آستانه¬ی برداشت کنگر برای تولید رسوب دکتر ایرج جباری ، بهروز برنا

نوع مقاله: مقاله پژوهشی

10.22111/gdij.2013.119

چکیده

چکیده
برداشت گیاهان خودرو، مانند کنگر، در اغلب دامنه­های پایین­دست نواحی کوهستانی باعث ایجاد گوال­های کوچکی می­گردد که در مواقع برداشت زیاد، ظاهر آشفته­ای را به دامنه­­ها می­بخشد. این آشفتگی خاک اغلب با بارش­های سنگین بهاری همراه می­شود که فرسایش خاک را تشدید می­کند. از سوی دیگر،  نیاز به برداشت این گیاهان به دلایل طبی، غذایی و همچنین امرار معاش تعداد زیادی از مردم در فصول برداشت، غیرقابل اجتناب است. ولی می­توان با شناخت آستانه­های فرسایشی میزان و شیوه­ی برداشت را مدیریت نمود. از این رو، در این پژوهش  سعی شد  با ساخت 16 کرت، در 4 شیب و 2 جهت مختلف، در دامنه­ی کوه ویس در نزدیک کرمانشاه و مقایسه­ی رسوب حاصل از کرت­های دارای کنگر و بدون کنگر،  مشخص شود که آیا اصلاً برداشت کنگر از دامنه­ها می­تواند عاملی برای تشدید فرسایش باشد و اگر چنین است این تأثیر در  جهت­ها و شیب­های مختلف تا چه اندازه می­تواند شستشوی دامنه­ها را  رونق  بخشد. بنابراین، مقدار رسوب حاصل از  9 رویداد بارش در اواخر زمستان 1384 و اوایل بهار 1385 از کرت­های آزمایشی اندازه­گیری شد.  آنالیز فاکتور این داده­ها نشان داد که علی­رغم معنی­دار بودن تولید رسوب در بارش­ها، در شیب­ها و جهت­های مختلف، رسوب تولید  شده­ی ناشی از برداشت کنگر تفاوت معنی­داری را ایجاد نمی­کند. ادامه­­ی تجزیه و تحلیل آماری و محدود نمودن آن  به شرایط تنها روزهای برداشت کنگر نشان داد که برداشت بین دو تا 4 کنگر از هر مترمربع در این منطقه باعث افزایش معنی­دار فرسایش نمی­گردد محل­هایی که برداشت در واحد سطح بیشتر صورت گیرد، تولید رسوب نیز ممکن است به سطح معنی­دار برسد.
کلیدواژه­ها: کنگر، فرسایش خاک، بار رسوب، کرمانشاه.

کلیدواژه‌ها


عنوان مقاله [English]

Geography and Development 10nd Year - No. 29 - Winter 2013 Received : 29/4/2011 Accepted : 17/7/2012 PP: 14 - 16 Threshold of Acanthus Harvesting to Sediment Produce Dr. Iraj Jabbari Associate Professor of Geomorphology University of Kermanshah Razi Behrooz Borna M.Sc of Geomorphology University of Kermanshah Razi

چکیده [English]

Introduction
 Harvesting of self-growing plants, like acanthus; from the down slopes of mountainous regions often causes disturbances to the appearance of the slopes if it is mowed intensively. 
These soil disturbances often occur with spring showers that accelerate soil erosion. On the other hand, the harvesting is inevitable because of acanthus clinical and sustenance uses and earning a livelihood for many local people who make a living with such crop in the harvesting seasons. So, as the spring season starts, the harvest of self growing plants becomes a usual phenomenon on the slopes in lower altitudes. The harvest of rooting plants as acanthus is in a way that makes pits on the ground and this may be agent of erosion when spring rain falls; specially, precipitation contact with plant germination in Iran. So, in this study, it has been tried to elucidate if the harvesting of acanthus makes erosion at every situation or reaching to erosion threshold needs to increase number of the harvesting in area unit as well as other location with more gradient and other characteristics.
 
Research Methodology
 In this survey has been taken into consideration the sediment producing in 16 plots with and without acanthus in the Viece Mountain, near Kermanshah city. Whereas, gradients and orientation are factors that play roles on erosion, in this research too, others aims purpose to study roles of acanthus harvesting on the different gradients and orientations on erosion acceleration. In this reason, these plots established on the four different slopes and two different aspects. The amount of sediment has been measured from plots in 9 time precipitation when it falls on late winter and early spring in 2007. Factor analyze and two ways ANOVA were the techniques that used for  data analyzing.   
 
Discussion and Results
A Max.  shower including 46.8 mm produced 5.8 L. runoff and 0.69 g/m2  sediment on a slope with 40% gradient and a  Min. rainfall with 1.4 mm precipitation set in motion only 0.175L runoff and 0.00153  g/m2  sediment from control plots on 15% slope.





 
Threshold of Acanthus Harvesting to Sediment Produce
 
 





Two ways ANOVAon obtained data shows that there is a significant difference between rainfall, slopes, aspects and erosion, that is, erosion have been deference on variety of showers, slopes and aspects. So, these results show that data have correctly been collected.
 
 
Using Factor Analysis method show that despite of a significant difference in the sediment producing on the different rainfall, gradient and precipitation times, there aren’t any significant difference of sediment producing between plots with and without acanthus plants(F1,71=0.944, P>0.05). The statistical analysis continued and limited to only days when harvesting occur. It illustrated that   erosion   don’t occur when acanthus harvesting become 2 - 4 per m2 as Kermanshah region, but erosion may be get a significant level  on regions where more harvesting acanthus occur.
 
Conclusion
This study is carried out at a region where slopes were not acute and the number of acanthus at area unit were less, whereas, there are a lot of regions at Kermanshah province  and even other neighbor provinces where slopes are more acute and acanthus grow up more per unit area . So, harvesting  from these regions may increase probability of erosion occurrence as the results of this study show that the amount of significant level goes up when the study is limited to only harvesting times.
 
Keywords: Acanthus, Sediment yield, Erosion, Kermanshah.
 
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کلیدواژه‌ها [English]

  • Keywords: Acanthus
  • Sediment yield
  • erosion
  • Kermanshah