Impact of floodplain and Stage 0 stream restoration on flood attenuation and floodplain exchange during small frequent storms

River flooding impacts human life and infrastructure, yet provides habitat and ecosystem services. Traditional flood control (e.g., levees, dams) reduces habitat and ecosystem services, and exacerbates flooding elsewhere. Floodplain restoration (i.e., bankfull floodplain reconnection and Stage 0) can also provide flood management, but has not been sufficiently evaluated for small frequent storms. We used 1D unsteady Hydrologic Engineering Center's River Analysis System to simulate small storms in a 5 km-long, second-order generic stream from the Chesapeake Bay watershed, and varied % channel restored (starting at the upstream end), restoration location, restoration bank height (distinguishes bankfull from Stage 0 restoration), and floodplain width/Manning's n. Stream restoration decreased (attenuated) peak flow up to 37% and increased floodplain exchange by up to 46%. Floodplain width and % channel restored had the largest impact on flood attenuation. The incremental effects of new restoration projects on flood attenuation were greatest when little prior restoration had occurred. By contrast, incremental effects on floodplain exchange were greatest in the presence of substantial prior restoration, setting up a tradeoff. A similar tradeoff was revealed between attenuation and exchange for project location, but not bank height or floodplain width. In particular, attenuation and exchange were always greater for Stage 0 than for bankfull floodplain restoration. Stage 0 thus may counteract human impacts such as urbanization.     

Impacts of climate change on rice production: evidence from 30 Chinese provinces

Environment, Development and Sustainability - This study examined the effects of climate change on rice production in 30 Chinese provinces spanning 1998–2017. The study used the pooled mean...     

Uranium enrichment by the separation-nozzle process

The Science of Nature - The development of reliable manufacturing methods for commercial separation elements, the successful operation of separative stages, and extensive tests performed on plant...     

Das RÄtsel der Exoelektronen Historie,gegenwärtiger Stand,Lösungsvorschläge

This paper deals with the history of exoelectron emission (EE), as well as with the experimental results and the attempts to explain them. The author concludes that thermally and optically stimulated EE (TSEE, OSEE) are different phenomena and that OSEE is mere photoeffect. The source of the energy causing the emission has been heatedly discussed. The author believes that most of the models can be ruled out by the fact that the activation energies do not depend on the nature of the metal nor on its oxide. He supposes the simplest model—direct thermal emission from surface traps—to be right. The author concludes that none of the excitation processes produces electron traps, as is often assumed. They only fill existing traps with electrons, e.g., radiation, mechanical treatment or a simple dip in water.