Interactions between dam-regulated river flow and riparian groundwater: a case study from the Yellow River, China (pages 1552–1560)

摘要

The Xiaolangdi Dam, completed in 2000, is second in scale in China to the Three Gorges Project. It has generated remarkableneconomic and social benefits but with profound impacts to the riverine and regional environments. This paper reports fieldnmonitoring of riparian groundwater in the Kouma section of the Yellow River to illustrate the interactions between damregulatednriver flow and riparian groundwater. The results show that the hydrological condition in riparian zones downstreamnfrom the dam has changed from a typical wet–dry cycle to a condition of semi-permanent dryness, resulting in degradation of thentypical attributes and functions of the wetland ecosystem. Hydrological processes in the riparian zone have changed from ancomplex multiple flooding regime to a simple regime of dominant groundwater drainage towards the river, which only reversesntemporarily during the water and sediment regulation period of the dam. Data on groundwater level and groundwater qualitynshow that there are two key points, at ca 200 and 400m from the river bank, which distinguish zones with different sensitivity tonchanges of river flow and indicate different interactions between river water and groundwater. The shallow groundwater qualitynalso is negatively affected by the intensive agricultural development that has occurred since the dam was completed. Ecologicalnrestoration needs to be carried out to construct a protective natural riparian zone within ca 200m from the river, this being annecotone, which is key to the protection of both riparian groundwater and the river. The riparian zone from 200 to 400m alsonshould be treated as a transitional zone. In addition, ecologically sensitive agriculture and ecotourism organized by localncommunities would be beneficial in the area beyond 400 m. Copyright © 2011 John Wiley & Sons, Ltd.