Publications by authors named "Daniel Olago"

Reliance on groundwater is increasing in Sub-Saharan Africa as development programmes work towards improving water access and strengthening resilience to climate change. In lower-income areas, groundwater supplies are typically installed without water quality treatment infrastructure or services. This practice is underpinned by an assumption that untreated groundwater is typically suitable for drinking due to the relative microbiological safety of groundwater compared to surface water; however, chemistry risks are largely disregarded.

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The shift in the geographical spread of invasive pests in Africa has rarely been linked directly to climate change. However, it is predicted that environmental changes play a significant role in spreading and expanding pests. The occurrence of new tomato invasive insect pests has been increasing in Uganda during the past century.

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Lake Victoria, a lifeline for millions of people in East Africa, is affected by anthropogenic activities resulting in eutrophication and impacting the aquatic life and water quality. Therefore, understanding the ongoing changes in the catchment is critical for its restoration. In this context, catchment and lake sediments are important archives in tracing nutrient inputs and their dominant sources to establish causality with human activities and productivity shifts.

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Transportation infrastructure, such as railways, roads and power lines, contribute to national and regional economic, social and cultural growth and integration. Kenya, with support from the Chinese government, is currently constructing a standard gauge railway (SGR) to support the country's Vision 2030 development agenda. Although the actual land area affected by the SGR covers only a small proportion along the SGR corridor, a significant proportion of the area supports a wide range of ecologically fragile and important ecosystems in the country, with potential wider impacts.

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Grassland degradation and the concomitant loss of soil organic carbon is widespread in tropical arid and semi-arid regions of the world. Afforestation of degraded grassland, sometimes by using invasive alien trees, has been put forward as a legitimate climate change mitigation strategy. However, even in cases where tree encroachment of degraded grasslands leads to increased soil organic carbon, it may come at a high cost since the restoration of grassland-characteristic biodiversity and ecosystem services will be blocked.

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Fluorescent natural organic matter at tryptophan-like (TLF) and humic-like fluorescence (HLF) peaks is associated with the presence and enumeration of faecal indicator bacteria in groundwater. We hypothesise, however, that it is predominantly extracellular material that fluoresces at these wavelengths, not bacterial cells. We quantified total (unfiltered) and extracellular (filtered at < 0.

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Access to water and sanitation remain a challenge in many developing countries, especially in pro-poor urban informal settlements where socioeconomic livelihoods are generally low. The aim of this study was to characterise the water and sanitation facilities in the informal settlements of Kisumu City and to evaluate their effect on community hygiene and health. The study focussed on the five urban informal settlements of Nyalenda A, Nyalenda B, Manyatta A, Manyatta B and Obunga, and the three Peri-urban informal settlements of Kogony, Usoma and Otonglo.

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The industrialization process taking place in Africa has led to an overall increase in groundwater abstraction in most countries in the continent. However, the lack of hydrogeological data, as in many developing countries, makes it difficult to properly manage groundwater systems. This study presents a real case study in which a combination of different hydrogeological tools together with different sources of information allow the assessment of how increased competition for water may be affecting groundwater systems by analysing the sustainability of new abstraction regimes under different real climatic condition (before, during and after La Niña 2016).

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In 2016-17 much of East Africa was affected by a severe drought which has been attributed to Indian Ocean Dipole and El Niño Southern Oscillation conditions. Extreme events such as this have immediate and knock-on effects on water availability for household, agricultural and industrial use. Groundwater resources can provide a buffer in times of drought, but may themselves be stressed by reduced recharge and increased usage, posing significant challenges to groundwater resource management.

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Tackling global inequalities in access to Water, Sanitation and Hygiene (WASH) remains an urgent issue - 58% of annual diarrhoeal deaths are caused by inadequate WASH provision. A global context of increasing urbanisation, changing demographics and health transitions demands an understanding and impact of WASH on a broad set of health outcomes. We examine the literature, in terms of health outcomes, considering WASH access and interventions in urban sub-Saharan Africa from 2000 to 2017.

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The global increase in vector borne diseases has been linked to climate change. Seasonal vegetation changes are known to influence disease vector population. However, the relationship is more theoretical than quantitatively defined.

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Background: The decline in global malaria cases is attributed to intensified utilization of primary vector control interventions and artemisinin-based combination therapies (ACTs). These strategies are inadequate in many rural areas, thus adopting locally appropriate integrated malaria control strategies is imperative in these heterogeneous settings. This study aimed at investigating trends and local knowledge on malaria and to develop a framework for malaria control for communities in Baringo, Kenya.

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The gradient of air temperature with elevation (the temperature lapse rate) in the tropics is predicted to become less steep during the coming century as surface temperature rises, enhancing the threat of warming in high-mountain environments. However, the sensitivity of the lapse rate to climate change is uncertain because of poor constraints on high-elevation temperature during past climate states. We present a 25,000-year temperature reconstruction from Mount Kenya, East Africa, which demonstrates that cooling during the Last Glacial Maximum was amplified with elevation and hence that the lapse rate was significantly steeper than today.

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Background: Rift Valley fever (RVF) is a vector-borne zoonotic disease that has an impact on human health and animal productivity. Here, we explore the use of vector presence modelling to predict the distribution of RVF vector species under climate change scenario to demonstrate the potential for geographic spread of Rift Valley fever virus (RVFV).

Objectives: To evaluate the effect of climate change on RVF vector distribution in Baringo County, Kenya, with an aim of developing a risk map for spatial prediction of RVF outbreaks.

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Groundwater is used extensively in the Central Kenya Rift for domestic and agricultural demands. In these active rift settings groundwater can exhibit high fluoride levels. In order to address water security and reduce human exposure to high fluoride in drinking water, knowledge of the source and geochemical processes of enrichment are required.

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This paper assesses the vulnerability of schools to floods in the Nyando River catchment (3,600 km(2)) in western Kenya and identifies measures needed to reduce this vulnerability. It surveys 130 schools in the lower reaches, where flooding is a recurrent phenomenon. Of the primary schools assessed, 40% were vulnerable, 48% were marginally vulnerable and 12% were not vulnerable.

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Hominin footprints offer evidence about gait and foot shape, but their scarcity, combined with an inadequate hominin fossil record, hampers research on the evolution of the human gait. Here, we report hominin footprints in two sedimentary layers dated at 1.51 to 1.

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Cholera epidemics have a recorded history in the eastern Africa region dating to 1836. Cholera is now endemic in the Lake Victoria basin, a region with one of the poorest and fastest growing populations in the world. Analyses of precipitation, temperatures, and hydrological characteristics of selected stations in the Lake Victoria basin show that cholera epidemics are closely associated with El Niño years.

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Lake Victoria is an international waterbody that offers the riparian communities a large number of extremely important environmental services. Over the past three decades or so, the lake has come under increasing and considerable pressure from a variety of interlinked human activities such as overfishing, species introductions, industrial pollution, eutrophication, and sedimentation. In this paper we examine the root causes for overfishing and pollution in Lake Victoria and give possible policy options that can help remediate or mitigate the environmental degradation.

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