Effects of Groundwater Level Changes Associated with Coastline Changes in Coastal Wetlands
- PDF / 1,505,263 Bytes
- 10 Pages / 595.276 x 790.866 pts Page_size
- 49 Downloads / 246 Views
WETLANDS RESTORATION
Effects of Groundwater Level Changes Associated with Coastline Changes in Coastal Wetlands Qiang Liu 1,2 & Liqiao Liang 3,4 & Xiaomin Yuan 1,2 & Xia Mou 1,2 & Liya Su 1,2 Received: 18 March 2019 / Accepted: 18 November 2019 # Society of Wetland Scientists 2020
Abstract Coastline changes caused by anthropogenic and natural influences inevitably alter coastal wetland groundwater levels. In this study, we apply Visual MODFLOW (VMOD) to assess the influence of different zonal coastline types (e.g., accretion, erosion, and stable zones) on groundwater levels of a coastal wetland in the Yellow River Delta (YRD), China. We also discuss the conceptual framework of groundwater level variation in accretion, erosion, and stable zones. Results show that: (i) The groundwater flow field varied with coastline changes in this seaside region, while a similar variation pattern was also found in both the upper southwestern region and the riverside of the Yellow River where groundwater levels are high; (ii) groundwater levels increased with the expansion in land area caused by silting, while groundwater levels exhibited a slightly decreasing trend in the erosion zone; and (iii) coastal wetland groundwater levels exhibited a progressively and significantly decreasing trend in zones protected by a dam. We found that the mechanisms that drive groundwater levels clearly responded to coastline alteration, and such findings could help in our understanding of how coastlines influence groundwater in freshwater wetlands and aid in maintaining the integrity of coastal wetlands. Keywords Coastal wetlands . Groundwater level . Coastline . Accretion . Erosion
Introduction A coastal wetland is defined as an ecosystem with a depth range between the lower subtidal zone where sunlight is able to penetrate and support benthic plant community photosynthesis and the landward edge where the sea cedes its hydrologic influence to groundwater and atmospheric processes (Perillo et al. 2009). Such wetlands, where land and sea are linked together, are characterized by complex hydrological processes that are prone to degradation (Dawson et al. 2011; Howes et al. 2010; Mitsch and Gosselink 2000). In addition to * Qiang Liu [email protected] * Liqiao Liang [email protected] Xiaomin Yuan [email protected]
hydrological gradients, coastal wetlands comprise of seagrass, tidal flats, tidal salt and freshwater marshes, and mangrove and tidal freshwater forests (Perillo et al. 2009). Impacted both anthropogenically and naturally, coastal wetlands have suffered great losses and severe degradation throughout the world, particularly in China (Yang et al. 2019), Europe (Almeida et al. 2014), the United States of America (Alizad et al. 2018), and Australia (Schuerch et al. 2018). As summarized by Liu and Mou (Liu and Mou 2016), water regimes and salinity are controlled by interactions between surface water and groundwater, which together 1
State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University,
Data Loading...
