Statistical Hydrology Case Study 2022

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Topic: STATISTICAL HYDROLOGY
By
(Name of Student)
Institutional Affiliation)
(Date of Submission)

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INTRODUCTION
General Statement
Natural hazards and floods leads to deaths, injury, destruction of agricultural lands, and loss
of properties such as buildings, bridges etc. (Fill & Stedinger, 2015). The method that is used
mostly in reducing flood destructions and economic damages is the use of frequency analysis
for finding out the approaches of hydraulic structures. In statistical hydrology, the estimation
of highest discharges for design reasons on catchment areas by use of the limited data
available has become a continuing challenge (Blazkovaa & Bevenb, 2017). An approach that
is believed to be promising t0o this challenge is the use of derived flood frequency. Reliable
estimations on water flow statistics like mean annual flow and the quantiles(s) of the flood
are required. The historic data or the data available may not be enough to act as the
representation of the basin-flow due to variation that may have occurred over the years such
as urbanization, deforestation soil erosion etc. (Pandey and Nguyen, 2009; Ouarda, et al,
2016).There the is need for this study to design a bridge for 50-year return period just
upstream of Wollomombi River at Coninside in NSW State and come up with a flood
discharge of 100year return period (Q50) recommendation.
Objectives of the project
The study is aimed to achieve the following objectives:
i. To fit Normal, Log Normal (LN), EV1 and Gamma distributions using Annual
maximum flow data at Site 206014 (NSW) for the period between 1995 to 2011 to
estimate Q50 at the given river location.
ii. To compare the estimated flood quantiles in (1) above by use of Normal, Log Normal
(LN), EV1, and Gamma by nonparametric method (flood frequency analysis method).

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iii. To state the limitations in our results and finally,
iv. To recommend a suitable flood discharge from the above results to be used for the
design of the bridge.
Structure of this Report
This report is divided into 5 sections. First section gives the general statement under
investigation, objectives of the study and the structure of the report. Section two, describes
the previous studies related to statistical hydrology. Section three which the methodology
part, it contains the equations and methods applied in the calculations used in this report. The
fourth section is the results and discussion section which involves the findings, interpretations
and discussions. The last section of the report is the conclusion, it presents the summary of
the report, giving major findings of the report, limitations of the investigation and scope of
further improvement.