Abstraction Strategies for Irrigation from Large Diameter Wells

作者：Rushton K R^*; de Silva C S

来源：Water Resources Management, 2017, 31(7): 2257-2270.

DOI：10.1007/s11269-017-1641-6

• Large diameter wells
• Conceptual models
• Computational model
• Abstraction strategies
• Irrigation

When large diameter wells in aquifers of limited saturated thickness are used for irrigation, there is often insufficient water towards the end of the growing season; the focus of this paper is to identify how abstraction can be maintained throughout the growing season. An earlier investigation used field data from two locations to develop conceptual and computational models which successfully replicated both water level fluctuations in the aquifer, and pumped and rest water levels in the well. That methodology is adapted to explore the impact on the long term well yield of various factors including the well diameter, the spacing between wells and too high an initial abstraction rate. Alternative annual abstraction strategies are explored which include the same abstraction each year, selecting a different abstraction each year so that the pumped water level falls almost to the bottom of the well and devising annual abstractions so that full water table recovery occurs at the end of each year. The resultant annual abstraction patterns have substantial differences; this indicates that many factors must be considered when devising an abstraction policy. The outcomes of more frequent irrigations and a crop with a shorter growing season are also examined. Monitoring of the water table elevation at the start of the irrigation season, to estimate the volume of water stored in the aquifer, is recommended.

• 出版日期2017-5