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Coastal reclamation can result in considerable changes in the quality and quantity of submarine groundwater at the land/sea interface. In this study, submarine groundwater monitoring wells and water samples were designed and implemented to get data of groundwater level, electrical conductivity, temperature, and hydrochemistry data to examine the responses of silty-sand submarine groundwater in different sedimentary strata to reclamation in south of Laizhou Bay. The submarine groundwater is mainly saline water and its salinity in the deep aquifer is higher than that of seawater and close to brine. It was formed in the Late Pleistocene and Holocene. Drilling core data indicates that there is a stratigraphic boundary at a depth of 18.58 m, with Holocene strata above, and Late Pleistocene strata below, this level. Continuous electrical conductivity data indicates that the submarine groundwater properties are stratigraphically distributed in this study area. And there is an interface at a depth of 38 m. Above the 38 m depth, the water quantity of submarine ground-saline water is freshening. The major ions showed a tendency to change continually above 25 m, but the tended to stabilize below 25 m depth. Freshwater is the major recharge source in the upper section of the Holocene strata, between the surface and 8.00 m depth, and the hydrochemical type has changed from Cl Na to Cl·HCO 3 Na. In the lower section of Holocene strata (8.00–23.00 m) and upper section of late Late Pleistocene strata (23.00–38.00 m), groundwater is influenced by seawater and groundwater of upper aquifer. The freshwater, seawater, and groundwater recharge in the upper aquifer has no influence on the groundwater in the section below the late Late Pleistocene (between 38.00 and 49.15 m) and the early Late Pleistocene strata (between 49.15 and 75.00 m). The filling layer, added in the coastal reclamation project, is comprised of clayey silt and fine sand, and its high porosity means that it is suitable for water storage. After the reclamation, meteoric water was stored in the filling layer that became the stable recharge resource. The recharge resource and the filling layer can improve the properties of the confined aquifer to increase the groundwater level. They may also influence the groundwater quantity and the flow direction. The groundwater in the Holocene strata is clearly influenced by recharge and the previously saline water aquifers receive freshwater on an on-going basis, such that the water is now becoming fresh. [ABSTRACT FROM AUTHOR]

The plant community is the basic landscape unit of the coastal green space. The study of the oil-contaminated coastal green space plant community has an important role in improving the landscape quality and aesthetics of the coastal green space. This article takes the oil pollution shoreline of Jiaozhou Bay as an entry point to build a plant community landscape evaluation model, analyzes and evaluates the most scenic plant community types in the coastal area of Qingdao Jiaozhou Bay in order to provide scientific basis for the plant community landscape configuration along the oil polluted coastline of Jiaozhou Bay, and provide reference for the evaluation and construction of plant community landscape in other cities. • The plant community is the basic landscape unit of the coastal green space. • Oil-contaminated coastal green space plant community has an important role in improving the landscape quality. • The configuration has significance for landscape evaluation and construction of plant communities in coastal green spaces. [ABSTRACT FROM AUTHOR]

Coastal aquifers provide fresh drinking water to over 20% of the world's population. In recent times, they have come under immense pressure due to salinization. This study aims to investigate the origin of groundwater salinity and elucidate the major processes controlling shallow groundwater (depth of 0–50 m) evolution in the Luanhe River Delta since the Holocene. Rapid increase in Electric Conductivity (EC) profile was observed in the area, as such, based on the vertical distribution of EC and sedimentary history, shallow groundwater was generalized into two zones for analysis: the groundwater in Holocene stratum (HSG) and groundwater in Late Pleistocene stratum (PSG). The isotopic (δ 18O, δ 2H and 14C) analyses showed that the HSG is recharged by modern surface water, while the PSG having enriched isotopic values could have been recharged during a warmer Holocene transgression period. The hydrochemistry analyses demonstrated that seawater is the major source of salinity in groundwater and over time a series of geochemical processes (mineral weathering and/or cation exchange) modified the chemistry of the groundwater. The combined use of Cl− and δ 18O yielded four classes of groundwater (fresh water, brackish water, saline water and brine), while the mixing phenomena between fresh water and seawater was identified to be the main evolutionary process of the shallow groundwater. To improve understanding of evolution of multiple groundwater types in a spatial context, a conceptual model was developed integrating the results derived from the presented study in a vertical cross-section. The conceptual model shows that the residual seawater mixes with freshwater from surface recharge at the shallow aquifer of the delta plain where the lagoon environment provides salinity concentration conditions for the formation of hyper-saline water. Due to the precipitation and accumulation of the salinity from hyper-saline water, some brine might form formed in late Pleistocene continental stratum. In addition, the submarine groundwater discharge may be mainly from deeper inland fresh groundwater, but it is not significantly affected by the hyper-saline water from the shallow aquifer in Luanhe River delta. • Trapped palaeo-seawater from marine sediments deposited during Holocene transgression is responsible for inland salinity in coastal delta. • Shallow saline groundwater is a mixture of fresh water and palaeo-seawater and salinity is marine source. • δ D and δ 18O of groundwater highlight the distinction between modern and paleo-recharge source. • A conceptual model is used to describe the evolution of shallow salty groundwater in Luanhe River Delta which may be relevant to other deltas. [ABSTRACT FROM AUTHOR]