EVOLUTION OF THE YELLOW RIVER ESTUARY AND ITS SEDIMENTATION PROBLEMS

 Wenxue LI

Reconnaissance, Planning, Design & Research Institute, Zhengzhou 450003

 Kairong WANG

Yellow River Institute of Hydraulic Research, No. 109 Jinshui Rd. Zhengzhou, 450003

Tel. (0371) 6025627 Fax. (0371) 5959236 Email: wxli@yrihr.com

Abstract:  This paper outlines the general situation of the Yellow River Estuary and summarizes the evolutional characteristics and laws of this estuary. Based on field data, characteristics of flow and sediment load and the evolutional status of the Qingshuigou path are analyzed. Measures for treating sediment in the estuary are evaluated and discussed.  This paper points out that the threats of flood and storm surge are still severe, the contradiction between demand and supply of water resources is becoming increasingly acute, and the ecological environment is worsening in the estuary. These are the three major problems existed in the process of harnessing and development of the Yellow River Estuary and must be paid ample attention to.

 Key words: Evolution, sediment, harnessing, The Yellow River Estuary.

MATHEMATICAL MODELING OF MORPHOLOGICAL CHANGE AT A RIVER MOUTH

Hitoshi TANAKA

Department of Civil Engineering, Tohoku University, 06 Aoba, Sendai 980-8579, Japan

E-mail: tanaka@tsunami2.civil.tohoku.ac.jp

Abstract:  A mathematical model for calculating river mouth width is introduced, by considering sediment intrusion by waves, as well as sediment flushing by river and tidal discharge. Behavior of an analytical solution is discussed for various combinations of opposing forces acting at a river mouth. Furthermore, the model is extended for predicting migration process of a river mouth. Both of the models are applied to the Nanakita River mouth, Japan.

Key words: River mouth, Sand spit, Migration, Mathematical model

Morphological developments and coastal zone management in the Netherlands.

 J.G. de RONDE, J.P.M. MULDER & R. SPANHOFF

National Institute for Coastal and Marine Management/RIKZ, Rijkswaterstaat

P.O.Box 20907, 2500 EX The Hague, The Netherlands

Corresponding author j.g.dronde@rikz.rws.minvenw.nl

SEDIMENTATION PROBLEMS RELATED TO REGULATION OF DEEP CHANNEL IN THE YANGTZE ESTUARY

Xiping DOU

Nanjing Hydraulic Research Institute, Nanjing 210029, China

E-mail: xpdou@njhri.edu.cn

Abstract: The deepwater navigation channel is a great project in China. The project is divided into three stages. The target water depths are -8.5m, -10m and -12.5m respectively. The total investment is 15,500,000,000 RMB yuan and the duration of construction is 9 years. The one-stage project started to be built in January 1998 and was completed in March 2000. The two-stage project started to be built in October 2003. In this paper, the dynamic conditions and sedimentation of the Yangtze Estuary are introduced. According to the similarity conditions of tidal currents and bed loads, a movable bed physical model of the Yangtze Estuary is designed to study the layout of regulating project of the deep channel and simulate bed load movement. In order to predict the siltation in the channel after regulation, a 2D numerical model is presented, in which total sediment transport, the actions of tidal currents and wind waves, the effect of salinity are considered. The annual siltation and short-term siltation in one-stage channel are calculated and compared with the dredging volumes in prototype.

Key words: Yangtze Estuary, Physical model, Numerical model, Sediment, Channel

On the Verification and Validation of Coastal Process Simulation Models

 Sam S.Y. Wang

F.A.P. Barnard Distinguished Professor and Director
National Center for Computational Hydroscience and Engineering
The University of Mississippi
Carrier Hall, Room 102
P.O. Box 1848
University, MS 38677-1848
TEL: (662) 915-7788/5083
FAX: (662) 915-7796
email: wang@ncche.olemiss.edu

Wuseng LUNG

University of Virginia, Charlottesville, VA 22904-4742, U.S.A

434-924-3722, WL@virginia.edu

Abstract: This paper presents an overview of estuarine eutrophication modeling for water quality management. The current modeling approach is first presented, followed by a discussion of key model components in estuarine models. Field data are shown to play a key role in supporting model development and calibration. The issue of linking different model components is also discussed. Finally, select case studies of modeling estuaries and tidal rivers are presented to demonstrate recent applications.

Key words: Eutrophication modeling; Estuaries; Dissolved oxygen

New Development in Numerical Simulation of the tidal bore

 Cunhong PAN

Zhejiang Institute of Hydraulics and Estuary, Hangzhou, 310020,China

E-mail: panch@mail.hz.zj.cn

 Bingyao LIN & Xianzhong MAO

Zhejiang Institute of Hydraulics and Estuary, Hangzhou, 310020,China

Abstract: Using Godunov-type scheme with water level-bottom topography formulation, the 2-D shallow-water equations with bottom topography can be solved. The Riemann solution of dry bed problem is applied to solve moving boundary. Based on verification of the typical shallow transcritical flows(Pan et al., 2003), the mathematical model is applied to simulate the formation, evolution and dissipation of the tidal bore on the Qiantang River. A good agreement is made between the computed and field measurements, and it also numerically replicates the phenomena of the intersecting, reflection of the tidal bores, line-type tidal bore, which leads to more understanding about the tidal bores on the Qiantang River.

 Key words:  The Qiantang River, Godunov scheme, Tidal bore, Numerical simulation, Moving boundary

ADVANCES IN MORPHODYNAMICS OF TIDAL RIVERS AND ESTUARIES

H.J. de Vriend

WL | Delft Hydraulics, P.O. Box 177, 2600 MH Delft, The Netherlands Delft, and

Delft University of Technology, Faculty of Civil Engineering and Geosciences,

P.O. Box 5048, 2600 GA Delft, the Netherlands

e-mail: huib.devriend@wldelft.nl

Abstract: Using examples from research project and studies on the morphological evolution of sandy estuaries and coastal lagoons in The Netherlands, the added value of simultaneously applying different methods of analysis or prediction is demonstrated. Where the methods overlap, they mutually validate each other, where they are complementary, they provide more complete information that may reduce uncertainty.

VARIATION OF TIDES AND RIVER REGIME AFTER RIVER TRAINING IN THE QIANTANG ESTUARY

 Zengcui HAN & Youcheng XU

Zhejiang Institute of Hydraulics and Estuary, Hangzhou 310020, China

 Binyan LIN & Weili XUAN

The Qiantang River Administration of Zhejiang Province, Hangzhou 310015, China

Abstract: The Qiantang estuary is situated in Zhejiang province along the coast of East China sea. Its large tidal range, spectacular tidal bore and frequently drastic change of river bed are not only matchless in China  but also rarely found around the world. In the last half century, large-scale river contraction and reclamation works have been carried on in the estuarine reach (transition reach) of the Qiantang estuary. Up to date, the river width has been narrowed down by one-half to three-quarters and 73000 ha of tidal flat has been reclaimed in the 106km stretch from Hangzhou to Ganpu， tremendous comprehensive benefits have thus been achieved. The large-scale river training and reclamation project results in the obvious changes of tides and river regime. This article relates a brief retrospect of the past regulation plans and practice; emphasizes the variation of tides, including high/low tide stages, tidal range, tidal flow, flood/ebb duration, etc., as well as the variation of river regime, such as the deduction of shifting range of the main channel，the tidal volume, cross-sectional area and the change of longitudinal profile, etc.. Some variation mechanisms were studied by means of numerical simulation or regime theory analysis.

Marcel J. F. STIVE

Faculty of Civil Engineering and Geosciences, Delft University of Technology, PO Box 5048, 2600 GA Delft, The Netherlands

Tel.: +31 15 2785487, Fax: +31 15 2785124, Email: m.j.f.stive@ct.tudelft.nl

Abstract: Coastal evolution due to natural and human-induced causes or factors can be rather variable on quite different temporal and/or spatial scales. Our capability to understand and especially predict this variability on the longer time scales is still limited. This can lead to misinterpretation of coastal change information, which hampers informed decision-making and the subsequent functional design process related to (soft) engineering interventions. Research progress aimed at understanding observations of long-term coastal evolution is important to support and improve the decision-making and functional design process. In this contribution an attempt is made to review recent research methodological advances and to illustrate the concept with one exemplary result.

Key words: Coastal tract, Coastal morphology, Hierarchical modelling, Tidal basin, Sea-level rise

PLANNING, REGULATION AND MANAGEMENT OF THE PEARL RIVER ESTUARY

Shikang ZHU

Pearl River Water Resource Commission, Guangzhou 510611, China

E-mail: zwzsk@163.net