Effects of water-saving irrigation planning on the underground water in the low area of Yellow River, China

The Yellow River Delta is considered one of the most water-stressed regions in China as the competition for water between various industrial sectors and agriculture is increasing. Since 2007, the regional governments have taken a leading role in agricultural water-saving planning by upgrading irrigation systems and constructing water-saving facilities. In this study, the effects of water-saving irrigation strategies on the groundwater table and quality, including both phreatic surface and deep confined aquifers were investigated in the Yellow River basin during the last two decades. The average phreatic water level of bore-wells was monitored as 13.47 m during 2011–2020 in comparison with the level of 12.09 m during 2011–2020. Besides, the depth of the deep confined aquifer dropped dramatically during 2001–2013 with a declining rate of 2.55 m/a compared to the value of 0.385 m/a after 2014, suggesting the reduced exploitation of deep groundwater and increased availability of groundwater after the water-saving campaign. In addition, the physicochemical parameters of both phreatic water and deep confined aquifer indicated improved water quality. Consequently, understanding how the water-saving planning influences the groundwater availability is important, which would provide an insightful guidance for the water managers to protect the groundwater environment in the Yellow River Delta.