Water surface flow model for al msharh channel

Dissertant

Nasr Allah, Shahla Abd al-Qadir

University

University of Technology

Faculty

-

Department

Department of Building and Construction Engineering

University Country

Iraq

Degree

Master

Degree Date

2008

English Abstract

This study is concerned with unsteady flow in open channels in boundary conditions that may exist in river or channel system.

A software Hydrologic Engineering Center-River Analysis System (HEC-RAS) was used for a case study.

The software contains a hydrodynamic model for simulating the unsteady flow in open channels based on a one-dimensional form of the Saint-Venant equations, by formulating a discrete form using the implicit finite difference scheme, then solving using the Newton-Raphson iteration procedure and the modified Gaussian elimination technique. The HEC-RAS has the interactive program features, such as multi windows facilities, which can treat any river system configurations with the ability of storing these configurations.

It can provide the user with a report showing the river system data and presenting the computation results by charts and'or tables. The case study adopted with the help of HEC-RAS application was applied to a reach of Al Msharah River (channel) between AL Msharah Barrage (upstream)and Ai Malah Bridge (Downstream) of the reach and length (49 Km), it divided to (52) cross sections. Calibration of the hydrodynamic model i$ achieved in a study reach using the observed data (water stage) along AL Msharah River. Verification of the hydrodynamic model is accomplished by application of the observed water stage data within the period (from January 2006 to July 2006). Model runs and the comparison of the resulting with actual field data is the most acceptable, where 0 is a weighting parameter and At is the time interval, This study has adopted three flow cases, Normal Flow, High Flow(peak flood Discharge) and High Flow with adjusted cross sections and remove culvert (without a replacing another structure).

Where culvert causes chucking, therefore, it is recommended to adjust cross sections. The results demonstrate that the area at Al Am'arah city at distance 17.5 Km from upstream (cross section 30) could be subjected to flooding at High Flow, therefore, it is recommended to adjust cross sections to prevent the flooding in this area. The water volume proiile decreases from Al Msharaii Barrage station towards Al Malah Bridge station in three cases due to fact that the water is consumed and lost along the study reach.

However, the maximum allowable water surface elevation in AI Huwayza Marsh, under the present condition of Al Msharah River, must be 5.5 m amsl at High Flow with adjusted cross sections to avoid flooding in the Marsh and achieve a convenient feeder for it.

Main Subjects

Civil Engineering

Topics

• Mathematical models
• Hydraulic engineering
• Iraq

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-305567