نوع مقاله : مقاله پژوهشی
1 دانشجوی دکتری ژئومورفولوژی، دانشکده ادبیات و علوم انسانی دکتر علی شریعتی، دانشگاه فردوسی مشهد، مشهد، ایران
2 دانشیار ژئومورفولوژی، دانشکده منابع طبیعی و محیط زیست، دانشگاه فردوسی مشهد، مشهد، ایران
3 استادیار گروه زمین شناسی، دانشکده علوم، دانشگاه فردوسی مشهد، مشهد، ایران
عنوان مقاله [English]
Geodiversity is a quality that we try to preserve. one of the important values for evaluating landforms in geomorphology is geodiversity, to provide accurate data for geoheritage conservation. therefore, it can be said that geodiversity reflects the remarkable complexities of a region in addition, by examining the world from the point of view of geodiversity, a better understanding of natural resources can be achieved. The term sensitivity refers to the inherent sensitivity of a feature to damage, which is a function of its inherent resilience, and sensitivity emphasizes the landform's ability to resist change, in other words, landform sensitivity is related to its erosion pattern and it affects that part of the geosystem that is under stress but has little resistance due to environmental characteristics, therefore, sensitivity analysis is designed to quantitatively measure the land's tolerance to change. Since exposure to geomorphological hazards is unavoidable, it is necessary to evaluate the sensitivity of the geosystem and determine the impact of each of the effective parameters on it to provide appropriate protection solutions. It is clear that by qualitatively examining and quantitatively calculating the sensitivity of the landforms and their relationship with the geological criteria of each geosystem, better and more effective solutions can be provided to increase their resistance. Due to the widespread interest in geodiversity studies, especially in recent decades, this research investigates the relationship between geological criteria and the degree of sensitivity of landforms in the eastern Kopet- Dagh zone with the geographical location of 59º 36' 56" to 61º 14' 58" East longitude and 35º 14' 05" to 37º 07' 58" north latitude are assigned.
This research was conducted to investigate the relationship between geological criteria and the degree of sensitivity of landforms in 2 sections and 7 stages. In the first part, the prioritization and determination of the impact of each of the selected criteria were done in the evaluation of geodiversity based on the degree of sensitivity of the geosystem using the Analytical Hierarchy (AHP) model. This section is done by Arc GIS Expert Choice software. In the second part, after creating sample points in the study area and calculating the degree of sensitivity of each of the sub-criteria, their relationship with the degree of sensitivity of the landforms was evaluated using Pearson's statistical test.
Results and Discussion
The results of the hierarchical analysis show that among the protection sub-criteria, landcover (0.495) has the highest level of importance from the experts' point of view and sub-criteria soil (0.240) has the lowest level of importance. In the criteria of vulnerability, the lithology sub-criteria with a weight of 0.336 is in the first place and the climate sub-criteria is in the second place with a weight of 0.285, and the lowest level of importance is related to the fossil sub-criteria with a weight of 0.052. After the weight obtained from the hierarchical analysis model was applied to the layer and the layers were overlapped, the result of this overlap created the landform protection layer and the landform vulnerability layer. In terms of landform protection, the studied area is mainly in medium sensitivity (40.8%) and high sensitivity (43.9%). Regarding the vulnerability of the landform, (47%) is in a state of moderate sensitivity, and (38.1%) is in a state of high sensitivity. Finally, the integration of the two layers of protection and sensitivity led to the creation of the zoning layer of geodiversity based on the degree of sensitivity, which indicates that the largest extent of the studied range is in the medium spectrum in terms of sensitivity, 23% of the range is in the low range and 32% is in the high range in terms of sensitivity. The results of the survey regarding the relationship between each geological sub-criteria and the level of sensitivity of the landform show that only the fossil sub-criteria has a negative relationship with the level of sensitivity and the coefficient of this relationship is -0.233, this means that there is no direct relationship between the increase in fossil diversity and the increase in sensitivity of geodiversity. The highest correlation coefficient is related to landcover, and the coefficient obtained for this sub-criteria is equal to 0.566, also, the coefficient obtained for each of the sub-criteria was at an average level in terms of the intensity of the relationship and each of the obtained correlation coefficients for the sub-criteria is acceptable with 99% confidence level, according to the obtained significance level which is equal to 0.000
The results of applying the weight of each of the sub-criteria in the layers and overlapping the layers and creating two layers of protection and vulnerability in the hierarchical method indicate that in general the degree of vulnerability and sensitivity increases from west to east as well as from north to south, which is due to the presence of more virgin rock outcrops, thin landcover, less slope of geomorphological units, the great diversity of geomorphological and hot, dry to hot and semi-arid weather in the above-mentioned areas, the findings of this research correspond to the features of the landforms and are not far from the mind. The results of the analysis using SPSS software show that there is no direct relationship between the increase in fossil diversity and the increase in the sensitivity of the studied area and the highest correlation coefficient is related to land cover. Based on the results obtained in this research, since the major part of the study area has geodiversity with a moderate and high degree of sensitivity, it can be said that the studied area is critical in terms of sensitivity and land degradation. Also, considering that land cover has the highest degree of correlation between geodiversity and the degree of sensitivity of the geosystem, therefore, this requires comprehensive attention and more detailed investigations to further protect the land cover of the eastern Kopet-Dagh zone against destructive factors.