Frequency analysis of the flood hydrology for the Blue Nile : study area El-Deim Station

Dissertant

Mahmud, Khalid Awad Mirghani

Thesis advisor

Bashshar, Kamal al-Din al-Sadiq

University

Omdurman Islamic University

Faculty

Unesco Chair in Water Resources

University Country

Sudan

Degree

Master

Degree Date

2007

English Abstract

In the study of hydrology it is very advantageous to predict a flood.

However, it is almost impossible to predict if a flood will occur.

Instead we try to predict the probability of a flood.

Some problems in hydrology where probability laws and models can be directly applied for making risk based design decisions.

Flood prediction and modeling generally involve approximate descriptions of the rainfall-runoff transformation processes.

These descriptions are based on either empirical, or physically-based, or combined conceptual physically-based descriptions of the physical processes involved.

Hydrologic flood prediction models may be categorized into physical models and mathematical models that can help as tools to manage the decision making by providing us with a view of what that can't be realized by our eyes.

At this dissertation we took the flow data of the Blue Nile River gauged at El-Deim Station which had been provided by UNESCO Chair in Water Resources data base and work on it by fitting of those independent data to a theoretical probability distribution by mathematical models that will appear in graphs and tables that will shed light and give a good understanding to the flood hydrology as an engineering tool to assist in decision making when it comes to designing water facilities on the Blue Nile.

The peak discharges were fitted to the seven major statistical distributions namely normal, exponential, extreme value type 1 (Gumbel), Pearson Type (iii), log normal by Chow’s table log-normal, two Parameter Log Normal and log-Pearson type (iii) while Weibull plotting position formula used to determining their probabilities of exceedance.

Results obtained showed that the annual maximum discharges at El-Deim station varied from 4470.72 Cumecs to 10809.42 Cumecs within duration of 33 years.

Weibull’s plotting position combined with two parameter log normal distribution gave the highest fit.

Main Subjects

Earth Sciences, Water and Environment

Topics

• Floods
• Hydrology
• Sudan
• Blue Nile

No. of Pages

112

Table of Contents

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-363678