نوع مقاله : مقاله پژوهشی

نویسندگان

• افشین اشرف زاده ¹
• جابر صالح پور لاقانی ²

¹ دانشیار منابع آب، گروه مهندسی آبیاری و آبادانی، دانشکدگان کشاورزی و منابع طبیعی، دانشگاه تهران، کرج، ایران.

² دانشجوی دکتری، گروه مهندسی آب، دانشگاه بین‌المللی امام خمینی (ره) قزوین، ایران.

چکیده

استان گیلان به‌دلیل وابستگی زیاد به سفیدرود و محدودیت منابع آب کشاورزی در سال‌های اخیر به دلیل اجرای برنامه‌­ها در بالادست حوضۀ سفیدرود، توسعه شهرنشینی و افزایش آلودگی‌های محیط‌زیستی، با چالش فزاینده‌ای در تأمین آب پایدار برای بخش کشاورزی مواجه است. از این‌رو بررسی راهکارهای جایگزین مانند استفاده از پساب تصفیه‌شده و شیوه‌های مناسب قیمت‌گذاری آن، ضرورتی روزافزون یافته است. این پژوهش با هدف بررسی ترجیحات مناطق مختلف در استان گیلان نسبت به روش‌های قیمت‌گذاری پساب تصفیه‌شده (هزینه‌محور، بازارمحور، یارانه‌ای، زیست‌محیطی) به­اجرا در آمده است. داده‌ها از 55 ذی­نفع شامل کشاورزان، کارشناسان منابع آب و محیط زیست و نمایندگان نهادهای محلی در چهار بخش متفاوت از استان گیلان و با اولویت‌های متفاوتِ رسیدگی به مشکلات ناشی از پساب، با استفاده از پرسشنامه جمع‌آوری شد و با رویکرد ترکیبی (کمی: کروسکال- والیس، جنگل تصادفی؛ کیفی: تحلیل موضوع و شبکۀ مفاهیم) تحلیل گردید. نتایج تحقیق نشان داد در مناطق با اولویت بسیار بالای رسیدگی به مسائل زیست‌محیطی (مانند رشت) روش یارانه‌ای (میانگین 4/73) و زیست‌محیطی (میانگین 4/42)، در مناطق با اولویت بالا (مانند صومعه‌سرا)، روش یارانه‌ای (میانگین 4/06)، در مناطق با اولویت متوسط (مانند لاهیجان) روش بازارمحور (میانگین 3/93)، و در مناطق با اولویت پایین (مانند خمام) روش هزینه‌محور (میانگین 3/93) غالب است. جنگل تصادفی، روش زیست‌محیطی با اهمیت 0/284 را مؤثرترین عامل در پیش‌بینی ترجیحات نشان داد. یافته‌ها نشان دادند که در مناطق با آلودگی زیست‌محیطی بالا، ترجیح ذی‌نفعان به روش‌های یارانه‌ای و زیست‌محیطی بیشتر است، در حالی‌که در مناطق با اولویت پایین‌تر، روش‌های بازارمحور و هزینه‌محور پذیرش بیشتری دارند. بر اساس نتایج به‌­دست آمده توصیه می‌شود سیاست‌گذاران از رویکرد تلفیقی در قیمت‌گذاری پساب بهره گیرند به‌گونه‌ای که در مناطق حساس‌تر از مدل‌های یارانه‌ای و زیست‌محیطی و در مناطق کمتر حساس، از روش‌های هزینه‌محور و بازارمحور استفاده شود.

کلیدواژه‌ها

• ترجیحات ذی‌نفعان
• سیاست‌گذاری آب
• تحلیل ترکیبی
• پساب بازچرخانی‌شده

موضوعات

• منابع و مصارف آب

عنوان مقاله [English]

Comparative Analysis of Pricing Methods for Treated Wastewater in Agricultural Applications in Guilan Province

نویسندگان [English]

• Afshin َAshrafzadeh ¹
• Jaber Salehpour Laghani ²

¹ Associate Professor of Water Resources, Department of Irrigation and Reclamation Engineering, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.

² PhD Student, Water Engineering Department, Imam Khomeini International University, Qazvin, Iran,

چکیده [English]

Introduction
       The management of treated wastewater is a critical issue in addressing water scarcity and ensuring environmental sustainability, particularly in regions like Guilan Province, Iran, where agricultural, urban, and industrial activities strain water resources. This study aims to investigate regional preferences for pricing methods of treated wastewater, cost-based, market-based, subsidized, and environmental, in various parts of Guilan, characterized by differing environmental priorities. The research addresses the problem of aligning pricing strategies with local needs to enhance sustainable wastewater reuse. Existing literature highlights the importance of wastewater reuse for agriculture and environmental protection (Areosa et al., 2024; Hajjar et al., 2025) and the role of pricing in resource management (Beecher & Gould, 2018; Fagundes & Marques, 2023). However, studies focusing on regional variations in pricing preferences, especially in Iran, remain limited (Deh-Haghi et al., 2020; Zafari Koloukhi et al., 2021). This study employs a mixed-methods approach, combining quantitative (Kruskal-Wallis test, Random Forest) and qualitative (thematic analysis, conceptual network) techniques to analyse data from 55 stakeholders across four regions with varying environmental priorities. The main results reveal distinct regional preferences, with subsidized and environmental methods favoured in high-priority areas and cost-based and market-based methods in lower-priority regions, underscoring the need for tailored pricing policies.
 Methodology
The research was conducted in Guilan Province, a key agricultural region in northern of Iran, known for its humid climate and sensitive ecosystems like the Anzali International Lagoon. The province was divided into four categories based on environmental priority: very high (e.g., Rasht, Anzali), high (e.g., Someh Sara), medium (e.g., Lahijan), and low (e.g., Khomam). Data were collected from 55 stakeholders, including farmers, experts in water and environmental issues, and representatives of local institutions, using a structured questionnaire. The questionnaire comprised demographic details, 20 Likert-scale questions assessing the four pricing methods, choice scenarios, and open-ended questions for qualitative insights. Quantitative analysis included descriptive statistics, Cronbach’s alpha for reliability, Kruskal-Wallis tests for inter-regional differences, and Random Forest modeling to identify influential factors. Qualitative analysis involved thematic analysis, keyword frequency counts, and conceptual network mapping using Python (version 3.8) and libraries like Pandas, Scikit-learn, and NetworkX. The research questions focused on identifying preferred pricing methods, their influencing factors, and qualitative explanations of these preferences. The mixed-methods approach was chosen to capture both statistical trends and nuanced stakeholder perspectives, ensuring relevance to both theoretical frameworks (e.g., sustainable resource pricing) and practical policy design.
 Results and Discussion
The findings indicate significant regional variation in pricing preferences. In very high-priority areas (e.g., Rasht), the subsidized method (mean score 4.73, 57.14% preference) and environmental method (mean 4.42, 28.57%) were most favored, reflecting the urgent need for government support and environmental protection amid severe pollution (e.g., Anzali Lagoon). In high-priority areas (e.g., Someh Sara), the subsidized method (mean 4.06) led, with cost-based (mean 3.76) and market-based (mean 3.57) methods also notable, suggesting a balance between affordability and economic considerations. Medium-priority areas (e.g., Lahijan) preferred the market-based method (mean 3.93, 64.29%), driven by high agricultural demand for wastewater, while low-priority areas (e.g., Khomam) favored the cost-based method (mean 3.93, 37.50%), emphasizing financial transparency. Kruskal-Wallis tests confirmed significant differences for subsidized (p=0.001) and environmental (p=0.001) methods across regions, but not for cost-based (p=0.206) or market-based (p=0.323) methods. Random Forest analysis identified the environmental method as the most influential (importance 0.284), followed by market-based (0.261), subsidized (0.228), and cost-based (0.226). Qualitative analysis revealed dominant themes: subsidized and environmental concerns in high-priority areas, market-based in medium-priority, and cost-based in low-priority areas. A conceptual network showed strong links between subsidized and environmental methods (weight 18), reflecting stakeholder priorities. These results align with studies emphasizing economic and environmental factors in wastewater pricing (Deh-Haghi et al., 2020; Obaideen et al., 2022) but offer novel insights into regional specificity.
 Conclusions
The study concludes that pricing preferences for treated wastewater in Guilan Province are closely tied to regional environmental priorities. Subsidized and environmental methods dominate in areas with severe pollution, while market-based and cost-based methods suit regions with stable water resources or lower pollution. Limitations include a modest sample size (55 stakeholders) and cross-sectional data, which may not capture long-term trends. The findings suggest that pricing policies must be region-specific to balance economic viability and environmental sustainability. Theoretical implications include reinforcing the role of context in resource pricing models, while practical implications involve guiding policymakers to prioritize subsidies in high-priority areas and market mechanisms in agricultural hubs. Future research should explore cost-benefit analyses and longitudinal impacts of pricing strategies.
 Acknowledgement
Hereby, we would like to express our sincere gratitude to the stakeholders in Guilan Province for their participation in completing the questionnaires. We also appreciate the provincial organizations for providing access to the data used in this study. Our heartfelt thanks go to the Editor-in-Chief and esteemed reviewers whose valuable comments greatly contributed to enhancing the quality of this article.

کلیدواژه‌ها [English]

• Stakeholder preferences
• Water policy
• Mixed-methods analysis
• Reclaimed wastewater