Objective: Qazvin Province is facing increasing environmental challenges, including soil pollution, severe groundwater depletion, degradation of traditional orchard landscapes, and uneven industrial distribution, highlighting the necessity of conducting a Strategic Environmental Assessment (SEA) of the provincial spatial planning program approved in 2020.
Method: This study employed a descriptive–analytical approach and matrix-based techniques to identify, refine, and evaluate 14 key environmental indicators for assessing the impacts of 10 strategic sectors included in the Qazvin Provincial Spatial Planning Program.
Results: A multidimensional impact assessment encompassing impact magnitude, direct and indirect effects, short- and long-term consequences, reversibility, and cumulative impacts revealed that the agricultural, industrial and mining, settlement development, commercial, tourism, and transportation strategies generate considerable adverse environmental effects across most indicators and therefore constitute the first-priority category. The advanced services and science and technology strategies, despite their overall positive contributions, produce negative impacts on certain indicators—particularly indirect and long-term effects—and were classified as second-priority strategies. Environmental and socio-cultural strategies exhibited no negative environmental impacts and were consequently assigned to the third-priority category.
Conclusions: The results indicate that the predominance of negative impacts stems from the development-oriented nature of the first-priority strategies, which emphasize land expansion, increased energy consumption, conversion of natural lands, large-scale infrastructure development, and intensified transportation activities, while giving limited consideration to environmental concerns. These processes contribute to pollution, groundwater depletion, and irreversible environmental degradation. The environmental strategy offsets only 8% of the negative impacts because it focuses primarily on improving existing conditions rather than preventing new environmental damage. Furthermore, temporal mismatches, the uneven concentration of activities within the Qazvin Plain, and the synergistic interaction between short-term impacts (e.g., air pollution) and long-term impacts (e.g., land subsidence) reduce opportunities for effective intervention. Sensitivity analysis conducted under three sustainability scenarios confirmed the robustness of the prioritization results and demonstrated that implementation of the proposed mitigation measures could reduce negative impacts by up to 54%. Recommended mitigation strategies include pollution reduction through continuous monitoring, wastewater treatment, and renewable energy adoption; water-demand management through tiered pricing mechanisms and efficient technologies; and conservation of natural vegetation through the restoration of traditional orchards. However, implementation is likely to face challenges related to financial constraints, stakeholder resistance, and inter-organizational coordination.