Assessment of rice hydraulic loading impacts on groundwater and salinity levels

作者：Khan Shahbaz^*; Rana Tariq; Carroll Jason; Gabriel Hamza

来源：Paddy and Water Environment, 2010, 8(1): 23-39.

DOI：10.1007/s10333-009-0171-0

• Surface-groundwater interactions
• Groundwater modelling
• Murrumbidgee irrigation area (MIA)
• MODFLOW
• Australia

This paper describes the impact of rice hydraulic loading (percentage area under rice crop) on groundwater levels and salinity in the Murrumbidgee irrigation area (MIA), Australia using a MODFLOW-based modelling approach. The model simulations show that the groundwater levels will be in equilibrium after a fall of approximately 1 m under most of the areas, however, the groundwater salinity levels will rise by more than 1,000 mu s/cm in most parts of irrigation area. If the rice growing area is reduced by 50 and 75%, there can be a net decline in groundwater levels during the first 2 years and then a new quasi-equilibrium will be established. To downscale these results at the farm level, SWAGMAN Farm model in conjunction with groundwater outflow rates obtained from a three-dimensional MODFLOW model was applied for determining net recharge rates under rice for different areas within the MIA. The highest net recharge during 2005-2006 season was 0.84 ML/ha (84 mm) in parts of the irrigation system, whereas the average net recharge due to rice hydraulic loading for the whole MIA during 2005-2006 season was estimated as 0.34 ML/ha (34 mm).

• 出版日期2010-3
• 单位CSIRO