برآورد نفوذ در آبیاری موجی با استفاده از روش نقطه‌ای نفوذسنج موجی

نوع مقاله : مقالات پژوهشی

نویسندگان

1 دانش آموخته کارشناسی ارشد رشته آبیاری و زهکشی گروه مهندسی آبیاری و آبادانی، دانشگاه تهران

2 استاد گروه مهندسی آبیاری و آبادانی، دانشگاه تهران

3 استادیار گروه علوم و مهندسی آب، دانشگاه زنجان

4 دانشجوی دکتری رشته آبیاری و زهکشی، دانشگاه تبریز

چکیده

یکی از مهمترین نکات طراحی سامانه­های آبیاری سطحی، تعیین پارامترهای نفوذ می­باشد. به خصوص اینکه در نظر گرفتن کاهش نفوذ بر پیچیدگی تخمین آن در آبیاری موجی افزوده است. هدف از پژوهش حاضر، ارزیابی مزرعه­ای روش نقطه­ای نفوذسنج موجی و مدل توسعه یافته نفوذ به منظور شبیه­سازی نفوذ در موج­های پیشروی آبیاری موجی می­باشد. به همین منظور، استوانه نفوذسنج موجی با قابلیت قطع و وصل جریان ورودی طراحی و ساخته شد. تعداد ۳۰ آزمایش نفوذسنجی در قالب چهار تیمار زمان و نسبت موج برای جریان موجی و یک تیمار جریان پیوسته که هر کدام در سه تکرار و در دو نوبت زمانی به فاصله هشت روز انجام گرفت. معادله نفوذ کوستیاکوف به منظور تخمین نفوذ در موج­های مختلف جریان آب  استفاده شد. در مدل توسعه داده شده، به منظور تطبیق دادن معادله نفوذ کوستیاکوف با شرایط خاک مزرعه در موج­های دوم و سوم، از یک ضریب کاهنده استفاده گردید. به منظور مقایسه تیمارهای مختلف از مقادیر نفوذ تجمعی و همچنین تغییرات آن در هر موج استفاده شد. نتایج نشان داد، مقدار نفوذ در موج­های دوم و سوم نسبت به موج اول کاهش قابل ملاحظه­ای دارد. بیشترین اثر موج بر کاهش نفوذ در موج دوم مشاهده شد به طوری که مقدار نفوذ تجمعی در موج دوم نسبت به موج اول به طور میانگین کاهش بیش از ۵۰ درصدی را داشت. نتایج به دست آمده از مدل توسعه یافته نفوذ انطباق قابل قبولی با داده­های مشاهداتی داشت به طوری که میانگین مقادیر ضریب تعیین و ریشه میانگین مربعات خطا به ترتیب ۹۳/۰ و ۰۹/۰ سانتی­متر برآورد شد. نتایج حاصل از آزمایش­های نفوذسنجی و همچنین مدل توسعه یافته نشان داد، جریان موجی موجب کاهش ۴۶ تا ۷۶ درصدی عمق آب نفوذ یافته تجمعی نسبت به جریان پیوسته می­گردد.

کلیدواژه‌ها


عنوان مقاله [English]

Point Estimation of Infiltration in Surge Irrigation Using Surge Infiltrometer Method

نویسندگان [English]

  • A. Zarei 1
  • T. Sohrabi 2
  • H. Ojaghlou 3
  • Z. Bigdeli 4
1 Graduated in Master Irrigation and Drainage , Department of Irrigation and Reclamination, University of Tehran
2 Professor, Department of Irrigation and Reclamination, University of Tehran
3 Assistant Professor, Department of Water Science and Engineering, University of Zanjan
4 Ph.D. Candidate, Water Engineering Department, University of Tabriz
چکیده [English]

Introduction: In recent years, to increase the efficiency of surface irrigation methods, new techniques such as surge irrigation have been developed. Numerous studies have shown that the surge flow can reduce water consumption in the advance phase and subsequently improve irrigation efficiency and water distribution uniformity. One of the factors affecting the performance of surface irrigation systems is the accurate estimation of infiltration. Due to continuous changes in the infiltration process during on-off cycles in surge irrigation, determining the empirical equation of infiltration in surge irrigation method is complex and requires time-consuming and costly field data. As a result, proper selection and parameterization of empirical equations with a simplified procedure are needed. The goal of this research was the field evaluation of the point method (surge infiltrometer) to simulate the infiltration process in advance phase surges.    
Materials and Methods: A field experiment was conducted at the experimental station of the College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran. A ring infiltrometer was modified by connecting a pipe arm for inward and outward water flow to the ring and from the ring to the pipe to create on-off surge cycles, respectively. Water entered the ring through the inlet hole at the top of the pipe arm and water depth was recorded at different time intervals during the on-time of each cycle. Four treatments were performed for infiltration tests under surge flow, including different cycle time and ratio. Also, infiltration tests were performed under continuous flow conditions. To simulate the first (dry soil) and second irrigation conditions, infiltration experiments were conducted twice on an 8-day interval. The Kostiakov infiltration equation was corrected by applying surge factors to predict infiltration water depth for subsequent surges, using first surge data. The empirical coefficients of the Kostiakov equation were calculated by applying the two-point technique. 
Results and Discussion: Results of the study revealed that the infiltration data simulated by the developed Kostiakov equation matched closely with those collected from the surge-ring infiltrometer. The coefficient of determination and the root mean square error were calculated to be 0.92 to 0.97 and 0.03 to 0.16 cm, respectively. In general, the amount of cumulative infiltration in the second and subsequent surges decreased. The ratio of the infiltration depth at the end of the second to the first surge was less than 0.5. In all experiments, the depth of water infiltrated in the third surge was significantly reduced and almost reached to the final infiltration rate. As the cycle ratio increased, the cumulative infiltration also increased. However, the effect of on-off time on the infiltrated water depth in the first experiment was greater than that in the second experiment. It was concluded that in the first experiments, the surging phenomena substantially reduced water movement and the reduction in cumulative infiltration ranged from 50 to 70% during the second surge and from 59 to 85% during the third surge. The above values were determined 52 to 76% and 61 to 88% for the second experiment, respectively. A significant difference was observed between surge and continuous flow tests. The surge flow led to a 46 to 76% reduction in the cumulative infiltration depth compared to the continuous flow. The effect of surge flow was greater in the first experiments.
Conclusion: One of the most important points in designing surface irrigation systems is to determine the infiltration equation parameters. In particular, the difficulty involved in the planning and design of surge irrigation systems is the prior knowledge and understanding of how infiltration changes occur during surging. The main objective of the present study was to evaluate the surge ring infiltrometer test to predict the infiltration in the second and third surges using the first surge data. The results obtained from the surge infiltrometer experiments showed that the use of surge irrigation has the potential to reduce infiltration. The observed and predicted cumulative infiltration for the second and third surges showed a good agreement. The surge-ring infiltrometer has the potential for creating an on-off mechanism and is best suited to determine the cumulative infiltration from surges for constant on-off time surge intervals.

کلیدواژه‌ها [English]

  • Surge flow
  • Ring infiltrometer
  • The Kostiakov equation
1-    Abbasi F., Sohrab F., and Abbasi N. 2016. Evaluation of irrigation efficiencies in Iran. Journal of Irrigation and Drainage Engineering Research 17(67): 113-128. (In Persian with English abstract)
2-    Al-Saud M., and Podmore T.H. 1999. Infiltration Rate Reduction Prediction under Surge Irrigation Using Management Variables and Soil Composition. Ph.D thesis, Department of Chemical and Bioresource Engineering, Colorado State University.
3-    Benham B.L., Reddel D.L., and Marek T.H. 2000. Performance of three infiltration models under surge irrigation. Irrigation Science 20: 37-43.
4-    Blair A.W., and Smerdon E.T. 1987. Modeling surge irrigation infiltration. Journal of Irrigation and Drainage Engineering 113(4): 497-515.
5-    Coolidg P.S., Walker W.R., and Bishop A.A. 1982. Advance and runoff surge flow furrow irrigation. Journal of the Irrigation and Drainage Division 108(1): 35-42.
6-    Ebrahimian H., Keshavarz M.R., and Playan E. 2014. Surface fertigation: a review, gaps and needs. Spanish Journal of Agricultural Research 12(3): 820-837.
7-    Elliott R.L., and Walker W.R. 1982. Field evaluation of furrow infiltration and advance functions. Transaction, ASAE 25: 396-400.
8-    Hamdi Ahmadabad Y., Liaghat A., Sohrabi T., and Rasoolzadeh A. 2017. Improving irrigation Performance by managing the irrigation cut-off time in SIRMOD (Case Study: Moghan Agro-Industry and Husbandry). Iranian Journal of Soil and Water Research 4(48): 811-822. (In Persian with English abstract)
9-    Heydari N., Das Gupta A., and Loof R. 2001. Salinity and sodicity influences on infiltration during surge flow irrigation. Irrigation Science 20(4): 165-173.
10- Mahmood S., and Latif M. 2005. A simple procedure for simulating surge infiltration using first-surge infiltrometer data. The Journal of the International Commission on Irrigation and Drainage 54(4):407-416.
11- Nazemi A., Parandin M., Sadraddini A., and Ghamarnia H. 2019. Effects of Surge Irrigation on Water Use Efficiency and Water Productivity of Maize in Islamabad-Gharb Area. Iranian Journal of Water Research in Agriculture (Formerly Soil and Water Sciences) 33(3): 353 -369. (In Persian with English abstract)
12- Ojaghlou H., Sohrabi T., Abbasi F., and Javani H. 2020. Development and evaluation of a water flow and solute transport model for furrow fertigation with surge flow. Irrigation and Drainage 69(4): 682-695.
13- Sohrabi T., Heydari N., Tavakoli A., and Nirizi S. 1375. Wave irrigation. National Irrigation and Drainage Committee, Ministry of Energy.
14- Stringham G.E. 1979. Surge flow for automatic irrigation. p. 132-142. In Irrigation and drainage in the nineteen eighties, Proceedings of the specialty conference of American Society of Civil Engineers, 345 east, 47th Street, New York.
15- Walker W.R. 1984. Surge flow in the west. Proceedings of the surge flow irrigation conference. Texas Agriculture Extension Service. Midland. 1-30.
16- Walker W.R., and Skogerboe G.V. 1987. Surface irrigation theory and practice. Prentice- Hall INC. New Jersey.
17- Walker W.R., Henggle J.C., and Bishap A.A. 1981. Effect of surge flow in level basins. ASAE, (81-25555): 13.
18- Walker W.R., and Humpherys A.S. 1983. Kinematic-wave furrow irrigation model. Journal of Irrigation and Drainage Engineering 109(4): 377-392.