Assessing the grapevine and environmental interactions: integrating weather and thermal satellite data in the context of climate change, South Africa
In the context of climate change and the complex terrain of the Western Cape, increased resolution of climate data is crucial for effective terroir zoning and adaptive strategies. Reliable climate data can be costly, and currently requires intensive data validation; hence the study aimed to find an alternative resource to quantify the climate over the spatial extent of the Western Cape, for possible semi-real time applications. This study focused on integrating climate and thermal satellite remote sensing data to assess the reaction of the grapevine to a changing environment. Sites were selected over a geographical climatic band; multiple factor analysis was used to evaluate the interaction of weather, specifically temperature, relative humidity and wind speed with grapevine phenology. The aims of the study were to quantify climate change and seasonal variability in the Western Cape with the best station network possible within the limits of the spatial and temporal resolution availability. The satellite land surface temperature and weather station data exhibited a significant linear relationship with a good prediction accuracy. Simple statistical models where employed, with robust resampling techniques achieving a high accuracy in the complex terrain of the Western Cape. Land surface temperature maps are intrinsically spatialised, providing daily temperature values that in the past would have only been possible by spatial interpolation of sparse weather station networks, which could only be as accurate as the input data. This study has provided insights into grapevine and environmental interactions being driven by seasonal variability within the climate shifts in the Western Cape. Grapevine responses such as flowering date were driven most prominently by climate, specifically the summer months of the previous harvest, emphasising the need and the potential use of thermal satellite products to supplement weather station networks.
Southey, T.O. and Strever, A.E. (2020). Assessing the grapevine and environmental interactions: integrating weather and thermal satellite data in the context of climate change, South Africa. Acta Hortic. 1276, 49-56
climate, thermal, remote sensing, MODIS, Vitis vinifera, grapevine, phenology