Extended Abstract
Introduction
With the continuous development of society, human disturbance to the ecosystem is also growing, and the ecological environment is gradually deteriorating. This will seriously affect the sustainable development of human society and the ecological environment on which it depends. Generally, ecological vulnerability is the variability of ecosystem under natural or human factors, and this variability is not conducive to the development of ecosystem and human society. Ecological vulnerability is characterized by weak resistance and low resilience of ecosystems in response to external disturbances, including both natural and anthropogenic drivers, within a specific spatial scale. Spatial assessments of ecological vulnerability help identify areas that are exposed to environmental disturbances or pressures, thereby providing a scientific basis for controlling environmental degradation and promoting regional ecological development. In the assessment of ecological vulnerability, multiple variables—such as climate, topography, land resources, and human activities—are influential. The present study aims to conduct a spatial analysis and zoning of ecological vulnerability in the Kaleybarchay watershed. This watershed, located in East Azerbaijan Province, is one of the key regions for nature tourism and ecotourism. Therefore, assessing its ecological vulnerability is essential for sustainable management and conservation. The watershed covers an area of approximately 1,201 km² on the northern slopes of the Qaradagh (Arasbaran) mountain range. Over 27% of the watershed area is covered by dense, semi-dense, or sparse forests. Due to the sensitivity and fragility of this ecosystem, evaluating the ecological vulnerability of the Kaleybarchay watershed is considered necessary.
Materials and Methods
To achieve the research objectives, the AHP-Fuzzy model and Critic model, the Digital Elevation Model (DEM) of the Kaleybarchay watershed, and Landsat 8 OLI satellite imagery were utilized. The criteria (natural and human) and sub-criteria—including elevation, slope, slope aspect, precipitation, temperature, distance from rivers, lithology, soil erosion, vegetation cover, land use, distance from roads, distance from mines and industries, and distance from residential areas—were determined based on theoretical foundations and previous studies using the Delphi technique. Weighting of the layers was performed using the Analytic Hierarchy Process (AHP) model, while the standardization of the layers was conducted through the Fuzzy logic model. The Critic model was used for validation. After integrating the weighted and standardized layers, a zoning map of ecological vulnerability for the Kaleybarchay watershed was produced.
Results and Discussion
According to the pairwise comparisons in the questionnaire, the average comparative weights of the criteria and sub-criteria related to ecological vulnerability zoning were obtained. Using the results from the Expert Choice software, weights for each criterion were determined. These weights were then applied to the shape file layers of the criteria in ArcGIS, and through map overlay, the final ecological vulnerability map was generated. The results showed that the criterion “distance from industries and mines” had the highest importance with a weight of 0.216, whereas “slope aspect” had the lowest importance with a weight of 0.009. Land-use change was identified as the second most influential factor affecting ecological vulnerability in the Kaleybarchay watershed. Zoning results indicated that approximately 40% of the watershed area exhibited high to very high ecological vulnerability, mainly concentrated in the central parts of the watershed. Meanwhile, about 40% of the area displayed low to very low vulnerability, predominantly located in the northern and southern regions of the basin.
Conclusion
The findings of this study indicate that human factors play a more significant role in the ecological vulnerability of the Kaleybarchay watershed. Human activities such as the expansion of industries and mines conflict with the ecological capacity of the region and lead to the degradation of environmental quality. Continued expansion of industrial and mining activities would likely increase the level of ecological vulnerability. Moreover, land-use and land-cover changes are among the major contributing factors. Overlaying the vulnerability map with land-use and vegetation cover layers revealed that areas with high and very high vulnerability mostly overlap with sparsely to moderately dense forests, medium rangelands, and agricultural lands. Among the natural factors, lithological units and soil erosion were identified as the most influential variables affecting ecological vulnerability within the watershed. Comparing the results of the two methods confirmed the accuracy of the zoning. Also, the correlation coefficient between the results of the two methods was 0.89%.