Objective:

This study evaluated the environmental impacts of the 5,000-hectare Shavur irrigation and drainage network in the central Karkheh Basin, Khuzestan Province. By utilizing both conventional and modified ICOLD matrix methods, the assessment focused on the physical, biological, and socio-economic environments during the project’s operation phase to compare the magnitude and direction of impacts across these critical components.

Results:

Findings revealed that the most significant positive outcomes occurred within the socio-economic sphere. Regarding the physical environment, the conventional method yielded 161 positive and 226 negative scores, while the modified method showed 303.57 positive and 435.91 negative scores, indicating that while the project offers physical benefits, it simultaneously poses notable adverse impacts that require careful management. In the biological environment, the conventional method produced 80 positive and 148 negative scores, compared to 111.51 positive and 286.87 negative scores via the modified approach. This suggests that vegetation, wildlife habitats, and ecological balance may face negative pressures. Conversely, the socio-economic environment demonstrated superior positive outcomes; the conventional method recorded 532 positive and 26 negative scores, whereas the modified method showed 1212 positive and 72 negative scores. These data underscore the project’s capacity to significantly boost agricultural productivity, employment, and local economic stability.

Conclusion:

Overall, the Shavur network acts as a catalyst for socio-economic growth, specifically increasing production, income, and employment. However, the project concurrently exerts negative pressures on physical and biological systems. Consequently, robust environmental management and mitigation strategies are vital to minimize ecological damage and ensure long-term environmental sustainability.