The version 4 SSEBop Evapotranspiration product incorporates dynamic, scene-specific c factor parameterization and improves the spatial accuracy of ET by sub-dividing and modeling each MODIS tile into 25 units. Furthermore, SSEBop v4 models every 1 km pixel of the landscape, including previously excluded low vegetation areas. In addition, we will provide map graphics and downloads of both actual ET data and anomalies.
Note: despite the improved accuracy, the ET product is still more reliable in a relative sense as in anomalies for drought monitoring purposes. The absolute accuracy can vary from region-to-region; thus, users are encouraged to evaluate and determine a one-time bias correction for water budget applications.
The NASA MODIS processing system transitioned from collection 5 (C5) to collection 6 (C6) as of 1 April 2017. Due to this change in data flow, the USGS FEWS NET eMODIS products/data are undergoing a transition beginning with April 2017 composites. We will be using MODIS Aqua C6 data and will only be processing dekadal (10-day) composites (36 per year) as opposed to overlapping 10-day composites, previously updated every 5 days. Additionally, our anomaly products will be compared to a 10-year median (2007-2016). We expect some delays for the first composite of April in Central Asia, but anticipate having products for Africa, Central America, and Hispaniola no later than 14 April. Our C5 history will be maintained for a short period of time beyond when the full time series of C6 data are available. Data and graphics for both collections will be available as separate data sets on our regional product pages (i.e. "eMODIS NDVI C5" and "eMODIS NDVI C6"). We will populate C6 historical data/graphics as they are produced. While data will be downloadable for both collections, we advise users not to consider the two collections as a continuous time series.
We apologize for any inconvenience that this might cause. Please feel free to email any concerns that you might have (mbudde@usgs.gov).
USGS FEWS NET Data Portal
The USGS FEWS NET Data Portal provides access to geo-spatial data, satellite image products, and derived data products in support of FEWS NET drought monitoring efforts throughout the world. This portal is provided by the USGS FEWS NET Project, part of the Early Warning Focus Area at the USGS Earth Resources Observation and Science (EROS) Center.
Data Portals
- Africa
- C.America/Caribbean/Mexico
- Central Asia
- Middle East
- South Asia
FEWS NET Software Tools
Interactive map viewers allow users to visualize administrative and crop zone time series of normalized difference vegetation index, dekadal (10-day) rainfall, and seasonal cumulative rainfall, including options for data download.
The Early Warning eXplorer (EWX) software is an interactive web-based mapping tool that allows users to visualize continental-scale rainfall estimate (RFE), land surface temperature (LST) and normalized difference vegetation index (NDVI) data and anomalies at varied time steps and review ...
The water point map viewer, which monitors 234 water points from Mali to Somalia, will help a range of government and non-government actors understand the current availability of water for livestock and human consumption. This will inform food security analysis, humanitarian assistance pl...
DSM (Drought Status Monitor) is an experimental decision support tool based on weather and crop conditions. It incorporates drought monitoring rules that distinguish severity and provide a generalized drought indicator at national and sub-national scales.
The GeoWRSI is a geo-spatial, stand-alone implementation of the Water Requirements Satisfaction Index (GeoWRSI), as it is implemented by the USGS for the FEWSNET Activity. The program runs a crop-specific water balance model for a selected region in the world, using raster data inputs. Th...