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Nowicki S, Birhanu B, Tanui F, Sule MN, Charles K, Olago D, Kebede S. Water chemistry poses health risks as reliance on groundwater increases: A systematic review of hydrogeochemistry research from Ethiopia and Kenya. Sci Total Environ 2023; 904:166929. [PMID: 37689199 DOI: 10.1016/j.scitotenv.2023.166929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 09/04/2023] [Accepted: 09/06/2023] [Indexed: 09/11/2023]
Abstract
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.
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Affiliation(s)
- Saskia Nowicki
- School of Geography and the Environment, University of Oxford, South Parks Road, OX1 3QY Oxford, United Kingdom.
| | - Behailu Birhanu
- School of Earth Sciences, Addis Ababa University, Arat Killo Campus, NBH1 King George VI St, Addis Ababa, Ethiopia
| | - Florence Tanui
- Department of Earth and Climate Sciences, University of Nairobi, P.O. Box 29053, Nairobi, Kenya; Institute for Climate Change and Adaptation, University of Nairobi, P.O. Box 30197-00100, Nairobi, Kenya
| | - May N Sule
- Cranfield Water Science Institute, School of Water, Energy and Environment, Cranfield University, College Road, MK43 0AL Cranfield, United Kingdom
| | - Katrina Charles
- School of Geography and the Environment, University of Oxford, South Parks Road, OX1 3QY Oxford, United Kingdom
| | - Daniel Olago
- Department of Earth and Climate Sciences, University of Nairobi, P.O. Box 29053, Nairobi, Kenya; Institute for Climate Change and Adaptation, University of Nairobi, P.O. Box 30197-00100, Nairobi, Kenya
| | - Seifu Kebede
- School of Earth Sciences, Addis Ababa University, Arat Killo Campus, NBH1 King George VI St, Addis Ababa, Ethiopia; Centre for Water Resources Research, University of KwaZulu Natal, Pietermaritzburg Private Bag X01, Scottsville, South Africa
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Gno-Solim Ela N, Olago D, Akinyi AD, Tonnang HE. Assessment of the effects of climate change on the occurrence of tomato invasive insect pests in Uganda. Heliyon 2023; 9:e13702. [PMID: 36865473 PMCID: PMC9971177 DOI: 10.1016/j.heliyon.2023.e13702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 01/31/2023] [Accepted: 02/08/2023] [Indexed: 02/17/2023] Open
Abstract
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. Assessing the impact of temperature, rainfall, relative humidity, and windspeed on the occurrence of invasive tomato insect pests, gives a better understanding of managing and limiting the bio-invasion process sustainably. We used the Mann Kendall trend Test to establish trends in climate variables from 1981 to 2020 and to document the trend in the occurrence of new invasive pests. The relationship between climate variables and pests occurrence is analyzed using Pearson's correlation and the Generalized Linear Model (GLM-quasi-Poisson) in R-software. The results showed that temperature and windspeed have significantly increased in both Kampala and Namutumba by 0.049 °C, 0.005 m s-1and by 0.037 °C, 0.003 m s-1 per year respectively while in Mbale there was no change in wind speed pattern and a non-significant decrease in temperature. There was an overall rainfall increase in Kampala (p = 0.029) by 0.241 mm, Mbale (p = 0.0011) by 9.804 mm, and Namutumba (p = 0.394) by 0.025 mm. On the other hand, humidity has decreased both in Kampala (p = 0.001) by 13.3% and in Namutumba (p = 0.035) by 13.2% while there was a no significant change in Mbale. The results of GLM showed that each variable, taken individually, had a direct effect on the pests' occurrence in all three districts. However, with all these climate variables taken together, the effect on the pests' occurrence varied with each of the three districts; Kampala, Mbale, and Namutumba. This study demonstrated that pest occurrence is different from one agroecology to another. Our findings suggest that climate change is a driver that favors bio-invasion of tomato invasive insect pests occurrence in Uganda. It calls for awareness to policymakers and stakeholders to consider climate-smart pest management practices and policies to deal with bio-invasion.
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Affiliation(s)
- N'dakpaze Gno-Solim Ela
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya,Institute for Climate Change and Adaptation, University of Nairobi and South Eastern Kenya University, P. O. Box 29053, Nairobi, Kenya
| | - Daniel Olago
- Institute for Climate Change and Adaptation, University of Nairobi and South Eastern Kenya University, P. O. Box 29053, Nairobi, Kenya
| | - Amwata Dorothy Akinyi
- Institute for Climate Change and Adaptation, University of Nairobi and South Eastern Kenya University, P. O. Box 29053, Nairobi, Kenya
| | - Henri E.Z. Tonnang
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya,Corresponding author.
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Njagi DM, Routh J, Odhiambo M, Luo C, Basapuram LG, Olago D, Klump V, Stager C. A century of human-induced environmental changes and the combined roles of nutrients and land use in Lake Victoria catchment on eutrophication. Sci Total Environ 2022; 835:155425. [PMID: 35489498 DOI: 10.1016/j.scitotenv.2022.155425] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 04/17/2022] [Accepted: 04/17/2022] [Indexed: 06/14/2023]
Abstract
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. In this study, we determine the 1) changes in concentrations of total organic carbon (TOC), black carbon (BC), total nitrogen (TN), C/N ratio, and phosphorous (P) fractions in catchment sediments and the open lake, 2) distribution of diatom population in the lake, and 3) land use and land cover changes in the catchment. The distribution of TOC, BC, TN, C/N, and P correlate while showing spatial and temporal variations. In particular, the steady increase in BC confirms atmospheric inputs from anthropogenic activities in the catchment. However, lake sediments show more variations than catchment-derived sediments in geochemical trends. Notably, the catchment has undergone dramatic land use changes since the 1960s (post-independence). This change is most evident in satellite records from 1985 to 2014, which indicate accelerated human activities. For example, urban growth (666-1022%) and agricultural expansion (23-48%) increased sharply at the expense of a decline in forest cover, grassland, and woodlands in the catchment. Cities like Kisumu and Homa Bay expanded, coinciding with rapid population growth and urbanization. Consequently, nutrient inputs have increased since the 1960s, and this change corresponds with the divergence of diatom communities in the lake. In addition, the transition to Nitzschia and cyanobacteria mark increasing cultural eutrophication in the lake. The geochemical trends and statistical data support our inference(s) and provide insights into urban development and agriculture practices, which propelled increased nutrients from the catchment and productivity shifts in the lake.
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Affiliation(s)
- Dennis M Njagi
- Department of Thematic Studies-Environmental Change, Linköping University, Linköping, Sweden; Department of Geology, University of Nairobi, P.O. Box 30197, Nairobi, Kenya
| | - Joyanto Routh
- Department of Thematic Studies-Environmental Change, Linköping University, Linköping, Sweden.
| | - Moses Odhiambo
- Department of Thematic Studies-Environmental Change, Linköping University, Linköping, Sweden
| | - Chen Luo
- Department of Thematic Studies-Environmental Change, Linköping University, Linköping, Sweden
| | - Laxmi Gayatri Basapuram
- Department of Thematic Studies-Environmental Change, Linköping University, Linköping, Sweden
| | - Daniel Olago
- Department of Geology, University of Nairobi, P.O. Box 30197, Nairobi, Kenya
| | - Val Klump
- Department of Biological Sciences and Department of Geosciences, Great Lakes WATER Institute, University of Wisconsin-Milwaukee, 600 East Greenfield Avenue, Milwaukee, WI, USA
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Campos LC, Olago D, Osborn D. Water and the UN sustainable development goals. UCL Open Environ 2022; 4:e029. [PMID: 37228457 PMCID: PMC10208314 DOI: 10.14324/111.444/ucloe.000029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Editorial call for contributions and invitation to join our synthetic effort and debate on Water and the UN Sustainable Development Goals (SDGs).
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Affiliation(s)
- Luiza C. Campos
- Department of Civil, Environment & Geomatic Engineering, Faculty of Engineering Science, University College London, Gower Street, London WC1E 6BT, UK
| | - Daniel Olago
- Department of Geology, University of Nairobi, University of Nairobi, P.O Box 30197, Nairobi, Kenya
| | - Dan Osborn
- Chair of Human Ecology, Department of Earth Sciences, University College London, 2 Taviton Street, London WC1H 0BT, UK
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Mbaabu PR, Olago D, Gichaba M, Eckert S, Eschen R, Oriaso S, Choge SK, Linders TEW, Schaffner U. Restoration of degraded grasslands, but not invasion by Prosopis juliflora, avoids trade-offs between climate change mitigation and other ecosystem services. Sci Rep 2020; 10:20391. [PMID: 33235254 PMCID: PMC7686326 DOI: 10.1038/s41598-020-77126-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 11/05/2020] [Indexed: 12/02/2022] Open
Abstract
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.
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Affiliation(s)
- Purity Rima Mbaabu
- Kenya Forestry Research Institute (KEFRI), Baringo Sub-Centre, P.O. Box 57-30403, Marigat, Kenya. .,Institute for Climate Change and Adaptation (ICCA), University of Nairobi, P.O. Box 30197-00100, GPO, Nairobi, Kenya. .,Faculty of Humanities and Social Sciences, Chuka University, P.O. Box 109-60400, Chuka, Kenya.
| | - Daniel Olago
- Institute for Climate Change and Adaptation (ICCA), University of Nairobi, P.O. Box 30197-00100, GPO, Nairobi, Kenya
| | - Maina Gichaba
- Institute for Climate Change and Adaptation (ICCA), University of Nairobi, P.O. Box 30197-00100, GPO, Nairobi, Kenya
| | - Sandra Eckert
- Centre for Development and Environment (CDE), University of Bern, Mittelstrasse 43, Bern, Switzerland
| | - René Eschen
- CABI, Rue des Grillons 1, Delémont, Switzerland
| | - Silas Oriaso
- Institute for Climate Change and Adaptation (ICCA), University of Nairobi, P.O. Box 30197-00100, GPO, Nairobi, Kenya
| | - Simon Kosgei Choge
- Kenya Forestry Research Institute (KEFRI), Baringo Sub-Centre, P.O. Box 57-30403, Marigat, Kenya
| | - Theo Edmund Werner Linders
- CABI, Rue des Grillons 1, Delémont, Switzerland.,Institute of Plant Sciences, University of Bern, Altenbergrain 21, Bern, Switzerland.,Senckenberg Biodiversity and Climate Research Centre (SBiK-F), Senckenberganlage 25, 60325, Frankfurt am Main, Germany
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Sorensen JPR, Carr AF, Nayebare J, Diongue DML, Pouye A, Roffo R, Gwengweya G, Ward JST, Kanoti J, Okotto-Okotto J, van der Marel L, Ciric L, Faye SC, Gaye CB, Goodall T, Kulabako R, Lapworth DJ, MacDonald AM, Monjerezi M, Olago D, Owor M, Read DS, Taylor RG. Tryptophan-like and humic-like fluorophores are extracellular in groundwater: implications as real-time faecal indicators. Sci Rep 2020; 10:15379. [PMID: 32958794 PMCID: PMC7505957 DOI: 10.1038/s41598-020-72258-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 06/17/2020] [Indexed: 12/17/2022] Open
Abstract
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 < 0.22 µm) TLF and HLF in 140 groundwater sources across a range of urban population densities in Kenya, Malawi, Senegal, and Uganda. Where changes in fluorescence occurred following filtration they were correlated with potential controlling variables. A significant reduction in TLF following filtration (ΔTLF) was observed across the entire dataset, although the majority of the signal remained and thus considered extracellular (median 96.9%). ΔTLF was only significant in more urbanised study areas where TLF was greatest. Beneath Dakar, Senegal, ΔTLF was significantly correlated to total bacterial cells (ρs 0.51). No significant change in HLF following filtration across all data indicates these fluorophores are extracellular. Our results suggest that TLF and HLF are more mobile than faecal indicator bacteria and larger pathogens in groundwater, as the predominantly extracellular fluorophores are less prone to straining. Consequently, TLF/HLF are more precautionary indicators of microbial risks than faecal indicator bacteria in groundwater-derived drinking water.
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Affiliation(s)
- James P R Sorensen
- British Geological Survey, Maclean Building, Wallingford, OX10 8BB, UK.
- Department of Geography, University College London, London, WC1E 6BT, UK.
| | - Andrew F Carr
- Department of Geography, University College London, London, WC1E 6BT, UK
| | - Jacintha Nayebare
- Department of Geology and Petroleum Studies, Makerere University, Kampala, Uganda
| | - Djim M L Diongue
- Department of Geology, Universite Cheikh Anta Diop, Dakar, Senegal
| | - Abdoulaye Pouye
- Department of Geology, Universite Cheikh Anta Diop, Dakar, Senegal
| | - Raphaëlle Roffo
- Department of Geography, University College London, London, WC1E 6BT, UK
| | - Gloria Gwengweya
- Chancellor College, University of Malawi, P.O. Box 280, Zomba, Malawi
| | - Jade S T Ward
- British Geological Survey, Keyworth, NG12 5GG, UK
- Department of Civil and Environmental Engineering, University of Surrey, Guildford, GU2 7XH, UK
| | - Japhet Kanoti
- Department of Geology, University of Nairobi, Nairobi, Kenya
| | - Joseph Okotto-Okotto
- Victoria Institute for Research on Environment and Development (VIRED) International, Rabuour Environment and Development Centre, Kisumu-Nairobi Road, P.O. Box, Kisumu, 6423-40103, Kenya
| | | | - Lena Ciric
- Department of Civil, Environmental and Geomatic Engineering, University College London, London, WC1E 6BT, UK
| | - Seynabou C Faye
- Department of Geology, Universite Cheikh Anta Diop, Dakar, Senegal
| | - Cheikh B Gaye
- Department of Geology, Universite Cheikh Anta Diop, Dakar, Senegal
| | - Timothy Goodall
- Centre for Ecology and Hydrology, Maclean Building, Wallingford, OX10 8BB, UK
| | - Robinah Kulabako
- Department of Civil and Environmental Engineering, Makerere University, Kampala, Uganda
| | - Daniel J Lapworth
- British Geological Survey, Maclean Building, Wallingford, OX10 8BB, UK
| | - Alan M MacDonald
- British Geological Survey, Lyell Centre, Research Avenue South, Edinburgh, EH14 4AP, UK
| | - Maurice Monjerezi
- Chancellor College, University of Malawi, P.O. Box 280, Zomba, Malawi
| | - Daniel Olago
- Department of Geology, University of Nairobi, Nairobi, Kenya
| | - Michael Owor
- Department of Geology and Petroleum Studies, Makerere University, Kampala, Uganda
| | - Daniel S Read
- Centre for Ecology and Hydrology, Maclean Building, Wallingford, OX10 8BB, UK
| | - Richard G Taylor
- Department of Geography, University College London, London, WC1E 6BT, UK
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Ferrer N, Folch A, Lane M, Olago D, Katuva J, Thomson P, Jou S, Hope R, Custodio E. How does water-reliant industry affect groundwater systems in coastal Kenya? Sci Total Environ 2019; 694:133634. [PMID: 31756808 DOI: 10.1016/j.scitotenv.2019.133634] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 07/03/2019] [Accepted: 07/26/2019] [Indexed: 06/10/2023]
Abstract
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). The area where this approach has been applied is Kwale County (in Coastal Kenya) in a hydrogeological context representative of an important part of the east coast of the continent, where new mining and agriculture activities co-exist with tourism and local communities. The results show that the lack of aquifer systems data can be overcome, at least partly, by integrating different sources of information. Most of the time, water-reliant users collect specific hydrogeological information that can contribute to defining the overall hydrogeological system, since their own main purpose is to exploit the aquifer with the maximum productivity. Therefore, local community water usage, together with different stakeholder's knowledge and good corporate water management act as a catalyst for providing critical data, and allows the generation of credible models for future groundwater management and resource allocation. Furthermore, complementary but simple information sources such as in situ interviews, Google Earth, Trip Advisor and easy-to use analytical methods that can be applied in the African context as in many developing countries, and enables groundwater abstraction to be estimated and the sustainability of the aquifer system to be defined, allowing potential future risks to be assessed.
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Affiliation(s)
- Nuria Ferrer
- Department of Civil and Environmental Engineering (DECA), Universitat Politècnica de Catalunya (UPC), Jordi Girona 1-3, 08034 Barcelona, Spain; Associated Unit: Hydrogeology Group (UPC-CSIC), Spain.
| | - Albert Folch
- Department of Civil and Environmental Engineering (DECA), Universitat Politècnica de Catalunya (UPC), Jordi Girona 1-3, 08034 Barcelona, Spain; Associated Unit: Hydrogeology Group (UPC-CSIC), Spain
| | | | - Daniel Olago
- Department of Geology, University of Nairobi, Kenya
| | - Jacob Katuva
- Smith School of Enterprise and the Environment, University of Oxford, United Kingdom
| | - Patrick Thomson
- Smith School of Enterprise and the Environment, University of Oxford, United Kingdom
| | - Sonia Jou
- Department of Civil and Environmental Engineering (DECA), Universitat Politècnica de Catalunya (UPC), Jordi Girona 1-3, 08034 Barcelona, Spain; Associated Unit: Hydrogeology Group (UPC-CSIC), Spain
| | - Rob Hope
- Smith School of Enterprise and the Environment, University of Oxford, United Kingdom
| | - Emilio Custodio
- Department of Civil and Environmental Engineering (DECA), Universitat Politècnica de Catalunya (UPC), Jordi Girona 1-3, 08034 Barcelona, Spain; Associated Unit: Hydrogeology Group (UPC-CSIC), Spain
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Ferrer N, Folch A, Lane M, Olago D, Odida J, Custodio E. Groundwater hydrodynamics of an Eastern Africa coastal aquifer, including La Niña 2016-17 drought. Sci Total Environ 2019; 661:575-597. [PMID: 30682610 DOI: 10.1016/j.scitotenv.2019.01.198] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 01/15/2019] [Accepted: 01/15/2019] [Indexed: 06/09/2023]
Abstract
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. In the context of East Africa, groundwater management is also hampered by a lack of information on aquifer characteristics. With the aim of addressing this knowledge gap, this study shows the hydrogeological behaviour before and during La Niña 2016/17 drought in southern coastal Kenya on a groundwater system which sits within a geological structure which is representative of an important portion of the East African coast. Diverse hydrochemical and isotopic campaigns, as well as groundwater head variation measurements, were carried out to study the groundwater hydrodynamics and thus characterize the aquifer system under climatic conditions before and during the La Niña event. This information is complemented with an estimation of changes in local recharge since 2012 using local data sets. The main consequence of the drought was a 69% reduction of recharge compared to an average climatic year. There was reduced recharge during the first rainy season (April-June) and no recharge during the second wet season (October-December). There was a concurrent increase in seawater intrusion even during the wet season.
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Affiliation(s)
- Núria Ferrer
- Department of Civil and Environmental Engineering, Universitat Politècnica de Catalunya, Jordi Girona 1-3, 08034 Barcelona, Spain; Associated Unit: Hydrogeology Group (UPC-CSIC), Barcelona, Spain.
| | - Albert Folch
- Department of Civil and Environmental Engineering, Universitat Politècnica de Catalunya, Jordi Girona 1-3, 08034 Barcelona, Spain; Associated Unit: Hydrogeology Group (UPC-CSIC), Barcelona, Spain
| | | | - Daniel Olago
- Department of Geology, University of Nairobi, Kenya
| | - Julius Odida
- Department of Geology, University of Nairobi, Kenya
| | - Emilio Custodio
- Department of Civil and Environmental Engineering, Universitat Politècnica de Catalunya, Jordi Girona 1-3, 08034 Barcelona, Spain; Associated Unit: Hydrogeology Group (UPC-CSIC), Barcelona, Spain; Royal Academy of Sciences of Spain, Spain
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Muhati GL, Olago D, Olaka L. Land use and land cover changes in a sub-humid Montane forest in an arid setting: A case study of the Marsabit forest reserve in northern Kenya. Glob Ecol Conserv 2018. [DOI: 10.1016/j.gecco.2018.e00512] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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Muhati GL, Olago D, Olaka L. Quantification of carbon stocks in Mount Marsabit Forest Reserve, a sub-humid montane forest in northern Kenya under anthropogenic disturbance. Glob Ecol Conserv 2018. [DOI: 10.1016/j.gecco.2018.e00383] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
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Muhati GL, Olago D, Olaka L. Participatory scenario development process in addressing potential impacts of anthropogenic activities on the ecosystem services of Mt. Marsabit forest, Kenya. Glob Ecol Conserv 2018. [DOI: 10.1016/j.gecco.2018.e00402] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Loomis SE, Russell JM, Verschuren D, Morrill C, De Cort G, Sinninghe Damsté JS, Olago D, Eggermont H, Street-Perrott FA, Kelly MA. The tropical lapse rate steepened during the Last Glacial Maximum. Sci Adv 2017; 3:e1600815. [PMID: 28138544 PMCID: PMC5271593 DOI: 10.1126/sciadv.1600815] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 12/19/2016] [Indexed: 06/01/2023]
Abstract
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. Comparison of our data with paleoclimate simulations indicates that state-of-the-art models underestimate this lapse-rate change. Consequently, future high-elevation tropical warming may be even greater than predicted.
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Affiliation(s)
- Shannon E. Loomis
- Department of Earth, Environmental, and Planetary Sciences, Brown University, 324 Brook Street, Box 1846, Providence, RI 02912, USA
| | - James M. Russell
- Department of Earth, Environmental, and Planetary Sciences, Brown University, 324 Brook Street, Box 1846, Providence, RI 02912, USA
- Institute at Brown for Environment and Society, Brown University, Providence, RI 02912, USA
| | - Dirk Verschuren
- Department of Biology, Limnology Unit, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Carrie Morrill
- Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, CO 80305–3328, USA
- National Centers for Environmental Information, National Oceanic and Atmospheric Administration, Boulder, CO 80305–3328 USA
| | - Gijs De Cort
- Department of Biology, Limnology Unit, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
- Department of Earth Sciences, Royal Museum for Central Africa, Leuvensesteenweg 13, 3080 Tervuren, Belgium
| | - Jaap S. Sinninghe Damsté
- Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, P.O. Box 59, 1790 AB Den Burg, Texel, Netherlands
- Faculty of Geosciences, University of Utrecht, P.O. Box 80.021, 3508 TA Utrecht, Netherlands
| | - Daniel Olago
- Department of Geology, University of Nairobi, P.O. Box 30197-00100, Nairobi, Kenya
- Institute for Climate Change and Adaptation, University of Nairobi, Nairobi, Kenya
| | - Hilde Eggermont
- Department of Biology, Limnology Unit, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
- Belgian Biodiversity Platform, Royal Belgian Institute for Natural Sciences, Vautierstraat 29, 1000 Brussels, Belgium
| | | | - Meredith A. Kelly
- Department of Earth Sciences, Dartmouth College, Hanover, NH 03750, USA
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13
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Bennett MR, Harris JWK, Richmond BG, Braun DR, Mbua E, Kiura P, Olago D, Kibunjia M, Omuombo C, Behrensmeyer AK, Huddart D, Gonzalez S. Early Hominin Foot Morphology Based on 1.5-Million-Year-Old Footprints from Ileret, Kenya. Science 2009; 323:1197-201. [PMID: 19251625 DOI: 10.1126/science.1168132] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Matthew R Bennett
- School of Conservation Sciences, Bournemouth University, Poole, BH12 5BB, UK.
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14
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Olago D, Marshall M, Wandiga SO, Opondo M, Yanda PZ, Kanalawe R, Githeko AK, Downs T, Opere A, Kavumvuli R, Kirumira E, Ogallo L, Mugambi P, Apindi E, Githui F, Kathuri J, Olaka L, Sigalla R, Nanyunja R, Baguma T, Achola P. Climatic, socio-economic, and health factors affecting human vulnerability to cholera in the Lake Victoria basin, East Africa. Ambio 2007; 36:350-8. [PMID: 17626474 DOI: 10.1579/0044-7447(2007)36[350:csahfa]2.0.co;2] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
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. Similarly, sustained temperatures high above normal (T(max)) in two consecutive seasons, followed by a slight cooling in the second season, trigger an outbreak of a cholera epidemic. The health and socioeconomic systems that the lake basin communities rely upon are not robust enough to cope with cholera outbreaks, thus rendering them vulnerable to the impact of climate variability and change. Collectively, this report argues that communities living around the Lake Victoria basin are vulnerable to climate-induced cholera that is aggravated by the low socioeconomic status and lack of an adequate health care system. In assessing the communities' adaptive capacity, the report concludes that persistent levels of poverty have made these communities vulnerable to cholera epidemics.
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Affiliation(s)
- Daniel Olago
- Department of Geology, University of Nairobi, Kenya.
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