Groundwater response to water diversion and surface-water management scenarios in the Yellow River Delta wetland reserve, China.

In order to restore degraded wetlands, restoration projects were implemented in the Yellow River Delta wetland reserve from 2010. Water was diverted from the Yellow River and was used to saturate artificial wetlands. This study used in-situ data and model simulations to investigate the effects of water diversion on groundwater systems in the artificial wetlands in 2010, 2011, and 2013. The objectives were to: (1) develop a model for simulating groundwater flow within the study area using Visual MODFLOW, (2) apply the model to simulate and compare the water-table and water-balance responses to water diversion between years, and (3) compare several landscape scenarios that combine artificial shallow ponds and canals and investigate potential water efficiency improvements in the wetland reserve. Results indicate that precipitation infiltration, evapotranspiration, and wetland leakage were the most dominant water budget components. Water diversion increased groundwater storage and shifted the water tables. Between 2010 and 2013, as the water diversion volume in the restoration area near the Diaokou Channel increased, wetland leakage increased, and the spatial effect (meaning impact range on groundwater) of diversion increased from 800 to 1,000 m. Based on the scenario analysis, wetland canals have lower evapotranspiration losses, thus diversion canals that retain water for a longer duration improve the efficiency of water use. Artificial shallow ponds and canals may enhance surface-water/groundwater interactions and restore plant biodiversity. This study can provide a design reference for the construction of artificial wetlands in semiarid areas. [ABSTRACT FROM AUTHOR]