晚更新世晚期以来的长江上游古洪水记录

长江上游三峡河段主要的古洪水记录有:1)三峡深槽的蚀积变化;2)长江阶地粗粒沉积;3)长江的泛滥沉积;4)长江的古洪水平流沉积。不同时间跨度不同类型古洪水记录的精度有较大的差别。古洪水记录显示,晚更新世晚期的40～30kaB.P.,长江上游大洪水比30kaB.P.以来的长江上游大洪水大得多;全新世以来,以3983aB.P.前后的大洪水为相对最大;公元1870年大洪水为3000aB.P.以来最大洪水;近百年来的实测洪水以公元1981年洪水为最大。     

Theoretical and experimental study of breaking wave on sloping bottoms

This paper studies the continuous evolution of breaking wave for the surface water waves propagating on a sloping beach. A Lagrangian asymptotic solution is derived. According to the solution coupled with the wave breaking criteria and the equations of water particles motion, the wave deformation and the continuous wave breaking processes for the progressive water waves propagating on a sloping bottom can be derived. A series of experiments are also conducted to compare with the theoretical solution. The results show that the present solution can reasonably describe the plunging or spilling wave breaking phenomenon.     

Design and implementation of a 3D ocean virtual reality and visualization engine

In this study,a 3D virtual reality and visualization engine for rendering the ocean,named VV-Ocean,is designed for marine applications.The design goals of VV-Ocean aim at high fidelity simulation of ocean environment,visualization of massive and multidimensional marine data,and imitation of marine lives.VV-Ocean is composed of five modules,i.e.memory management module,resources management module,scene management module,rendering process management module and interaction management module.There are three core functions in VV-Ocean:reconstructing vivid virtual ocean scenes,visualizing real data dynamically in real time,imitating and simulating marine lives intuitively.Based on VV-Ocean,we establish a sea-land integration platform which can reproduce drifting and diffusion processes of oil spilling from sea bottom to surface.Environment factors such as ocean current and wind field have been considered in this simulation.On this platform oil spilling process can be abstracted as movements of abundant oil particles.The result shows that oil particles blend with water well and the platform meets the requirement for real-time and interactive rendering.VV-Ocean can be widely used in ocean applications such as demonstrating marine operations,facilitating maritime communications,developing ocean games,reducing marine hazards,forecasting the weather over oceans,serving marine tourism,and so on.Finally,further technological improvements of VV-Ocean are discussed.     

Evolution of the Moxizhuang Oil Field, Central Junggar Basin, Northwest China

Current oil saturation in the Moxizhuang (莫西庄) Oil Field in central Janggar (准噶尔) basin was evaluated by logging interpretation and measured on core samples, and the paleo-oil saturation in both the pay zones and water zones was investigated by graln-containing-oil inclusion (GOI) analysis.The pay zones in this field have low oil saturation and display low resistivity and small contrast between pay zones and water zones, and are classified as low-porosity, low oil saturation, and low resistivity reservoirs. Both the current low oil-saturation pay zones and the water zones above 4 365 m have high GOI values (up to 38%), suggesting high paleo-oil saturation. The significant difference between current oil saturation from both logging interpretation and core sample measurement and paleo-oil saturation indicated by GOI analysis suggests that this low oil-saturation field evolved from a high oil-saturation pool. Lateral re-migration and spill of formally trapped oil owing to changes in structural configuration since Neogene was the most plausible mechanism for oil loss in the Moxizhuang Oil Field.The combined effects of differential accumulation in the charge phase and the differential re-migration and spill of accumulated oil in Neogene are responsible for the complicated correlation between residual oil saturation and porosity/permeability of the reservoir sandstones and the distribution of low oil-saturation pay zones and paleo-oil zones (current water zones).     

Theoretical and Experimental Study of Breaking Wave on Sloping Bottoms

This paper studies the continuous evolution of breaking wave for the surface water waves propagating on a sloping beach. A Lagrangian asymptotic solution is derived. According to the solution coupled with the wave breaking criteria and the equations of water particles motion, the wave deformation and the continuous wave breaking processes for the progressive water waves propagating on a sloping bottom can be derived. A series of experiments are also conducted to compare with the theoretical solution. The results show that the present solution can reasonably describe the plunging or spilling wave breaking phenomenon.     

长江河口北支倒灌盐水输送机制分析

基于三维数值模式ECOM-si,采用通量机制分析的方法,对长江河口北支倒灌盐水的输送机制进行了定量研究.模式计算了南北支分叉口和南支河段的潮平均单宽盐通量、各叉道上10个断面的潮平均盐通量和上述两者的机制分解项.基于计算结果讨论了北支倒灌盐水输送的动力机制,发现Lagrange余流输送和潮泵输送在倒灌盐水的输送中起主导作用.讨论了南支各叉道输送倒灌盐水的数量关系,给出了北支盐水倒灌输送的主要路径.     

晚更新世晚期以来的长江上游古洪水记录

长江上游三峡河段主要的古洪水记录有:1)三峡深槽的蚀积变化;2)长江阶地粗粒沉积;3)长江的泛滥沉积;4)长江的古洪水平流沉积。不同时间跨度不同类型古洪水记录的精度有较大的差别。古洪水记录显示,晚更新世晚期的40～30kaB.P.,长江上游大洪水比30kaB.P.以来的长江上游大洪水大得多;全新世以来,以3983aB.P.前后的大洪水为相对最大;公元1870年大洪水为3000aB.P.以来最大洪水;近百年来的实测洪水以公元1981年洪水为最大。     

Experimental Study on the Bed Shear Stress Under Breaking Waves

The object of present study is to investigate the bed shear stress on a slope under regular breaking waves by a novel instrument named Micro-Electro-Mechanical System (MEMS) flexible hot-film shear stress sensor. The sensors were calibrated before application, and then a wave flume experiment was conducted to study the bed shear stress for the case of regular waves spilling and plunging on a 1:15 smooth PVC slope. The experiment shows that the sensor is feasible for the measurement of the bed shear stress under breaking waves. For regular incident waves, the bed shear stress is mainly periodic in both outside and inside the breaking point. The fluctuations of the bed shear stress increase significantly after waves breaking due to the turbulence and vortexes generated by breaking waves. For plunging breaker, the extreme value of the mean maximum bed shear stress appears after the plunging point, and the more violent the wave breaks, the more dramatic increase of the maximum bed shear stress will occur. For spilling breaker, the increase of the maximum bed shear stress along the slope is gradual compared with the plunging breaker. At last, an empirical equation about the relationship between the maximum bed shear stress and the surf similarity parameter is given, which can be used to estimate the maximum bed shear stress under breaking waves in practice.     

河口水环境遥感监测研究进展——以赤潮和溢油为例

从河口地区对赤潮和溢油的监测需求出发,阐述了利用遥感技术监测赤潮和溢油等问题的有效性和优越性。回顾了河口地区赤潮和溢油遥感监测的发展历程、探测机理和影响因素,并探讨了历史上不同卫星传感器对赤潮和溢油监测的优势和不足。通过对最新研究成果的总结,讨论了水环境遥感监测存在的问题,并对未来水环境遥感平台发展趋势和新的研究方向进行了展望。     

渤海海域溢油应急预测预警系统研究Ⅱ. 系统可视化及业务化应用

本系统基于.NET平台,采用C#作为开发语言,对ArcEngine 9.3进行二次开发,融.NET平台的可移植性与ArcEngine 9.3的可视化和空间显示分析功能于一体,实现了溢油行为与归宿预测模块与GIS平台的统一。把溢油漂移的计算结果与地理信息系统等平台相结合,建立了渤海海域应急预测预警系统。也集成了环境敏感资源信息数据库、应急设备、队伍信息数据库和溢油漂移模型,为溢油应急提供溢油敏感资源及应急资源的日常管理,实现溢油漂移预测结果与敏感资源图的叠加耦合,达到对环境敏感资源的快速预警,形成了溢油敏感资源及应急资源管理系统。作为该系统研制中的第二部分,主要介绍了系统的可视化、系统的预报流程、系统案例验证以及业务化应用的研究工作。