Document Type : Research Article
Authors
1
Golestan university
2
Department of Civil Engineering, Non-Profit-Non-Governmental Institute, Lampi Gorgani Institute
3
General Department of Meteorology of Golestan Province
Abstract
The present research based on the nature of the problem and subject under investigation, adopts a descriptive-analytical approach with the aim of identifying ecological stressors caused by climate change in wetlands. In the climate change section, simulation data of average rainfall from the HadCM3 model using LARS-WG under the SRES A1B scenario for the period 2021–2050 were utilized. The AHP method and Expert Choice software were employed to weight risk factors and assess the indicators influencing risk levels. According to the modeling results, the rainfall series at the Inche-Brun station shows a decreasing trend. Additionally, both maximum and minimum temperatures exhibit an increasing trend. The primary risks threatening the wetland include drought, water shortage, increased evaporation and transpiration, sedimentation and infilling, and habitat loss. Since the most significant risks, as identified based on the ALARP principle, are classified as high or medium, it is essential to control, eliminate, or reduce these risks. Given the ongoing degradation of wetlands, it is crucial to incorporate these processes and their consequences into future wetland management plans. As drought has been identified as the most critical risk, establishing a drought monitoring network and calculating and allocating environmental water rights for wetlands are the most important management strategies to prevent a drought crisis.
Extended Abstract
Introduction
Wetlands should be considered as biological reservoirs, and international programs for the reasonable and rational protection and exploitation must be prepared and implemented in order to ensure the survival of wetlands and their biodiversity. Environmental risk assessment is a step beyond human risk assessment, and in it, in addition to examining and analyzing various aspects of risk, a full understanding of the environment of the affected area, its sensitivity, and its special ecological values are also analyzed and evaluated.
Climate change refers to changes in the climatic behavior of a region compared to historical or expected patterns over a long period of time. This phenomenon is one of the most important challenges in sustainable development, with significant negative effects on land and sea ecosystems. Until recently, climate change was considered to be caused by natural factors only, but in recent years, human activity has also contributed to the climate change process. Climate change and loss of biodiversity are among the global challenges that may lead to an increased risk of losing ecosystem services.
Various studies have been conducted on the evaluation of the vulnerability of wetlands worldwide, focusing on the impacts of climate change. Using climate scenarios, models, and change analysis, it was determined that about 10% of wetland functions will be affected in the future due to climate change.
Jafari-Azer et al. (2017), in their article, evaluated and analyzed the environmental risks of Khorkhoran International Wetland using multi-criteria decision-making methods. They identified wetland risk indicators using the Delphi method and ranked and prioritized threats using AHP and TOPSIS methods. The results indicate that, according to the degree of closeness (CL+), among the environmental criteria, oil pollution (0.88), illegal fishing (0.87), and fuel smuggling (0.71), and among the natural criteria, drought and climate change (0.72), are the top risks.
Panahi et al. (2023), in an article titled "Investigation of climate change and transformation of natural components with emphasis on floods" (case study: Gorganrood watershed), used LARS-WG and HadCM3 model under the SRA1B scenario between 2011 and 2045. The results showed that human intervention in main streams, urban and rural expansion, dam construction, pasture degradation, and forest destruction are among the primary causes of sudden flooding in the region. This integrated approach highlighted the necessity of continuous evaluation and validation of hydrological and hydraulic models in the Gorganrood basin and its ephemeral streams.
Karami et al. (2023) assessed the vulnerability of ecosystem services of the Hamoon International Wetland to climate change. The results showed that climate change, drought, water diversion in the upstream basin, and livestock and vehicle traffic are the main threats. Diplomatic efforts to secure water supplies are the most important management strategy to reduce vulnerability.
This research provides a framework for managing climate change-related risks in wetlands. Its main purpose is to investigate temperature, precipitation, and climate indicators in the Alagol, Ajigol, and Almagol wetlands. Using statistical data and satellite images, climate changes over different time periods are modeled. Risks are then calculated based on severity and likelihood. A multi-criteria decision-making process is used to prioritize these risks. Finally, suitable management solutions are presented to reduce unacceptable risks.
Material and Methods
Alagol, Ajigol, and Almagol international wetlands are located in Golestan Province, near the Iran–Turkmenistan border, at relatively close distances from one another in the Dashli-Borun region. In this research, the assessment of climate change risks on wetland ecosystems was conducted using the GCM model.
To implement the research objectives—including modeling climate change, forecasting ecological conditions, and identifying and prioritizing ecological risks—20 years of data (2001–2020) on monthly and annual average precipitation and temperature from local meteorological stations were used.
Precipitation and temperature forecasts were generated using outputs from the HadCM3 model, a coupled atmosphere–ocean general circulation model (AOGCM). ArcGIS 10.8 was used for initial data preparation, ENVI 5.3 for radiometric and atmospheric corrections, and IDRISI TerrSet for image classification, pre-processing, change analysis, and model validation. Simulated rainfall data from HadCM3 in LARS-WG under the SRA1B scenario (2021–2050) were analyzed. Statistical indicators such as ME, RMSE, and MSE were used to select the best interpolation method.
Results and Discussion
The region's temperature between 2021 and 2050 is expected to increase by 0.5 to 1.5°C compared to the base period. The results indicate temperature increases across all months and climate scenarios. Scenario A2 shows the highest increase, B1 the lowest (optimistic), and A1B a moderate rise.
Rainfall percentage changes under the three scenarios indicate a decline in most months. Annual rainfall will decrease by 6–8% compared to the base period. Scenario A2 shows the greatest reduction, particularly in March (up to 75%), while B1 shows the smallest, particularly in February (up to 55%). In a few months, slight increases in rainfall are observed, though these are not significant in dry months.
To compare the ecological risks of natural origin with those caused by human activity, the AHP method and Expert Choice software were used. The analysis shows high importance for natural-origin risks. Ecological and human-origin risks each make up nearly half of total risks.
Drought has the highest risk weight at 0.19. Natural-origin risks make up 51%, and human-origin risks 49%. Ten key risks were identified based on ecological conditions, field visits, expert interviews, and previous studies. All identified risks are present and will intensify under future climate conditions.
The most significant climate-related threats to the wetlands include: drought and water shortage, increased evaporation and transpiration, sedimentation and infilling, and habitat loss. According to the ALARP principle, high and medium-level risks must be controlled, reduced, or eliminated. Risks with higher occurrence probability, severity, and extent require prioritized control measures. However, this does not imply that other risks are unimportant, as the final scores were derived by integrating all three risk indicators.
Conclusion
The prioritization results show that the key threats to Alagol, Ajigol, and Almagol wetlands are drought/dehydration, increased evaporation and transpiration, sedimentation and filling, and habitat loss.
By 2035, the area of Alagol, Almagol, and Ajigol wetlands is expected to reach 1747.50 ha, 102.30 ha, and 33.90 ha, respectively. This reflects reductions in Almagol and Ajigol, although Alagol shows a slight increase—still indicating an overall decline in extent over the study period.
Predicted land use maps for 2035 show saline land occupying 13,346.55 ha (63%), vegetation 5,601.78 ha (26.4%), and water surface 2,265.75 ha (10.6%). This reveals decreased water levels and increased salt marshes, signifying drought and reduced rainfall.
The effectiveness of the modeling methods and climate scenarios (HadCM3, A2, A1B1, B2, and LARS-WG) is consistent with the findings of Arkhi et al. (2024), Panahi et al. (2023), and Karami et al. (2022). Additionally, the environmental risk evaluation aligns with the multi-criteria methods used by Jafar-Azer et al. (2019) and Jafari-Azer et al. (2017).
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