Dr Ha Thanh Nguyen1, Dr Roger Lawes1, Dr. Cindy Ong1, Stuart Brown1, Mr Tony Swan1
1CSIRO, Canberra, Australia
Biography:
I am a researcher in global environmental changes with domain expertise in vegetation dynamics (yield, carbon exchange, phenology, quality and health in response to climate extremes and variability). My work focuses on developing and deploying analytics from datasets of heterogenous size, structure, spatiotemporal resolutions, instrument, and access configurations. I also maintain active engagement in co-designing and delivering decision-ready solutions to help stakeholders’ future proof against climate extremes and variability.
Abstract:
Australia is facing an increase in cold extremes associated with damaging spring frost events in recent decades. Frost can have negative impacts on both crop yield and crop quality, hence rapid estimation of frost damage is essential to avoid yield losses. The potentiality of remote and proximal sensing techniques to evaluate the changes in physiological and biochemical parameters of crops suffered from frost damage have been demonstrated in the controlled setting at the plot/ leaf scale. However, the optimal spectral region for frost damage detection and mapping at the field scale is still unknown. In this study, we tested the hypotheses that (1) narrowband reflectance from spaceborne hyperspectral imagery differ before and after frost occurrence and (2) such differences can be used to spatially estimate frost response on the paddock. We analysed two pairs of spaceborne hyperspectral imagery acquired over the Boorowa Research Farm before and after two spring frost events in 2023. We identified several spectral regions between the visible and the red edge that showed the largest reflectance change before and after frosts. However, the regression between these narrowband reflectance’s and canola pod damage indicators were statistically inconclusive, suggesting that longer wavelengths in the shortwave infrared region should be explored for frost damage detection.