珠江口东平海域海采工程后泥沙蚀淤趋势预测研究  

Sedimentary Process Simulation after Dongping Mining Engineering at Pearl River Mouth

作　　者：陈正新[1,2] 陈小英[1,2] 魏合龙[1,2] 黄晓彬[3] 吴建政[4] 朱龙海[4] 

机构地区：[1]国土资源部海洋油气资源和环境地质重点实验室,山东青岛266071 [2]青岛海洋地质研究所,山东青岛266071 [3]加拿大阿尔伯达大学计算机系 [4]中国海洋大学,山东青岛266071

出　　处：《沉积学报》2011年第6期1164-1169,共6页Acta Sedimentologica Sinica

基　　金：国家自然科学基金青年基金(批准号:40906033)资助

摘　　要：通过收集和实测到的研究区水位、潮位、潮流验证、沉积物类型和粒度参数、水深地形、风、径流值等边界条件,运用泥沙运动控制方程、泥沙再悬浮及再沉积方程,进行了工区泥沙运移相关参数的计算和模拟分析,并预测了工程实施后,工区内、外动力作用的程度和泥沙的蚀淤趋势发展。结果表明:开采区海采项目结束后,其淤积速度自NE 2～5 cm/a向SW 0.2～0.5 cm/a减小,NE部离珠江口较近,其淤积速度可达5～10 cm/a,SE和SW波浪作用影响较小,沉积物搬运主要受潮流控制,淤积速率为0.2～0.5 cm/a;施工期间的一个潮周期内,悬浮泥沙最大增量为42.5mg/L,近岸开挖点10 mg/L浓度悬浮泥沙在E—W向的最大可能扩散距离约为3.0 km,S—N向的最大可能扩散距离约2.2 km;远岸开挖点10 mg/L浓度悬浮泥沙在E—W向的最大可能扩散距离约为1.7 km,S—N向的最大可能扩散距离约1.6 km;珠江口门处最大侵蚀速率为10 cm/a,最大淤积速率为13 cm/a,海砂开采后对海底的蚀淤变化影响范围仅局限于其附近海域,对近岸和珠江口门区没有明显影响;一个水深30～60 m,开挖深度为10 m的采坑以淤积速率0.2～5 cm/a速度计,要使开采区淤平至少要200a或更长时间。This paper presents a data-based study of water level,tide level,tidal currents,sediment type and sediment grain size,winds,runoff,subaqueous bedforms and so on including the application of ECOMSED model to analyze related sediment transporting parameters and forecast hydrodynamic condition and sedimentary processes in the study area.The results showed that sedimentary processes decreased from a rate of 2~5cm/a in northeast to 0.2~0.5cm/a in southwest.In particular,the sedimentation rate got to 5~10cm each year at the northeast of the study area because it is closed to the Pearl River Mouth and easy to get sediment supply from the river mouth.However,the depositional depth was only 0.2~0.5 cm each year at southeast and southwest of the area because tidal currents played a great role in sediment transport in this area.Suspended sediment concentration increased 42.5 mg/L at most in one tidal period.Along coasts,suspended sediment of 10mg/L could be transported to 3.0 km away at E-W and 2.2 km away at S-N.Around offshore area,suspended sediment of 10 mg/L could be taken to 1.7 km away at E-W and 1.6 km away at S-N.The largest erosional rate was 10 cm/a and the largest depositional rate was 13 cm/a at the Pearl River Mouth.Furthermore,the exploitation of sea sand has affected the deposition and erosion near the sea area of engineering and had no obvious influence in the Pearl River mouth and coastal area.According to calculation,if a 10m deep pit was excavated at the water area with the depth of 30~60 m,the exploitation area would need 200 years or longer to restore original topography at a sedimentation rate of 0.2~5 cm/a.

关 键 词：珠江口 海采工程 模拟预测 泥沙淤蚀 

分 类 号：P512.2[天文地球—地质学]