River reaches downstream dams where a constant residual flow discharge is imposed, often lack sediment supply and periodic inundation due to the absence of natural flood events. In this study, a two-year return flood was released from an upstream reservoir and combined with sediment replenishment to enhance instream habitat conditions downstream of Rossens hydropower dam on the Sarine River in western Switzerland. Sediment replenishment consisted of four sediment deposits distributed as alternate bars along the river banks, a solution which was previously tested in laboratory. The morphological evolution of the replenishment and of the downstream riverbed were surveyed including pre- and post-flood topography. A hydro-morphological index to evaluate the quality of riverine habitats, based on the variability of flow depth and flow velocity in the analyzed reach, was investigated. The combination of the artificial flood with sediment replenishment proved to be a robust measure to supply a river with sediment and to enhance hydraulic habitat suitability.
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http://dx.doi.org/10.1038/s41598-019-41575-6 | DOI Listing |
Nature
January 2025
School of Natural Sciences, Macquarie University, North Ryde, New South Wales, Australia.
The cratonic crust contains abundant mineral deposits of metals such as gold, copper and rare earths and is underlain by a thick mantle lithosphere rich in the volatiles carbon, sulfur and water. Although volatiles are known to be key components in metallogenesis, how and where they are distributed in the cratonic lithosphere mantle and their role in the initial enrichment of metals have not been sufficiently explored. Here we compile sulfur and copper contents of global cratonic peridotites, identifying sulfide-rich and copper-rich continental roots at depths of 160-190 km at cratonic margins.
View Article and Find Full Text PDFSensors (Basel)
October 2024
Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China.
Due to the complex intersection and control of multiple structural systems, the hydrogeological conditions of the Laiyuan Basin in China are complex. The depth of research on the relationship between geological structure and groundwater migration needs to be improved. The supply relationship of each aquifer is still uncertain.
View Article and Find Full Text PDFMar Pollut Bull
December 2024
Research Center for Environmental Functional Materials, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, PR China. Electronic address:
There are multiple sources of microplastic contamination in freshwater aquaculture areas, such as water inputs, use of plastic farming tools and weathering of discarded plastics, leading to microplastic contamination of aquaculture environments, but microplastics in freshwater aquaculture areas are still limited. In our study, we investigated the distribution of microplastics (MPs) in the aquaculture water, sediments and crabs during the growth cycle of crabs with different culture modes. The results show that from May to October, MPs in surface water first increased and then decreased, which is related to water evaporation and river water recharge caused by local hot and sunny weather.
View Article and Find Full Text PDFJ Environ Manage
November 2024
Water Systems and Global Change Group, Wageningen University and Research, Wageningen, the Netherlands.
Rampant and illegal river sand mining in the Vietnamese Mekong Delta (VMD) has led to substantial sediment losses and bank erosion. However, regulation of this issue remains a significant challenge due to insufficient monitoring and enforcement efforts, partly attributed to limited data and technology. To support an improved monitoring system in the VMD, this study investigates the spatiotemporal changes in sand mining hotspots and their underlying drivers.
View Article and Find Full Text PDFWater Res
November 2024
Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China. Electronic address:
Periodic oxygen permeation is critical for pollutant removal within intertidal sediments. However, tidal effects on the vertical redox profile associated with cable bacterial activity is not well understood. In this study, we simulated and quantified the effects of tidal flooding, exposing, and their periodic alternation on vertical redox reactions and phenanthrene removal driven by cable bacteria in the riverbank sediment.
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