Geoscience Reference
In-Depth Information
DROUGHT ANALYSIS AND COMPARISON
OF METHODS: A CASE STUDY OF WESTERN UGANDA
A. I. RUGUMAYO
∗
andJ.M.MAITEKI
†
∗
Department of Civil Engineering Makerere University, Uganda
†
National Water and Sewerage Corporation, Uganda
There are several methods of analyzing meteorological drought. These include
the drought volumes method and the Standard Precipitation Index. In the
former, deficiencies are calculated between the expected and actual rainfall.
In the latter, the ratio of the difference between the measured rainfall and
the long-term mean to the standard deviation is calculated. In this study,
stations that have su
cient years of data were selected. The objectives being
to determine the extent of drought in the drought prone areas and derive a
relationship between the two methods so that by applying one method, the
appropriate values for the other method can be derived, which may be used
in future assessments and prediction. The analysis of drought shows that the
two regions have similar drought event patterns and that Rakai experiences
more severe drought than Masindi. The two methods are related by a linear
relationship. This study can be extended to other regions in Uganda.
1. Introduction
Drought is not a new phenomenon in Uganda. Many areas are often hit by
severe drought events causing intensive search for water for domestic and
agricultural use.
1
Drought events recur continuously and researchers are
able to predict their occurrence using the science of meteorology, statistical
and probabilistic models. There is no universal definition of drought;
2
thus
various perspectives on drought are in existence including meteorological,
hydrological, agricultural, socio-economic, and physiological perspectives,
amongst many others. The objectives of the study were to study the drought
characteristics of two climatic regions using two different methods and com-
pare the methods such that if one method is used results for the other can
be obtained. In each case drought is said to occur when the parameter
under consideration is lower than the expected amount in a given period.
A drought may be simply defined as an abnormal moisture deficiency in
relation to some need. This study relates to meteorological drought.
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