Toward a Multi-objective Decision Framing for Tea Fields Management under Water Stress

Climate change–induced droughts have intensified water stress in rain-fed agricultural systems, challenging traditional management practices that often optimize for single objectives, such as yield or water use efficiency. Tea fields in Pinglin, Taiwan, are particularly sensitive to hydroclimatic variability, as tea growth and quality depend strongly on soil moisture dynamics, evapotranspiration, and microclimatic conditions.

Previous studies have demonstrated that organic and conventional tea fields exhibit distinct soil water dynamics and energy partitioning, suggesting potential trade-offs between water use, microclimate regulation, and production-related management objectives.

Building on existing empirical and modeling-based insights into tea field hydrology, this study aims to reframe tea plantation management through the lens of a Water–Energy–Food Nexus. By treating management as a clear multi-objective decision problem, we reframe the competing objectives between water availability, irrigation, energy dynamics, and food production relevant to tea yield and quality.

To operationalize this decision framework at the field level, this study employs the Conditional Water Depletion Index (CWDI) to translate physical water demand (evapotranspiration) and supply(rainfall and irrigation) into a dimensionless indicator of system scarcity. The CWDI effectively represents the vulnerability and sensitivity of the tea field. This quantified state serves as the basis for informing the timing and intensity of management interventions.

By clarifying the structure of water–energy–production trade-offs in tea fields, this exploratory study provides a conceptual and analytical basis for future research that may incorporate dynamic decision-making and learning-based approaches to enhance agricultural resilience under increasing climate and water uncertainties.