HRMET Code + Manual now on GitHub: https://github.com/szipper/HRMET
One challenge for precision agriculture is quantifying spatial variability in plant water use, or evapotranspiration, at high (~1 m) spatial resolutions. To address this challenge, I developed the surface energy balance model High Resolution Mapping of Evapotranspiration (HRMET), described in a 2014 publication (link) (pdf). HRMET is designed to take very few inputs (meteorological data, canopy surface temperature, and a vegetation index) and calculate instantaneous evapotranspiration (ET) rates, without the requirement of 'dry' and 'wet' pixels characteristic of many remotely sensed techniques. This advance allows HRMET to be used during both open- and closed-canopy conditions with homogeneous cover, e.g. agroecosystems.
Key Publications
Zipper SC & SP Loheide II (2014). Using evapotranspiration to assess drought sensitivity on a subfield scale with HRMET, a high resolution energy balance model. Agricultural & Forest Meteorology, 197: 91-102. DOI: 10.1016/j.agrformet.2014.06.009 (link) (pdf)
One challenge for precision agriculture is quantifying spatial variability in plant water use, or evapotranspiration, at high (~1 m) spatial resolutions. To address this challenge, I developed the surface energy balance model High Resolution Mapping of Evapotranspiration (HRMET), described in a 2014 publication (link) (pdf). HRMET is designed to take very few inputs (meteorological data, canopy surface temperature, and a vegetation index) and calculate instantaneous evapotranspiration (ET) rates, without the requirement of 'dry' and 'wet' pixels characteristic of many remotely sensed techniques. This advance allows HRMET to be used during both open- and closed-canopy conditions with homogeneous cover, e.g. agroecosystems.
Key Publications
Zipper SC & SP Loheide II (2014). Using evapotranspiration to assess drought sensitivity on a subfield scale with HRMET, a high resolution energy balance model. Agricultural & Forest Meteorology, 197: 91-102. DOI: 10.1016/j.agrformet.2014.06.009 (link) (pdf)
By comparing normalized ET rates across dry & wet image collection dates, HRMET can be used as a non-destructive tool to map drought sensitivity at meter-scale within agricultural fields:
I am working with collaborators to test HRMET in other crop types (potatoes & beans) in the Central Sands region of Wisconsin to better understand how cropping decisions impact the water balance in a region with baseflow-dominated streams and many groundwater-dependent ecosystems.
