Floods are natural disasters that occur when an area experiences an overflow of water onto normally dry land. These events can result from various causes and have significant impacts on communities, the environment, and infrastructure. Here are key aspects of floods:
Heavy Rainfall: Prolonged and intense rainfall can lead to the saturation of soil, exceeding its capacity to absorb water. This runoff contributes to surface water accumulation and potential flooding.
Storm Surges: Coastal areas can experience flooding due to storm surges, which are abnormal rises in sea level generated by storms, especially tropical cyclones.
Snowmelt: Spring thaw or sudden warming can cause the melting of snow, leading to increased water runoff and the potential for river or urban flooding.
Dam or Levee Failures: Failure of dams or levees can release large volumes of water, causing downstream flooding.
Types of Floods
Flash Floods: Flash floods result from intense rainfall over a short period, often in mountainous or urban areas. They can lead to rapid and unexpected rises in water levels.
River Flooding: Overflow of rivers and streams due to excessive rainfall or the melting of snow in upstream areas can lead to river flooding.
Coastal Floods: Result from storm surges, high tides, or tsunamis, causing seawater to inundate coastal areas.
Urban Floods: Occur in urban areas due to inadequate drainage systems overwhelmed by heavy rainfall.
Pluvial Floods: Also known as surface water floods, these happen when heavy rainfall creates a flood event independent of an overflowing water body.
Impacts of Floods
Infrastructure Damage: Floodwaters can damage roads, bridges, buildings, and other infrastructure, disrupting transportation and utilities.
Loss of Lives and Property: Floods pose a significant risk to human life and property. Rapidly rising water levels can lead to evacuations and, in severe cases, loss of life.
Economic Impact: Flooding can have long-term economic consequences, affecting agriculture, businesses, and communities. Recovery efforts can be costly.
Environmental Consequences: Floods can alter ecosystems, impact wildlife, and introduce pollutants into water bodies, affecting the environment.
Public Health Risks: Contaminated floodwaters can pose health risks, including the spread of waterborne diseases.
Flood Data Analysis
FEMA flood products
Dataset
Description
Map viewer link
Data download link
FEMA Flood map
FEMA[2] provides flood maps for people to understand the flood risk of their community. The map can be accessed via an online viewer.
An interactive data tool to understand the flood cost. Flooding cost data is estimated using insurance claims from National Flood Insurance Program (data website) and FEMA's Individuals and Households Program (data website), which is also available for downloading.
NRI is a dataset and online tool built by FEMA[2] to help illustrate the risk of United States communities for 18 natural hazards. It was calculated expected annual loss resulting from hazards times social vulnerability and then divided by resilience. Both composite index of all 18 hazards as well as index for each individual hazard are given. Social vulnerability and community resilience information are also given.
This dataset contains financial assistance values, including the number of approved applications, as well as individual, public assistance, and hazard mitigation grant amounts.
FEMA also provides many other open datasets on disaster information, emergency management, assistance, hazard mitigation etc. in industry standard, machine-readable formats.
Detailed site-level data about stream flow, such as gage height, discharge, both real-time monitoring, historical information, and 7-day forecast is provided. Gage data typically are recorded at 15- to 60-minute intervals.
Dynamical downscaled future climate projection including temperature, precipitation, and fire weather index provided by the Center for Climate Resilience and Decision Science (CCRDS) at Argonne National Laboratory[6]. Data is at a resolution of 12 km2.
It map the major flood events recorded by the DFO Flood Observatory since the beginning of the satellite records, using NASA's Aqua and Terra satellites. Population exposure estimates are derived from overlaying the flood maps with the Global Human Settlement Layer (GHSL) population data. ML-based precipitation estimates are also provided at 0.25degree resolution from 1983 to 2021.
It contains statistics of flood, such as number, duration, causes, severity, as well as consequences of flood such as fatalities, displaced and damage, from year 1985 to 2002. Note, some of the information on the website is no longer available or maintained.
RAPID NRT Flood Maps
Near Real-time and archival data of High-resolution (10 m) flood inundation dataset over the Contiguous United States, developed based on the Sentinel-1 SAR imagery (2016-current) archive, using an automated Radar Produced Inundation Diary (RAPID) algorithm. NRT data will be update as soon as SAR images available and done processed.
A global flood monitoring system based on a hydrological runoff and routing model, developed by University of Maryland. It uses real-time satellite retrieved precipitation as input and has streamflow as output. 3-hourly flood Detection/Intensity for year 2001-2022 at 1/8th degree resolution is available for downloading.
Detailed site-level data about stream flow, such as gage height, discharge, both real-time monitoring, historical information, and 7-day forecast is provided. Gage data typically are recorded at 15- to 60-minute intervals.
Flood and other hydrometeorological forecast by regional river forecast centers. For some river forecast center, for example, SE forecast center, flood inundation zone forecast is also given.
The National Water Model (NWM) is a US-wide water resource model launched by NOAA in 2016. It forecasts key water variables like snowpack, soil moisture, and streamflow using data from meteorological models. The Short Range Forecast cycles hourly and provides streamflow predictions up to 18 hours ahead. The data is updated in four-week intervals.
120-day forecast for some river gages are provided. A seasonal Columbia river minimum stage outlook is also provided to assist with long-range planning.
