'n Ruimtelike-analitiese ondersoek na seisoenale reënval- en temperatuurpatrone oor suidelike Afrika

[摘要] English: Changes in climatic variability and extremes of weather and climate events havereceived increased attention in the last few years. Many studies have been done onclimate trends, especially for precipitation and temperature, compared to the timebefore the issue of climate change became more prominent during the 1980s. Sincethen, one of the biggest motivations for such studies is to establish if and how globalwarming might have influenced the climate on a global as well as regional scale.Southern Africa is predominantly semi-arid region with generally a high inter-annualrainfall variability and pronounced seasonal cycle. Climate variability and long-termchange thus pose serious challenges for southern Africa. The main aim for this studyis to investigate the seasonal trends of rainfall and surface temperature from 1950 to1999 and to compare these seasonal trends with yearly trends.Rainfall and temperature data of the 1 946 Quaternary catchments in South Africa,Swaziland and Lesotho were used as input data. Correlation coefficients weredetermined and mapped using Geographic Information Systems ArcMap. HotSpotanalysis was used to calculate the Getis-Ord Gi* statistic (Z score) for each featurein the data set.Results show more pronounced trends in rainfall and surface temperature during thedifferent seasons.

[发布机构] University of the Free State