Dissertation
Irrigation strategies for water conservation: evaluation of sprinkler discharge efficiency, uniformity, and runoff under a linear-move irrigation system
Doctor of Philosophy (PhD), Washington State University
01/2016
Handle:
https://hdl.handle.net/2376/111642
Abstract
Due to the scarcity of water for agricultural use and the increase in costs of energy, it is very important to use irrigation systems that apply water more efficiently and uniformly with lower energy cost. To achieve this goal, low pressure sprinkler irrigation systems such as center pivots and linear move-move laterals have been developed. These systems irrigate nearly half of the total irrigated fields in the United States. This study investigated the efficient approaches for improving the efficiency of these irrigation systems. It also examined the correct method of measuring the sprinkler discharge efficiency (SDE) and uniformity of these irrigation systems, and suggest what time of day and how frequent irrigations should be applied. As part of this study, a section of a standard linear-move system was converted to offset booms and its efficacy in reducing runoff was compared to that of the standard in-line drops (SILD). It was found that offset booms, compared to SILD, significantly (P < 0.05) reduced runoff by 26 % when operated on bare soil. This study also examined the effects of collector’s opening diameters (8.3, 10.9, 16.1 and 27.1 cm) on the measurements of SDE and uniformity of a linear-move system. This experiment was conducted twice per day (early morning and afternoon) to compare the SDE and uniformity between times of day. It was found that collector with the smallest opening diameter measured higher SDE compared to all other collectors. However, collector with the largest diameter measured higher uniformity compared to the remaining collectors. The results also revealed that irrigating in the morning resulted in greater SDE (85%) than irrigating in the afternoon (78%). Finally, drainage lysimeter method was used to examine evaporation losses under two irrigation frequencies: irrigating every day and irrigating every five days. It was found that higher irrigation frequency resulted in greater total evaporation losses due to more frequent exposure of water to air which triggers water evaporation rates.
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Details
- Title
- Irrigation strategies for water conservation: evaluation of sprinkler discharge efficiency, uniformity, and runoff under a linear-move irrigation system
- Creators
- Mohammad Zaman Amini
- Contributors
- Troy Peters (Advisor)Claudio O Stockle (Committee Member)Pete W Jacoby (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Department of Biological Systems Engineering
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 84
- Identifiers
- 99900581632401842
- Language
- English
- Resource Type
- Dissertation