نوع مقاله : پژوهشی

نویسنده

استادیار گروه جغرافیا، دانشگاه زنجان

چکیده

سیرک های یخچالی نشان دهنده خصوصیات یخچالها و اقلیمهای گذشته می باشند. در این تحقیق به تحلیل 39 سیرک یخچالی در حوضه آبریز رودخانه جاجرود پرداخته شد. برای بررسی مورفومتری سیرکها از پارامترهای طول، عرض، ارتفاع راس سیرک، ارتفاع کف سیرک، مساحت، محیط، نسبت طول به عرض، نسبت طول به ارتفاع کف و نسبت پهنا به ارتفاع کف استفاده شد. برای هر یک از پارامترهای مورفومتریک، فاکتورهای آماری ضریب تغییرات، انحراف معیار، میانگین، ماکزیمم و مینیمم در Excel محاسبه و برآورد شد. سپس مقادیر ضریب تعیین برای هر یک از پارامترها برآورد شده و نمودار پراکنش ترسیم شد. در نهایت ماتریس همبستگی با بهره گیری از ضریب همبستگی پیرسون برای تمامی فاکتورها برآورد شد. بیشترین میزان فراوانی سیرک در جهت جنوب غربی واقع شده است. حداکثر ارتفاع سیرک ها به میزان 3800 متر نیز متعلق به جهت جغرافیایی جنوب می باشد. بیشترین همبستگی ها بین پارامتر طول و عرض به میزان 9936/0 مشاهده شد. این امر نشان دهنده تغذیه بالای این سیرک ها و حجم قابل توجه آنها در دوره پلیستوسن می باشد. بررسی ها نشان داد که سیرک های تکامل یافته تر نسبت به سیرک های کمتر توسعه یافته از مساحت بیشتر، ارتفاع کمتر و نسبت طول به عرض کمتری برخوردار هستند.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Morphometric analysis of controlling parameters of glacial cirques in Jajrud river basin

نویسنده [English]

  • mehdi feyzolahpour

department of geography, faculty of human science, universty of zanjan, zanjan, iran

چکیده [English]

Glacier cirques show the characteristics of past glaciers and climates. In this research, the analysis of 39 glacial cirques in the catchment area of Jajrud River was done. For this purpose, Arc GIS software and Google Earth images were used. The parameters of length, width, height of the top of the circus, height of the floor of the cirques , area, perimeter, ratio of length to width, ratio of length to height of floor and ratio of width to height of floor were used to check the morphometry of cirques. For each of the morphometric parameters, statistical factors of coefficient of variation, standard deviation, average, maximum and minimum were calculated and estimated in Excel. Then R2 values or coefficient of determination were estimated for each of the parameters and a scatter diagram was drawn. Finally, the correlation matrix was estimated using the Pearson correlation coefficient for all factors. The highest abundance of cirques is located in the southwest direction. The maximum height of the cirques is 3800 meters and belongs to the geographical direction of the south.The highest correlations between length and width parameters were observed at the rate of 0.9936. The results show that the cirques in the north-facing slopes have a lower height. This indicates the high nutrition of these cirques and their significant volume in the Pleistocene period. Investigations showed that more developed cirques have more area, less height and less length to width ratio than less developed cirques .

کلیدواژه‌ها [English]

  • Correlation
  • morphometry
  • Pleistocene
  • glacial cirques
  • Jajrud
Ahmadabadi, A., Karam, A., & Sargsyan, V. (2018). The Identification of Glacial Cirques of ZardKuh Based on Morphometric Features, Hydrogeomorphology, 5, 1-16.
Ahmadabadi, A., Fathollahzadeh, M., Kiani, T., & Emadodin, F. (2019). Using NDSI to identify the Glacier Cirques of Oshtorankuh, Hydrogeomorphology, 6(19), 1-18.
Aniya, M., & Welch, R. (1981). Morphometric analyses of Antarctic cirques from photogrammetric measurements. Geografiska Annaler: Series A, 63 (12), 41–53.
Baranipour, A., & Seif, A. (2022). Identification, classification and analysis of morphometric indicators of glacial cirques in Silveh basin, Quantitative Geomorphological Research, 11, 32-51.
Barr,I.D., & Spagnolo, M. (2015). Glacial cirques as palaeoenvironmental indicators: Their potential and limitations. Earth Sci. Rev, 151, 48-78.
Barr, I.D., Ely, J.C., Spagnolo, M., Evans, I.S., & Tomkins, M.D. (2019). The dynamics of mountain erosion: cirque growth slows as landscapes age. Earth surf. Process. Landf, 44, 2628- 2637.
Battey, M.H. (1960). Geological factors in the development of Veslgjuv-Botn and veslskautbotn. In: Lewis, W.V, Norwegian cirque Glaciers. Royal geographical society research series, 15, 5-10.
Beheshti Javid, E., & Esfandyari, F. (2018). Extraction and Identification of glacial landforms using object-oriented methods (Case Study: glacial Cirques Sabalan), Quantitative Geomorphological Research, 6, 88-102.
Beiranvand, H., & Seif, A. (1400). Morphometric parameters of Glacial Cirques in the highlands of ventral Kerman Province, Geography, 19, 129- 149.
Beranvand, H., & Saife, A. (2020). Identification, Classification and morphometry of glacial cirque in Jupar altitude of Kerman, Quantitative Geomorphological Research, 4, 63-80.
Evans, I.S. (2021). Glaciers, rock avalanches and the buzzsaw in cirque development: why mountain cirques are of mainly glacial origin. Earth surf. Process. Landf, 46, 24-46.
Evans, I.S., & Mindrescu, M. (2014). Cirque form and development in Romania: Allometry and the buzzsaw hypothesis, Geomorphology, 208, 117- 136.
Evans, I.S., Cilgin, Z., Bayrakdar, C., & Canpolat, E. (2021). The form, distribution and paleoclimatic implications of cirques in southwest Turkey (Western Taurus), Geomorphology, 391, 107- 124.
Evans, I.S. (2006). Allometric development of glacial cirque form: geological, relief and regional effects on the cirques of Wales. Geomorphology, 80 (3), 245–266.
Evans, I.S. (1977). World-wide variations in the direction and concentration of cirque and glacier aspects. Geografiska Annaler: Series A, 59 (4), 151–175.
Evans, I.S., & Cox, N.J. (1995). The formof glacial cirques in the English Lake District, Cumbria. Zeitschrift für Geomorphologie N.F, 39 (2), 175–202.
Federici, P.R., & Spagnolo, M. (2004). Morphometric analysis on the size, shape and areal distribution of glacial cirques in the Maritime Alps (Western French‐Italian Alps). Geografiska Annaler: Series A, 86 (3), 235–248.
García–Ruiz, J.M., Gómez–Villar, A., Ortigosa, L., & Martí–Bono, C. (2000). Morphometry of glacial cirques in the Central Spanish Pyrenees. Geografiska Annaler: Series A 82 (4), 433–442.
Graf,W.L., 1976, Cirque as glacier location. Arct. Alp. Res, 3, 79-90.
Harker, A. (1901). Ice erosion in the Cuillin Hills, Skye. Transactions of the Royal Society of Edinburgh, 40 (2), 221–252.
Helland, A. (1877). On the Ice-Fjords of North Greenland, and on the Formation of Fjords, Lakes, and cirques in Norway and Greenland. Quarterly Journal of the Geological Society, 33 (4), 142–176.
Hughes, P.D., Gibbard, P.L., & Woodward, J.C. (2007). Geological controls on Pleistocene glaciation and cirque form in Greece. Geomorphology, 88 (3), 242–253.
Ipsen, H.A., Principato, S.m., Grube, R.E., & Lee, J.F. (2018). Spatial analysis of cirques from three regions of Iceland: implications for cirque formation and palaeoclimate. Boreas, 47, 565- 576.
Jafari, G., & Hazrati, N. (2018). Reconstruction of Quaternary ELA of the Zagros geomorphic unit of Iran, Geography and environmental sustainability, 28, 33-49.
Oien, R., Spagnolo, M., Rea, B., Barr, I., & Bingham, R. (2020). Climatic controls on the equilibrium-line altitudes of Scandinavian cirque glaciers, Geomorphology, 352, 106- 127.
Oliva, L., Cioccale, M.A., & Rabassa, J.O. (2020). Morphometry and spatial distribution of glacial cirques in the western Fuegian Andes of Argentina, southernmost south America. Andean Geol, 47, 316- 350.
Pedraza, J., Carrasco, R.M., Villa, J., Soteres, R.L., Karampaglidis, T., & Fernandez Lozano, J. (2019). Cirques in the Sierra de guadarrama and Somosierra moutains: shape, size and controlling factors. Geomorphology, 341, 153- 168.
Pelto, M.S. (1992). Equilibrium line altitude variations with latitude, today and during the late Wisconsin. Palaeogeogr.  Palaeoclimatol. Palaeoecol, 95, 41-46.
Péwé, T.L., Burbank, L., & Mayo, L.R. (1967). Multiple glaciations of the Yukon-Tanana upland, Alaska. US Geological Survey. Misc. Geol. Invest. Map 1–105, scale 1/ 500,000.
Porter, S.C. (1964). Composite Pleistocene snow line of Olympic mountains and Cascade Range, Washington. Geol. Soc. Am. Bull, 75, 477- 482.
Rudberg, S. (1994). Glacial cirques in Scandinavia. Norsk Geografisk Tidsskrift—Norwegian Journal of Geography, 48 (4), 179–197.
Ruiz-Fernández, J., Poblete-Piedrabuena, M.A., Serrano-Muela, M.P., Martí-Bono, C., García-Ruiz, J.M. (2009). Morphometry of glacial cirques in the Cantabrian Range (Northwest Spain). Zeitschrift für Geomorphologie N.F, 53 (1), 47–68.
Sharp, R.P., Allen, C.R., & Meier, M.F. (1959). Pleistocene glaciers on southern California mountains. American Journal of Science, 257 (2), 81–94.
Steffanová, P., & Mentlík, P. (2007). Comparison of morphometric characteristics of cirques in the Bohemian Forest. Silva Gabreta, 13 (3), 191–204.
Walder, J.S., & Hallet, B. (1986). The physical basis of frost weathering: toward a more fundamental and unified perspective. Arct. Alp. Res, 18, 27-32.
Wallick, K.N., & principato, S.M. (2020). Quantitative analyses of cirques on the Faroe islands: evidence for time transgressive glacier occupation. Boreas, 49, 828- 840.
White, W.A. (1970). Erosion of cirques. J. Geol, 78, 123-126.
Williams, L.D. (1975). The variation of corrie elevation and equilibrium lime altitude with aspect in eastern Baffin island, NWT, Canada. Arct. Alp. Res, 7, 169-181.
Zhang, Q., Fu, P., Yi, C., Wang, N., Wang, Y., capolongo, D., & Zech, R. (2020). Palaeoglacial and palaeoenvironmental conditions of the Gangdise Mountains, southern Tibetan Plateau, as revealed by an ice-free cirque, morphology analysis, geomorphology, 370, 112-138.