MODIS Water Flux Maps for Okavango Delta Savanna

Three gridded binary image files map daily evapotranspiration for the Okavango Delta region in Botswana during September 2001. The data were generated by NASA using the ESTA model, which integrates MODIS satellite reflectance data with meteorological observations from the Maun flux tower. This physically-based model simulates surface energy and water balances for a heterogeneous savanna landscape.

Use Cases

• Validating land surface model outputs for soil and turbulent heat fluxes using ground measurements from soil heat flux plates and an eddy-correlation system.
• Analyzing spatial patterns of daily water loss (evapotranspiration in mm/day) across a savanna-wetland landscape.
• Studying the relationship between MODIS-derived surface temperature, albedo, vegetation indices, and resultant evapotranspiration.
• Assessing energy balance components for a heterogeneous land surface using a model driven by remotely sensed surface temperature, reflection, and vegetation density.

Strengths

• Model outputs were validated using in-situ net radiometer data and soil heat flux measurements from the Maun flux tower site.
• Integrates multiple data sources, including MODIS satellite bands (visible, near infrared, thermal) and near-surface meteorological observations.
• Provides spatially explicit data at a 1 km resolution for a key wetland region during the dry season.

Limitations

• Temporal coverage is extremely limited, containing data for only three specific days in September 2001.
• Spatial resolution was reduced to 1 km, coarser than the original 250-500 meter resolution of some MODIS bands.
• Conflicting metadata exists: the last updated date is reported as 2026-03 12 on Data.gov but 2001-09-29 on NASA Earthdata.

Provenance

Source

National Aeronautics and Space Administration

Collection Method

Physically-based ESTA model applied to MODIS satellite reflectance data and Maun flux tower meteorological observations.

Time Range

2001-09-02 to 2001-09-29

Freshness

2026-03-12 21:47:18.693932

Geography

Okavango Delta region, near Maun, Botswana