Bernard Moeketsi Hlalele
Abstract
A dry spell is defined as the consecutive number of days with precipitation less than a specified threshold value of a standardised precipitation index (SPI). A cumulative effect of these dry spells amount to drought events and thereby negatively affect socio-economic activities in the communities. The ...
Read More
A dry spell is defined as the consecutive number of days with precipitation less than a specified threshold value of a standardised precipitation index (SPI). A cumulative effect of these dry spells amount to drought events and thereby negatively affect socio-economic activities in the communities. The current study aimed at determining the influence of El Niño-Southern Oscillation (ENSO) aided by Southern Oscillation Index (SOI) in order to make easy prediction given clear SOI cyclicity of anything from 3 to 7 years. The study used SPI to define dry spells and was also used a conceptual framework to quantify dry spells. A spectral analysis was also applied to SPI-1 time series datasets to determine return levels to provide government and all relevant authorities with behavioural characteristics of dry spells in the area for proactive mitigation strategies. Main results of this study ENSO having no direct influence over all the selected station’s precipitation. All the stations showed an average of 12 months or 1 year return level. This implies that after every 1 year, the study area is highly likely to experience dry spells which could lead to detrimental effects of the most important amenities of the study area. This phenomenon provides authorities with relevant information to plan proactively as dry spells may amount or graduate to drought events and thereby adversely affect water consuming activities in the area.
