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Flood Forecasting
Flood forecasting is the process of predicting the occurrence, magnitude, timing, and duration of floods in a specific area, often by analysing various hydrological, meteorological, and environmental factors. The primary goal of flood forecasting is to deliver timely and accurate information to decision-makers, empowering them to take appropriate actions to mitigate the potential consequences of flooding on human lives, property, and the environment. By accounting for the various dimensions of a flood event, such as occurrence, magnitude, duration, and spatial extent, flood forecasting models can offer a more holistic and detailed representation of the impending risks and facilitate more effective response strategies. Flood forecasting is a multifaceted discipline that aims to predict various aspects of flood events, including their occurrence, magnitude, timing, duration, and spatial extent. However, the scope and definition of flood forecasting can differ across scientific publica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precipitation (meteorology)
In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls from clouds due to gravitational pull. The main forms of precipitation include drizzle, rain, rain and snow mixed ("sleet" in Commonwealth usage), 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; their water vapor does not condense sufficiently to precipitate, so fog and mist do not fall. (Such a non-precipitating combination is a colloid.) Two processes, possibly acting together, can lead to air becoming saturated with water vapor: 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 shower (p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Runoff Model
A runoff models or rainfall-runoff model describes how rainfall is converted into runoff in a drainage basin (catchment area or watershed). More precisely, it produces a surface runoff hydrograph in response to a rainfall event, represented by and input as a hyetograph. Rainfall-runoff models need to be calibrated before they can be used. 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. Linear reservoir The hydrology of a linear r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streamflow Routing
Streamflow, or channel runoff, is the flow of water in streams and other channel (geography), channels, and is a major element of the water cycle. It is one runoff (hydrology), runoff component, the movement of water from the land to Body of water, 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 (hydrology), discharge of water flowing in a channel is measured using stream gauges or can be estimated by the Manning formula, 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 Water cycle, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drainage Basin
A drainage basin is an area of land in which 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 the drainage divide line. A drainage basin's boundaries are determined by watershed delineation, a common task in environmental engineering and science. In a closed drainage basin, or endorheic basin, rather than flowing to the ocean, water converges toward the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flood Warning
A flood warning or flood alert is the task of making use of flood forecasts to make decisions about whether warnings should be issued to the general public or if 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 of time that the public would need to respond effectively to a warning. * The delay between a warning being initiated and it being received by the public. * The need to avoid issuing warnings unnecessarily, because of the wasted efforts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Runoff Model (reservoir)
A runoff models or rainfall-runoff model describes how rainfall is converted into runoff in a drainage basin (catchment area or watershed). More precisely, it produces a surface runoff hydrograph in response to a rainfall event, represented by and input as a hyetograph. Rainfall-runoff models need to be calibrated before they can be used. 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. Linear reservoir The hydrology of a linear r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flood Alert
A flood warning or flood alert is the task of making use of flood forecasts to make decisions about whether warnings should be issued to the general public or if 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 of time that the public would need to respond effectively to a warning. * The delay between a warning being initiated and it being received by the public. * The need to avoid issuing warnings unnecessarily, because of the wasted efforts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flood Modeller Pro
Flood Modeller is a computer program developed by Jacobs that assesses flood risk by simulating 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. The software has been independently benchmarked by the Environment Agency and is used extensively to undertake modelling of flood risk, develop flood risk management schemes and provide flood forecasting services. Development History Initially developed by Halcrow Group and then CH2M Hill, Flood Modeller is now developed by Jacobs Solutions. Flood Modeller was previously known as "ISIS" (after the local name for the Upper Thames). 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 modelling u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weather Forecasting
Weather forecasting or weather prediction is the application of science and technology forecasting, to predict the conditions of the Earth's atmosphere, atmosphere for a given location and time. People have attempted to predict the weather informally for thousands of years and formally since the 19th century. Weather forecasts are made by collecting quantitative data about the current state of the atmosphere, land, and ocean and using meteorology to project how the atmosphere will change at a given place. Once calculated manually based mainly upon changes in atmospheric pressure, barometric pressure, current weather conditions, and sky conditions or cloud cover, weather forecasting now relies on numerical weather prediction, computer-based models that take many atmospheric factors into account. Human input is still required to pick the best possible model to base the forecast upon, which involves pattern recognition skills, teleconnections, knowledge of model performance, and kn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
