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UN-SPIDER Knowledge Portal
Flood is usually used as a general term to describe the overflow of water from a stream channel into normally dry land in the floodplain (riverine flooding), higher-than–normal levels along the coast and in lakes or reservoirs (coastal flooding) as well as ponding of water at or near the point where the rain fell (flash floods) (IRDR Glossary).
Floods are the natural hazard with the highest frequency and the widest geographical distribution worldwide. According to the Organization for Economic Cooperation and Development (OECD) flooding is one of the most common, widespread and destructive natural perils, affecting approximately 250 million people worldwide and causing more than $40 billion in damage and losses on an annual basis (OECD).
Flooding occurs most commonly from heavy rainfall when natural watercourses lack the capacity to convey excess water. It can also result from other phenomena, particularly in coastal areas, by a storm surge associated with a tropical cyclone, a tsunami or a high tide. Dam failure, triggered by an earthquake, for instance, will lead to flooding of the downstream area, even in dry weather conditions.
Various climatic and non-climatic processes can result in different types of floods: riverine floods, flash floods, urban floods, glacial lake outburst floods and coastal floods.
Flood magnitude depends on precipitation intensity, volume, timing and phase, from the antecedent conditions of rivers and the drainage basins (frozen or not or saturated soil moisture or unsaturated) and status. Climatological parameters that are likely to be affected by climate change are precipitation, windstorms, storm surges and sea-level rise (UNDRR).
When floodwaters recede, affected areas are often blanketed in silt and mud. The water and landscape can be contaminated with hazardous materials such as sharp debris, pesticides, fuel, and untreated sewage. Potentially dangerous mold blooms can quickly overwhelm water-soaked structures. Residents of flooded areas can be left without power and clean drinking water, leading to outbreaks of deadly waterborne diseases like typhoid, hepatitis A, and cholera (UNDRR).
Landsat 9 was successfully launched on Monday, Sept. 27, 2021 from Vandenberg Space Force Base in California. Landsat 9 data is publicly available from USGS.
Landsat 9—a partnership between NASA and the U.S. Geological Survey— continues the Landsat program’s critical role in monitoring, understanding and managing the land resources needed to sustain human life.
Today’s increased rates of global land cover and land use change have profound consequences for weather and climate change, ecosystem function and services, carbon cycling and sequestration, resource management, the national and global economy, human health, and society.
Landsat is the only U.S. satellite system designed and operated to repeatedly observe the global land surface at a moderate scale that shows both natural and human-induced change.
Since reducing the risk of a Landsat data gap is a high priority of the U.S. Sustainable Land Imaging Program, Landsat 9 has a design very similar…read more
The Sentinel-6 Michael Freilich satellite was launched into orbit on November 21, 2020. The launch was a culminated European-American effort that involved organisations from both sides of the atlantic. The European Space Agency (ESA), the European Organisation for the Exploitation of Meterological Satellites (EUMETSAT), the National Aeronautics and Space Administration (NASA), the National Oceanic and Atmospheric Administration (NOAA) and the National Centre for Space Studes (CNES) all collaborated together to make the launch of Sentinel-6 Michael Freilich a reality. The Sentinel-6 Michael Freilich satellite is the first of the Sentinel-6 satellites. An identical satellite, Sentinel-6B will follow in 2025. At an altitude of 1336 km the Sentinel-6 Michael Freilich satellite will use instruments on board to provide highly accurate measurements of the sea level in an effort to combat…
The Argentinean Microwaves Observation Satellite 1B (SAOCOM 1B) was launched into orbit on August 30, 2020 from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida, United States of America. Developed by the National Argentinean Space Commission (CONAE) in corporation with the Italian Space Agency (ASI), this new satellite joined SAOCOM 1A and four Italian COSMO-SkyMed to complete the Italian-Argentinean Satellite System for Emergency Management (SIASGE). The SAOCOM 1B satellite orbits at 620 km above the earth's surface and is fitted with a Synthetic Aperture Radar (SAR) sensor that makes use of microwaves in the electromagnetic L-band. The spatial resolution of its imagery ranges between 10 and 100 meters. The data collected by SAOCOM 1B helps monitor climatological disasters (forest fires, glacial lake outbursts, droughts) and hydrological disasters (landslides and floods).
The Argentinean Microwaves Observation Satellite 1B (SAOCOM 1B) was launched into orbit on August 30, 2020 from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida, United States of America. Developed by the National Argentinean Space Commission (CONAE) in corporation with the Italian Space Agency (ASI), this new satellite joined SAOCOM 1A and four Italian COSMO-SkyMed to complete the Italian-Argentinean Satellite System for Emergency Management (SIASGE). The SAOCOM 1B satellite orbits at 620 km above the earth's surface and is fitted with a Synthetic…read more
Comprised of three identical Earth observation satellites working together, Canada's RADARSAT Constellation Mission (RCM) provides daily information about the condition of the Earth's surface. Launched on 12 June 2019, the satellites build upon a legacy of Canadian RADARSAT satellites that spans over twenty years. The RCM will ensure that this data remains available to Canadians, and will provide information to assist in areas such as maritime surveillance, disaster management, and ecosystem monitoring. In terms of maritime surveillance, information collected by the RCM contributes to ice, surface wind, oil pollution, and ship monitoring. RCM information can aid disaster management efforts in terms of mitigation, warning, recovery, and response, and can allow for detailed ecosystem monitoring including in the areas of agriculture, wildlife habitat, wetlands, forestry, and coastal change. The constellation's use of Synthetic Aperture Radar (SAR) allows data to be collected day…read more
MetOp-C is the third and last satellite of the MetOp series that forms the space segment of the EUMETSAT Polar System (EPS).
MetOp (Meteorological Operational) is Europe's first polar-orbiting operational meteorological satellite. It is the European contribution to the Initial Joint Polar System (IJPS), a co-operative agreement between Eumetsat and the US National Oceanic and Atmospheric Administration (NOAA) to provide data for climate and environmental monitoring and improved weather forecasting.
MetOp-A (launched on 19 October 2006), MetOp-B (launched on 17 September 2012) and MetOp-C (launched 7 November 2018) are in a lower polar orbit, at an altitude of 817 kilometres, to provide more detailed observations of the global atmosphere, oceans and continents. The three satellites will operate in unison for as long as Metop-A's available capacities bring benefits to users. NOAA still continues to operate its mid-afternoon orbit satellite service as part of the…
NovaSAR-1 was launched into orbit on September 16, 2018 from Satish Dhawan Space Centre in Sriharikota, India. It was developed by the United Kingdom Space Agency (UKSA) in cooperation with the Indian Space Research Organisation (ISRO), the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and the Department of Science and Technology-Advanced Science and Technology Institute (DOST-ASTI) of the Republic of the Philipines. NovaSAR-1 orbits at 583 km above the earth's surface and is fitted with a Synthetic Aperture Radar (SAR) sensor that makes use of microwaves in the electromagnetic S-band. The spatial resolution of its imagery ranges between 6 and 30 metres. The data collected by NovaSAR-1 helps monitor climatological disasters (forest fires and droughts) and hydrological disasters (floods).read more
Carrying a suite of cutting-edge instruments, Sentinel-3 will measure systematically Earth’s oceans, land, ice and atmosphere to monitor and understand large-scale global dynamics. It will provide essential information in near-real time for ocean and weather forecasting.
The mission is based on two identical satellites orbiting in constellation for optimum global coverage and data delivery. For example, with a swath width of 1270 km, the ocean and land colour instrument will provide global coverage every two days. Sentinel-3B was launched on 25 April 2018.
With a focus towards our oceans, Sentinel-3 measures the temperature, colour and height of the sea surface as well as the thickness of sea ice. These measurements will be used, for example, to monitor changes in sea level, marine pollution and biological productivity.
Over land, this innovative mission will provide a bigger picture by monitoring wildfires, mapping the way land is used, provide indices of…
NOAA-20, designated JPSS-1 prior to launch, is the first of the United States National Oceanic and Atmospheric Administration's latest generation of U.S. polar-orbiting, non-geosynchronous, environmental satellites called the Joint Polar Satellite System. NOAA-20 was launched on 18 November 2017 and joined the Suomi National Polar-orbiting Partnership satellite in the same orbit. NOAA-20 operates about 50 minutes ahead of Suomi NPP, allowing important overlap in observational coverage. Circling the Earth from pole-to-pole, it crosses the equator about 14 times daily, providing full global coverage twice a day. This will give meteorologists information on "atmospheric temperature and moisture, clouds, sea-surface temperature, ocean color, sea ice cover, volcanic ash, and fire detection" so as to enhance weather forecasting including hurricane tracking, post-hurricane recovery by detailing storm damage and mapping of power outages.
The project incorporates five instruments,…read more
Cartosat-2 is an advanced remote sensing satellite with a single panchromatic camera (PAN) capable of providing scene-specific spot imageries for cartographic applications. The camera is designed to provide imageries with better than one meter spatial resolution and a swath of 10 km. The satellite will have high agility with capability to steer along and across the track up to + 45 degrees. It will be placed in a sun-synchronous polar orbit at an altitude of 630 km. It will have a revisit period of four days. The re-visit can be improved to one day with suitable orbit manoeuvres.
Several new technologies like two mirror on axis single camera, Carbon Fabric Reinforced Plastic based electro optic structure, lightweight, large size mirrors, JPEG like data compression, advanced solid state recorder, high-torque reaction wheels and high performance star sensors are being employed in Cartosat-2.
Beginning with Cartosat 2C, a Multi-spectral camera was added and…read more