ارزیابی اثربخشی جنگل‌کاری‌ها در کنترل بیابان‌زایی و گرد و غبار در ریگزارهای خوزستان، کرمان و اصفهان

Extended Abstract



1. Introduction

Wind erosion in desert regions and the accumulation of aeolian sediments result in the formation of sand dunes, which are the outcome of interactions between wind regimes and sedimentation processes. Due to their dynamic nature, sand dunes have become environmental crisis centers, posing threats to urban and rural settlements, economic infrastructures, and agriculture by reducing productivity through sand movement. Although dunes are part of the natural landscape, their uncontrolled expansion disrupts ecological balance and accelerates desertification. Because of low moisture and insufficient vegetation cover, they are highly prone to wind erosion, making their stabilization essential. In Iran, various measures—including afforestation and the establishment of vegetation cover—have been undertaken to stabilize shifting sands. This method creates a protective plant layer that prevents sand displacement and enhances dune stability. Considering the varying success rates of these vegetation projects in different regions, the present study evaluates the effectiveness of afforestation initiatives implemented in the sand dune areas of Khuzestan, Kerman, and Isfahan provinces.



2. Research Methodology

In this study, the main data sources included the digital layer of afforestation areas in Iran, MODIS satellite imagery, and Google Earth images. The primary tools utilized were ArcGIS, Google Earth, and the Google Earth Engine platform. Based on the study objectives, the research was conducted in several stages. In the first stage, the boundaries of the sand dune areas were delineated, and afforested regions were identified. In the second stage, to evaluate dust concentration levels within the sand dune zones, the Google Earth Engine system and MODIS satellite images from 2019 to 2023 were used, and dust concentration maps were produced separately for each province (Khuzestan, Kerman, and Isfahan). In the third stage, Google Earth images from 2005 and 2020 were analyzed to assess the displacement and movement of sand dunes in the study areas.



3. Discussion and results

Given the negative environmental impacts of sand dunes, various stabilization methods—such as afforestation—have been implemented in recent years. This study aimed to assess the effectiveness of afforestation efforts by examining their environmental impacts in the sand dune areas of Khuzestan, Kerman, and Isfahan provinces. According to the results, the total areas afforested within the dune regions of Khuzestan, Kerman, and Isfahan in recent years were approximately 563, 425, and 1,820 square kilometers, respectively. The evaluation of afforestation impacts on dust concentration levels showed that the greatest effect was observed in the sand dunes of Kerman Province, where the pixel correlation coefficient between vegetation cover and dust concentration was 0.51. This value was 0.44 for Isfahan and 0.23 for Khuzestan. Based on these findings, it can be concluded that the established forest cover in the sand dune regions of Khuzestan and Isfahan has had relatively limited effectiveness in reducing dust concentration compared to Kerman.







4. Conclusion

The results of evaluating the effects of afforestation on sand dune displacement in the studied regions indicate that the highest level of dune stabilization occurred in the isolated dunes of Khuzestan, which experienced approximately 1 meter of movement. Following this, the dunes surrounding the cities of Kerman and Ardestan showed the next highest degree of stabilization and control, with displacements of less than 10 meters. Accordingly, it can be concluded that the established forest cover has played a significant role in stabilizing sand dunes in some areas; however, in certain regions—such as the central parts of Khuzestan’s dunes, the dunes near Shahdad, and the northern areas of Band Rig in Kashan—its impact on stabilization and control has been limited. Overall, the findings demonstrate that afforestation has had positive effects on reducing dust concentration and controlling sand dune movement. Nonetheless, due to the observed variation in effectiveness, it is necessary to evaluate the types of forest cover used and the quality of implementation in areas with lower impact to identify and address the main causes of reduced effectiveness. To enhance the effectiveness of afforestation efforts, it is recommended that in areas with lower efficiency, native plant species that are resistant to local climatic conditions be used, and periodic monitoring through satellite imagery and wind modeling be conducted to assess the stability of dune stabilization. Additionally, the participation and education of local communities in maintaining afforestation projects can play a significant role in sustaining the results. A combination of biological and mechanical methods, such as planting vegetation and installing windbreaks or surface coverings, is recommended for more effective control of sand dune movement, and the development of a long-term management plan in collaboration with environmental and natural resource agencies is essential for the restoration of critical areas.