طبقه‌بندی انواع دشت سر مبتنی بر رویکرد ژئومورفومتری در منطقه اشکذر یزد

نوع مقاله : مقاله پژوهشی

نویسندگان

1 استادیار گروه ژئومورفولوژی، دانشکده علوم جغرافیایی، دانشگاه خوارزمی تهران

2 دانشجوی دکترای رشته ژئومورفولوژی، دانشکده علوم جغرافیایی، دانشگاه خوارزمی تهران

چکیده

دشت سر از مهم ترین واحد های ژئومورفولوژی محسوب شده و شناسایی و طبقه بندی آنها از اهمیت زیادی در تهیه نقشه ژئومورفولوژی برخوردار است، بطورکلی واحد دشت سر به سه تیپ؛ دست سر فرسایشی، آپانداژ و پوشیده تقسیم می شود. رویکرد غالب در شناسایی انواع دشت سر مبتنی بر تفسیر بصری از روی داده های هوایی و ماهواره ای است که دارای سرعت کم و وابسته به دانش مفسر است. امروزه رویکرد ژئومورفومتری که بر مبنای سنجش و اندازه گیری اشکال ژئومورفولوژی است می تواند در شناسایی لندفرم ها کمک نماید. در این تحقیق بر اساس رویکرد ژئومورفومتری و با استفاده از مدل رقومی ارتفاعی ASTERGDEM ، شاخصهای انحناء و شاخص RTP انواع دشت سر در منطقه اشکذر یزد شناسایی و استخراج شده است. نتایج نشان می دهد شاخص های ژئومورفومتری شامل:  انحنای پروفیل، انحنای پلانیمتریک، انحنای طولی و انحنای کلی به دلیل میزان اختلاف میانگین های محاسبه شده قدرت تفکیک پذیری مناسبی برای تفکیک تیپ های مختلف دشت سر از یکدیگر دارند و می توان با استفاده از این پارامترها به تفکیک واحد های دشت سر پرداخت و در بین آنها پارامتر انحنای پلانیمتریک و پروفیل و شاخص RTP دقت بیشتری در تفکیک واحدهای دشت سر دارند.

کلیدواژه‌ها


عنوان مقاله [English]

Classification of pediments based on a geomorphometric approach in Ashkezar zone, Yazd

نویسندگان [English]

  • Ali Ahmadabadi 1
  • Masoomeh Hashemi 2
1 Assistant Professor, Department of Geomorphology, Faculty of Geographical Sciences, Kharazmi University of Tehran
2 Ph.D. student of geomorphology, Faculty of Geographical Sciences, Kharazmi University of Tehran
چکیده [English]

Pediments are one of the most important natural formations whose identification and classification helps to make geomorphological maps. In general, pediments are divided into three types: eroded, mantled, and covered. The dominant approach in identifying types of plains is the visual interpretation of low-velocity aerial and satellite data and dependency on the interpreter's background knowledge. Nowadays, a geomorphometric approach based on measuring geomorphological forms can help to identify landforms. In this research, based on the geomorphometric approach and using the ASTERGDEM digital elevation model, the curvature indices and the RTP index of various plains in Ashkezar area of Yazd are identified and extracted. The results show that the geomorphometric indices including profile curvature, planimetric curvature, longitudinal curvature and general curvature have a good resolution to differentiate the different types of plains from one another. Due to the differences among the calculated mean values for the mentioned parameters, it is possible to classify pediments. Of the parameters studied, In addition, the profile and planimetric curvatures and the RTP index the most accurate parameters for the classification of pediments.

کلیدواژه‌ها [English]

  • Ashkezar
  • Geomorphometric parameter
  • pediment
  • RTP index
  1. Adediran, A.O., Parcharidis, I., Poscolieri, M., Pavlopoulos, K., (2004). Computerassisted discrimination of morphological units on north-central Crete (Greece) by applying multivariate statistics to local relief gradients. Geomorphology 58, 357–370.
  2. Ahmadi, Hassan.(2009). Applied Geomorphology, Vol 2, Desert and Wind Erosion. University of Tehran.
  3. Azimzadeh, Hamid Reza, Mohammad Reza Ekhtesassi (2002). Wind erosion: A study of the effect of soil physical andchemical properties on erosion susceptibility and its predictive direction in Yazd-Ardakan difficulty. Journal of Agricultural Sciences and Natural Resources, Gorgan, number 1, pp139- 152
  4. Bolongaro-Crevenna, A., Torres-Rodríguez, V., Sorani, V., Frame, D., Ortiz, M.A.,(2005). Geomorphometric analysis for characterizing landforms in Morelos State, Mexico. Geomorphology 67, 407–422.
  5. Cooke, R.U.,Warren, A. & Goudie, A. (1993). Desert Geomorphology. London: UCL Press, Ltd.526 pp.
  6. Dehn,m.holger,g.and Richard,d.(2001). Principles of semantic modelling of landform structures,computer and science,27: 1005-1010
  7. Ehsani, Amir Hoshang.(2010). Mega Yardong Geomorphometry of Lut, Natural Geography Research, No. 74
  8. Evenari, M. (1985). The desert environment. In: Evenari, M., Noy-Meir, I. & Goodall, D.W. (Eds), Hot Deserts and Arid Shrublands, Part A, pp. 1–22. New York, NY: Elsevier Science Publishing Company. pp. 365
  9. Etzelmqller, B., Sulebak, J.R., (2000). Developments in the use of digital elevation  models in periglacial geomorphology and glaciology. PhysischeGeographie, vol. 41. Geographisches Institute der Universit7t Zqrich, pp. 35– 58                                                                                                               
  10. Ehsani, Amir Houshang, Quiel, F, A (2009).semi-automatic method for analysis of landscape elements using Shuttle Radar Topography Mission and Landsat ETM+ data, Computers & Geosciences 35،  pp 373–389
  11. Fotouhi, Farzaneh. Hamidreza Azimzadeh, Mohammad Reza Ekhtesasi & Ali Talebi (2010). Investigation of Hazard Reduction of Arid Landscapes Due to Desert Pavement and its Impact on Adaptation Erosion and Wind Erosion Threshold Speed (Case Study: Part of Yazd-Ardakan Plain, First National Desert Conference, Opportunities and Threats. Birjand University.
  12. Gorabi, Abolghasem, Mostafa Karimi (2012). A New Method to Extract Alluvial Cones from Digital Elevation Modeling, Quantitative Geomorphology Research, No. 3, pp. 89- 100
  13. Hengl, T., Reuter, H, Development in Soil Science, Vol 33. Geomorphometry.(2009) - Napieralski.J, Nalepa.N ,2010, The application of control charts to determine the effect of grid cell size on landform morphometry ,Computers & Geosciences ,36, pp.222–230
  14. Jamieson, S.S.R., Sinclair, H.D., Kirstein, L.A.,Purves, R.S.,) 2004(, Tectonic Forcing of Longitudinal Valleys in the Himalaya: Morphological Analysis of the Ladakh Batholith, North India, Geomorphology 58, PP. 49–65.
  15. Jenness, J., (2002), Topographic Position Index (tpi_jen.avx) Extension for ArcView 3.x, JennessEnterprises, Retrieved from: http://www.jennessent.com.
  16. Mahmoudi, Farajollah (1998). Dynamic Geomorphology, Payame Noor University
  17. Pelletier, Jon D. How do pediments form?: A numerical modeling investigation with comparison to pediments in southern Arizona, USA, Department of Geosciences, University of Arizona, Geological Society of America,2010
  18. Pike, R.J., Dikau, R., 1995. Advances in geomorphometry. Z. Geomorphol., N.F. Suppl. Bd. 101, 238.
  19. Pike ,R.J, I.S. Evans and T. Hengl,( 2009) Geomorphometry: A Brief Guide, Developments in Soil Science, Volume 33, chapture 1, Elsevier,
  20. Shayan, Siavash, Ali Ahmad Abadi, Mojtaba Yamani, Manouchehr Farajzadeh Asl, Ehsanullah Kabir. (2012), Evaluation of Geomorphometric Indicators Performance by Wood Method in Dry Land Classification, Space Planning and Planning, Vol 16 - Number 5
  21. Shayan, Siavash.(1991). Culture of Natural Geography, School Publications.
  22. Summerell, G.K., Vaze, J., Tuteja, N.K., Grayson, R.B., Beale, G., Dowling, T.I., (2005). Delineating   the major landforms of catchments using an objective hydrological terrain analysis method. Water Resources Research 41, 1–12 (W12416).
  23. Tazeh, Mehdi; Gholamreza Zahhtabian; Hasan Ahmadi;Ali Akbar Nazari Samani& Amiroushang Ehsani (2014). Determination of the most important granulometric parameters of desert pavement in different types of plain head (Case Study: Khazrabad), Quantitative Geomorphology Research, No. 2, pp. 31-43
  24. Tazeh, Mehdi; Gholamreza Zahhtabian, Hasan Ahmadi, Ali Akbar Nazari Samani, Amir Hooshang Ehsani (2013). Determine the most suitable plot size for the sample of paving the desert, Quantitative Geomorphology Research, No. 4, pp. 61-72
  25. Wood, J., (1996).The Geomorphological Characterization of Digital Elevation Models, in Department of Geography, Leicester: University of Leicester, UK.