Data Sheet 1_From river health to sustainable irrigation water resources: a five-year integrated ecological assessment for climate-resilient food systems in semi-arid Iraq.pdf

Overall, 90.3% of observations exhibited slight-to-moderate salinity restriction, whereas severe salinity occurred only in Al-Diwaniyah. Hydroclimatic variability was associated with temporal salinity risk, with the strongest EC anomalies occurring during the summers of 2022 and 2024 and significant negative associations between EC and both SPEI-3 and SPEI-6. Biological condition declined along the same gradient: diatom and macroinvertebrate diversity, EPT representation, habitat condition, and dissolved oxygen were highest in the Euphrates and lowest in Al-Diwaniyah.

Principal component analysis explained 89.67% of total variance on the first two axes and clearly contrasted biological condition with salinity, ionic enrichment, and nutrient concentrations. Crop-specific assessment further showed increasing agricultural constraints, with maize being the most sensitive crop and constrained in 100% of observations at all Al-Diwaniyah stations. These findings demonstrate that river ecological condition, irrigation-water reliability, hydroclimatic variability, and crop-specific suitability are closely interconnected.

Integrating these dimensions can support more adaptive water allocation and climate-resilient irrigation management in semi-arid food-production systems.</p>