters. The Bonnet Carré Spillway diversion would be built within the spillway, on
4841-717: The adverse ecological impact of the inundation. That impact may also be adverse in a hydrogeological sense if the inundation lasts a long time. Examples for uncontrolled inundations are the second Siege of Leiden during the first part of the Eighty Years' War , the flooding of the Yser plain during the First World War , and the Inundation of Walcheren , and the Inundation of the Wieringermeer during
4944-423: The amount of water damage and mold that grows after an incident. Research suggests that there will be an increase of 30–50% in adverse respiratory health outcomes caused by dampness and mold exposure for those living in coastal and wetland areas. Fungal contamination in homes is associated with increased allergic rhinitis and asthma. Vector borne diseases increase as well due to the increase in still water after
5047-490: The bluegill is deprived of its various sensory abilities, it utilizes its pectoral fins in navigation. If the bluegill's visual input or lateral line input were to be compromised, its pectoral fins are then able to be utilized as mechanosensors through the bending of the fin(s) when the fish comes into contact with its environment. In standard swimming the bluegill sunfish relies on its caudal (tail) fin, dorsal fin, and anal fin. The bluegill's caudal fin muscles are important in
5150-436: The center of colonies. Populations with large males are increasingly difficult to find, and are usually only found in remote locations without angling pressure or in more southern regions where growth rates are high. Reduced bag limits appear to show potential for improving size-structure in over-fished populations. Bluegills play an important role in pond and lake management to keep crustacean and insect populations low, as
5253-645: The cost and maintenance between the Federal Government at 75%, Louisiana at 20% and Mississippi at 5%. Louisiana and Mississippi must agree to a final project design, but in July 1996, Louisiana withdrew as a sponsor, and as of 2016 an agreement has not been reached. 30°0′8″N 90°26′29″W / 30.00222°N 90.44139°W / 30.00222; -90.44139 [REDACTED] This article incorporates public domain material from the United States Army Corps of Engineers Flood#Flood defences, planning, and management A flood
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#17327722721795356-475: The daylight hours. The mouth of the bluegill is very small and requires the use of the pharynx to suck in prey. The bluegill sunfish relies heavily on the flexibility of its fins to maintain maneuverability in response to fluid forces. The bluegill's segmentation in its pectoral fin rays mitigates the effects of fluid forces on the fish's movement. The bluegill has a variety of unusual adaptations that allow it to navigate different environments. In conditions where
5459-434: The deadliest floods worldwide, showing events with death tolls at or above 100,000 individuals. Floods (in particular more frequent or smaller floods) can also bring many benefits, such as recharging ground water , making soil more fertile and increasing nutrients in some soils. Flood waters provide much needed water resources in arid and semi-arid regions where precipitation can be very unevenly distributed throughout
5562-558: The east bank of the Mississippi, allowing up to 25,000 c.f.s. (i.e. ft/s) of fresh water and sediment diversion into Lake Pontchartrain and the Mississippi Sound . The diversion would slow or stop subsidence , reducing marsh loss by 10,500 acres in the next 50 years, providing fish and wildlife protection, as well as further storm surge protection. The diversion was authorized by the Water Resources Development Act of 1988 (WRDA 1988), and Congress (1990) split
5665-441: The edge of the nest. As a female approaches, the male will begin circling and making grunting noises. The motion and sound of the males seem to attract the females. Females are very choosy and will usually pick males with larger bodies and "ears", making larger size a desirable trait for males to have. If the female enters the nest, both the male and female will circle each other, with the male expressing very aggressive behavior toward
5768-403: The female's eggs in the water. Smaller males will often hide in nearby weeds and dart into the nest as they attempt to fertilize the eggs. They then quickly dart away. The size of the female plays a large role in how many eggs will be produced. A small female can produce as few as 1,000 eggs, and a large, healthy female can produce up to 100,000 eggs. The male continues to watch over the nest until
5871-430: The female. If the female stays, the pair will enter the nest and come to rest in the middle. With the male in an upright posture, the pair will touch bellies, quiver, and spawn . These actions are repeated at irregular intervals several times in a row. Once the spawning is done, the male will chase the female out of the nest and guard the eggs. The fertilization process is entirely external. The male's sperm combines with
5974-552: The females of one species to prefer the nest of another. Bluegill can theoretically hybridize with all other species in the genus lepomis, though the most common hybrid is the Greengill . The hybrid fish are aggressive and have larger mouths than their Bluegill parent. These fish also grow faster than other small mouth fish due to its bigger mouth. Greengills or hybrid bluegills are the most efficient in growth and can reach approximately 2 lbs or 0.91 kg in one year. [1] The bluegill
6077-576: The field that is intended to impede the movement of the enemy. This may be done both for offensive and defensive purposes. Furthermore, in so far as the methods used are a form of hydraulic engineering, it may be useful to differentiate between controlled inundations and uncontrolled ones. Examples for controlled inundations include those in the Netherlands under the Dutch Republic and its successor states in that area and exemplified in
6180-472: The first time in the spillway's history that it was opened twice in one year. In April 2020 the Spillway was again opened from April 3, 2020, until May 1, 2020, a total of 29 days. The Bonnet Carré Spillway consists of two basic components: a control structure along the east bank of the Mississippi River and a floodway that transfers the diverted flood waters to the lake. The control structure, located between
6283-401: The fish must get within 1.75 centimeters of the prey. In turn, bluegill are prey to many larger species, including largemouth bass , smallmouth bass , striped bass , trout , muskellunge , turtles , northern pike , yellow perch , walleye , catfish , and even larger bluegill. Herons , kingfishers , and otters have also been witnessed catching bluegill in shallow water. However,
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#17327722721796386-422: The fish's slow swimming and also important in the beginning stages of the fish increasing its swimming speed. The dorsal and anal fins are two types of median fins that work in parallel to balance torque during steady swimming. When swimming backwards, the bluegill utilizes a plethora of fin muscles located in various parts of its body. Backward swimming in the bluegill is more complex than steady swimming, as it
6489-470: The flood process; before, during and after. During floods accidents occur with falling debris or any of the many fast moving objects in the water. After the flood rescue attempts are where large numbers injuries can occur. Communicable diseases are increased due to many pathogens and bacteria that are being transported by the water .There are many waterborne diseases such as cholera , hepatitis A , hepatitis E and diarrheal diseases , to mention
6592-492: The flood thus advances more slowly than later and higher flows. As a result, the rising limb of the hydrograph becomes ever quicker as the flood moves downstream, until the flow rate is so great that the depletion by wetting soil becomes insignificant. Coastal areas may be flooded by storm surges combining with high tides and large wave events at sea, resulting in waves over-topping flood defenses or in severe cases by tsunami or tropical cyclones. A storm surge , from either
6695-403: The floods have settled. The diseases that are vector borne are malaria , dengue , West Nile , and yellow fever . Floods have a huge impact on victims' psychosocial integrity . People suffer from a wide variety of losses and stress . One of the most treated illness in long-term health problems are depression caused by the flood and all the tragedy that flows with one. Below is a list of
6798-428: The flow rate exceeds the capacity of the river channel , particularly at bends or meanders in the waterway . Floods often cause damage to homes and businesses if these buildings are in the natural flood plains of rivers. People could avoid riverine flood damage by moving away from rivers. However, people in many countries have traditionally lived and worked by rivers because the land is usually flat and fertile . Also,
6901-656: The form of diverting flood waters in a river at flood stage upstream from areas that are considered more valuable than the areas that are sacrificed in this way. This may be done ad hoc , or permanently, as in the so-called overlaten (literally "let-overs"), an intentionally lowered segment in Dutch riparian levees, like the Beerse Overlaat in the left levee of the Meuse between the villages of Gassel and Linden, North Brabant . Military inundation creates an obstacle in
7004-403: The land in quantities that cannot be carried within stream channels or retained in natural ponds, lakes, and human-made reservoirs . About 30 percent of all precipitation becomes runoff and that amount might be increased by water from melting snow. River flooding is often caused by heavy rain, sometimes increased by melting snow. A flood that rises rapidly, with little or no warning, is called
7107-443: The levee system. It also involves reservoirs and pumping stations for flood control drainage. The following chart shows the years when the spillway was opened, number of days it remained open, peak number of bays opened, percent of maximum flow at peak, and peak flow rate. The spillway has a design capacity of 250,000 cu ft/s when all 350 bays are fully open, or approximately 714 cu ft/s per bay. There are two cemeteries located in
7210-614: The livelihood of individuals. As a result, there is also significant socio-economic threats to vulnerable populations around the world from flooding. For example, in Bangladesh in 2007, a flood was responsible for the destruction of more than one million houses. And yearly in the United States, floods cause over $ 7 billion in damage. Flood waters typically inundate farm land, making the land unworkable and preventing crops from being planted or harvested, which can lead to shortages of food both for humans and farm animals. Entire harvests for
7313-417: The location of the flood. Damage to roads and transport infrastructure may make it difficult to mobilize aid to those affected or to provide emergency health treatment. Flooding can cause chronically wet houses, leading to the growth of indoor mold and resulting in adverse health effects, particularly respiratory symptoms. Respiratory diseases are a common after the disaster has occurred. This depends on
7416-436: The loss of power. This includes loss of drinking water treatment and water supply, which may result in loss of drinking water or severe water contamination. It may also cause the loss of sewage disposal facilities. Lack of clean water combined with human sewage in the flood waters raises the risk of waterborne diseases , which can include typhoid , giardia , cryptosporidium , cholera and many other diseases depending upon
7519-490: The management of the spillway. The 2019 opening began February 27, 2019, when river levels were predicted to rise to minor flood stage in New Orleans on March 19, 2019. The Army Corps of Engineers initially opened 38 of the 350 bays and increased this number to 206 bays when the flood crest arrived later in March. The Army Corps of Engineers closed the spillway on April 11, 2019, only to reopen it again on May 10, 2019. This marks
7622-493: The method of cooking them, bluegills are often called panfish . The IGFA all tackle world record for the species stands at 2.15 kg (4 lb 12 oz) caught from Ketona lake in Alabama in 1950. Bluegill populations are notably vulnerable to effects of angling and harvest, particularly in size-structure. Large males appear to be especially vulnerable to effects of fishing because of their tendency to guard nests in
7725-457: The period of time between observations. This intensity will be less than the actual peak intensity if the duration of the rainfall event was less than the fixed time interval for which measurements are reported. Convective precipitation events (thunderstorms) tend to produce shorter duration storm events than orographic precipitation. Duration, intensity, and frequency of rainfall events are important to flood prediction. Short duration precipitation
7828-586: The result of sustained rainfall, rapid snow melt, monsoons , or tropical cyclones . However, large rivers may have rapid flooding events in areas with dry climates, since they may have large basins but small river channels, and rainfall can be very intense in smaller areas of those basins. In extremely flat areas, such as the Red River Valley of the North in Minnesota , North Dakota , and Manitoba ,
7931-480: The risks associated with large debris entrained by the flow motion. Floods can be a huge destructive power. When water flows, it has the ability to demolish all kinds of buildings and objects, such as bridges, structures, houses, trees, and cars. Economical, social and natural environmental damages are common factors that are impacted by flooding events and the impacts that flooding has on these areas can be catastrophic. There have been numerous flood incidents around
8034-454: The rivers provide easy travel and access to commerce and industry. Flooding can damage property and also lead to secondary impacts. These include in the short term an increased spread of waterborne diseases and vector-bourne disesases , for example those diseases transmitted by mosquitos. Flooding can also lead to long-term displacement of residents. Floods are an area of study of hydrology and hydraulic engineering . A large amount of
8137-414: The shallow waters of many lakes and ponds, along with streams, creeks, and rivers. They prefer water with many aquatic plants, and seclude themselves within or near fallen logs, water weeds or any other structure (natural or manmade) that is under water. They can often be found around weed beds, where they search for food or spawn . In the summer, adults move to deep, open water where they suspend just below
8240-439: The shape of the fish makes them hard to swallow. Raccoons are also believed to be among their predators. Bluegills have the ability to travel and change directions at high speeds by means of synchronized fin movements. They use notched caudal fins, soft dorsal fins , body undulations, and pectoral fins to move forward. Having a notched caudal fin allows them to accelerate quickly. The speed of their forward motion depends on
8343-497: The shore areas. Extreme flood events often result from coincidence such as unusually intense, warm rainfall melting heavy snow pack, producing channel obstructions from floating ice, and releasing small impoundments like beaver dams. Coincident events may cause extensive flooding to be more frequent than anticipated from simplistic statistical prediction models considering only precipitation runoff flowing within unobstructed drainage channels. Debris modification of channel geometry
8446-404: The sides of its body immediately after being caught as part of its threat display. It typically has a yellowish breast and abdomen, with the breast of the breeding male being a bright orange. The bluegill has three anal fin spines, ten to 12 anal fin rays, six to 13 dorsal fin spines, 11 to 12 dorsal rays, and 12 to 13 pectoral rays. They are characterized by their deep, flattened bodies. They have
8549-538: The smallest ephemeral streams in humid zones to normally-dry channels in arid climates to the world's largest rivers. When overland flow occurs on tilled fields, it can result in a muddy flood where sediments are picked up by run off and carried as suspended matter or bed load . Localized flooding may be caused or exacerbated by drainage obstructions such as landslides , ice , debris , or beaver dams. Slow-rising floods most commonly occur in large rivers with large catchment areas . The increase in flow may be
8652-568: The spawning season usually occurs in June in waters of 67 to 80 °F (19 to 27 °C). The male bluegills arrive first at the mating site. They will make a spawning bed of six to 12 inches in diameter in shallow water, clustering as many as 50 beds together. The males scoop out these beds in gravel or sand. Males tend to be very protective and chase everything away from their nests, especially other male bluegills. Some bluegills, regardless of their small size, will even attack snorkelers if they approach
8755-464: The spillway. The cemeteries contain the remains of enslaved persons of African descent and free African-Americans, and the historic ground surface is under several feet of sediment. When the spillway gates are opened, the cemeteries are flooded. The location of the gravesites was a mystery until May 1975, when the US Army Corps of Engineers excavated a ditch in the spillway. During that process,
8858-569: The strength of which they abduct or adduct fins. The flat, slender body of the bluegill lowers water resistance and allows the bluegills to cut effectively through water. The large, flexible pectoral fins allow the fish to decelerate quickly. This superior maneuverability allows the bluegill to forage and escape predators very successfully. Bluegills have a lateral line system, as well as inner ears, that act as receptors for vibration and pressure changes. However, bluegills rely heavily on sight to feed, especially in their foraging. Optimal vision occurs in
8961-527: The supply of vegetation that can absorb rainfall. During times of rain, some of the water is retained in ponds or soil, some is absorbed by grass and vegetation, some evaporates, and the rest travels over the land as surface runoff . Floods occur when ponds, lakes, riverbeds, soil, and vegetation cannot absorb all the water. This has been exacerbated by human activities such as draining wetlands that naturally store large amounts of water and building paved surfaces that do not absorb any water. Water then runs off
9064-955: The surface and feed on plankton and other aquatic creatures. Bluegill try to spend most of their time in water from 60 to 80 °F (16 to 27 °C), and tend to have a home range of about 320 square feet (30 m ) during nonreproductive months. They enjoy heat, but do not like direct sunlight – they typically live in deeper water, but will linger near the water surface in the morning to stay warm. Bluegill are usually found in schools of 10 to 20 fish, and these schools will often include other panfish, such as crappie , pumpkinseeds , and smallmouth bass . Young bluegills' diet consists of rotifers , copepods , water fleas , and insects (mainly chironomids ). The adult diet consists of aquatic insect larvae ( mayflies , caddisflies , dragonflies ), but can also include terrestrial insects, zooplankton , shrimp , crayfish , leeches , other worms , snails , and other small fish (such as minnows ). If food
9167-440: The third most important factors for small and large watersheds, respectively. Time of Concentration is the time required for runoff from the most distant point of the upstream drainage area to reach the point of the drainage channel controlling flooding of the area of interest. The time of concentration defines the critical duration of peak rainfall for the area of interest. The critical duration of intense rainfall might be only
9270-439: The time of day or season. The bluegill is noted for the large black appendage (the "ear") on each side of the posterior edge of the gill covers as well as the base of the dorsal fin. The sides of its head and chin are commonly a dark shade of blue, hence the name "bluegill". The precise coloration will vary due to the presence of neurally controlled chromatophores under the skin. The fish usually displays 5–9 vertical bars on
9373-407: The towns of Montz and Norco , is a mechanically controlled concrete weir that extends for over a mile and a half parallel to the river. When opened, the control structure allows overflow volume to flow into Lake Pontchartrain. The lake's opening to the gulf is sufficient to absorb and dissipate any conceivable volume of flood flow. Thus, the flood surcharge portion of the water from the Mississippi
9476-699: The two Hollandic Water Lines , the Stelling van Amsterdam , the Frisian Water Line , the IJssel Line , the Peel-Raam Line , and the Grebbe line in that country. To count as controlled , a military inundation has to take the interests of the civilian population into account, by allowing them a timely evacuation , by making the inundation reversible , and by making an attempt to minimize
9579-600: The two cemeteries. Additional research on the cemeteries was done in 2002–2005 and archaeological investigations in 2008–2009. The cemeteries, named the Kenner Cemetery and the Kugler Cemetery, are black burial plots which appear to date from the early 1800s and were in use until 1929. Several African-American US Army Civil War veterans were moved from the spillway cemeteries to Chalmette National Cemetery in 1930. The total number of burials in either cemetery
9682-441: The water cycle and sea level rise . For example, climate change makes extreme weather events more frequent and stronger. This leads to more intense floods and increased flood risk. Natural types of floods include river flooding, groundwater flooding coastal flooding and urban flooding sometimes known as flash flooding. Tidal flooding may include elements of both river and coastal flooding processes in estuary areas. There
9785-499: The water flow into the spillway. Gaps built into each bay allow limited seepage anytime the river level reaches the bottom of the bays. Removal of all 7000 needles takes about 36 hours but is usually done over a period of several days. The spillway is part of the United States Army Corps of Engineers ' multi-state plan, called the Mississippi River and Tributaries Project (MR&T), providing flood protection for
9888-487: The water overtops or breaks levees , resulting in some of that water escaping its usual boundaries. Flooding may also occur due to an accumulation of rainwater on saturated ground. This is called an areal flood . The size of a lake or other body of water naturally varies with seasonal changes in precipitation and snow melt. Those changes in size are however not considered a flood unless they flood property or drown domestic animals . Floods can also occur in rivers when
9991-515: The waters in a flood are very deep and have strong currents . Deaths do not just occur from drowning, deaths are connected with dehydration , heat stroke , heart attack and any other illness that needs medical supplies that cannot be delivered. Injuries can lead to an excessive amount of morbidity when a flood occurs. Injuries are not isolated to just those who were directly in the flood, rescue teams and even people delivering supplies can sustain an injury. Injuries can occur anytime during
10094-450: The world which have caused devastating damage to infrastructure, the natural environment and human life. Floods can have devastating impacts to human societies. Flooding events worldwide are increasing in frequency and severity, leading to increasing costs to societies. Catastrophic riverine flooding can result from major infrastructure failures, often the collapse of a dam . It can also be caused by drainage channel modification from
10197-557: The world's population lives in close proximity to major coastlines , while many major cities and agricultural areas are located near floodplains . There is significant risk for increased coastal and fluvial flooding due to changing climatic conditions. Floods can happen on flat or low-lying areas when water is supplied by rainfall or snowmelt more rapidly than it can either infiltrate or run off . The excess accumulates in place, sometimes to hazardous depths. Surface soil can become saturated, which effectively stops infiltration, where
10300-503: The year and kills pests in the farming land. Freshwater floods particularly play an important role in maintaining ecosystems in river corridors and are a key factor in maintaining floodplain biodiversity . Flooding can spread nutrients to lakes and rivers, which can lead to increased biomass and improved fisheries for a few years. Bluegill Lepomis purpurescens Cope , 1870 The bluegill ( Lepomis macrochirus ), sometimes referred to as "bream", "brim", "sunny", or, as
10403-765: Was heavy, a fast snowmelt can push water out of the banks of a tributary river so that it moves overland, to a point further downstream in the river or completely to another streambed. Overland flooding can be devastating because it is unpredictable, it can occur very suddenly with surprising speed, and in such flat land it can run for miles. It is these qualities that set it apart from simple "overland flow". Rapid flooding events, including flash floods , more often occur on smaller rivers, rivers with steep valleys, rivers that flow for much of their length over impermeable terrain, or normally-dry channels. The cause may be localized convective precipitation (intense thunderstorms ) or sudden release from an upstream impoundment created behind
10506-451: Was not restored until 1883. The spillway was built in response to the Great Mississippi Flood of 1927 that inundated much of the Mississippi River basin. It was first opened during the flood of 1937 . In 2007, extraction operations began on a 42-acre (170,000 m) square section of spillway property. The 7,600-acre (31 km) spillway, designed to divert rising water out of the Mississippi River during flooding seasons, long has been
10609-477: Was recovered from the site. The Kugler Cemetery, located on the former Hermitage Plantation, was reported to contain iron crosses and a metal fence. One such iron cross and remnants of what could have been the fence were recovered during the 1986 archaeological investigations. At present, the cemetery sites have been demarcated by young live oak trees. The success of the Caernarvon Freshwater and
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