طراحی و ساخت شبیه ساز باران قابل حمل

نوع مقاله : پژوهشی

نویسندگان

1 استادیار، گروه منابع طبیعی، پردیس کشاورزی و منابع طبیعی، دانشگاه رازی، کرمانشاه

2 دانشیار، پژوهشکدۀ حفاظت خاک و آبخیزداری، سازمان تحقیقات، آموزش و ترویج کشاورزی، تهران

چکیده

شبیه‏سازی باران یکی از روش‏های مهم برای اندازه‏گیری فرایندهای هیدرولوژیکی و فرسایش خاک است. ارزیابی سریع و قابلیت تکرار زیاد از مزایای استفاده از شبیه‏ساز باران است. شبیه‏ساز ساخته‌شده به وزن تقریبی 20 کیلوگرم قابلیت شبیه‏سازی باران با شدت‏های 8/2 تا 5/9 سانتی‏متر بر ساعت در سطح کرت آزمایشی با مساحت یک تا سه مترمربع را دارد. اندازه‏گیری قطر قطرات از روش‏های گلولۀ آردی و لکۀ رنگی به‏دست آمد. روش گلولۀ آردی به‌دلیل بیشتربودن ضریب تبیین انتخاب و نتایج آن ‌بررسی شد. بیشترین ضریب یکنواختی (6/96 درصد) مربوط به شدت 3/8 سانتی‏متر بر ساعت و کمترین ضریب (6/90 درصد) مربوط به شدت 5/9 سانتی‏متر بر ساعت به‏دست آمد که بیشتر از حد قابل قبول است. دامنۀ قطر متوسط قطرات از 97/0 میلی‏متر در شدت 8/2 سانتی‏متر بر ساعت تا 22/1 میلی‏متر در 1/7 سانتی‏متر بر ساعت تغییر می‏کند که در محدودۀ باران‏های طبیعی قرار دارد. همچنین، دامنۀ تغییرات سرعت از 58/3 تا 21/4 متر بر ثانیه است. با توجه به مجموعه ویژگی‏های یادشده یک شبیه‏ساز باران قابل حمل بسیار مناسب با دقت قابل قبول برای مطالعات رواناب، نفوذپذیری، فرسایش و رسوب در صحرا ساخته شد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Designing and construction of a portable rainfall simulator

نویسندگان [English]

  • Soheila Aghabeigi Amin 1
  • Mahmood Arabkhedri 2
2 Water & Soil Conservation Dep., SCWMRI
چکیده [English]

Rain simulation is one of the important methods for measuring hydrological and soil erosion processes. Rapid evaluation and high repeatability capabilities are the advantages of using the rainfall simulator. The weight of constructed simulator is approximately 20 kg, can simulate rainfall at 28 to 95 mm / h intensity on the plot area of one up to three square meters. The droplet diameter was measured using flour pellet method and stain method. Flour pellet method was selected due to higher determination factor, and then its results were applied to continue the study. The highest uniformity coefficient (96.6%) was obtained at the intensity of 8.3 cm/h and the lowest coefficient (90.6%) was obtained at 9.5 cm/h intensity, which is higher than the acceptable level. The average diameter of the droplets is from 0.97 mm at intensity of 2.8 cm/h to 1.22 mm at 7.1 cm/ h, which lies within the range of natural precipitation. Also, the range of velocity variations is from 3.58 to 4.21 m/s. According to the mentioned specifications, a suitable portable rainfall simulator was designed with acceptable accuracy for runoff, permeability, erosion and sedimentation studies in field.

کلیدواژه‌ها [English]

  • Velocity and kinetic energy of rainfall
  • Christiansen uniformity coefficient
  • Flour pellet method
  • Nozzle
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دوره 5، شماره 1
فروردین 1397
صفحه 229-239
  • تاریخ دریافت: 31 مرداد 1396
  • تاریخ بازنگری: 26 شهریور 1396
  • تاریخ پذیرش: 14 دی 1396
  • تاریخ اولین انتشار: 01 فروردین 1397