作者机构：
[Jiang, Changbo; Wu, Zhiyuan; Deng, Bin; Chen, Lie] Changsha Univ Sci & Technol, Sch Hydraul Engn, Changsha 410114, Hunan, Peoples R China.;[Jiang, Changbo; Wu, Zhiyuan; Deng, Bin; Chen, Lie] Key Lab Water Sediment Sci & Water Disaster Preve, Changsha 410114, Hunan, Peoples R China.;[Wu, Zhiyuan] Univ Massachusetts Dartmouth, Sch Marine Sci & Technol, New Bedford, MA 02744 USA.;[Liu, Xiaojian; Wu, Zhiyuan] Minist Water Resources, Key Lab Pearl River Estuarine Dynam & Associated, Guangzhou 510611, Guangdong, Peoples R China.
通讯机构：
[Jiang, Changbo] C;[Jiang, Changbo] K;Changsha Univ Sci & Technol, Sch Hydraul Engn, Changsha 410114, Hunan, Peoples R China.;Key Lab Water Sediment Sci & Water Disaster Preve, Changsha 410114, Hunan, Peoples R China.
关键词：
sensitivity analysis;typhoon track and intensity;horizontal and vertical resolutions;Typhoon Kai-tak;WRF
摘要：
To determine the grid resolutions of the WRF model in the typhoon simulation, some sensitivity analysis of horizontal and vertical resolutions in different conditions has been carried out. Different horizontal resolutions (5, 10, 20, 30 km), nesting grids (15 and 5 km), different vertical resolutions (35-layers, 28-layers, 20-layers) and different top maximum pressures (1 000, 2 000, 3 500, 5 000 Pa) had been used in the mesoscale numerical model WRF to simulate the Typhoon Kai-tak. The simulation results of typhoon track, wind speed and sea level pressure at different horizontal and vertical resolutions have been compared and analyzed. The horizontal and vertical resolutions of the model have limited effect on the simulation effect of the typhoon track. Different horizontal and vertical resolutions have obvious effects on typhoon strength (defined by wind speed) and intensity (defined by sea level pressure, SLP), especially for sea level pressure. The typhoon intensity simulated by the high-resolution model is closer to the real situation and the nesting grids can improve computational accuracy and efficiency. The simulation results affected by vertical resolution using 35-layers is better than the simulation results using 20-layers and 28-layers simulations. Through comparison and analysis, the horizontal and vertical resolutions of WRF model are finally determined as follows: the two-way nesting grid of 15 and 5 km is comprehensively determined, and the vertical layers is 35-layers, the top maximum pressure is 2 000 Pa.
作者机构：
[冯璐; 郑睿] School of Hydraulic Engineering, Changsha University of Science & Technology, Changsha, 410114, China;Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province, Changsha, 410114, China;Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha, 410114, China;[蒋昌波; 邓斌; 陈杰] School of Hydraulic Engineering, Changsha University of Science & Technology, Changsha, 410114, China, Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province, Changsha, 410114, China, Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha, 410114, China
期刊：
Journal of Offshore Mechanics and Arctic Engineering,2019年141(6):061801 ISSN：0892-7219
通讯作者：
Liu, Xiaojian
作者机构：
[Liu, Xiaojian; Liu, Cheng; He, Yong] Minist Water Resources, Pearl River Water Resources Commiss, Pearl River Hydraul Res Inst, Guangzhou 510611, Guangdong, Peoples R China.;[Jiang, Changbo; Liu, Xiaojian; Deng, Bin; Wu, Zhiyuan] Changsha Univ Sci & Technol, Sch Hydraul Engn, Changsha 410114, Hunan, Peoples R China.;[Liu, Xiaojian] Sun Yet Sen Univ, Sch Civil Engn, Guangzhou 510611, Guangdong, Peoples R China.;[Duan, Zihao] Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Key Lab Ecosyst Network Observat & Modeling, Beijing 100101, Peoples R China.
通讯机构：
[Liu, Xiaojian] M;[Liu, Xiaojian] C;[Liu, Xiaojian] S;Minist Water Resources, Pearl River Water Resources Commiss, Pearl River Hydraul Res Inst, Guangzhou 510611, Guangdong, Peoples R China.;Changsha Univ Sci & Technol, Sch Hydraul Engn, Changsha 410114, Hunan, Peoples R China.
关键词：
solitary wave;Navier-Stokes equations;sandy beach;sediment transport
摘要：
To improve our current understanding of tsunami-like solitary waves interacting with sandy beach, a nonlinear three-dimensional numerical model based on the computational fluid dynamics (CFD) tool OpenFOAM (R) is first self-developed to better describe the wave propagation, sediment transport, and the morphological responses of seabed during wave runup and drawdown. The finite volume method (FVM) is employed to discretize the governing equations of Navier-Stokes equations, combining with an improved volume of fluid (VOF) method to track the free surface and a k-epsilon model to resolve the turbulence. The computational capability of the hydrodynamics and the sediment transport module is well calibrated by laboratory data from different published references. The results verify that the present numerical model can satisfactorily reproduce the flow characteristics, and sediment transport processes under a tsunami-like solitary wave. The water-sediment transport module is then applied to investigate the effects of prominent factors, such as wave height, water depth, and beach slope, in affecting the beach profile change. Finally, a dimensionless empirical equation is proposed to describe the transport volume of onshore sediment based on simulation results, and some proper parameters are recommended through the regression. The results can be significantly helpful to evaluate the process of transported sediment by a tsunami event.
摘要：
Reservoir inflow forecasts are important for guiding reservoir operation. This study proposes an integrated framework of incorporating different forms of seasonal inflow forecasts in identifying the optimal releases policy. Gridded precipitation forecasts from climate models have been widely used for forecasting inflow. Both precipitation forecasts and soil moisture estimates are used as predictors to provide one-season-ahead reservoir inflow forecasts by constructing a regression problem. Principal component analysis is used to reduce the dimension of the regression problem, and a Bayesian regression technique is employed to generate various forms of inflow forecasts such as deterministic, probabilistic and ensemble forecasts. Two optimization models are constructed to couple with different forms of inflow forecasts. The first model aims to maximize hydropower generation and the second one aims to minimize end-of-season reservoir storage deviation from the target storage. Both single-value inflow and ensemble forecasts are incorporated to find the optimal water releasing policy considering inflow uncertainty and end-of-season reservoir storage requirement. The proposed methodology is demonstrated for Huangcai Reservoir in southern China. Bayesian regression technique shows good performance of seasonal inflow forecasts with a Pearson correlation of 0.8 and rank probability score of 0.4, which outperforms climatology. The coupling of ensemble inflow forecasts and optimization models provides water managers a set of release policies considering inflow uncertainty.
关键词：
Microplastics;Sediment;Surface water;The Tibet plateau
摘要：
The Tibet Plateau, the so-called Third Pole of the world, is home to the headstreams of many great rivers. The levels of microplastic pollution in those rivers, however, are unknown. In this study, surface water and sediment samples were collected from six sampling sites along five different rivers. The surface water and sediment samples were collected with a large flow sampler and a stainless steel shovel, respectively. The abundance of microplastics ranged from 483 to 967 items/m(3) in the surface water and from 50 to 195 items/kg in the sediment. A large amount of small, fibrous, transparent microplastics were found in this study. Five types of microplastics with different chemical compositions were identified using micro-Raman spectroscopy: polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyamide (PA). These results demonstrate that rivers in the Tibet Plateau have been contaminated by microplastics, not only in developed areas with intense human activity but also in remote areas, where microplastic pollution requires further attention. (C) 2019 Elsevier Ltd. All rights reserved.
作者机构：
[何飞; 彭浩] School of Hydraulic Engineering, Changsha University of Science & Technology, Changsha, 410114, China;Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha, 410114, China;Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province, Changsha, 410114, China;Engineering and Technical Center of Hunan Provincial Environmental Protection for River-Lake Dredging Pollution Control, Changsha, 410114, China;[蒋昌波; 陈杰] School of Hydraulic Engineering, Changsha University of Science & Technology, Changsha, 410114, China, Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha, 410114, China, Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province, Changsha, 410114, China
通讯机构：
[Chen, J.] S;School of Hydraulic Engineering, Changsha University of Science & Technology, Changsha, China
