Impacts of evaporation and inundation on near-surface salinity at a coastal wetland park

Abstract

Salinization is one of the main causes of conversion between different ecosystems and landuse functions in coastal wetlands. In this paper, we studied the spatiotemporal dynamics of soil moisture and salinity in a reclaimed national wetland park in Guangdong Province, China. We found that diel evaporation affected soil water up to 40 cm deep. Extreme rainfall only increased topsoil moisture with limited leaching effects on soil salinity. Salt accumulation occurred between 40 and 70 cm depth in rainy season, lasting until the end of monitoring period. Whereas the topsoil was salinized between land-surface to 30 cm deep in dry season, which was recovered after rainfall. This result suggested that the force balance between capillarity and gravity created a relative stable saline layer which was not flushed out during inundation. Therefore, considering these site-specific features could lead to the improved understanding of the migration of salinity in the soil profiles.