Sharma et al. (2026) Hydrological flux effectiveness index for assessing rainfall partitioning and hydrological functioning under climate change

Identification

• Journal: Journal of Hydrology
• Year: 2026
• Date: 2026-10-01
• Authors: Rahul Sharma, S. Sreekesh
• DOI: 10.1016/j.jhydrol.2026.136494

Research Groups

• Centre for the Study of Regional Development, Jawaharlal Nehru University, New Delhi, India

Short Summary

This study proposes a novel Hydrological Flux Effectiveness Index (HFEI) to quantify rainfall partitioning effectiveness and evaluate watershed hydrological functioning under changing climatic conditions. It demonstrates that HFEI effectively captures spatial heterogeneity and robustly identifies climate-driven shifts in hydrological partitioning.

Objective

• To propose and implement a novel Hydrological Flux Effectiveness Index (HFEI) for quantifying rainfall partitioning effectiveness and evaluating watershed hydrological functioning under changing climatic conditions.

Study Configuration

• Spatial Scale: Chaliyar River Basin (CRB)
• Temporal Scale: Historical baseline (implied by z-score standardization) and future projections for 2025–2095.

Methodology and Data

• Models used: Soil and Water Assessment Tool (SWAT), Sequential Uncertainty Fitting algorithm (SUFI-2), Coupled Model Intercomparison Project Phase 6 (CMIP6) General Circulation Models (GCMs).
• Data sources: SWAT simulated hydrological fluxes, bias-corrected CMIP6 climate projections (SSP2 and SSP5 scenarios), multi-site observational data for model calibration and validation.

Main Results

• The Hydrological Flux Effectiveness Index (HFEI) effectively captures strong spatial heterogeneity in hydrological effectiveness, differentiating subsurface-dominated sub-basins from runoff-dominated systems.
• Ensemble results from CMIP6 projections indicate robust but spatially variable climate-driven shifts in hydrological partitioning within the basin.
• Sensitivity analysis confirmed the stability of the equal-weighting structure and the overall robustness of the HFEI formulation.

Contributions

• Introduces a novel Hydrological Flux Effectiveness Index (HFEI) that integrates key gain and loss processes controlling subsurface storage and runoff generation into a single framework, unlike conventional assessments focusing on precipitation magnitude or isolated flux components.
• Provides a physically based and scalable framework for assessing hydrological resilience and understanding rainfall partitioning effectiveness under changing climatic conditions.

Funding

• Not specified in the provided text.

Citation

@article{Sharma2026Hydrological,
  author = {Sharma, Rahul and Sreekesh, S.},
  title = {Hydrological flux effectiveness index for assessing rainfall partitioning and hydrological functioning under climate change},
  journal = {Journal of Hydrology},
  year = {2026},
  doi = {10.1016/j.jhydrol.2026.136494},
  url = {https://doi.org/10.1016/j.jhydrol.2026.136494}
}