تعیین شرایط آستانه توپوگرافی گسترش فرسایش خندقی با استفاده از سیستم اطلاعات جغرافیایی (مطالعه موردی: حوزه آبخیز ریحانلو-آذربایجان‏غربی)

نوع مقاله: مقاله پژوهشی

نویسندگان

1 فارغ التحصیل کارشناسی ارشد علوم خاک، دانشگاه آزاد اسلامی واحد تبریز

2 استادیار گروه علوم خاک، دانشکده کشاورزی، دانشگاه تبریز

3 استادیار مرکز تحقیقات کشاورزی و منابع‏طبیعی استان آذربایجان‏غربی

4 استادیار گروه علوم خاک، دانشکده کشاورزی، دانشگاه آزاد اسلامی واحد تبریز

چکیده

پیش‏بینی مکان‏های مستعد فرسایش خندقی به منظور تمرکز دادن کارهای حفاظتی و جلوگیری از هدر رفت منابع بسیار مهم است. محدوده مورد مطالعه در منطقه ریحانلو در شهرستان چالدران و در شمال استان آذربایجان‏غربی واقع شده است. در این تحقیق 20 خندق فعال و معرف برای مطالعه در سال 1390 انتخاب شدند. سپس محدوده حوزه آبخیز خندق‏ها با استفاده از عکس هوایی 1:40000، نقشه‏های توپوگرافی 1:25000 و سیستم موقعیت‏یاب جهانی (GPS) مشخص و ترسیم شد. سپس برخی ویژگی‏های حوزه آبخیز خندق‏های منتخب از جمله شیب متوسط حوزه‏آبخیزرأس خندق (S) و مساحت حوزه ‏آبخیز رأس خندق (A) به‏وسیله نرم‏افزارArc-GIS بر روی نقشه‏های توپوگرافی تعیین شد. تجزیه خوشه‏ای خندق‎ها براساس ویژگی‏های توپوگرافی به روش Ward و مقیاس مجذور فاصله اقلیدسی، توسط نرم‏افزار SPSS انجام گرفت. نتایج حاصل از تجزیه خوشه­ای بر اساس روش تابع تشخیص در سه گروه طبقه‏بندی شدند که از لحاظ ویژگی‏های توپوگرافی شامل ارتفاع، مساحت، درصد شیب، جهت شیب و نوع فرآیندهای دخیل در گسترش رأس، خندق‏ها بسیار شبیه به هم می­باشند. بررسی ویژگی‏های ریخت‎شناسی خندق‎ها نشان می‏دهد که مساحت حوزه‏آبخیز رأس خندق در منطقه ریحانلو بین 2300 مترمربع تا 109300 مترمربع متغیر می‏باشد. میانگین شیب حوزه ‏آبخیز رأس خندق‏ها 6/25 درصد می‏باشد که از 5/6% تا 1/43 % تغییر می‏کند. همچنین با بررسی رابطه شیب و مساحت حوزه‏آبخیز رأس خندق‏های منطقه ریحانلو رابطه نمایی 18/0A81/3=S با 16/0=R2برای تعیین حدود آستانه توپوگرافی بدست آمد. با بکار بردن رابطه S-A (شیب - مساحت حوضه آبخیز رأس خندق) می‏توان مکان‏های مستعد فرسایش خندقی را پیش‏بینی کرد. با توجه به این که ضریب تببین به دست آمده برای رابطه بالا کوچک می‎باشد بنابراین می‌توان نتیجه گرفت که حد آستانه توپوگرافی تنها عامل تعیین‏کننده گسترش فرسایش خندقی نمی‏باشد و برای تعیین حد آستانه شروع فرسایش خندقی عوامل موثر دیگر از جمله خصوصات خاک، پوشش گیاهی و غیره نیز بایستی در نظر گرفته شود.

کلیدواژه‌ها


عنوان مقاله [English]

Determination Topographical Threshold Condition for Initiation of Gully Erosion with Using GIS (Case Study: Reyhanlou- West Azerbaijan)

نویسندگان [English]

  • Naser Balandeh 1
  • Abbas Ahmadi 2
  • Reza Sokouti 3
  • Samad Darbandi 4
1 M.Sc. student of soil science Department – Faculty of Agriculture - Islamic Azad University of Tabriz
2 Assistant professor of Soil Science Department, Faculty of Agriculture, University of Tabriz
3 Head of Research Center of Agricultural and Natural Resources of Urmia-Iran
4 Department of Soil Science, College of Agriculture, Tabriz Islamic Azad University, Tabriz
چکیده [English]

Predicting vulnerable areas to gullying, focus on conservation tasks and prevent loss of resources is very important. The study area is located in the Reyhanlou region of Chaldoran city in the northern of West Azerbaijan province. In this research 20 active gullies were selected in Reihanlu area in 2011. Boundaries of the gullies and gullies head drainage-basins were delimited with using aerial photographs (1:40000), topographic maps (1:25000) and global positioning system (GPS). Some gully properties include mean slope of gullies head drainage-basins (S, %) and gullies head drainage-basins areas (A, m2) at the point of gullies initiation were determined by Arc-GIS software with using topographic maps. The statistical analysis such as clustering classification based on gullies topographic characteristics were done by SPSS 16 software. The cluster analyses were classified gullies into three groups. The classified gullies are very similar terms of topographical characteristics including altitude, area, slope percent, slope aspect and processes involved in the development of the gully heads. The investigation of the morphological properties of gullies in the study area showed that the areas of gullies head drainage-basins are variable (2300 m2 - 109300 m2). The mean slope of gullies head drainage-basins was %25.6 (slope was between %6.5 to %43.1). The relationship between the slope (S, %) and area (A, m2) was evaluated and the exponential equation (S=3.81A0.18) to was obtained (R2=0.16). The positive sign of exponent (b) in the (S=aAb) equation also indicate that sub surface runoff is dominant on gully development. Application of  S-A relation showed that it is possible to predict the location of gullies. Due to the correlation coefficient was low (R2=0.16), so can be concluded that the topographical threshold condition is not the only factor to develop the gully erosion and to determination of topographical threshold conditions for gully erosion, other factors, such as soil properties, vegetative cover should also be considered.

کلیدواژه‌ها [English]

  • threshold
  • topographical characteristics
  • gully erosion
  • GIS
References

Abtahi A, Haji-Rasouli Sh, Haghnia GH, Siadat H, Kalbasi-Ashtari M, Maftoun M. 2004. Culture of agriculture and natural resources. TehranUniversity Press. Volumes 10. pp: 80. (In Farsi with English Summary)

Ahmadi A, Sokouti R, Broushke E and Soufi M. 2005. Morphoclimatic classification of gullies-West Azerbaijan province. Ministry of Agriculture. Agricultural Research and Education Organization. Soil Conservation and Watershed Management Research Institute. pp. 1-99. (In Farsi with English Summary)

Ahmadi H. 2007. Applied geomorphology (water erosion). 4ed Edition. University of Tehran Press. 688p. (In Farsi with English Summary)

Balandeh N, Ahmadi A, Sokouti R and Darbandi S. 2011. Active processes in the development of gully erosion in the Chaldoran region of West Azerbaijan province. 12th Iranian Soil Science Congress. TabrizUniversity. 3-5 September. (In Farsi with English Summary)

Bayati Khatibi, M. (2004).The analysis and research on role of topographical and morphological properties on gulling. Geographic Research, Vol 49: 53-70. (In Farsi with English Summary)

Bou Kheir R, Cerdan O and abdallah C. 2006. Regional soil erosion risk mapping in Lebanon. Geomorphology 82: 374-359.

Capra A and Scicolone B. 2002. Ephemeral gully erosion in a wheat cultivated area in Sicily (Italy). Biosystems Eng. 83 (1): 119–126.

El Maaoui MA, Sfar Felfoul M, Rached Boussema M, Snane MH. 2012. Sediment yield from irregularly shaped gullies located on the Fortuna lithologic formation in semi-arid area of Tunisia. Catena, 93. Pp: 97–104.

Horton RE. 1945. Erosional development of streams and their drainage basins; hydrophysical approach to quantitative morphology. Geo. Society of America Bulletin, 56: 275–370.

King C, Lecomte V, Le Bissonnais Y, Baghdadi N, Souchere V, and Cerdan O. 2005. Remote-sensing data as an alternative input for the "STREAM" runoff model. Catena, 62:125-135.

Kukal SS, and Matharu GS. 2002. Behavior of gully erosion in relation to catchment characteristics in foothills of lower Shivaliks. 17th WCSS. Thailand.

Lamarche JL. 2001. Effects of forest roads on flood flows in the Descutes river,Washington. Earth surface processes and landforms, 26. 115-134.

Miller SN, Semmens DJ, Goodrich DC, Hernandez M, Miller RC, Kepner WG and Guertin DP. 2007. The automated geospatial watershed assessment tool. Environmental Modelling & Software, 22: 365-377.

Morgan RPC and Mngomezulu D. 2003. Threshold conditions for initiation of valley-side gullies in the middle Veld of Swaziland. Catena, 50: 401-414.

Nazari samani AA, Ahmadi H, Jafari M and Ghoddousi J. 2008. Effect of incipient gullying mechanisms on topographic threshold conditions for gully initiation in southwestern Iran (Boushehr-samal watershed). Desert, 13: 31-43.

Nazari samani AA, Ahmadi H, Jafari M, Boggs M, Ghoddousi J and Malekian A. 2009. Geomorphic threshold conditions for gully erosion in Southwestern Iran (Boushehr-Samal watershed). Journal of Asian Earth Sciences, 35: 180–189.

Patton PC, and Schumm SA. 1975. Gully erosion, Northern Colorado: A threshold phenomenon. Geology, 3: 88–90.

Poesen JJ, Nachtorgale J and Verstrac G. 2003. Gully erosion and environmental change: importance and research needs. Catena, 50: 91-133.

Refahi H. 2009. Soil erosion by water & conservation. TehranUniversity Press. pp 10-202. (In Farsi with English Summary)

Sayadi MJ. 2006. Investigate the effects of some factors influencing the development of gully erosion in loess formation (case study: watershed Ag-Imam- Kichik, Golestan province). MSc Thesis, University of Agricultural Sciences and Natural Resources Gorgan. (In Farsi with English Summary)

Soleimanpour SM, Soufi M and Ahmadi A. 2009. Determining effective factors on gully development in Konartakhte Region, FarsProvince. Journal of Water and Soil, 23: 131-141. (In Farsi with English Summary)

Soleimanpour SM. 2007. Comparison of gullies sediment delivery and its relationship with watershed characteristic & geological formation in Fars province climate. MSc Thesis, Islamic Azad University, Tehran Science and Research branch. Pp 23. (In Farsi with English Summary)

Soufi M. 2003. Investigation of morphoclimatic characteristic of gullies in FarsProvince. Proceedings of the 3rd Scientific Conference Morphoclimatic Investigation and Classification of Iran's Gullies. Tehran. pp. 37-55. (In Farsi with English Summary)

Soufi M. 2005. Investigation topographic threshold in the development of gully in FarsProvince. First Conference of Management & Sustainable Agriculture in Iran. pp 4. (In Farsi with English Summary)

Vandaele K, Poesen J, Govers G and Vanwesemael B. 1996. Geomorphic threshold conditions for ephemeral gully incision. Geomorphology, 16(2): 161-173.

Vandekerckhove L, Poesen J, Oostwoud Wijdenes D, Nachtergaele J, Kosmas CM, Roxo MJ and de Figueiredo T. 2000. Thresholds for gully initiation and sedimentation in Mediterranean Europe. Earth Surface Processes and land Forms, 25: 1201-1220.

Zachar D. 1982. Soil erosion. Elsevier Scientific Publishing Company. No 584.

Zanjani-Jam M. 2005. The relationship between gully development and different climates of the Zanjan province using GIS. Iranian Geomati, (In Farsi with English Summary)