Strengthening regional governance to protect the marine environment in Northeast Asia: From a fragmented to an integrated approach

Northeast Asia is failing in its attempts to protect its regional seas from irreversible ecological damage and contamination. At the policy level, the regional architecture for marine protection has several glaring structural problems that need to be identified and resolved in an expeditious and politically sensitive manner. Although the UNDP/GEF Yellow Sea Large Marine Ecosystem Project (YS LME) and the Northwest Pacific Action Plan (NOWPAP) are the two most likely institutions from which to build the next phase of regional marine cooperation, synergies between the two institutions remain limited. Both institutions are endowed with unique opportunities, challenges and limitations that must be taken into full consideration when planning the next step of coordinated action for regional marine protection. For the purpose of developing a more effective phase of marine cooperation in Northeast Asia, this paper advocates the formation of a Marine Environmental Community based on an integrated approach towards Northeast Asia's regional marine programs. This will facilitate improvements in funding, policy coordination through high level policy dialogue, transparency and efficiency of information sharing systems and full participation of all the coastal states in the region.     

Alteration of hydrologic indicators for Korean catchments under CMIP5 climate projections

The change of hydrological regimes may cause impacts on human and natural system. Therefore, investigation of hydrologic alteration induced by climate change is essential for preparing timely proper adaptation to the changes. This study employed 24 climate projections from the Coupled Model Intercomparison Project Phase 5 (CMIP5) under Representative Concentration Pathway (RCP) 4.5 scenario. The climate projections were downscaled at a station‐spacing for seven Korean catchments by a statistical downscaling method that preserves a long‐term trend in climate projections. Using an ensemble of future hydrologic projections simulated by three conceptual rainfall‐runoff models (GR4J, IHACRES, and Sacramento models), we calculated Hydrologic Alteration Factors (HAFs) to investigate degrees of variations in Indicators of Hydrologic Alteration (IHAs) derived from the hydrologic projections. The results showed that the seven catchments had similar trend in terms of the HAFs for the 24 IHAs. Given that more frequent severe floods and droughts were projected over Korean catchments, sound water supply strategies are definitely required to adapt to the alteration of streamflow. A wide range of HAFs between rainfall‐runoff models for each catchment was detected by large variations in the magnitude of HAFs with the hydrologic models and the difference could be the hydrologic prediction uncertainty. There were no‐consistent tendency in the order of HAFs between the hydrologic models. In addition, we found that the alterations of hydrologic regimes by climate change are smaller as the size of catchment is larger. Copyright © 2016 John Wiley & Sons, Ltd.     

A note on ship-motion prediction based on wave-excitation inputestimation

In order to predict the motion of a ship effectively, a new algorithm is developed in which the wave-excitation input information is extracted from the estimated ship-motion data, and a prediction is made by extrapolating the governing equation of the ship motion. Simulations performed with the algorithm and the conventional ship-motion prediction algorithm based on the standard Kalman filter are compared     

Geological and Geotechnical Characteristics of Marine Clays at the Busan New Port

Despite a number of geotechnical investigations that have been carried out in the Busan new port area of South Korea, the local practicing engineers have been unable to deduce successfully the geotechnical properties of the clays due to their spatial variation. In the area, clay deposits, so-called Pusan clays, are unusually thick, varying from 20 m to 70 m in thickness. For this study, comprehensive geological and geotechnical investigations were carried out with sophisticated sampling techniques, in situ and laboratory tests as well as geological analyses at an additional three locations. As a result of the investigations, it was found that depositional environments are closely related to the relative changes in sea level and have different features depending on location and depth. The clays consist of soft and stiff clays in the upper and the lower layers, respectively, which are classified as normally consolidated and cemented clay. Moreover, most of the geotechnical properties undergo small changes due to their depositional environment. Information about these effects would be quite helpful to understand the spatial variation of geotechnical properties as well as the effect of sample disturbance. Some correlations which reflect the geological history of the deposts were conducted for physical indexes and mechanical properties.     

Iranian ultrapotassic volcanism at ~11 Ma signifies the initiation of post‐collisional magmatism in the Arabia–Eurasia collision zone

Ultrapotassic rocks are a common, but volumetrically minor, hallmark of post‐collisional magmatism along the Alpine–Himalayan orogenic belt. Here, we document the occurrence of ultrapotassic volcanic rocks from the Eslamy peninsula, NW Iran in the Arabia–Eurasia collision zone. Our results indicate that magma genesis involved melting of phlogopite‐ and apatite‐bearing peridotites in the sub‐continental lithospheric mantle at ~11 Ma. These peridotites likely formed by metasomatism involving components derived from subducted sediments during Neotethyan subduction. The ~11 Ma ultrapotassic volcanism was preceded by a magmatic gap of ~11 Ma after the cessation of arc magmatism in NW Iran and Armenia, thus likely representing the initiation of post‐collisional magmatism. The age coincides with the onset of collision‐related magmatic activity and topographic uplift in the Caucasus–Iran–Anatolia region, and also with other regional geological events including the closure of the eastern Tethys gateway, the end of Arabian underthrusting and the start of escape tectonics in Anatolia.     

A continuum‐discrete model using Darcy's law: formulation and verification

This paper presents a numerical scheme for fluid‐particle coupled discrete element method (DEM), which is based on poro‐elasticity. The motion of the particles is resolved by means of DEM. While within the proposition of Darcian regime, the fluid is assumed as a continuum phase on a Eulerian mesh, and the continuity equation on the fluid mesh for a compressible fluid is solved using the FEM. Analytical solutions of traditional soil mechanics examples, such as the isotropic compression and one‐dimensional upward seepage flow, were used to validate the proposed algorithm quantitatively. The numerical results showed very good agreement with the analytical solutions, which show the correctness of this algorithm. Sensitivity studies on the effect of some influential factors of the coupling scheme such as pore fluid bulk modulus, volumetric strain calculation, and fluid mesh size were performed to display the accuracy, efficiency, and robustness of the numerical algorithm. It is revealed that the pore fluid bulk modulus is a critical parameter that can affect the accuracy of the results. Because of the iterative coupling scheme of these algorithms, high value of fluid bulk modulus can result in instability and consequently reduction in the maximum possible time‐step. Furthermore, the increase of the fluid mesh size reduces the accuracy of the calculated pore pressure. This study enhances our current understanding of the capacity of fluid‐particle coupled DEM to simulate the mechanical behavior of saturated granular materials. Copyright © 2014 John Wiley & Sons, Ltd.