Sadeghi et al. (2026) National watershed health diagnosis: A pressure-state-response assessment of Iran's 3rd-order watersheds

Identification

• Journal: Ecological Indicators
• Year: 2026
• Date: 2026-01-31
• Authors: Seyed Hamidreza Sadeghi, Negin Behnia, Reza Chamani, Vahid Moosavi, Ali Nasiri Khiavi, Mohammad Hossein Shoushtari, Hamid Nouri, Padidehsadat Sadeghi, Mahin Kalehouei, Sudabeh Gharemahmudli, Mohammd Tavosi, Mostafa Zabihi Silabi, Abdulvahed Khaledi Darvishan, Mehdi Vafakhah, Hamidreza Moradi Rekabdarkolaei
• DOI: 10.1016/j.ecolind.2025.114572

Research Groups

• Department of Watershed Management Engineering, Faculty of Natural Resources, Tarbiat Modares University, Noor, Iran
• Ardabil Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Ardabil, Iran
• Institute of Geophysics, University of Tehran, Tehran, Iran
• Department of Range and Watershed Management, Faculty of Natural Resources, Malayer University, Iran
• University of Birjand, Iran

Short Summary

This study conducted the first national-scale assessment of watershed health (WH) and ecological security (ES) across 640 3rd-order watersheds in Iran using a Pressure-State-Response (PSR) framework. It revealed moderate WH (mean 0.47 ± 0.02) but critically low ES (mean 0.25 ± 0.05) nationwide, with WH disproportionately dependent on institutional responses (64.36%) over entrenched pressures and fragile ecological states.

Objective

• To conduct a comprehensive national assessment of the health and ecological security (ES) of 3rd-order watersheds in Iran using the Pressure-State-Response (PSR) framework and big-data analytics, aiming to provide a more comprehensive understanding of spatial patterns, identify major ecological stressors, and offer policy-relevant insights applicable to other arid and semi-arid regions.

Study Configuration

• Spatial Scale: 640 3rd-order watersheds across the entire country of Iran (total area 1,648,195 km², with individual watersheds approximately 253,521.4 ± 226,998.4 ha).
• Temporal Scale: Up-to-date variables were used, implying data up to at least 2025, with some variables representing annual means or standard deviations.

Methodology and Data

• Models used: Pressure-State-Response (PSR) framework, Variance Inflation Factor (VIF) method for variable reduction, ArcGIS, Google Earth Engine, TerrSet, Fragstats, SPSS.
• Data sources: Satellite imagery (MODIS, Landsat, Sentinel LU/LC, Sentinel-5P, ALOS PALSAR Dem), observation data (Iran Meteorological Organization, Iran Water Resources Management Company, Natural Resources and Watershed Management Organization, Iranian Department of Environment, Iranian Statistical Yearbooks, Iran Flood Map, Iran Stream Map, Iran Mines Map, National Comprehensive Watershed Management Master Plan), reanalysis data (GLDAS, IDAHO/TerraClimate database), global databases (soilgrids.org).

Main Results

• The mean Watershed Health Index (WHI) across Iran's 3rd-order watersheds was 0.47 ± 0.02, indicating moderate health with low variability.
• The mean Ecological Security Index (ESI) was 0.25 ± 0.05, showing unnerving levels of insecurity with high variability.
• Watershed health disproportionately depends on institutional responses (64.36%), significantly overshadowing entrenched pressures (20.32%) and critically fragile ecological states (15.32%).
• Most watersheds (≈86.7%) exhibit a Moderate-Negative Tendency for WHI (0.4–0.5), indicating widespread degradation.
• A substantial majority of watersheds (≈84.2%) show a Relatively Low-to-Negative Tendency for ESI (0.2–0.3), particularly in agriculture-rich central and eastern regions.
• Northern and western watersheds (Alborz and Zagros ranges) show modest resilience, while central and eastern plateaus face severe stress, including groundwater declines exceeding 2 m per year, wind erosion rates exceeding 50 tonnes per hectare per year, and land subsidence often greater than 30 cm per year.
• Climatic pressures (rising temperatures, intensifying drought, high inter-annual climatic variability) interact with anthropogenic stressors (mining expansion, rapid urbanization) to deteriorate watershed resilience.

Contributions

• Developed the first national baseline of watershed health and ecological security for 640 3rd-order watersheds in Iran, providing high-resolution, data-driven insights.
• Introduced sustainable agriculture and soil health measures into the Pressure-State-Response (PSR) framework.
• Leveraged big data analytics to quantify the direct impacts of various pressures on watershed conditions and inform appropriate responses.
• Revealed a critical "governance-action paradox," quantitatively demonstrating that watershed health is disproportionately dependent on institutional responses over inherent pressures and fragile ecological states.
• Developed a transferable model and valuable lessons for application in other semi-arid and arid regions facing similar hydrological and environmental crises.
• Contributes to achieving United Nations Sustainable Development Goals (SDG) 6 (Clean Water and Sanitation), 13 (Climate Action), and 15 (Life on Land).

Funding

• Iran National Science Foundation (INSF) under project No. 4038982.

Citation

@article{Sadeghi2026National,
  author = {Sadeghi, Seyed Hamidreza and Behnia, Negin and Chamani, Reza and Moosavi, Vahid and Khiavi, Ali Nasiri and Shoushtari, Mohammad Hossein and Nouri, Hamid and Sadeghi, Padidehsadat and Kalehouei, Mahin and Gharemahmudli, Sudabeh and Tavosi, Mohammd and Silabi, Mostafa Zabihi and Darvishan, Abdulvahed Khaledi and Vafakhah, Mehdi and Rekabdarkolaei, Hamidreza Moradi},
  title = {National watershed health diagnosis: A pressure-state-response assessment of Iran's 3rd-order watersheds},
  journal = {Ecological Indicators},
  year = {2026},
  doi = {10.1016/j.ecolind.2025.114572},
  url = {https://doi.org/10.1016/j.ecolind.2025.114572}
}