Chen et al. (2026) Regional patterns of parameter sensitivity in the plant hydraulics scheme of Noah-MP: Insights into plant-water interactions

Identification

• Journal: Agricultural and Forest Meteorology
• Year: 2026
• Date: 2026-01-05
• Authors: Weijing Chen, Jinliang Hou
• DOI: 10.1016/j.agrformet.2026.111018

Research Groups

• School of Aeronautic Engineering, Changsha University of Science & Technology, Changsha, Hunan, China
• State Key Laboratory of Cryospheric Science and Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China

Short Summary

This study identifies key parameters within the Noah-MP model's plant hydraulic scheme that influence evapotranspiration, soil moisture, gross primary productivity, and root water flux, revealing their regional sensitivity patterns and informing targeted model optimization.

Objective

• To identify the key parameters in the Noah-MP plant hydraulic scheme affecting evapotranspiration (ET), soil moisture (SMC), gross primary productivity (GPP), and water flux absorbed by plant roots (Qroot) using global sensitivity analysis.
• To evaluate the spatial variability of parameter sensitivity and investigate the influence of aridity index, precipitation, and vapor pressure deficit on regional sensitivity patterns.

Study Configuration

• Spatial Scale: Regional patterns, spatial variability across different regions.
• Temporal Scale: Not explicitly stated for the study period, but the analysis of parameter sensitivity and its spatial variability implies a focus on the model's general behavior over relevant hydrological cycles, rather than a specific short-term event.

Methodology and Data

• Models used: Noah-MP model with an integrated plant hydraulic scheme (PHS). Global sensitivity analysis method (Sobol’ indices).
• Data sources: Model simulations, station measurements, satellite data.

Main Results

• Sobol’ indices for individual parameters show noticeable differences depending on the data source used for evaluation.
• Leaf turgor loss water potential (TLP) and xylem saturated water conductivity (Ks,sat) significantly influence evapotranspiration (ET) and gross primary productivity (GPP).
• Soil moisture (SMC) and water flux absorbed by plant roots (Qroot) simulations are jointly affected by multiple parameters, with root distribution parameter (ri) and stem volume specific water capacitance (Cstem) playing leading roles, respectively.
• Dominant parameters vary across regions, but their sensitivity indices show no strong correlation with aridity index, precipitation, or vapor pressure deficit.
• Model validation against observation data shows relatively high accuracy for ET, GPP, and Qroot, though performance declines in arid regions.
• Simulation accuracy for SMC exhibits greater spatial variability and performs worse in areas with dense vegetation cover.

Contributions

• Provides a systematic analysis of parameter sensitivity in the Noah-MP plant hydraulic scheme, identifying key parameters for different hydrological and carbon cycle variables.
• Evaluates the spatial variability of these sensitivities and explores the influence of climate factors on regional sensitivity patterns.
• Offers valuable guidance for region-specific model parameter optimization, suggesting that targeted optimization or new scheme integration can significantly enhance specific variable simulations.

Funding

• Not specified in the provided text.

Citation

@article{Chen2026Regional,
  author = {Chen, Weijing and Hou, Jinliang},
  title = {Regional patterns of parameter sensitivity in the plant hydraulics scheme of Noah-MP: Insights into plant-water interactions},
  journal = {Agricultural and Forest Meteorology},
  year = {2026},
  doi = {10.1016/j.agrformet.2026.111018},
  url = {https://doi.org/10.1016/j.agrformet.2026.111018}
}