摘要
基于2014年最新的洪、枯季节实测资料,分析了南渡江河口海域水文泥沙的季节性变化特征,借助台风"海鸥"过境期间的河道监测数据,研究了台风天气造成的洪水事件对河流入海水沙通量的影响。研究结果表明:(1)洪、枯季节河口海域的水体层化作用不强,洪季的水温高于枯季,但盐度低于枯季。水温呈现向海递减的趋势,而盐度整体分布较为均匀;(2)河口水体含沙量近岸大于远岸,枯季河口三角洲泥沙向西输运。洪季含沙量明显高于枯季,大量泥沙在台风季节被冲刷入海,而后向海或向西输运扩散;(3)河口海域为不规则全日潮,呈现东西向往复流特征。温度、盐度和浊度均呈现较强的潮汐性变化特征;(4)枯季河道内存在明显的盐水楔,锋面处的垂向梯度很大,在口门向陆大约12—15 km以远的河道水体不再受潮汐影响;(5)台风"海鸥"影响下,南渡江洪峰期间的径流量和含沙量均远远超过多年平均值,反映了南渡江河口地区"台风季节"的特点。
We studied the seasonal variations in hydrodynamics and sedimentology in Nandu River estuary based on observation data collected in 2014 in flood and dry seasons. We find that water column was less stratified and saltier, but warmer in the flood season than in the dry season. The temperature decreased from shallow to deep water, and the salinity was relatively stable. The spatial patterns of suspended sediment concentration in bottom layer decreased significantly seaward. In the dry season, under flood tidal current and southeast wind, the suspended sediment originated from the abandon shore to the east of the delta was transported westward along coast. Suspended sediment concentration was greater in flood season than in dry season, as a large amount of sediment was taken into the sea, and diffused seaward or westward. The flow pattern in the estuary was characteristic of irregular diurnal tide and east-west reciprocating flow. Temperature, salinity, and turbidity varied clearly and periodically with tidal changes. In the dry season, a clear salt wedge appeared in the middle and lower reaches, resulting in a greater vertical gradient in salinity. Under the influence of typhoon ＂Kalmaegi＂, runoff and sediment concentration were much boosted above the normal average, recording the imprints of ＂the typhoon season＂ in the Nandu River estuary.
出处
《海洋与湖沼》
CAS
CSCD
北大核心
2015年第6期1279-1291,共13页
Oceanologia Et Limnologia Sinica
基金
科技基础性工作专项项目
2013FY112200号
国家自然科学基金重点项目
41330964号
国家自然科学基金项目
41406081号
关键词
南渡江
季节性变化
水文环境
台风
水沙
Nandu River
seasonal variation
hydrology
sedimentation
typhoon
runoff and sediment discharge
