Water stress detection in the Amazon using radar

Water stress detection in the Amazon using radar

van Emmerik, T.H.M. (TU Delft Water Resources)
Steele-Dunne, S.C. (TU Delft Water Resources)
Paget, Aaron (University of Connecticut)
Oliveira, Rafael S. (University of Campinas)
Bittencourt, Paulo R.L. (University of Campinas)
Barros, Fernanda de V. (University of Campinas)
van de Giesen, N.C. (TU Delft Water Resources)

2017-07-16

The Amazon rainforest plays an important role in the global water and carbon cycle, and though it is predicted to continue drying in the future, the effect of drought remains uncertain. Developments in remote sensing missions now facilitate large-scale observations. The RapidScat scatterometer (K_u band) mounted on the International Space Station observes the Earth in a non-Sun-synchronous orbit, which allows for studying changes in the diurnal cycle of radar backscatter over the Amazon. Diurnal cycles in backscatter are significantly affected by the state of the canopy, especially during periods of increased water stress. We use RapidScat backscatter time series and water deficit measurements from dendrometers in 20 trees during a 9 month period to relate variations in backscatter to increased tree water deficit. Morning radar bacskcatter dropped significantly with increased tree water deficit measured with dendrometers. This provides unique observational evidence that demonstrates the sensitivity of radar backscatter to vegetation water stress, highlighting the potential of drought detection and monitoring using radar.

Amazon
drought
hydrology
radar
vegetation
water stress

http://resolver.tudelft.nl/uuid:d99677f9-7b59-45ce-b4b0-1397a7a7849a

https://doi.org/10.1002/2017GL073747

2018-01-01

0094-8276

Geophysical Research Letters, 44 (13), 6841-6849

Institutional Repository

journal article

© 2017 T.H.M. van Emmerik, S.C. Steele-Dunne, Aaron Paget, Rafael S. Oliveira, Paulo R.L. Bittencourt, Fernanda de V. Barros, N.C. van de Giesen