Topography around the Yellow River mouth has changed greatly in recent years, but studies on the current state of ma- rine dynamics off the Yellow River mouth are relatively scarce. This paper uses a two-dimension num...Topography around the Yellow River mouth has changed greatly in recent years, but studies on the current state of ma- rine dynamics off the Yellow River mouth are relatively scarce. This paper uses a two-dimension numerical model （MIKE 21） to reveal the tidal and wave dynamics in 2012, and conducts comparative analysis of the changes from 1996 to 2012. The results show that M2 amphidromic point moved southeastward by 11 kin. It further reveals that the tides around the Yellow River mouth are relatively stable due to the small variations in the tidal constituents. Over the study period, there is no noticeable change in the distribution of tidal types and tidal range, and the mean tidal range off the river mouth during the period studied is 0.5-1.1 m. However, the tidal currents changed greatly due to large change in topography. It is observed that the area with strong tidal currents shifted from the old river mouth （1976-1996） to the modem river mouth （1996-present）. While the tidal current speeds decreased continually off the old river mouth, they increased off the modem river mouth. The Maximum Tidal Current Speed （MTCS） reached 1.4 m s-1, and the maximum current speed of 50-year return period reached 2.8 m s-1. Waves also changed greatly due to change in topography. The significant wave height （H1/3） of 50-year return period changed proportionately with the water depth, and the ratio of Hi/3 to depth being 0.4-0.6. H1/3 of the 50-year return period in erosion zone increased continually with increasing water depth, and the rate of change varied between 0.06 and 0.07myr-1. Based on the results of this study, we infer that in the future, the modem river mouth will protrude gradually northward, while the erosion zone, comprising the old river mouth and area between the modern river mouth and the old river mouth （Intermediate region） will continue to erode. As the modem river mouth protrudes towards the sea, there will be a gradual increase in the current speed and decrease in wave height. Conversely, the old river mouth will retreat, with gradual decrease in current speed and increase in wave height. As more coastal constructions spring up around the Yellow River mouth in the future, we recommend that variation in hydrodynamics over time should be taken into consideration when designing such coastal constructions.展开更多
利用欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts,ECMWF)提供的ERA5再分析资料,分析了西非几内亚湾及邻近海域1979—2020年间的能流密度空间分布、季节特征和多年变化趋势。结果表明:①该地区的波浪能呈...利用欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts,ECMWF)提供的ERA5再分析资料,分析了西非几内亚湾及邻近海域1979—2020年间的能流密度空间分布、季节特征和多年变化趋势。结果表明:①该地区的波浪能呈现出西南高、东北低的由海向陆衰减态势。波浪能季节分布差异明显:夏季的波浪能主要呈现出南北向分布差异,能流密度值较大,而冬季的波浪能主要呈现出东西向分布差异,能流密度值较小,春秋季作为过渡季节,量值和分布介于两者之间。②研究海域多数地区的波浪能均呈现出显著的增长态势,增速大值中心位于海域东南角,每年约增加0.06 kW·m^(-1),增长速度由东南向西北逐渐衰减。③从区域平均角度而言,研究海域的整体波浪能以每年增长0.025 kW·m^(-1)的速度逐年增加,而引起该地波浪能增加的主要原因为夏季波浪能的增长。各季节下的波浪能变化趋势表现不一:秋冬两季波浪能占比小,年际变化不明显,春夏季的波浪能占比大,年际变化趋势显著,春季的波浪能大致以每年0.05%的占比向夏季转移。展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 41030856 and 41006024)the Foundation of Shandong Province (Grant No. BS2012HZ022)+1 种基金the Project of China Geological Survey (Grant No. GZH201100203)the Project of Taishan Scholar
文摘Topography around the Yellow River mouth has changed greatly in recent years, but studies on the current state of ma- rine dynamics off the Yellow River mouth are relatively scarce. This paper uses a two-dimension numerical model （MIKE 21） to reveal the tidal and wave dynamics in 2012, and conducts comparative analysis of the changes from 1996 to 2012. The results show that M2 amphidromic point moved southeastward by 11 kin. It further reveals that the tides around the Yellow River mouth are relatively stable due to the small variations in the tidal constituents. Over the study period, there is no noticeable change in the distribution of tidal types and tidal range, and the mean tidal range off the river mouth during the period studied is 0.5-1.1 m. However, the tidal currents changed greatly due to large change in topography. It is observed that the area with strong tidal currents shifted from the old river mouth （1976-1996） to the modem river mouth （1996-present）. While the tidal current speeds decreased continually off the old river mouth, they increased off the modem river mouth. The Maximum Tidal Current Speed （MTCS） reached 1.4 m s-1, and the maximum current speed of 50-year return period reached 2.8 m s-1. Waves also changed greatly due to change in topography. The significant wave height （H1/3） of 50-year return period changed proportionately with the water depth, and the ratio of Hi/3 to depth being 0.4-0.6. H1/3 of the 50-year return period in erosion zone increased continually with increasing water depth, and the rate of change varied between 0.06 and 0.07myr-1. Based on the results of this study, we infer that in the future, the modem river mouth will protrude gradually northward, while the erosion zone, comprising the old river mouth and area between the modern river mouth and the old river mouth （Intermediate region） will continue to erode. As the modem river mouth protrudes towards the sea, there will be a gradual increase in the current speed and decrease in wave height. Conversely, the old river mouth will retreat, with gradual decrease in current speed and increase in wave height. As more coastal constructions spring up around the Yellow River mouth in the future, we recommend that variation in hydrodynamics over time should be taken into consideration when designing such coastal constructions.
文摘利用欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts,ECMWF)提供的ERA5再分析资料,分析了西非几内亚湾及邻近海域1979—2020年间的能流密度空间分布、季节特征和多年变化趋势。结果表明:①该地区的波浪能呈现出西南高、东北低的由海向陆衰减态势。波浪能季节分布差异明显:夏季的波浪能主要呈现出南北向分布差异,能流密度值较大,而冬季的波浪能主要呈现出东西向分布差异,能流密度值较小,春秋季作为过渡季节,量值和分布介于两者之间。②研究海域多数地区的波浪能均呈现出显著的增长态势,增速大值中心位于海域东南角,每年约增加0.06 kW·m^(-1),增长速度由东南向西北逐渐衰减。③从区域平均角度而言,研究海域的整体波浪能以每年增长0.025 kW·m^(-1)的速度逐年增加,而引起该地波浪能增加的主要原因为夏季波浪能的增长。各季节下的波浪能变化趋势表现不一:秋冬两季波浪能占比小,年际变化不明显,春夏季的波浪能占比大,年际变化趋势显著,春季的波浪能大致以每年0.05%的占比向夏季转移。
