Role of biophysical canopy traits on evapotranspiration and its impact on soil water dynamics within the vadose zone

Climate, hydrology, and plant processes are three factors that are intrinsically linked to one another. Integration of dynamic vegetation and canopy level processes governed by leaf biochemical traits with the subsurface water flow will help us to make more reliable and actionable predictions in the context of climate change. The limitations of hydrological works that consider plants to be statistical components are highlighted by a number of hydrological studies.

This study aims to highlight how crucial it is to include plant and plant physiological processes as a significant and dynamic component when modeling hydrological processes. For this purpose, we demonstrate the impact of stomatal conductance, photosynthesis, and other biophysical traits on the soil water dynamics within the vadose zone under current and projected (in future) climate scenarios using a process-based crop growth model BioCro II which uses climate variables as its input. We compare our results with those obtained using HYDRUS 1-D, which is a state-of-art model that has a wide range of applications in agriculture and irrigation. HYDRUS 1-D is a model capable of simulating one-dimensional water, heat, and solute transport through an unsaturated porous media. We also discuss the merits of coupling these two models to address some of the future challenges.