Abstract:
Rainfall and temperature are important climatic factors for crop production and affects
humans’ basic needs such as health, shelter, food and water in Ghana. However extreme
rainfall causes flooding which can lead to loss of lives, properties among others. Extreme
temperature also causes drought, hot and cold spells among others which have adverse
implications on human beings and agriculture. It is therefore important to know about
occurrences of such extreme events and their chances of occurring. Extreme value theory
gives us a statistical approach for the occurrences and the magnitude of these extreme cases
or rare event that are beyond the scope of available data. In this thesis, we used “extreme
value theory” to model the tail distributions of temperature and rainfall in Ghana. Daily data
on rainfall and temperature was obtained and it spanned the period January 1960 to
December 2012. “Extreme value theory” was used to estimate the extreme occurrence to be
expected once every 5, 10, 20, 50 and 100 years respectively. It was observed that the
extreme occurrences of temperature and rainfall can be modelled using Weibull and Frechet
family of distributions in Ghana respectively. A maximum temperature of 34.7cC , 34.66oC ,
and 39.6oC was predicted to occur in Accra, Ashanti and Northern regions respectively once
every five years. Furthermore, it was estimated that an amount of 88.38mm, 85.61mm, and
81.98mm will be recorded in Accra, Ashanti, and Northern regions once every 5 years
respectively. It was recommended that Government should employ all necessary legislative
policies to help manage the issue of Global warming considering the substantial rise in
temperature in the years ahead based on our forecasted predictions.
