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59-532: The Imperial Bureau of Mycology was established in 1920 as a centre for accumulating and disseminating information on plant pathogenic fungi in the British empire and for undertaking systematic research into such fungi. It was initially based in two houses at Kew , but in 1930 moved into a purpose-built building in the grounds of the Royal Botanic Gardens . In the same year, it became part of

118-449: 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

177-646: 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

236-515: 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

295-484: 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

354-468: 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

413-538: 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

472-627: 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

531-605: 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

590-728: 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 ;

649-486: 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

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708-671: A single causal organism; however, some plant diseases have been shown to be interactions between multiple pathogens. To colonize a plant, pathogens have specific pathogenicity factors , of five main types: uses of cell wall–degrading enzymes, toxins , effector proteins, phytohormones , and exopolysaccharides . Some abiotic disorders can be confused with pathogen-induced disorders. Abiotic causes include natural processes such as drought , frost , snow and hail ; flooding and poor drainage; nutrient deficiency ; deposition of mineral salts such as sodium chloride and gypsum ; windburn and breakage by storms; and wildfires . Epidemiology

767-411: A single solution there are limits. Bertolini et al. 2001, Ito et al. 2002, and Ragozzino et al. 2004 developed PCR methods for multiplexing six or seven plant pathogen molecular products and Persson et al. 2005 for multiplexing four with RT-PCR. More extensive molecular diagnosis requires PCR arrays . The primary detection method used worldwide is enzyme linked immunosorbent assay . Crop rotation

826-413: 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

885-520: 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

944-433: Is a traditional and sometimes effective means of preventing a parasitic population from becoming well-established. For example, protection against infection by Agrobacterium tumefaciens , which causes gall diseases in many plants, by dipping cuttings in suspensions of Agrobacterium radiobacter before inserting them in the ground to take root. Plant pathology has developed from antiquity, starting with Theophrastus in

1003-405: 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,

1062-419: 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

1121-493: 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

1180-400: 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

1239-461: 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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1298-734: Is the scientific study of plant diseases caused by pathogens (infectious organisms) and environmental conditions (physiological factors). Plant pathology involves the study of pathogen identification, disease etiology , disease cycles, economic impact, plant disease epidemiology , plant disease resistance , how plant diseases affect humans and animals, pathosystem genetics, and management of plant diseases. Plant pathogens, organisms that cause infectious plant diseases , include fungi , oomycetes , bacteria , viruses , viroids , virus -like organisms, phytoplasmas , protozoa , nematodes and parasitic plants . In most plant pathosystems , virulence depends on hydrolases and enzymes that degrade

1357-452: Is the study of factors affecting the outbreak and spread of infectious diseases. A disease triangle describes the basic factors required for plant diseases. These are the host plant, the pathogen, and the environment. Any one of these can be modified to control a disease. Plant disease resistance is the ability of a plant to prevent and terminate infections from plant pathogens. Structures that help plants prevent pathogens from entering are

1416-776: The Bibliography of Systematic Mycology in 1947. In 1943, the first edition of the standard reference work, the Dictionary of the Fungi was published. A culture collection of living fungi was initiated in 1947. In 1948, IMI changed its name to the Commonwealth Mycological Institute and in 1986 to the International Mycological Institute. In 1993, it was moved from Kew to Egham , Surrey, and in 1998 it merged with

1475-562: 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

1534-418: The cell wall . The vast majority of these act on pectins (for example, pectinesterase , pectate lyase , and pectinases ). For microbes, the cell wall polysaccharides are both a food source and a barrier to be overcome. Many pathogens grow opportunistically when the host breaks down its own cell walls, most often during fruit ripening . Unlike human and animal pathology, plant pathology usually focuses on

1593-562: 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

1652-630: The Imperial Agricultural Bureaux and was renamed the Imperial Mycological Institute (IMI). IMI provided an identification service for pathogenic fungi from 1921 onwards and in 1922 started publishing abstracts of research literature in the Review of Applied Mycology . An herbarium of fungal specimens was also established. The journal Index of Fungi , covering all new fungal names, began in 1940 and

1711-577: The International Institute of Entomology, the International Institute of Biocontrol, and the International Institute of Parasitology to form CAB International . In 2010, the former IMI herbarium was merged with that of the Royal Botanic Gardens, Kew. This article about a mycological organization is a stub . You can help Misplaced Pages by expanding it . Plant pathology Plant pathology or phytopathology

1770-717: 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

1829-423: 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

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1888-533: The ancient era, but scientific study began in the Early Modern period with the invention of the microscope , and developed in the 19th century. Flood A flood 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

1947-678: The cuticular layer, cell walls, and stomata guard cells. Once pathogens have overcome these barriers, plant receptors initiate signaling pathways to create molecules to compete against the foreign molecules. These pathways are influenced and triggered by genes within the host plant and can manipulated by genetic breeding to create resistant varieties. Ancient methods of leaf examination and breaking open plant material by hand are now augmented by newer technologies. These include molecular pathology assays such as polymerase chain reaction (PCR), RT-PCR and loop-mediated isothermal amplification (LAMP). Although PCR can detect multiple molecular targets in

2006-434: 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

2065-806: 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 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

2124-576: 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

2183-470: 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

2242-492: 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

2301-403: 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

2360-428: 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,

2419-656: 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

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2478-403: 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

2537-614: 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

2596-417: 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

2655-436: 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

2714-457: 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

2773-586: 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 ,

2832-480: 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

2891-454: 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

2950-497: 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

3009-538: 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

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3068-527: 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

3127-440: 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

3186-699: 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

3245-487: 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

3304-515: 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

3363-450: 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

3422-557: 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

3481-765: 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

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