Establishing an irrigation management plan of sustainable groundwater based on spatial variability of water quality and quantity

SummaryConditions of water quality and quantity are two key factors impacting groundwater utilization for irrigation. To obtain pristine groundwater and reduce pumping impacts on aquifers, this study establishes an irrigation management plan of sustainable groundwater in the Pingtung Plain in Taiwan based on the spatial variability of water quality and quantity parameters. According to an irrigation water quality standard, multivariate indicator kriging (IK) was adopted to estimate the integration of hydrochemical parameters in groundwater. IK was also used to grade transmissivity fields representing the pumping capacity of aquifers. Six risk categories of recommended groundwater used for irrigation were spatially delineated based on combinations of five levels of groundwater quality and quantity determined by estimated probabilities. The analyzed results indicate that 54.4% of aquifers are recommended to extract groundwater for irrigation. The aquifers belonging to excellent categories are the optimal locations, where groundwater can be used for irrigation without dilution. The aquifers belonging to ordinary categories are the regions, where groundwater mixed with surface water is appropriate for use in irrigation.

► An irrigation plan is established according to groundwater quality and quantity.
► MVIK is used to grade groundwater quality based on an irrigation regulation.
► IK is used to assess transmissivity fields denoting the pumping capacity of aquifers.
► Six types of combining groundwater quality and quantity are mapped for irrigation.
► Approximately 54.4% of aquifers are suggested to pump groundwater for irrigation.