Flood Forecasting

	Flood Forecasting Flood forecasting is the use of forecasted precipitation and streamflow data in rainfall-runoff and streamflow routing models to forecast flow rates and water levels for periods ranging from a few hours to days ahead, depending on the size of the watershed or river basin. Flood forecasting can also make use of forecasts of precipitation in an attempt to extend the lead-time available. Flood forecasting is an important component of flood warning, where the distinction between the two is that the outcome of flood forecasting is a set of forecast time-profiles of channel flows or river levels at various locations, while "flood warning" is the task of making use of these forecasts to tell decisions on warnings of floods. Real-time flood forecasting at regional area can be done within seconds by using the technology of artificial neural network. Effective real-time flood forecasting models could be useful for early warning and disaster prevention. AI can assist us in predicting floo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Precipitation (meteorology) In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravitational pull from clouds. The main forms of precipitation include drizzle, rain, sleet, snow, ice pellets, graupel and hail. Precipitation occurs when a portion of the atmosphere becomes saturated with water vapor (reaching 100% relative humidity), so that the water condenses and "precipitates" or falls. Thus, fog and mist are not precipitation but colloids, because the water vapor does not condense sufficiently to precipitate. Two processes, possibly acting together, can lead to air becoming saturated: cooling the air or adding water vapor to the air. Precipitation forms as smaller droplets coalesce via collision with other rain drops or ice crystals within a cloud. Short, intense periods of rain in scattered locations are called showers. Moisture that is lifted or otherwise forced to rise over a layer of sub-freezing air at the surface may be condense ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Streamflow Streamflow, or channel runoff, is the flow of water in streams and other channels, and is a major element of the water cycle. It is one component of the movement of water from the land to waterbodies, the other component being surface runoff. Water flowing in channels comes from surface runoff from adjacent hillslopes, from groundwater flow out of the ground, and from water discharged from pipes. The discharge of water flowing in a channel is measured using stream gauges or can be estimated by the Manning equation. The record of flow over time is called a hydrograph. Flooding occurs when the volume of water exceeds the capacity of the channel. Role in the water cycle Streams play a critical role in the hydrologic cycle that is essential for all life on Earth. A diversity of biological species, from unicellular organisms to vertebrates, depend on flowing-water systems for their habitat and food resources. Rivers are major aquatic landscapes for all manners of plants and animals. Ri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Runoff Model A runoff model is a mathematical model describing the rainfall– runoff relations of a rainfall ''catchment area'', drainage basin or ''watershed''. More precisely, it produces a surface runoff hydrograph in response to a rainfall event, represented by and input as a hyetograph. In other words, the model calculates the conversion of rainfall into runoff. A well known runoff model is the ''linear reservoir'', but in practice it has limited applicability. The runoff model with a ''non-linear reservoir'' is more universally applicable, but still it holds only for catchments whose surface area is limited by the condition that the rainfall can be considered more or less uniformly distributed over the area. The maximum size of the watershed then depends on the rainfall characteristics of the region. When the study area is too large, it can be divided into sub-catchments and the various runoff hydrographs may be combined using flood routing techniques. Rainfall-runoff models need t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Streamflow Routing Streamflow, or channel runoff, is the flow of water in streams and other channels, and is a major element of the water cycle. It is one component of the movement of water from the land to waterbodies, the other component being surface runoff. Water flowing in channels comes from surface runoff from adjacent hillslopes, from groundwater flow out of the ground, and from water discharged from pipes. The discharge of water flowing in a channel is measured using stream gauges or can be estimated by the Manning equation. The record of flow over time is called a hydrograph. Flooding occurs when the volume of water exceeds the capacity of the channel. Role in the water cycle Streams play a critical role in the hydrologic cycle that is essential for all life on Earth. A diversity of biological species, from unicellular organisms to vertebrates, depend on flowing-water systems for their habitat and food resources. Rivers are major aquatic landscapes for all manners of plants and animals. Riv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Drainage Basin A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, the '' drainage divide'', made up of a succession of elevated features, such as ridges and hills. A basin may consist of smaller basins that merge at river confluences, forming a hierarchical pattern. Other terms for a drainage basin are catchment area, catchment basin, drainage area, river basin, water basin, and impluvium. In North America, they are commonly called a watershed, though in other English-speaking places, "watershed" is used only in its original sense, that of a drainage divide. In a closed drainage basin, or endorheic basin, the water converges to a single point inside the basin, known as a sink, which may be a permanent lake, a dry lake, or a point where surface water is lost underground. Drainage basins are similar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Flood Warning A flood warning is closely linked to the task of flood forecasting. The distinction between the two is that the outcome of flood forecasting is a set of forecast time-profiles of channel flows or river levels at various locations, while "flood warning" is the task of making use of these forecasts to make decisions about whether warnings of floods should be issued to the general public or whether previous warnings should be rescinded or retracted. The task of providing warning for floods is divided into two parts: * decisions to escalate or change the state of alertness internal to the flood warning service provider, where this may sometimes include partner organisations involved in emergency response; * decisions to issue flood warnings to the general public. The decisions made by someone responsible for initiating flood warnings must be influenced by a number of factors, which include: * The reliability of the available forecasts and how this changes with lead-time. * The amount ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Runoff Model (reservoir) A runoff model is a mathematical model describing the rainfall–runoff relations of a rainfall ''catchment area'', drainage basin or ''watershed''. More precisely, it produces a surface runoff hydrograph in response to a rainfall event, represented by and input as a hyetograph. In other words, the model calculates the conversion of rainfall into runoff. A well known runoff model is the ''linear reservoir'', but in practice it has limited applicability. The runoff model with a ''non-linear reservoir'' is more universally applicable, but still it holds only for catchments whose surface area is limited by the condition that the rainfall can be considered more or less uniformly distributed over the area. The maximum size of the watershed then depends on the rainfall characteristics of the region. When the study area is too large, it can be divided into sub-catchments and the various runoff hydrographs may be combined using flood routing techniques. Rainfall-runoff models need to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Flood Alert Flood alerts are issued by weather agencies to alert residents that flood conditions are a possibility. Types of flood alerts in the United States In the United States, a flash flood watch is issued by the National Weather Service (NWS) when weather conditions are favorable for very heavy rain that could cause flooding or flash flooding. A watch does not mean that flooding is occurring, only that weather conditions have created or will create a significant risk for it. If flooding occurs, a flood warning or flash flood warning would be issued and immediate action should be taken. A flood warning or flash flood warning is issued when flooding is imminent or already occurring. When flood warnings are issued, it means that area waterways will likely soon be in flood. Not all flood watches suggest that large-scale flooding, such as during landfalling tropical cyclones, is possible. Flood alerts in other countries In Canada, a heavy rainfall warning, which indicates rainfall amounts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Flood Modeller Pro Flood Modeller is a computer program developed by Jacobs that simulates the flow of water through river channels, urban drainage networks and across floodplains using a range of one- and two-dimensional hydraulic solvers. The software incorporates a user interface for building, running and viewing the results of models, including a GIS map interface. Flood Modeller was previously known as ISIS software (named after the local name for the Upper Thames). The software has been independently benchmarked by the Environment Agency and has helped thousands of users transform how they undertake modelling and how they share and communicate flood-related information with clients and members of the public. Initially developed by Halcrow Group and then CH2M Hill, Flood Modeller is now developed by Jacobs Engineering group. Solvers 1D solvers Flood Modeller includes steady-state and unsteady 1D river solvers for modelling open-channels. It also provides a 1D urban solver for mod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]