A Formal Method for Enhancing Irrigation Control of Iraqi Multi-Crops Farms
Author(s)
Primary Supervisor
Lewis, Andrew J
Other Supervisors
Kaparaju, Laxmi Narasimha Prasad
Mizhir, Thair J
Year published
2022-03-03
Metadata
Show full item recordAbstract
The specific focus of this work is conserving irrigation water in Iraq. Agriculture is the main sector that consumes fresh water globally, mostly for irrigation, and it will be the sector most affected by increasing water scarcity. Nowadays, the low-pressure sprinkler has been widely used to replace highpressure impact sprinklers in linear-move sprinkler irrigation systems due to its low operating cost and high efficiency. However, the hazard of increased surface runoff represents the biggest obstacle for low-pressure sprinkler systems. Variable-rate irrigation (VRI) techniques have been used to apply variable irrigation ...
View more >The specific focus of this work is conserving irrigation water in Iraq. Agriculture is the main sector that consumes fresh water globally, mostly for irrigation, and it will be the sector most affected by increasing water scarcity. Nowadays, the low-pressure sprinkler has been widely used to replace highpressure impact sprinklers in linear-move sprinkler irrigation systems due to its low operating cost and high efficiency. However, the hazard of increased surface runoff represents the biggest obstacle for low-pressure sprinkler systems. Variable-rate irrigation (VRI) techniques have been used to apply variable irrigation water volume under the linear move irrigation system to match site-specific crop water requirements. However, VRI methods have been reported to have issues delivering an inaccurate volume of variable depth and having an unacceptable level of longitudinal uniformity, especially for lower irrigation depths. This study aims to develop a Variable Pulsed Irrigation Algorithm (VPIA) based on the principle of an ON-OFF pulsing technique. The proposed VPIA aims to balance four critical goals: 1) reduce the runoff losses while delivering the highest possible infiltration depth, 2) deliver precise variable irrigation depth, 3) ensure a high level of longitudinal uniformity, 4) using the lowest number of pulses to ensure the sustainability of sprinkler mechanical parts. The VPIA controls the number and width of OFF and ON pulses to achieve these aims while considering soil and irrigation machine properties. The proposed algorithm, soil infiltration rate, and sprinkler application rate were numerically simulated. The simulation results show that the VPIA reduced runoff loss to its minimal value while delivering the highest possible irrigation depth with a high level of longitudinal uniformity using the lowest number of pulses. Also, the results demonstrated the VPIA had achieved more accurate variable infiltration depth with a high level of longitudinal uniformity using fewer pulses compared with two standard VRI methods.
View less >
View more >The specific focus of this work is conserving irrigation water in Iraq. Agriculture is the main sector that consumes fresh water globally, mostly for irrigation, and it will be the sector most affected by increasing water scarcity. Nowadays, the low-pressure sprinkler has been widely used to replace highpressure impact sprinklers in linear-move sprinkler irrigation systems due to its low operating cost and high efficiency. However, the hazard of increased surface runoff represents the biggest obstacle for low-pressure sprinkler systems. Variable-rate irrigation (VRI) techniques have been used to apply variable irrigation water volume under the linear move irrigation system to match site-specific crop water requirements. However, VRI methods have been reported to have issues delivering an inaccurate volume of variable depth and having an unacceptable level of longitudinal uniformity, especially for lower irrigation depths. This study aims to develop a Variable Pulsed Irrigation Algorithm (VPIA) based on the principle of an ON-OFF pulsing technique. The proposed VPIA aims to balance four critical goals: 1) reduce the runoff losses while delivering the highest possible infiltration depth, 2) deliver precise variable irrigation depth, 3) ensure a high level of longitudinal uniformity, 4) using the lowest number of pulses to ensure the sustainability of sprinkler mechanical parts. The VPIA controls the number and width of OFF and ON pulses to achieve these aims while considering soil and irrigation machine properties. The proposed algorithm, soil infiltration rate, and sprinkler application rate were numerically simulated. The simulation results show that the VPIA reduced runoff loss to its minimal value while delivering the highest possible irrigation depth with a high level of longitudinal uniformity using the lowest number of pulses. Also, the results demonstrated the VPIA had achieved more accurate variable infiltration depth with a high level of longitudinal uniformity using fewer pulses compared with two standard VRI methods.
View less >
Thesis Type
Thesis (PhD Doctorate)
Degree Program
Doctor of Philosophy (PhD)
School
School of Eng & Built Env
Copyright Statement
The author owns the copyright in this thesis, unless stated otherwise.
Subject
irrigation water
fresh water
Variable-rate irrigation
Variable Pulsed Irrigation Algorithm (VPIA)
sustainability
runoff losses