Research Projects

Terrestrial vegetation plays a central role in mediating the exchange of carbon, water, and energy between the land surface and the atmosphere. This coupling is especially critical in the context of Indian agroecosystems, where climatic variability and water scarcity increasingly threaten crop productivity and food security. Traditional remote sensing indices such as Normalized Difference Vegetation Index or Enhanced Vegetation Index provide structural information about vegetation greenness but are limited in capturing early physiological stress. This limitation highlights the urgent need for mechanistic, physiologically grounded approaches to monitor plant function and stress responses in dynamic, heterogeneous agricultural landscapes. The core rationale of this research is to develop a scalable, integrative framework that combines high-resolution remote sensing observations with advanced process-based modeling to detect and understand vegetation responses to heat and water stress. The project is built on the hypothesis that solar-induced chlorophyll fluorescence (SIF), when used in conjunction with hyperspectral reflectance, lidar and thermal data, can effectively capture real-time physiological regulation of photosynthesis and transpiration—thereby serving as a powerful diagnostic tool for vegetation stress across scales. Furthermore, we hypothesize that coupling detailed models such as Simple Soil–Plant–Atmosphere Transfer Model (SiSPAT) and Soil Canopy Observation, Photosynthesis, and Energy Fluxes (SCOPE) will provide a comprehensive representation of the soil–plant–atmosphere continuum (SPAC), enabling robust simulations of stress propagation from root zone to canopy. The scientific objectives are threefold: (1) to investigate plant functional responses to heat and water stress using high-frequency, ground-based measurements of fluxes and SIF; (2) to develop and validate a coupled SCOPE–SiSPAT model that simulates energy, carbon, and water exchange processes under variable environmental conditions; and (3) to scale the insights from local observations using satellite data from OCO-2, TROPOMI, EMIT, GEDI, and ERA5 to map stress dynamics across Indian agroecosystems. The project will implement a series of coordinated experiments, beginning with the enhancement of an existing eddy covariance tower at Berambadi, Karnataka. This site will be equipped with custom-designed spectrometers to capture SIF, canopy temperature, and VSWIR reflectance. Ancillary physiological and structural measurements (e.g., LAI, chlorophyll, leaf gas exchange) will be collected to support ground validation. The coupled SCOPE–SiSPAT model will be calibrated and tested using this dataset, and subsequently driven by satellite observations to simulate vegetation stress across spatial scales. By integrating physiology-based measurements with physical modeling and remote sensing, this project offers a transformative approach for understanding and monitoring vegetation stress in the tropics. It offers the potential to significantly advance fundamental understanding of plant acclimation, water-use efficiency, and energy balance under climatic stress. In terms of applications, the framework will enable improved early warning systems for drought and crop failure, precision irrigation advisories, and climate-resilient agricultural management. It will also contribute to international efforts in Earth system modeling, ecohydrology, and satellite product validation. The project thus represents a critical advancement in both theoretical and applied environmental science, with strong implications for sustainability in data-scarce, climate-sensitive regions.