THE MORPHOLOGY AND GENESIS OF COLD-PHASE DIAMICTS IN HIGH ALTITUDE LAKE SEDIMENTS OF MOUNT KENYA, KENYA

Lake sediment cores spanning the last interglacial-glacial-present interglacial cycle have been recovered from Sacred Lake and Lake Nkunga on the northeastern flank of Mount Kenya, Kenya. Within these cores are diamicts which occur at the last interglacial-glacial transition (ca.110,000 yr BP) and between 58,000 and 48,000 yr BP. The occurrence of the diamicts (formed by active freeze-thaw processes in the lake catchments) is associated with periglacial and concurrent relatively humid conditions at the altitudes of the lakes. In addition, their temporal occurrence is correlated with abrupt low temperature extremes and/or rapid transition rates to lower temperature regimes at high latitude regions. Close modern corollaries of such sediments have been documented at higher altitude on Mount Kenya, but there is no known documentation of such sediments in the late Quaternary records of the tropical high mountains.Keywords: Lake sediments, Diamicts, Morphology, Genesis, Mount Keny

The Potential for CO2 Geosequestration in Kenya: A Suitability Assessment of the Lamu Basin

There is a consensus that current trends in climate change may be due to increasing concentrations of greenhouse gases (predominantly methane and carbon dioxide) from anthropogenic emissions. Among measures proposed for curbing this increase is Carbon Capture and Sequestration (CCS) in geological media. CCS incorporates three technologies comprising; (a) carbon capture, (b) compression and transportation, and (c) injection into geological media. This paper focuses on CO2 injection into geological media and its applicability to the Lamu basin. Sedimentary basins, which host the geological formations suitable for subsurface CO2 storage, are ideal to varied extents determined by such factors as their tectonic settings. A (coarse) basin scale suitability assessment of the Lamu basin was undertaken using the following parameters; size and depth, tectonic and structural settings, seismicity, geothermal-hydrodynamic regimes, basin maturity (based on hydrocarbon well density) and economic resources. The assessed attributes are used to constrain GIS data, delineating possible CCS trap areas with the production of a preliminary map of potential trap areas. Also, a suitability matrix table is generated in comparison with analogous basins such as the Alberta basin in Canada. Following this assessment, the Lamu basin can be considered geologically suitable for geosequestration given its stable tectonic settings, good depth and size. However, the western flanks of the basin and the coastal strip are unsuitable due to shallowness, population and protected zones respectively

Water and the UN sustainable development goals

Water is essential for life, but we need to balance human needs with those of the environment on which we depend for our wellbeing, our health and much of our wealth. Not all of us are lucky enough to have access to adequate water resources and services linked to water, such as readily available low-cost drinking water and sanitation systems. According to the World Health Organization and United Nations Children’s Fund (WHO/UNICEF), hundreds of millions of people are still without access to safely managed drinking water and sanitation services. Their Joint Monitoring Programme (JMP) report, Progress on Drinking Water, Sanitation and Hygiene 2000–2020, found that although considerable progress has been made in achieving universal access to basic water services, the proportion of improved water sources that are accessible, available and free from contamination varies widely between countries. This indicates that many countries are facing a challenge to meet the Sustainable Development Goal (SDG) target for safely managed services. In addition, despite increasing the rural coverage of safely managed water services in some countries, and in other countries this coverage is similar to the urban coverage, there is a huge gap in terms of water quality. Many aquatic ecosystems (freshwater, brackish and oceanic) also are under threat with knockon consequences for humanity. Large quantities of inadequately treated or untreated wastewater are still being discharged into our surface, ground and coastal waters. The WHO reports that at least 2 billion people globally consume water from a source contaminated with faeces. Faecal contamination in the water supply system, whether rudimentary or complex, is a major cause of infectious diseases such as cholera, typhoid fever, diarrhoea, dysentery, hepatitis A and polio. As a result, 1.2 million people die every year from water related diseases. According to the Global Water Institute, in low- and middle-income countries, almost 50% of the population can link health problems to waterborne diseases. In addition, emergent pollutants such as microplastics, antibiotics, per- and polyfluoroalkyl substances (PFAS) and their degradation products found in water sources and in the environment pose a health risk to humans and animals

The Shrinking Grazing Fields of the Maasai Land Under the Changing Climate System in Kajiado County, Kenya

The Maasai pastoralists have in the last decade experienced disruptions in their economies and livelihoods following climate shifts. For instance, they have been losing up to 30 % of their herd annually to drought related disasters, yet information on the various land uses is still fragmented. This has been worsened by the shortening famine cycles which has impacted pastoral livelihood system as they highly depend on natural resource. Yet, these key resources have been dwindling over the past 30 years compromising their ability to meet basic need such as food. To address this gap, the study focused on long term evaluation of land use. The study’s objective was to determine land use transformations and their impacts particularly on the pastoral livelihood system. Keywords: Climate change, Arid and Semi-Arid Lands, Natural resources, food insecurity, pastoral livelihood system, socio-ecological system

Characterization of Major Ion Chemistry and Hydro-Geochemical Processes in Mt. Elgon Trans-Boundary Aquifer and Their Impacts on Public Health

There is a gradual paradox shift from the utilization of surface water to groundwater in both urban and rural Kenya. This is because surface water is both diminishing in quantity due to climate variability and deteriorating in quality due to high levels of anthropogenic contamination. In the quest to attain the Sustainable Development Goal number 6 that aim at ensuring access to safe water by all by 2030, the Government of Kenya is encouraging the development of groundwater resources whose potential is enormous though it has not been quantified. The Inter-governmental Authority on Development (IGAD) supported this research on the shared Mt. Elgon trans-boundary aquifer between Kenya and Uganda aimed at understanding its dynamics. Mt. Elgon is a Tertiary age mountain that straddles the Kenya-Uganda border and has a trans-boundary aquifer. This study investigated the groundwater chemistry and its implication on water management and human health. Physico-chemical parameters of water that included electrical conductivity, pH, and temperature were measured in the field and the major cations and anions were measured at the Central Laboratories of the State Department for Water. Geological mapping and identification of sanitary risks were undertaken during the field work. The study revealed that the concentration of cations and anions in the groundwater varied spatially and temporally.  Abundance of these ions were in the order Ca²⁺ > Na⁺ > Mg²⁺ > K⁺ for most samples and HCO₃⁻ > Cl⁻ > SO₄²⁻ >NO₃⁻. Interpretation of hydro-chemical data suggests that calcium carbonate dissolution, halite dissolution, Ca/Na ion exchange and Mg/Na ion exchange are the major processes that control the ground-water chemistry. Chemical results indicate further that the groundwater is suitable for domestic use but is threatened by both anthropogenic and geological factors. Extensive use of fertilizer and the destruction of the catchment area coupled with low permeability and rock-water interactions in the metamorphic rock terrains are the main threats to groundwater quality in the region. A few water points had water with some ionic composition exceeding WHO and the local KEBS maximum limits for drinking water. Such water pose a risk to human health. Keywords: Transboundary aquifer, groundwater chemistry, Human health, Carbonate dissolution, Mt. Elgo, Kenya DOI: 10.7176/JEES/9-4-06 Publication date: April 30th 201

Assessing the underlying drivers of change over two decades of land use and land cover dynamics along the Standard Gauge Railway corridor, Kenya

We acknowledge funding from the UK Research and Innovation’s Global Challenges Research Fund (UKRI GCRF) through the Development Corridors Partnership project (project number: ES/P011500/1).Land cover has been modified by anthropogenic activities for thousands of years, although the speed of change has increased in recent decades, particularly driven by socio-economic development. The development of transport infrastructure can accelerate land use land cover change, resulting in impacts on natural resources such as water, biodiversity, and food production. To understand the interaction between land cover and social–ecological drivers, changing land cover patterns and drivers of change must be identified and quantified. This study documents land cover dynamics along the Standard Gauge Railway (SGR) corridor in Kenya and evaluates the underlying drivers of this change from 2000 to 2019. The study utilised GIS and remote sensing techniques to assess the land use and land cover changes along the SGR corridor, while correlational and regression analyses were used to evaluate various drivers of the changes. Results showed that built-up areas, bare lands, water bodies, croplands and forests increased by 144.39%, 74.73%, 74.42%, 9.32% and 4.85%, respectively, while wetlands, grasslands and shrub lands reduced by 98.54%, 67.00% and 33.86%, respectively. The underlying drivers responsible for these land use and land cover dynamics are population growth, urbanisation, economic growth and agro-ecological factors. Such land cover changes affect environmental sustainability, and we stress the need to adequately identify and address the cumulative social and environmental impacts of mega-infrastructure projects and their interacting investments. The findings of this study provide an evidence base for the evaluation of the social–ecological impacts of the SGR and the implementation of best practices that will lead to enhanced sustainability in the development corridors in Kenya and beyond.Publisher PDFPeer reviewe

Effects of Shallow Water Table on the Construction of Pit Latrines and Shallow Wells in the Informal Settlements of Kisumu City

Kisumu city, like many cities in the developing world, has increased burden of urban informal settlements where access to basic sanitation and water remain a challenge. Despite several studies focussing on sanitation and water situation within Kisumu environment, elaborate research on the influence of shallow water table on the construction of facilities and quality of structures has however not been extensively reported. In order to discuss potential implications of sanitation facility quality on public health in the informal settlements, this study characterised sanitation facilities by depth and quality of superstructure, analysed association between depth of pit latrines and types, and between depth of pit latrines and shallow wells (SWs). The study targeted five urban informal settlements in Kisumu city namely Nyalenda A, Nyalenda B, Manyatta B, Manyatta A and Obunga, and two peri-urban informal settlements of Korando and Kogony. The study involved physical ground surveys on all SWs in the study area and convenience sampling of toilet facilities within 30 m radius to the water points. Analysis was carried descriptively and with the help of GIS spatial analysis tool. A total of 100 SWs and 400 pit latrines were studied. Our findings revealed some evidence of the influence of shallow water table on the construction quality and depth of pit latrines and SWs both in the urban informal settlements and those of the peri-urban. The mean depth of pit latrines and SWs in the urban informal settlements ranged from 0.25 m–3.8 m and 0.0 m–4 m, respectively, while peri-urban areas ranged from 3.5 m–8.1 m and 7.6 m–14.4 m. The study also established that most pit latrines were raised to a mean height of 0.25 m–0.5 m above ground. Analysis of depth revealed that the depth of pit latrines and shallow wells in the urban informal settlements were overlapped while those of the peri-urban were not overlapped. Moreover, majority of pit latrines in the urban informal settlements were raised by an average 0.25 m–0.5 m above mean ground level, a strategy, identified by residents, to overcoming the double challenge of flooding and cross contamination. Overall, the study established that, where construction depth of both pit latrines and shallow wells is limited, the incentive to construct quality pit latrines or SWs lessens, the possible reason for the prevalence of low quality and less durable facilities in the urban informal settlements as opposed to peri-urban areas where deeper and improved pit latrines and wells exist. In conclusion, the high prevalence of poor-quality pit latrines and SWs in the informal settlement predisposes residents in these settlements to public hygiene challenges with potential escalation during floods. Creation of awareness on improved toilet facilities with potential of withstanding the challenges of raised water table and frequent flood risks is recommended in the short term while development of specific toilet construction guidelines concerning depth and superstructure recommended on the long term

Restoration of degraded grasslands, but not invasion by Prosopis juliflora, avoids trade-offs between climate change mitigation and other ecosystem services

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. We assessed how invasion by Prosopis juliflora and restoration of degraded grasslands in a semi-arid region in Baringo, Kenya affected soil organic carbon, biodiversity and fodder availability. Thirty years of grassland restoration replenished soil organic carbon to 1 m depth at a rate of 1.4% per year and restored herbaceous biomass to levels of pristine grasslands, while plant biodiversity remained low. Invasion of degraded grasslands by P. juliflora increased soil organic carbon primarily in the upper 30 cm and suppressed herbaceous vegetation. We argue that, in contrast to encroachment by invasive alien trees, restoration of grasslands in tropical semi-arid regions can both serve as a measure for climate change mitigation and help restore key ecosystem services important for pastoralists and agro-pastoralist communities

Water chemistry poses health risks as reliance on groundwater increases: a systematic review of hydrogeochemistry research from Ethiopia and Kenya

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. This article systematically reviews groundwater chemistry results from 160 studies to evaluate potential health risk in two case countries: Ethiopia and Kenya. Most studies evaluated drinking water suitability, focusing on priority parameters (fluoride, arsenic, nitrate, or salinity; 18 %), pollution impacts (10 %), or overall suitability (45 %). The remainder characterised general hydrogeochemistry (13 %), flow dynamics (10 %), or water quality suitability for irrigation (3 %). Only six studies (4 %) reported no exceedance of drinking water quality thresholds. Thus, chemical contaminants occur widely in groundwaters that are used for drinking but are not regularly monitored: 78 % of studies reported exceedance of contaminants that have direct health consequences ranging from hypertension to disrupted cognitive development and degenerative disease, and 81 % reported exceedance of aesthetic parameters that have indirect health impacts by influencing perception and use of groundwater versus surface water. Nevertheless, the spatiotemporal coverage of sampling has substantial gaps and data availability bias is driven by a) the tendency for research to concentrate in areas with known water quality problems, and b) analytical capacity limitations. Improved in-country analytical capacity could bolster more efficient assessment and prioritisation of water chemistry risks. Overall, this review demonstrates that universal and equitable access to safe drinking water (Sustainable Development Goal target 6.1) will not be achieved without wider implementation of groundwater treatment, thus a shift is required in how water systems are designed and managed