ارزیابی وضعیت فعلی بیابان‌زایی و شناخت مهم‌ترین عوامل تخریب با استفاده از مدل ایرانی ارزیابی پتانسیل بیابان‌زایی (مطالعة موردی: منطقة دامغان)

نوع مقاله : مقاله پژوهشی

نویسندگان

1 استادیار دانشکدة کویرشناسی، دانشگاه سمنان

2 استاد دانشکدة منابع طبیعی، دانشگاه تهران

3 دانشیار دانشکدة منابع طبیعی، دانشگاه تهران

چکیده

مبارزه با بیابان‌زایی، که امروزه تهدیدی جدی برای محیط و رفاه انسان به‌شمار می‌رود، نیازمند درک مسائل پیچیدة این پدیده از طریق ارزیابی، آگاهی از شدت عمل فرایند‌ها، و مشخص‌نمودن عوامل آن است. بنابراین، در این بررسی، پس از مطالعة شرایط حاکم بر منطقة دامغان، که نشان‌دهندة وجود بیابان‌زایی است، شدت و وضعیت فعلی بیابان‌زایی با تکیه بر معیارهای اقلیم، آب، زمین‌شناسی- ژئومورفولوژی، خاک، و فرسایش بادی، به عنوان مهم‌ترین معیارهای بیابان‌زایی، ارزیابی شد. با توجه به اعتبار بیشتر مدل‌های منطقه‌ای و مدل‌های دارای قابلیت بازنگری و اصلاح، در اینجا از مدل ایرانی ارزیابی پتانسیل بیابان‌زایی (IMDPA)، که برای استفاده در مناطق خشک واسنجی شده است، برای ارزیابی بیابان‌زایی استفاده شد. نخست شاخص فصلی‌بودن بارش، با توجه به ویژگی‌های خاص اقلیمی منطقه، به مدل اضافه شد. سپس، ارزیابی اولیة بیابان‌زایی انجام شد. سپس، با توجه به نتایج ارزیابی اولیه، شرایط منطقه، و مسائل مطرح‌شده در مراحل مختلف ارزیابی، اصلاحات لازم در مدل انجام شد و ارزیابی نهایی بیابان‌زایی و ارائة نقشة آن صورت گرفت. نتایج به‌دست‌آمده نشان داد که شدت بیابان‌زایی در 94/33 درصد از سطح منطقه شدید و در 06/66 درصد از سطح آن متوسط است. همچنین، اقلیم، شورشدن منابع آب و خاک، کاربری نامناسب اراضی، بهره‌برداری بی‌رویه از منابع آب زیرزمینی، شیوة نامناسب آبیاری، و چرای مفرط مهم‌ترین عوامل بیابان‌زایی در منطقه است.
 

کلیدواژه‌ها


عنوان مقاله [English]

Assessment of Current Desertification Status using IMDPA and Determination of Effective Factors of Land Degradation (Case Study: Damghan region)

نویسندگان [English]

  • shima nikoo 1
  • Hossein Azarnivand 2
  • Gholam Reza Zehtabiyan 2
  • Hasan Ahmadi 2
  • Mohammad Ali Zare Chahouki 3
1 scientific board member of/ Semnan University
2 scientific board member / University of Tehran
3 scientific board member/University of Tehran
چکیده [English]

Combating desertification which is a serious threat for the environment and human welfare requires understanding complex issues of this phenomenon using evaluation, awareness of severity of it's processes and determination of it's factors. So here, after recognizing the characteristics of the region showing existence desertification, we assess its current status with emphasis on climate, water, geology-geomorphology, soil and wind erosion as the most criteria of desertification. According to more consensus on regional model or flexible model to modify, Iranian Model for Desertification Potential Assessment (IMDPA) ,which is calibrated to use in arid area of Iran, was chosen. At first the rainfall seasonality indicator was added to the model as a special climate character. Then primary assessment of desertification was done. At last according to the result of primary assessment, the area environmental conditions and revealed issues during assessment the model was modified, final assessment and mapping of desertification were done. At last according to the result of primary assessment, the area environmental conditions and revealed issues during assessment the model was modified, final assessment and mapping of desertification were done. Based on the results desertification intensity in 33/94% and 66/06% of the area are severe and moderate respectively. Also the major factors affecting desertification across Damghan region are climate, salinization of water and soil resources, improper land use, over exploitation of underground water, over grazing and improper irrigation method.

کلیدواژه‌ها [English]

  • Desertification assessment
  • Desertification intensity
  • Modified IMDPA
  • Desertification
  • fators
  • Damghan region
[1] Abdi, zh. (2007). Determination and mapping of desertification based on water and soil in Abuzeyd Abad region, Ms.c thesis of Tehran University, 118pp.
[2] Ahmadi, H. (2006). Calibration of Desertification Assessment Indices and Criteria in Iran (Dasht-e-Segzi of Isfehan), Iran Forests, Range & Watershed Management Organization.
[3] Azarnivand, h. (1990). Study of vegetation cover and soil in relation to geomorphologic units of Damghan, M.S.c thesis of Tarbiat Modarres University, 162pp.
[4] Baradaran Nasiri, M. (1993). Determination of the souces of Damghan playa salt deposits, Ms.c thesis of Tehran University, 175pp.
[5] DESERTLINK (2004). Desertification Indicators System for Mediterranean Europe,336pp.
[6] Dregne, H.E. (1999). Desertification assessment and control .In: The United Nations University (Ed.). New Technologies to Combat Desertification, Proceedings of the International Symposium held in Tehran, Iran,12-15 October 1998, 121pp.
[7] Farajzadeh, M. and Nik Eghbal, M. (2007). Evaluation of MEDALUS Model for Desertification Hazard Zonation Using GIS in Izad Khast Plain, Iran, Pakistan journal of Biological Sciences, 10(16):2622-2630.
[8] Hastenrath, S. (1991). Climate dynqmics of the tropics, 512p.
[9] Iran Meteorological Organization (2011). Scientific journal of Meteorological Organization of Semnan province, Journal of Arid Environments, 66, 751-763.
[10] Katyal, R.K., Zhang, Y., Jones, R.H. and Dyer, P.D. (1997). Atmospheric mold spore counts in relation to meteorological parameters, Journal of Biometeorology, 41, 17-22.
[11] Mohammadghasemi, S. (2006). Assessment and mapping of desertification intensity based on water and soil in Zabol, Ms.c thesis of Tehran University, 134pp.
[12] Nateghi, S., Zehtabiyan, GH.R. and Ahmadi, H. (2009). Determination of desertification intensity using IMDPA model in Segzi plain, Iranian journal of Natural Resources, 62(3): 419-430
[13] Natural Resources office of Semnan province (2005). The plan of combating desertification in Amir Abad of Damghan, 265pp.
[14] Nikoo, Sh. (2006). Study of effective environmental factors on distribution of vegetation cover in Damghan region, Ms.c thesis of Tehran University, 105pp.
[15] Razavi, S.M. (2009). Determination of desertification intensity using IMDPA model with emphasis on water, soil, vegetation cover and climate criterias in Kavir-e-Mighan of Arak, Ms.c thesis of Tehran University, 100pp.
[16] Reynolds, J.F. and Stafford Smith, D.M. (2002). Global Desertification: Do Humans Cause Deserts?, Dahlem University Press, Berlin, 88, 437.
[17] Shokouhi, E.S. (2011). Study of desertification status using IMDPA model with emphasis on water and soil criterias in Khezr Abad-Elah Abad of Yazd, Ms.c thesis of Tehran University, 120pp.
[18] Torabi, S.R. (2003). Water and soil salinization factor in Baram region of Damghan, Ms.c thesis of Tehran University, 146pp.
[19] UN (United Nations) (1994). UN Earth Summit, Convention on Desertification, UN Conference in Environment and Development, Rio de Janeiro, Brazil, June 3-14, 1992. DPI/SD/1576. United Nations, New York.
[20] Veron, S.R., Paruelo, J.M. and Oesterheld, M. (2006). Assessing desertification, Journal of Arid Environment, 66, 751-763.
[21] Walsh, P.D. and Lawler, DM. (1981). Rainfall seasonality: description, spatial patterns and change through time, Weather journal, 36, 201-208.
[22] Zerey, E.W. (2010). Critical Reading of Desertification Indicators, EDN/CSFD contribution to a European proposal of a minimum set of indicators for the UNCCD 10 year Strategy.