Nationwide temporal variability of droughts in the Kingdom of Eswatini: 1981-2018.

For adequate mitigation and adaptation measures, it is essential to have detailed analysis of droughts patterns. This study determined the i) occurrence and severity of droughts ii) drought recurrence frequencies and iii) drought trends across different agro-ecological zones in the Kingdom of Eswatini for the period 1981 to 2018. A Standardised Precipitation Index (SPI) computed from long-term precipitation data measured from six meteorological stations was used to determine drought occurrence and severity. Python software (Version 3.6) was applied on the SPI values to predict the recurrence of drought events over time in years. The SPI showed that in the Highveld, 42% of the droughts were moderate, 32% were severe and the remaining 26%, which all occurred post 1980 were extreme (SPI -2.34 to -2.82). The Middleveld had an even proportion of drought categories (29-35%). The Lowveld recorded 62% of moderate, 8% severe and 30% extreme droughts of which 70% occurred post 2000. Moderate droughts were found to recur every 4-5 years while extreme droughts are expected every 13-21 years. These findings are essential for mitigation and adaptation measures geared towards the adverse effects of droughts.

Evaluation of high fluoride contaminated fractured rock aquifer in South Africa - Geochemical and chemometric approaches.

The first systematic study on high fluoride contaminated fractured rock aquifer in South Africa using geochemical and chemometric approach is presented. Groundwater samples were collected from 49 boreholes and analysed for EC, pH, major and minor ions. The groundwater with high fluoride is associated with NaCl water types. The groundwater chemistry is governed by mineral weathering, evaporation and wastewater infiltration. PHREEQC modelling indicates that carbonate mineral saturation is decreasing with increasing salinity due to evaporation whereas fluorite saturation increases with increasing F being one of the prime controlling factors. Silicate minerals namely chalcedony, quartz and talc express saturation and over-saturation while chrysotile and sepiolite are undersaturated in most of the samples. PCA provided four factors and justified the role of mineral weathering, evaporation, ion exchange, longer residence time and anthropogenic impacts on water chemistry. R-mode and Q-mode cluster analysis resulted in four clusters. In cluster 1, (29%) of groundwater is less mineralized due to recent recharge. In cluster 2 (45%), groundwater chemistry is governed by weathering of silicates and fluorite minerals. Cluster 3 (20%) reveals the impact of anthropogenic activities and induced mineral weathering. Cluster 4 shows high EC, TDS, major ions, F and low HCO3 implying that groundwater is affected by evaporation and longer residence time promoting mineral-water interaction and precipitation of carbonate minerals. More than 50% of the study area is degraded due to fluoride contamination which requires proper remedial actions and further investigations on human health risk due to impact of fluoride contamination in groundwater is recommended.

Building capacity for improved veterinary epidemiosurveillance in southern Africa.

A workshop to produce recommendations on training requirements for improved epidemiosurveillance of livestock diseases in southern Africa was organised at the Department of Veterinary Tropical Diseases in the Veterinary Faculty of the University of Pretoria. It was attended by 23 persons representing 10 different southern African countries. The majority of the participants were actively involved in veterinary epidemiosurveillance and many of them were members of the SADC Epidemiology and Informatics Subcommittee. Discussions focused on (i) epidemiosurveillance networks and their 2 main components, i.e. (ii) diagnosis and (iii) information flow. The debates were guided by 3 questions; (i) what are the requirements for an effective network, (ii) what cannot be achieved with existing capacity and (iii) how can the current capacity be improved. Workshop participants developed lists of realistic capacity building needs, which were divided into structural needs and training requirements. Structural needs mainly concerned communication means and quality assurance. With regard to training, the need for appropriate continuing education of all actors at the various disease management levels (non-professional, para-professional, professional) was expressed. Special emphasis was put on capacity building at the lowest level, i.e. the livestock owner and the para-professionals at the community level. At the international level, it was felt that special emphasis should be put on building capacity to improve the understanding of international agreements on trade in animals and animal products and to improve the capacity of negotiating such agreements.