TITLE:
Characterizing Rainfall of the Great Kei River Catchment, Eastern Cape Province, South Africa
AUTHORS:
Francis Wasswa Nsubuga, Luyanda Mthethwa
KEYWORDS:
Rainfall Concentration Index, Drought Potential, Rainfall Variability, Trend Analysis
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.12 No.9,
September
27,
2024
ABSTRACT: This study seeks to understand long-term changes of rainfall for the Great Kei River catchment (GKRc) in South Africa for water resources management and planning. Monthly and annual rainfall time series data from 1950 to 2017 for 11 rainfall gauging stations are analyzed using various statistical methods. Data obtained from South African Weather Services (SAWS) was quality controlled to enable the use of Mann-Kendall (MK), Theil Sen’s method, Precipitation Concentration Index (PCI), among others to characterise rainfall. Rainfall in the catchment is seasonal (particularly wet in spring and summer) and highly variable with a PCI of 17.2. Years which received rain above and below the mean inter-annually were 46% and 54%, respectively. Seasonality trends also confirm that the GKRc has been progressively receiving less rainfall since 1950, especially in the autumn. The methods are novel in understanding historical and existing trends, variability and characteristics that control freshwater availability in this catchment.