Rapid growth of agriculture, industries and urbanization within the Awash basin, Ethiopia, as well as population growth is placing increasing demands on the basin’s water resources. In a basin known for high climate variability involving droughts and floods, climate change will likely intensify the existing challenges. To quantify the potential impact of climate change on water availability of the Awash basin in different seasons we have used three climate models from Coupled Models Inter-comparison Project phase 5 (CMIP5) and for three future periods (2006–2030, 2031–2055, and 2056–2080). The models were selected based on their performance in capturing historical precipitation characteristics. The baseline period used for comparison is 1981–2005. The future water availability was estimated as the difference between precipitation and potential evapotranspiration projections using the representative concentration pathway (RCP8.5) emission scenarios after the climate change signals from the climate models are transferred to the observed data. The projections for the future three periods show an increase in water deficiency in all seasons and for parts of the basin, due to a projected increase in temperature and decrease in precipitation. This decrease in water availability will increase water stress in the basin, further threatening water security for different sectors, which are currently increasing their investments in the basin such as irrigation. This calls for an enhanced water management strategy that is inclusive of all sectors that considers the equity for different users.
1 September 2016 in Environmental Impact Assessment Review
Like most cities in developing countries, Kigali is experiencing rapid urbanisation leading to an increase in the urban population and rapid growth in the size and number of informal settlements. More than 60% of the city’s population resides in these settlements, where they experience inadequate and poor quality urban services including sanitation. This article discusses the issues and constraints related to the provision of sustainable sanitation in the informal settlements in Kigali. Two informal settlements (Gatsata and Kimisagara) were selected for the study, which used a mixed method approach for data collection. The research found that residents experienced multiple problems because of poor sanitation and that the main barrier to improved sanitation was cost. Findings from this study can be used by the city authorities in the planning of effective sanitation intervention strategies for communities in informal settlements.
Aim: To investigate the potential health hazard from infectious viruses where coliphages, or viruses by polymerase chain reaction (PCR), have been detected in groundwater. Two aspects were investigated: the relationship between infectivity and detection by PCR and the stability of coliphage compared to human viruses. Methods and Results: Virus decay (1 year) and detection (2 years) studies were undertaken on groundwater at 12°C. The order of virus stability from most to least stable in groundwater, based on first‐order inactivation, was: coliphage ΦX174 (0·5 d−1) > adenovirus 2 > coliphage PRD1 > poliovirus 3 > coxsackie virus B1 (0·13 d−1). The order for PCR results was: norovirus genotype II > adenovirus > norovirus genotype I > enterovirus. Conclusions: Enterovirus and adenovirus detection by PCR and the duration of infectivity in groundwater followed similar trends over the time period studied. Adenovirus might be a better method for assessing groundwater contamination than using enterovirus; norovirus detection would provide information on a significant human health hazard. Bacteriophage is a good alternative indicator. Significance and Impact of the Study: PCR is a useful tool for identifying the health hazard from faecal contamination in groundwater where conditions are conducive to the survival of viruses and their nucleic acid.