Floods

Mapping floodwater extent for active floods is critical for local and regional officials and for disaster relief organizations that need to ascertain where to focus their efforts. NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE) provides data to the Dartmouth Flood Observatory and the near real-time (NRT) Global MODIS Flood Mapping initiative.

Users can visualize imagery related to floods in Worldview, or download data using the links below.

  • Register to start downloading data.
  • Read the disclaimer for more information about using the data.

Corrected Reflectance Imagery

Corrected Reflectance Imagery

MODIS and VIIRS Corrected Reflectance imagery are available only as near real-time imagery. The imagery can be visualized in Worldview and Global Imagery Browse Services (GIBS). More:

Information on MODIS Corrected Reflectance Imagery layers including

  • Corrected Reflectance True Color (Bands 1-4-3)
  • Corrected Reflectance (Bands 3-6-7)
  • Corrected Reflectance (Bands 7-2-1)

Information on VIIRS Corrected Reflectance Imagery layers including

  • Corrected Reflectance True Color (Bands I1-M4-M3)
  • Corrected Reflectance (Bands M3-I3-M11)
  • Corrected Reflectance (Bands M11-I2-I1)

Browse Corrected Reflectance imagery in Worldview

For more on the difference between Corrected Reflectance and Surface Reflectance Imagery

Land Surface Reflectance

Land Surface Reflectance

In comparison with the MODIS Corrected Reflectance product, the MODIS Land Atmospherically Corrected Surface Reflectance product (MOD09) is a more complete atmospheric correction algorithm that includes aerosol correction, and is designed to derive land surface properties.

Product: Instrument, Platform and Download Link

Description

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MODIS (Aqua) MYD09



MODIS (Terra) MOD09

doi: 10.5067/MODIS/MYD09.NRT.006 (Aqua) and doi: 10.5067/MODIS/MOD09.NRT.006 (Terra)

More information on MODIS Land Surface Reflectance Products including:

  • MODIS (Aqua/Terra) Land Surface Reflectance True Color (Bands 1-4-3)
  • MODIS (Aqua/Terra) Land Surface Reflectance True Color (Bands 7-2-1)
  • MODIS (Aqua/Terra) Land Surface Reflectance True Color (Bands 1-2-1)
VIIRS (Suomi-NPP)
VNP09_NRT

VIIRS Land Surface Reflectance
The VIIRS Surface Reflectance provides continuity with the EOS-MODIS Land Surface Reflectance product.The Suomi-NPP/VIIRS surface reflectance products are estimates of surface reflectance in each of the VIIRS reflective bands I1-I3, M1-M5, M7, M8, M10, and M11. Surface reflectance for each moderate-resolution (750m) or imagery-resolution (375m) pixel is retrieved separately for the Level-2 products and is obtained by adjusting top-of-atmosphere reflectance to compensate for atmospheric effects. Corrections are made for the effects of molecular gases, including ozone and water vapor, and for the effects of atmospheric aerosols. The inputs to the surface reflectance algorithm include top-of-atmosphere reflectance for the VIIRS visible bands (VNP02MOD, VNP02IMG), the VIIRS cloud mask and aerosol product (NPP-CMIP_L2), aerosol optical thickness (NPP_VAOTIP_L2, NPP_VAMIP_L2), and atmospheric data obtained from a reanalysis (surface pressure, atmospheric precipitable water, and ozone concentration). All surface reflectance products are produced for daytime conditions only.

Surface Reflectance Browse imagery

Coming soon

Precipitation Estimate

Precipitation Estimate

The AIRS Precipitation Estimate Day/Night layer is an estimate of daily precipitation measured in millimeters (mm) using cloud-related parameters of cloud-top pressure, fractional cloud cover, and cloud-layer relative humidity.

The precipitation algorithm is a regression between these parameters and some observed precipitation data. It is an estimate from AIRS using a TOVS-like algorithm and is intended for merging into the precipitation product of the Global Precipitation Climatology Project (GPCP).

Product and Download Link

Description

Browse imagery in Worldview

AIRS (Aqua)

AIRS2SUP_NRT.006

AIRS Precipitation Estimate

The AIRS Precipitation Estimate (AIRG2SSD) layer is a is a variable of the AIRS Level 2 Near Real Time Support Retrieval (AIRS) (AIR2SUP_NRT). The imagery resolution is 2 km and sensor resolution is 45 km. The temporal resolution is daily.

References: GES DISC - AIRS2SUP_NRT: AIRS/Aqua L2 Near Real Time (NRT) Support Retrieval (AIRS-only) V006; GES DISC - Near Real-Time Data

AIRS Precipitation Estimate


Soil Moisture

Soil Moisture

Product and Download Link

Description

Browse imagery in Worldview

AMSR2

(GCOM-W1)

AU_Land_NRT_R01

AMSR-U2 Soil Moisture Normalized Polarization Difference (Day | Night)

The AMSR-U2 Soil Moisture Single Channel Algorithm layer indicates the amount of soil moisture over land masses in grams per cubic centimeters (g/cm3).

AMSR-U2 Soil Moisture Single Channel Algorithm (Day | Night)

The AMSR-U2 Soil Moisture Single Channel Algorithm layer indicates the amount of soil moisture over land masses in grams per cubic centimeters (g/cm3).

Both layers were constructed by using the Single Channel Algorithm (SCA) using resampled brightness temperature data. The AMSR-E/AMSR2 Unified Level-2B land product provides a long-term data record by combining AMSR-E and AMSR2 data. The imagery resolution is 25 kilometers, and the temporal resolution is daily.

NRT AMSR2 Unified L2B Half-Orbit 25 km EASE-Grid Surface Soil Moisture Beta Version 1

AMSR-U2 Soil Moisture: Normalized Polarization Difference (Day | Night) and Soil Moisture Single Channel Algorithm (Day| Night)


Snow Cover

Snow Cover

The MODIS snow cover layer shows the presence of snow cover over land and water bodies as an index related to the presence of snow. It is based on a Normalized Difference Snow Cover Index (NDSI) that is derived from the cloud free snow reflectance sensed by the MODIS instrument, and hence this layer shows presence of snow during day time and under cloud clear condition only. NDSI snow cover though could be retrieved in the valid range of (0, 1.0) at every pixel, additional tests like surface temperature screening linked with the surface height is used for accurate detection. Snow is precipitation that forms from water vapor in the atmosphere where temperatures are below 0° Celsius. If the ground temperature is also below freezing, snow will accumulate on the ground as bright, white layer of snowpack. Snow cover reflects sunlight back into the atmosphere, helping to cool the Earth’s surface. Snowmelt is used for drinking water, water for crop irrigation, and can moisturize soil to reduce the risk of wildfire in many areas in the world. When snow melts in the spring, too much snow can cause springtime flooding.

Product and Download Link

Description

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MODIS (Terra) MOD10_L2

MODIS (Aqua) MYD10_L2

MODIS Snow Cover

The MODIS Snow Cover layer is available from NASA's Terra and Aqua satellites. The sensor and imagery resolution is 500 m and the temporal resolution is daily. DOI: doi: 10.5067/MODIS/MOD10_L2.NRT.006 and doi: 10.5067/MODIS/MYD10_L2.NRT.006

MODIS Snow Cover


Snow Water Equivalent

Snow Water Equivalent

The AMSR2 Snow Water Equivalent layer indicates the amount of water that is contained in snowpack in the Northern and Southern Hemispheres measured in millimeters (mm). Another way to think of it is if all the snow were melted instantaneously, it would be the depth of that water. The snow water equivalent layer is useful for assessing the amount of water that is present in the snowpack and can be used to assess surface runoff when the snow melts and to assess water availability for regions in lower elevations. The Advanced Microwave Scanning Radiometer 2 (AMSR2) instrument is a conically scanning passive microwave radiometer sensing microwave radiation at 12 channels and 6 frequencies ranging from 6.9 to 89 GHz on board the Global Change Observation Mission – Water 1 (GCOM-W1) satellite.

Product and Download Link

Description

Browse imagery in Worldview

(GCOM W-1)
A2_DySno_NRT

AMSR2 Snow Water Equivalent

This layer is part of the GCOM-W1 AMSR2 Level-3 Snow Water Equivalent (SWE) data set, which contains snow water equivalent (SWE) data and quality assurance flags mapped to the Northern and Southern Hemisphere 25 km Equal-Area Scalable Earth Grids (EASE-Grids). As NRT Tb Level -1R data are received from the Japanese Aerospace Exploration Agency throughout the day, partial daily products are generated and identified with a product maturity code of "P" in the filename. Once all Level-1R inputs are available, the complete daily product contains product maturity code "R" (near Real time) in the filename. Incremental processing makes data available to the user as it is received, rather than at the end of the day. The imagery resolution is 2 km and sensor resolution is 5 km. The temporal resolution is daily (partial NRT files updated throughout the day to a final product). More: LANCE AMSR2 Near Real-Time Snow Products Available,

AMSR2 Snow Water Equivalent

LANCE imagery can be overlaid with the following data sets from NASA's Socioeconomic Data and Applications Center (SEDAC), which are also available as layers in Worldview: Flood Hazard Frequency and Distribution, Flood Hazard-Mortality Risk and Flood Hazard Economic Risk.

Floods Moz

Visualize NRT data related to Floods in Worldview

This image shows flooding in Mozambique. By January 2013, the Limpopo River had spilled over its banks with water spanning more than 10 kilometers in certain areas. Read more at NASA's Earth Observatory.

Last Updated: May 28, 2019 at 1:06 PM EDT