Page 205 - Contributed Paper Session (CPS) - Volume 1

CPS1280 Willard Z. et al.

Spatial analysis of winter rainfall variability of a
selected region in South Africa
1
1
Willard Zvarevashe , Symala Krishnannair , Venkataraman Sivakumar 2
1 University of Zululand, KwaDlangezwa, South Africa
2 University of Kwazulu-Natal, Durban, South Africa

Abstract
Quantitative and qualitative understanding of the multi-scale shifts in the
rainfall is very crucial for better preparedness and management. The South
Western region of Western Cape, South Africa depends on winter rainfall for
its water requirements. However, in recent years there has been water
challenges in the region with it being mainly attributed to draught and
reduced rainfall. In this study Mann-Kendell and kriging is used to carry out
analysis of spatial variability for the winter rainfall. The eleven stations used in
the study shows that there is generally monotonic decreasing trend for the
months of May and August and increasing trend for June for the period 1980
to 2017. There was also high rainfall variability for May and August and the
month of June recorded the least variability.

Keywords
Rainfall; Kriging; Trend Analysis

1. Introduction
South Africa experiences different types of rainfall seasons with most of
the country receiving austral summer rainfall and south western parts of the
country receiving austral winter rainfall (Dieppois et al., 2016). In recent years
the country has been experiencing draughts and sometimes floods, all this
adding to the unpredictability of the rainfall patterns. The rainfall trends in
South Africa are less uniform with large spatial variability over different regions
(Jury, 2012). These extreme rainfall patterns have adverse effects on
agriculture, water resources and economy (Niang et al., 2014). The Western
Cape province has been facing water challenges recently mainly attributed to
decrease of rainfall (Nxumalo, 2017). A study of the rainfall patterns is very
essential for future planning.
A study by MacKeller et al., (2014) indicated that there were drier
conditions along the southern coastal regions and an increase of rain days in
the west coast of Western Cape province. The study was based on the period
1960 to 2010. However, another study for a period from 1921 to 2015 by
Kruger and Nxumalo (2017) showed that there is rainfall increase of more than
2.5mm per decade for the June- July-August season for the regions located in
the province.
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