Document Type : Original Article

Authors

• Seyyed Farhad Shohadie ¹
• Hassan Ahmadzadeh ²
• Nader Habibzadeh ³
• Ehsan Atazadeh ⁴

¹ Ph.D. Candidate, Department of Environmental Sciences, Ta. C., Islamic Azad University, Tabriz, Iran.

² Associate Professor, Department of Geography and Urban Planning, Tabriz Branch, Islamic Azad University, Tabriz, Iran.

³ Associate Professor, Department of Environmental Sciences, Ta. C., Islamic Azad University, Tabriz, Iran.

⁴ Associate Professor, Department of Plant, Cell and Molecular Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran.

Abstract

Objective: The present study aimed to investigate the effects of land use/land cover changes on water quality in the Satarkhan Dam in Ahar.
Methodology: Satellite imagery was acquired for the period from 1994 to 2024. Image analysis was performed using Object-Based Image Analysis (OBIA) techniques.
Results: The results indicated that cultivated land exhibited the most significant positive change over the 30-year period, increasing by 162.66 km², accounting for approximately 28.35% of the total changes. This increase occurred primarily during the intervals of 2004–2014 (with an increase of 21.403 km² and an importance index of 42.76%) and 1994–2024 (with an importance index of 45.77%). Barren land, on the other hand, experienced a substantial decrease over the 30-year period (a reduction of 147.70 km² with an importance index of 47.44%). This decline mainly took place during the first and third periods, namely 1994–2004 (a decrease of 28.325 km², importance index of 19.6%) and 2014–2024 (a decrease of 29.8 km², importance index of 43.02%).
Conclusion: A comparison of changes before and after the dam construction revealed that, overall, following the dam's construction, the share of water resource-dependent land uses such as fallow and agricultural lands increased, while the share of barren lands and rangelands decreased during the first decade after dam construction. The findings indicate that the expansion of built-up areas is strongly associated with increased eutrophication over the three decades, highlighting the need for sustainable watershed planning and management to mitigate nutrient runoff and preserve the vital services of freshwater ecosystems.

Keywords

• LULC changes
• Eutrophication
• Water Quality
• Object-Based Image Analysis
• Sattarkhan dam
• Ahar

Main Subjects

• Remote sensing and Gis