تحلیل مقایسه‌ای اثر شدت باران و شیب پلات‌های آزمایشگاهی بر مؤلفه‌های فرسایش ناشی از اثر قطره‌های باران (RIIE)

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی دکتری گروه مهندسی آبخیزداری، دانشکدة منابع‌طبیعی و علوم دریایی، دانشگاه تربیت مدرس، مازندران، نور

2 استاد گروه مهندسی آبخیزداری، دانشکدة منابع‌طبیعی و علوم دریایی، دانشگاه تربیت مدرس، مازندران، نور

3 دانشیار گروه علوم خاک، دانشگاه گیلان

چکیده

جدایش پاشمانی و انتقال ذرات خاک به‌وسیلة اثر قطره‌های باران در خاک سطحی شروع روند فرسایش آبی محسوب می‌شود. این در حالی است که به تحلیل فرایندی و اثر عوامل مختلف روی آن کمتر توجه شده است. به‌همین منظور پژوهش حاضر با هدف تحلیل مقایسه‌ای اثر شیب و شدت باران بر مؤلفه‌های فرسایش ناشی از اثر قطره‌های باران (RIIE) در خاک لوم رسی شنی در مقیاس آزمایشگاهی برنامه‌ریزی شد. برای این کار، 81 آزمایش شبیه‌سازی بارش در پلات‌های 1×6 متر در شیب‌های 5، 15 و 25 درصد متناسب با شرایط فعلی منطقه و در شدت‌های 30، 60 و 90 میلی‌متر بر ساعت با استفاده از منحنی شدت، مدت و فراوانی منطقه و در سه تکرار با شبیه‌ساز باران و در بالادست و پایین‌دست فنجان پاشمان مورگان و در سه موقعیت بالادست، وسط و پایین‌دست پلات‌ها صورت گرفت. طبق نتایج پژوهش حاضر، تأثیرپذیری تمامی متغیرهای مورد بررسی شامل پاشمان بالادست و پایین‌دست و پاشمان کل و خالص ناشی از شدت بارش و تغییرات مکانی در سطح 99 درصد معنا‌دار بود. تنها تأثیر تغییرات مکانی بر پاشمان خالص معنا‌دار نبود (13/0 ≥ P). همچنین تحلیل نتایج، بر نبود اثر معنا‌دار شیب بر متغیرها (11/0 ≥ P) به جز پاشمان خالص (01/0 P ≤) دلالت داشته است.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Comparative Analysis of the Effects of Rainfall Intensity and Experimental Plot Slope on Raindrop Impact Induced Erosion (RIIE)

نویسندگان [English]

  • Mahboobeh Kiani Harchegani 1
  • Seyed Hamid Reza Sadeghi 2
  • Hossein Asadi 3
1 PhD candidate, Department of Watershed Management Engineering, College of Natural Resources, Tarbiat Modarres University, Noor, Mazandaran, Iran
2 Professor, Department of Watershed Management Engineering, College of Natural Resources, Tarbiat Modarres University, Noor, Mazandaran, Iran
3 Associate Professor, Department of Soil Science, University of Guilan
چکیده [English]

Splash detachment and transport of soil particles through the impact of raindrops on the soil surface form the initiating mechanisms of water erosion. However, mechanistic analysis of different affecting factors has less been taken into account. The present study was therefore formulated for a comparative analysis of the effective intensities as well as slopes on Raindrop Impact Induced Erosion (RIIE) components within a laboratory scale and for a sandy clay loam soil. Towards this end, a total of 81 rainfall simulation experiments were conducted in a set of 1 × 6 m plots with varying slopes of 5, 15 and 25% while using the current situation prevalent in the region. The experiments were performed in three replications and with simulated rainfall intensities of 30, 60, and 90 mm h-1 using region IDF. The experiments were also adopted while using rainfall simulation system along with upward as well as downward Morgan’s splash cups placed at upper, middle and lower parts of the plot. Results indicated that all the study variables viz. total vs net splash and upward downward splash were significantly (p ≤ 0.01) influenced by rainfall intensity and cups' locality, but net splash was not statistically influenced (p ≥ 0.13) by spatial variation of cups. In addition, the results showed that slope did not affect any study variables (p ≥ 0.11) except the phenomenon of net splash (p ≤ 0.01).

کلیدواژه‌ها [English]

  • Erosion factors
  • Rainfall erosion
  • Rainfall simulator
  • Soil erosion process
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