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The hurricane's remnants continued wreaking havoc Saturday, bringing record-breaking river flooding to the southern Appalachians. [ABSTRACT FROM AUTHOR]

An application of the Weakly compressible Smoothed Particle Hydrodynamics (WSPH) numerical method is presented here for the case of two-dimensional flow in a long channel with a partially open sluice gate. The results are compared with an analytical solution provided by shallow water equations (SWE) and available experimental data for instantaneous discharge depth at the gate. Of particular interest is the application of this numerical method to a sluice gate case with a high ratio of channel length to depth, which tends to amplify the effects of the chosen numerical resolution. General model congruence was within 5 % of a margin error even for relatively low vertical resolution, and some side effects of the equations used to describe the boundary conditions were identified. [ABSTRACT FROM AUTHOR]

Dispatches from Ukraine. Day 470. [ABSTRACT FROM AUTHOR]

It has been argued that dam construction and irrigation projects in Turkey and Syria would diminish the flow of the Euphrates River and increase salinity levels. However, previous studies have not systematically defined the baseline changes in the quantity and quality of the river water. In this study, we associate variations in flow quantity and quality of water with natural aspects. We analysed flow data from 1970 to 2010 for the river at the Turkish-Syrian border to assess the effect of upstream dam construction, correlating these data with precipitation variation in Syria in the same period. In addition, we compared flow data between Syria and Iraq in a period with no dam construction in those countries (2000 to 2010). Regarding water quality, we collected samples from the Turkish-Syrian and Syrian-Iraqi borders to identify levels of salinity through laboratorial analysis. We complemented the data analysis with fieldwork along the river basin, and with evidence from the literature. We conclude that the slight diminishing of flow as well as the increasing salinity towards downstream are both associated with natural aspects of the landscape, more than human actions. [ABSTRACT FROM AUTHOR]

Dispatches from Ukraine. Day 240. [ABSTRACT FROM AUTHOR]

Dispatches from Ukraine. Day 239. [ABSTRACT FROM AUTHOR]

Kinematic boundary condition is usually used when dealing with transient free-surface flow problems in isotropic media. When dealing with anisotropic problems, a transformation can transform the anisotropic media to an equivalent isotropic media for seepage analysis, but the kinematic boundary condition cannot be used directly in the transformed media. A generalization of the kinematic boundary condition along any arbitrary direction is derived for use in the transformed domain for general three-dimensional anisotropic problems. A boundary element method for solving transient free-surface seepage problems is developed and the treatment of the proposed kinematic boundary condition in the boundary element method is given. Three examples have been solved to show the reliability and flexibility of the model. Examples are verified with some available experimental and numerical cases to show the accuracy of the model for predicting the phreatic surface and it is shown that anisotropy has a very important and non-neglecting effect in the behavior and the shape of phreatic surface. [ABSTRACT FROM AUTHOR]

Dams created by American beavers (Castor canadensis) are associated with positive and negative values, and beaver management decisions are based on stakeholder perception and levels of tolerance. Lethal trapping is a widely used and accepted tool to reduce beaver damage caused by flooding; however, acceptable and efficacious non-lethal tools are increasingly desired by the public. We traced the origin of non-lethal tools used to reduce beaver flooding as far back as the early 20th century, when beavers received protective status and were reintroduced to many areas across North America. These tools focus on 2 general factors--exclusion and deception--and can be categorized as fence systems and pipe systems. We found few technological advances in tools to reduce beaver flooding until the 1980-1990s, when fence systems and pipe systems were integrated to create "flow devices." There are few studies that evaluate fence systems, pipe systems, and flow devices; however, we address their findings in chronological order. We recommend that natural resource managers avoid using fence systems or pipe systems alone, unless they can be used in areas where maintenance requirements and expected damage are extremely low. Flow devices are not intended to replace lethal control; however, we recommend use of flow devices as part of integrated management plans where beaver flooding conflicts are expected and where local conditions allow flow-device installation and maintenance. Future research should evaluate flow devices under a range of environmental conditions and include considerations for fish passage. [ABSTRACT FROM AUTHOR]

Fishermen often anecdotally report an unexpected increase of fish caught in small tributary streams during floods, presumably due to refuge-seeking behavior from the main stem. From a population perspective; this implies the significance of refuge habitats and connectivity for population viability against natural disturbances. Despite the plausibility, however, surprisingly few studies have examined the tributary refuge hypothesis, mainly due to the difficulty in field survey during floods. Here, we made use of a large-scale controlled flood to assess whether fishes move into tributaries during flooding in the main stem. A planned water release from the Satsunai River Dam located on Hokkaido Island in Japan rapidly increased the main stem discharge by more than 20- fold. Before, during, and after flooding censuses in four tributaries provided evidence of the refuge- seeking behavior of fishes from the main stem. For example, more than 10 Dolly Varden char, a salmonid fish, were caught in a tributary during the flood, even though almost no individuals were captured before or after the flood. The fish responded immediately to the flooding, suggesting the need for studies during disturbances. In addition, the likelihood of refuge movements varied among tributaries, suggesting the importance of local environmental differences between tributary and the main stem habitats. This is the first study to experimentally confirm the tributary refuge hypothesis, and underscores the roles of habitat diversity and connectivity during disturbances, even though some habitats are not used during normal conditions. [ABSTRACT FROM AUTHOR]

Abstract: A three-dimensional boundary element solution for the seepage analysis in multi-domain general anisotropic media has been developed based on the transformation approach. Using analytical eigenvalues and eigenvectors of the hydraulic conductivity tensor, a closed-form coordinate transformation matrix has been provided to transform the quadratic form of governing equation of seepage for the general anisotropic media to the Laplace equation. This transformation allows the analysis to be carried out using any standard BEM codes for the potential theory on the transformed space by adding small pre- and post-processing routines. With this transformation, any physical quantity like the total head remains unchanged at corresponding nodes on the physical and transformed space, and the normal gradient across the domain boundaries should also be transformed. In multi-domain problems, compatibility equations (equality of the potential on corresponding nodes on the interface) and equilibrium equations (conservation of the flux across the interface boundaries of adjacent domains) on the corresponding nodes of interface between two neighbor domains are needed for boundary element method. In the transformed space, the compatibility equation remains unchanged. However, due to the distortion of boundaries in the mapped space and therefore misalignment of the unit outward normal vectors along the inter-domain boundaries, the equilibrium of the normal fluxes have to be transformed accordingly. Based on the proposed transformation, the normal to boundary flux boundary conditions in the mapped space and the transformed equilibrium equation for interface of adjacent zones have been given in this paper. Examples have been solved with the proposed scheme and the results were verified with the finite element method. Excellent agreement of the results shows the veracity of the proposed transformation and the formulas given for transformation of equilibrium equation for multi-domain general anisotropic media. [Copyright &y& Elsevier]

Abstract: Coupling the adjacent zones for seepage analysis in porous media needs compatibility and equilibrium equations (equality of potential on coinciding nodes and conservation of flowing mass between zones, respectively). When stretched coordinate transformation is applied to the anisotropic zones, the Dirichlet boundary conditions remain unchanged, but the Neumann boundary condition should also be transformed. Similarly in a zoned problem, for the interface between zones, compatibility equations remain unchanged during the transformation while the equilibrium equations should be transformed. In this paper, transformed Neumann boundary conditions and equilibrium equations for the interface of neighbor anisotropic zones for seepage problems have been developed in three dimensions. A computer program for seepage analysis of zoned anisotropic media based on the Boundary Element Method is developed. The code is used to solve several examples with isotropic and anisotropic zones. Some examples are also solved by finite element method for verification. Illustrated results show the ability and accuracy of the mathematical and the numerical model for solving different types of applied three-dimensional seepage problems that arise in engineering practice. [Copyright &y& Elsevier]

Abstract: A comparison between weak form meshless local Petrov–Galerkin method (MLPG) and strong form meshless diffuse approximate method (DAM) is performed for the diffusion equation in two dimensions. The shape functions are in both methods obtained by moving least squares (MLS) approximation with the polynomial weight function of the fourth order on the local support domain with 13 closest nodes. The weak form test functions are similar to the MLS weight functions but defined over the square quadrature domain. Implicit timestepping is used. The methods are tested in terms of average and maximum error norms on uniform and non-uniform node arrangements on a square without and with a hole for a Dirichlet jump problem and involvement of Dirichlet and Neumann boundary conditions. The results are compared also to the results of the finite difference and finite element method. It has been found that both meshless methods provide a similar accuracy and the same convergence rate. The advantage of DAM is in simpler numerical implementation and lower computational cost. [Copyright &y& Elsevier]

Abstract: A numerical model coupling boundary and finite elements suitable for dynamic dam–reservoir interaction is presented herein. This model involves standard finite element idealization of the dam structure displacements and a new symmetric boundary element formulation of the unbounded reservoir domain leading to an equivalent symmetric stiffness matrix for the discretized pressure field. These two basic parts of the computation are directly coupled by imposing an equilibrium condition at the fluid–structure interface, then the resulting algebraic system is reduced by localizing the coupled terms in the global mass matrix such as usually achieved in the added-mass formulation. Finally, the performance and the accuracy of this model are examined by comparing its results to those obtained from three other numerical models. [Copyright &y& Elsevier]

The article focuses on Mekong River, a 4,350 kilometer river that start in Tibetan plateau in Qinghai province, China and flows in Asian countries. It discloses that the river serves as a source of water for irrigation as well as power production; however, this cause conflict among countries. It says that the river is a vital source of protein for people living near the river because of the over 1,200 species of fishes identified.

Today's regional news: online funerals in Russia; Uzbek dam bursts; Bulgaria eases lockdown; Croatia eyes tourists; and keeping the memory of the Sarajevo siege alive. [ABSTRACT FROM AUTHOR]

Today's regional roundup: Moscow weekend protests continue; high-placed heads roll in Romania; Chinese and Serbians; Vaira Vike-Freiberga; and the Rogun dam. [ABSTRACT FROM AUTHOR]

Authorities want to exploit Caucasus gorge's hydropower potential but face growing local opposition. [ABSTRACT FROM AUTHOR]

The environmental secretariat of Brazil's southeastern Minas Gerais state, Semad, has suspended a license granted in 2015 for Vale to operate the Laranjeiras tailings dam, connected to the Brucutu iron ore mine. [ABSTRACT FROM AUTHOR]

Asian ferrous scrap prices are climbing due to steel mills looking to secure more steelmaking raw materials. [ABSTRACT FROM AUTHOR]

Rogun dam project was for long a sore point with neighbor Uzbekistan, but international investors felt the potential gains outweighed the risk. [ABSTRACT FROM AUTHOR]

BHP shares hit new 10-year low after hits back at claim that toxic sludge is poisoning large areas of Brazil after a lethal dam burst three weeks ago. [ABSTRACT FROM PUBLISHER]

A toxic mix of water and residue from iron mining operations smothered a village [ABSTRACT FROM PUBLISHER]

The mud is from an open-pit iron ore mine [ABSTRACT FROM PUBLISHER]

Construction of the Ilisu Dam threatens the ancient village of Hasankeyf. [ABSTRACT FROM PUBLISHER]

Latin America's largest country is blazing a sustainable energy path, despite some objections [ABSTRACT FROM AUTHOR]

Spurred on by economic factors, renewable energy has seen considerable growth across the continent both at a large and much smaller scale [ABSTRACT FROM AUTHOR]

With the rise of cheaper and safer alternatives, in addition to the Fukushima Dai'ichi disaster in 2011, is this the end of the line for nuclear power? [ABSTRACT FROM AUTHOR]

The 'unproven' technology may finally prove its worth as projects around the world are getting the green light, writes Robin M Mills [ABSTRACT FROM AUTHOR]

China could take the lead in low-carbon energy as it battles deadly smog to calm rising social unrest [ABSTRACT FROM AUTHOR]

Abundant gas reserves are here to stay. But can the world afford to burn them all? [ABSTRACT FROM AUTHOR]

As pressure to de-carbonise grows, the industry faces a stark choice [ABSTRACT FROM AUTHOR]

The supermajors have fallen on hard times - costs have surged, output has fallen. Investors have grown frustrated by low returns and high oil prices have not proven to be the remedy they had hoped. What comes next? [ABSTRACT FROM AUTHOR]

Rising fuel-economy standards, shifts in consumer behaviour and new technologies should make road transportation much more efficient, even as the total number of vehicles rises [ABSTRACT FROM AUTHOR]

If you're looking to Europe and the US to set the pace for the growth in renewable energy solar generation you're looking in the wrong place. Try the Middle East instead. Chris Nelder explains why [ABSTRACT FROM AUTHOR]

Sun comes into its own as power generation sector looks for viable alternatives to fossil fuels [ABSTRACT FROM AUTHOR]

Innovation is happening more rapidly than expected -- and it will vastly improve energy efficiency in the next few years [ABSTRACT FROM AUTHOR]

Rising costs and improving technology will be the driving forces behind future energy [ABSTRACT FROM AUTHOR]