Gilbert Ouma | University of Nairobi, Kenya (original) (raw)

Papers by Gilbert Ouma

Kenya Policy Briefs, Feb 26, 2021

The research was conducted to validate the pastoralists' and agro-pastoralists' claim that there ... more The research was conducted to validate the pastoralists' and agro-pastoralists' claim that there has been an increasingly variable and changing climate in the study area. The station average and Theissen polygon methods were used to estimate the mean areal precipitation of the small (Mogotio and Baringo South Sub-counties) and the large area (Baringo County), respectively. The aim of the current study is to analyse rainfall time series over long term observed precipitation and a wide area, detecting potential trends and assessing their significance. Monthly precipitation data for the period 1974-2003 from six weather stations, located mainly in Mogotio and Baringo South sub-counties and covering 3906km 2 were used in the analysis. The data were quality controlled to ensure no missing data and any inconsistencies. Linear regression analysis of the database highlighted that; the trends were predominantly negative, both where the average and Theissen polygon methods were used and over the whole reference period. The negative trends are not significant. This finding implies that the study area has been suffering a precipitation decrease especially in the period under review.

Africa Journal of Physical Sciences ISSN: 2313-3317, Jun 30, 2021

Rock geochemistry influences groundwater quality and the aquifer processes of an area. The geolog... more Rock geochemistry influences groundwater quality and the aquifer processes of an area. The geology of the study area comprises quartzo-feldspathic gneiss and biotite gneiss of the Precambrian basement, sedimentary Turkana Grits and Holocene sediments, Tertiary volcanics comprising nepheline phonolites and augite basalts, alluvial deposits along the banks of major streams and laggas (ephemeral streams), and Quaternary sands that blanket much of the area. This paper evaluates the influence of rock chemistry on groundwater quality in Lodwar area. Conventional petrography and geochemistry techniques involving measurement of major elements using X-ray fluorescence (XRF) and trace elements using and X-ray diffraction (XRD) in 69 rock samples to evaluate their mineralogical compositions. The major rock-forming in rocks of the study area include pyroxenes, olivine, kaolinite, siderite, fluorite calcite and dolomite. These minerals release major ions to groundwater through weathering, leaching, oxidation, dissolution and precipitation, and ion exchange reactions during rock-water interactions. The rocks in study area have generally low amounts of Na and K with modal values < 2.00 wt%, suggesting other sources of Na + and K + ions in groundwater. In contrast, Ca, Mg, Al, Fe and Mn are released to groundwater from rocks, as shown by high modal compositions of individual elements and associated oxides. The higher concentrations of Na + , K + , Ca 2+ and Mg 2+ in the groundwater of the Turkana Grit aquifer relative to the grit rock samples suggest a long history of dissolution and recycling of the groundwater. The ratio SiO2:Al2O3 was found to be greater than 8.0 implying a high degree of maturity of the grits. The results presented by this study show that geological factors and processes have location-specific influence on groundwater quality and should be considered in aquifer water quality studies and supply development across Africa's vast ASAL regions.

American Journal of Climate Change, 2022

River basins in the drylands of Sub-Saharan Africa have traditionally been utilized for pastoral ... more River basins in the drylands of Sub-Saharan Africa have traditionally been utilized for pastoral livelihoods under communal land tenure. Communities in West Pokot in Kenya have continued to experience increased precipitation and temperature as a result of climate variability and change. This study aimed at assessing the impact of climate variability and change at micro-basin level in order to address research and policy gaps on climate change and food security as policy arena shifts from centralized to decentralized governance in Kenya. Primary quantitative data was collected from 387 households' perceptions of climate variability and change and its implications on food security were measured. Food security index score was calculated. The annual rainfall trend over Suam river basin for the period (1981-2020), was characterized by a linearly increasing annual rainfall trend. Mann Kendall test Z-statistics and Tau were at 2.3578 and 0.0720 respectively. The basin experienced the highest rainfall variability during the first decade (1981-1990) with the highest coefficient of rainfall variation noted at 11.5%. The highest temperature was recorded in the third decade (2001-2010) and fourth decade (2011-2020) at 27.0 and 28.2 degrees Celsius respectively. However, the overall index score for food security was 55.78 with food availability scoring the highest index, mean (SD) of 63.41 (36.52). This was attributed to households' practice of both nomadic pastoralism and agro-pastoralism activities. Climate variability and change, have resulted in increased amount of rainfall received providing for opportunity investment in rain water harvesting to support both pastoralism and agro-pastoralism production to enhance food security.

American Journal of Climate Change

A quality decline trend is suspected to be ensuing in the water originating from boreholes in Lan... more A quality decline trend is suspected to be ensuing in the water originating from boreholes in Langata sub-County; a region located to the south of Nairobi, the capital city of Kenya in East Africa. Despite the existence of this worrisome suspicion, no investigation has been conducted to assuage the fears of the exposed population. This situation however contradicts the great augmenting role of borehole water delivered by vendors to consumers as a coping strategy against the pervasive drought induced water shortage challenge afflicting households in Langata. Hence, a question arose as to whether the identified past drought events have had any chance of influencing the ongoing declining trend of the area’s ground water quality. The purpose of this study was therefore to assess the impact of historical drought events on the ground water quality in Langata Sub County. The profile of drought indices was superimposed over the area’s time series geochemical water quality indices’ profile. ...

African Journal of Agricultural Research, 2021

The Maasai pastoralists inhabiting Kajiado County are known for rearing large herds of animals. L... more The Maasai pastoralists inhabiting Kajiado County are known for rearing large herds of animals. Livestock has enabled them to attain food and nutritional security. However, natural resources are dwindling fast under the swift development context. The private holding of land is becoming more prevalent in an area formally known for its communal land setup. The emerging land tenure systems have disregarded the traditional production systems. Consequently, their herds have exhibited poor health status and low productivity. To address these problems, the study focussed on the Maasai pastoralists' perception to evaluate their cultural dispositions. The study employed a cross-sectional design which consisted of semi-structured questionnaires. The qualitative data generated were subjected to thematic analysis and thereafter, translated into meaningful actions and summarised. The quantitative data was aggregated into frequencies and composite scores computed. The results revealed increased production risks, changes in land utility and notable growing numbers of Maasai pastoralists being dispossessed from their customary land by private landholders. Despite the aforementioned hurdles, the Maasai pastoralists had shown cohesiveness in rangeland management. It was also evident that the Maasai pastoralists were embracing different livelihoods, conservation, tourism and institutional support based on their strategic priorities to enhance their resilience. Thus, the study recommends that the Maasai pastoralists be assigned a proactive role as the Government relooks at territorial demarcations in the ongoing land registration process.

The long rains occurring in March-April-May (MAM) in East Africa have been notoriously difficult ... more The long rains occurring in March-April-May (MAM) in East Africa have been notoriously difficult to capture in climate models and the CMIP5 ensemble. This is highlighted by the fact that CMIP5 models show increasing MAM rainfall in East Africa while measurements show a drying at the end of the 20th century. Evaluating models with a process-based analysis is key to selecting which models to use for projections on a regional scale, but the MAM season poses an extra challenge in this regard since the processes governing the rainfall are hard to pinpoint in the historical period.

1 Improving water security for the poor in Kenya 1.1 Kenya-profile and progress 1.2 Decentralisat... more 1 Improving water security for the poor in Kenya 1.1 Kenya-profile and progress 1.2 Decentralisation-bringing power to the people? 1.3 Reducing vulnerabilities to climate shocks 1.4 Inequality and poverty 1.5 Mobile ecosystems 2.1 Poverty and welfare 2 Understanding the 'real nature' of poverty in Kenya 2.2 Policy and progress 2.3 Risks and vulnerability 3 Addressing water security risks to poverty in Kenya 3.1 Summary 3.2 Water Security Observatory 3.3 Small towns in fragile lands 3.4 Building water secure institutions 4 Conclusion Key references Cover photo: Tim Foster Executive summary Kenya is one of Africa's most dynamic and entrepreneurial economies, but one with increasing water security risks. Kenya's implementation of decentralisation from 2010 reflects its commitment to reduce enduring inequalities by establishing 47 county governments in 2013. With a clear mandate, county governments offer a new institutional architecture to address a portfolio of growth and development challenges, including water security for the poor. Current income poverty and multidimensional welfare monitoring do not capture the impact and implications of water shocks or long-term human exposure to water risks. Periodic surveys provide snapshots which weakly relate to major flood or drought shocks, chronic exposure to poor water quality or exclusion from basic water resources or services. Vulnerable individuals (children, urban poor, elderly, ill) are merged into household data and are thus largely invisible or ignored. With increasing water security risks there is a need for 'climate services', whereby scientists work with decision makers to explore the resilience of their decisions to climate variability and change. Current gaps include lack of data about rainfall variability, extremes and future changes, which are relevant both for short-term operational decisions and for long-term strategic planning. These data needs to be presented considering impactrelevant water security metrics with user defined thresholds and decision-relevant spatial scales. This knowledge will help establish whether strategies put in place for current water security will survive the near-term manifestation of climate change. Kenya's advances in mobile ecosystems are one response to its water security and poverty challenges. Mobile technologies offer 'accidental infrastructure' to provide high quality, low cost and remote data to support decision-making. Mobile platforms narrow the distance between data and decision-making. Political accountability can be enhanced with electoral cycles and physical proximity recalibrating decision-making processes and priorities. The University of Oxford is building sciencepractitioner partnerships with county governments, the Ministry of Water and Irrigation, the Water Services Regulatory Board, UNICEF, the University of Nairobi to establish Water Security Observatories for 'small towns and fragile lands' in Turkana County and 'build water secure institutions' in Kitui County. Impacts and implications of the work will support wider regional initiatives to improve water security for millions of poor people.

Journal of Water Resource and Protection, 2019

This study aimed at identifying the most preferred water quality tracking system (WQTS) for adopt... more This study aimed at identifying the most preferred water quality tracking system (WQTS) for adoption and the determining factors for the same among the Langata sub County households in Nairobi city, Kenya. Perrenial municipal water shortage in this neighborhood has forced the residents to depend on vended water supplication but whose quality is not possible to verify at the moment. Accordingly, a mobile phone quality tracing application running on blockchain technology platform was developed to fill the gap of provenance tracking. A non-market discrete choice experiments (DCEs) model was deployed in which four-option attribute bundles; with one being the "status quo" choice were presented to each of the 382 randomly sampled respondents from the five wards within the area. Results indicated that Option 2; the communally managed WQTS emerged as the most preferred choice at 53.9%. Secondly, the male factor was identified as the major determinant to this decision. In conclusion, the study proposes for the installation of this new WQTS which will trigger a 12% adjustment of the average household's monthly water bill. In addition, this paper recommends for a city-wide assessment of residents' willingness to pay (WTP) for this WQTS, which it deems as an improved response to water shortage problem. Finally, the study contributes to the application of DCEs model in technology adoption literature.

Journal of Science and Technology (Ghana), 2011

The daily meteorological data of relative humidity, maximum, minimum, and average temperatures ob... more The daily meteorological data of relative humidity, maximum, minimum, and average temperatures obtained from five stations of the Kenya Meteorological Department over the period 1986 to 2005 were filtered and reduced to monthly means. Monthly data of solar indices: Sunspot number, F10.7 cm solar radio flux and Mg II core-towing ratio covering the same period were employed to model the meteorological variables using the linear multivariate model and applying least square fittings. Validity of the models was tested using Mean Bias Error (MBE) and Root Mean Square Error (RMSE) statistical indicators. The correlations between the observed and predicted values from the models were significant at above 95% level of confidence. The models show the effect of solar forcing on the climatic parameters at different locations in Kenya. Solar forcing of climate is evident in Kenya.

Contribution of Agricultural …, 2010

to investigate the ethnobotanical and chemical characterization of selected medicinal plants grow... more to investigate the ethnobotanical and chemical characterization of selected medicinal plants growing in South Nandi District in the year 2004 and 2005. Subsequently, propagation studies were carried out on the identified endangered medicinal plants. Local communities who use medicinal plants were interviewed. Ethnobotanical data on families, plant species, botanical name, local name, part (s) used, popular ethnobotanical medicinal use, forms of preparation and applications of the herbal remedies were collected. Plants were collected, pressed, dried, preserved, mounted and identified through available literature and voucher specimens at the University of Nairobi and National Museum Laboratories. From the surveys carried out it was observed that the endangered plants were Asystasia schimperi, Carissa edulis, Toddalia asiatica .These were propagated using stem cuttings subjected to different concentrations of auxin in a polypropagator in a completely randomized design experiment. It was found that as auxin concentration increased from 100 ppm to 500 ppm, there was increase in rooting and growth in the decreasing order of Asystasia schimperi, Carissa edulis and T. asiastica. The treated cuttings were planted in polythene pots, which were placed in a non-mist propagator. The duration of the experiment on propagation was four months and the data taken were number of rooted plants, plant height, and number of leaves. The data on propagation was subjected to analysis of variance and Least Significant Difference (LSD = P< 0.05) separation of means. The results showed that hormone concentration, species and date of sampling significantly (P< 0.05) affected the number of leaves, plant height, and number of rooted cuttings. A. schimperi had the best rooting and subsequent growth followed by Carissa edulis and lastly Toddalia asiastica. It is concluded that Asystasia schimperi and C. edulis can be easily propagated by stem cuttings hence introduced to the farmers of South Nandi District. 2 INTRODUCTION: Man uses plants in many different ways to meet his basic needs food, clothing and shelter. Wild plants supply medicine, crafts and cosmetics to rural and urban communities.. In addition, wild

Bulletin of the American Meteorological Society

The Turkana Low-level Jet (LLJ) is an intrinsic part of the African climate system. It is the pri... more The Turkana Low-level Jet (LLJ) is an intrinsic part of the African climate system. It is the principle conduit for water vapour transport to the African interior from the Indian Ocean, and droughts in East Africa tend to occur when the jet is strong. The only direct observations of the Turkana Jet come from manual tracking of pilot balloons in the 1980s. Now, modern reanalysis datasets disagree with one another over the strength of jet winds and underestimate the strength of the jet by 25-75% compared to the pilot balloon data. This article gives an overview of a month-long field campaign based in northwest Kenya - the Radiosonde Investigation For the Turkana Jet (RIFTJet) - which measured the Turkana Jet for the first time in forty years using modern technologies. Radiosonde data reveal a persistent low-level jet, which formed on every night of the campaign, with an average low-level maximum wind speed of 16.8 m.s-1 at 0300LT. One of the latest reanalysis datasets (ERA5) underesti...

Encyclopedia of the UN Sustainable Development Goals, 2019

Journal of Water Resource and Protection, 2019

Interest on the investigation of groundwater depletion threat is growing globally and Langata sub... more Interest on the investigation of groundwater depletion threat is growing globally and Langata sub County in Nairobi, the capital city of the Republic of Kenya, is not an exception. Because of drought-induced water shortage, households in Langata do rely on borehole water to augment their intermittent municipal water supply system. Consequently, there is an upsurge of borehole developments as drought events unfold. Previous studies here have focused on impact of borehole depths and density yet little seems to have been done to compute the correlation coefficient between drought events data and historical borehole development records as an assessment for groundwater "grab" syndrome. This study used drought index computation method (SPI) alongside other statistical methods to seek the answer to the problem. Using 57 years of monthly rainfall data and 26 years of borehole development data, the study established that, there is a positive correlation coefficient. Similarly, a trend analysis of borehole drilling and struck water level depths indicated a positive parallel rising trend on both. Further, when the borehole distribution map and struck water level contour maps were plotted, a sign of a probable well interference during pumping was detected, which however, requires a new investigation to confirm the syndrome of groundwater depletion threat. The study has contributed to the groundwater depletion research by deploying statistical research methods for risk detection. Finally, the study has proposed for a new groundwater management policy that will encourage initiation of artificial recharge schemes for the study site and beyond.

Applied Physics Research, 2016

In this study, a statistical analysis between three solar activity indices (SAI) namely; sunspot ... more In this study, a statistical analysis between three solar activity indices (SAI) namely; sunspot number (ssn), F10.7 index (sf) and Mg II index (mg) and total column ozone (TCO) time series over three cities in Kenya namely; Nairobi (1.17º S; 36.46º E), Kisumu (0.03º S; 34.45º E) and Mombasa (4.02º S; 39.43º E) for the period 1985 - 2011 are considered. Pearson and cross correlations, linear and multiple regression analyses are performed. All the statistical analyses are based on 95% confidence level. SAI show decreasing trend at significant levels with highest decrease in international sunspot number and least in Mg II index. TCO are highly correlated with each other at (0.936< r < 0.955, p < 0.001). SAI are also highly correlated with each other at (0.941< r < 0.976, p < 0.001) and are significantly positively correlated with TCO over the study period except Mg II index at Kisumu. TCO and SAI have correlations at both long and short lags. At all the cities, F10.7...

Keziya Magawa, a farmer with Nazareti Womens' Group, tends maize in a field school in Chibel... more Keziya Magawa, a farmer with Nazareti Womens' Group, tends maize in a field school in Chibelela, Tanzania. Photo: IDRC/ F. Nzema ... Lessons from participatory action research in sub-Saharan Africa ... Contributing authors: Ignitius Chagonda Jacob Churi Amadou ...

Many pilot-based initiatives have been developed to promote awareness and use of climate informat... more Many pilot-based initiatives have been developed to promote awareness and use of climate information services among vulnerable smallholder farmers in Africa through million-dollar investments. However, despite their experimental nature, these pilot projects have been successful in raising participating farmers' awareness and use of climate information services and they can inform transferrable good practices. Through a systematic literature review approach, this review sought to understand ways in which these past pilot projects have contributed to climate risk management in the context of smallholder farming and the factors that led to their success. Results showed that climate information services main contribution to climate risk management has been through facilitating farm level decision making. Factors that led to success of the pilots include: use of downscaled information; building institutional partnerships to add value to climate information; involving farmers through the co-designing and co-developing process; face-to-face way of communication; embedding pre-seasonal workshops in the activities of local institutions for sustainability; using diversity of communication channels to enhance reach among others. These factors can be borrowed as good practices to inform future efforts focused on increasing adoption of climate information services among a wider population beyond pilot project reach.

Kenya Policy Briefs, Feb 26, 2021

The research was conducted to validate the pastoralists' and agro-pastoralists' claim that there ... more The research was conducted to validate the pastoralists' and agro-pastoralists' claim that there has been an increasingly variable and changing climate in the study area. The station average and Theissen polygon methods were used to estimate the mean areal precipitation of the small (Mogotio and Baringo South Sub-counties) and the large area (Baringo County), respectively. The aim of the current study is to analyse rainfall time series over long term observed precipitation and a wide area, detecting potential trends and assessing their significance. Monthly precipitation data for the period 1974-2003 from six weather stations, located mainly in Mogotio and Baringo South sub-counties and covering 3906km 2 were used in the analysis. The data were quality controlled to ensure no missing data and any inconsistencies. Linear regression analysis of the database highlighted that; the trends were predominantly negative, both where the average and Theissen polygon methods were used and over the whole reference period. The negative trends are not significant. This finding implies that the study area has been suffering a precipitation decrease especially in the period under review.

Africa Journal of Physical Sciences ISSN: 2313-3317, Jun 30, 2021

Rock geochemistry influences groundwater quality and the aquifer processes of an area. The geolog... more Rock geochemistry influences groundwater quality and the aquifer processes of an area. The geology of the study area comprises quartzo-feldspathic gneiss and biotite gneiss of the Precambrian basement, sedimentary Turkana Grits and Holocene sediments, Tertiary volcanics comprising nepheline phonolites and augite basalts, alluvial deposits along the banks of major streams and laggas (ephemeral streams), and Quaternary sands that blanket much of the area. This paper evaluates the influence of rock chemistry on groundwater quality in Lodwar area. Conventional petrography and geochemistry techniques involving measurement of major elements using X-ray fluorescence (XRF) and trace elements using and X-ray diffraction (XRD) in 69 rock samples to evaluate their mineralogical compositions. The major rock-forming in rocks of the study area include pyroxenes, olivine, kaolinite, siderite, fluorite calcite and dolomite. These minerals release major ions to groundwater through weathering, leaching, oxidation, dissolution and precipitation, and ion exchange reactions during rock-water interactions. The rocks in study area have generally low amounts of Na and K with modal values < 2.00 wt%, suggesting other sources of Na + and K + ions in groundwater. In contrast, Ca, Mg, Al, Fe and Mn are released to groundwater from rocks, as shown by high modal compositions of individual elements and associated oxides. The higher concentrations of Na + , K + , Ca 2+ and Mg 2+ in the groundwater of the Turkana Grit aquifer relative to the grit rock samples suggest a long history of dissolution and recycling of the groundwater. The ratio SiO2:Al2O3 was found to be greater than 8.0 implying a high degree of maturity of the grits. The results presented by this study show that geological factors and processes have location-specific influence on groundwater quality and should be considered in aquifer water quality studies and supply development across Africa's vast ASAL regions.

American Journal of Climate Change, 2022

River basins in the drylands of Sub-Saharan Africa have traditionally been utilized for pastoral ... more River basins in the drylands of Sub-Saharan Africa have traditionally been utilized for pastoral livelihoods under communal land tenure. Communities in West Pokot in Kenya have continued to experience increased precipitation and temperature as a result of climate variability and change. This study aimed at assessing the impact of climate variability and change at micro-basin level in order to address research and policy gaps on climate change and food security as policy arena shifts from centralized to decentralized governance in Kenya. Primary quantitative data was collected from 387 households' perceptions of climate variability and change and its implications on food security were measured. Food security index score was calculated. The annual rainfall trend over Suam river basin for the period (1981-2020), was characterized by a linearly increasing annual rainfall trend. Mann Kendall test Z-statistics and Tau were at 2.3578 and 0.0720 respectively. The basin experienced the highest rainfall variability during the first decade (1981-1990) with the highest coefficient of rainfall variation noted at 11.5%. The highest temperature was recorded in the third decade (2001-2010) and fourth decade (2011-2020) at 27.0 and 28.2 degrees Celsius respectively. However, the overall index score for food security was 55.78 with food availability scoring the highest index, mean (SD) of 63.41 (36.52). This was attributed to households' practice of both nomadic pastoralism and agro-pastoralism activities. Climate variability and change, have resulted in increased amount of rainfall received providing for opportunity investment in rain water harvesting to support both pastoralism and agro-pastoralism production to enhance food security.

American Journal of Climate Change

A quality decline trend is suspected to be ensuing in the water originating from boreholes in Lan... more A quality decline trend is suspected to be ensuing in the water originating from boreholes in Langata sub-County; a region located to the south of Nairobi, the capital city of Kenya in East Africa. Despite the existence of this worrisome suspicion, no investigation has been conducted to assuage the fears of the exposed population. This situation however contradicts the great augmenting role of borehole water delivered by vendors to consumers as a coping strategy against the pervasive drought induced water shortage challenge afflicting households in Langata. Hence, a question arose as to whether the identified past drought events have had any chance of influencing the ongoing declining trend of the area’s ground water quality. The purpose of this study was therefore to assess the impact of historical drought events on the ground water quality in Langata Sub County. The profile of drought indices was superimposed over the area’s time series geochemical water quality indices’ profile. ...

African Journal of Agricultural Research, 2021

The Maasai pastoralists inhabiting Kajiado County are known for rearing large herds of animals. L... more The Maasai pastoralists inhabiting Kajiado County are known for rearing large herds of animals. Livestock has enabled them to attain food and nutritional security. However, natural resources are dwindling fast under the swift development context. The private holding of land is becoming more prevalent in an area formally known for its communal land setup. The emerging land tenure systems have disregarded the traditional production systems. Consequently, their herds have exhibited poor health status and low productivity. To address these problems, the study focussed on the Maasai pastoralists' perception to evaluate their cultural dispositions. The study employed a cross-sectional design which consisted of semi-structured questionnaires. The qualitative data generated were subjected to thematic analysis and thereafter, translated into meaningful actions and summarised. The quantitative data was aggregated into frequencies and composite scores computed. The results revealed increased production risks, changes in land utility and notable growing numbers of Maasai pastoralists being dispossessed from their customary land by private landholders. Despite the aforementioned hurdles, the Maasai pastoralists had shown cohesiveness in rangeland management. It was also evident that the Maasai pastoralists were embracing different livelihoods, conservation, tourism and institutional support based on their strategic priorities to enhance their resilience. Thus, the study recommends that the Maasai pastoralists be assigned a proactive role as the Government relooks at territorial demarcations in the ongoing land registration process.

The long rains occurring in March-April-May (MAM) in East Africa have been notoriously difficult ... more The long rains occurring in March-April-May (MAM) in East Africa have been notoriously difficult to capture in climate models and the CMIP5 ensemble. This is highlighted by the fact that CMIP5 models show increasing MAM rainfall in East Africa while measurements show a drying at the end of the 20th century. Evaluating models with a process-based analysis is key to selecting which models to use for projections on a regional scale, but the MAM season poses an extra challenge in this regard since the processes governing the rainfall are hard to pinpoint in the historical period.

1 Improving water security for the poor in Kenya 1.1 Kenya-profile and progress 1.2 Decentralisat... more 1 Improving water security for the poor in Kenya 1.1 Kenya-profile and progress 1.2 Decentralisation-bringing power to the people? 1.3 Reducing vulnerabilities to climate shocks 1.4 Inequality and poverty 1.5 Mobile ecosystems 2.1 Poverty and welfare 2 Understanding the 'real nature' of poverty in Kenya 2.2 Policy and progress 2.3 Risks and vulnerability 3 Addressing water security risks to poverty in Kenya 3.1 Summary 3.2 Water Security Observatory 3.3 Small towns in fragile lands 3.4 Building water secure institutions 4 Conclusion Key references Cover photo: Tim Foster Executive summary Kenya is one of Africa's most dynamic and entrepreneurial economies, but one with increasing water security risks. Kenya's implementation of decentralisation from 2010 reflects its commitment to reduce enduring inequalities by establishing 47 county governments in 2013. With a clear mandate, county governments offer a new institutional architecture to address a portfolio of growth and development challenges, including water security for the poor. Current income poverty and multidimensional welfare monitoring do not capture the impact and implications of water shocks or long-term human exposure to water risks. Periodic surveys provide snapshots which weakly relate to major flood or drought shocks, chronic exposure to poor water quality or exclusion from basic water resources or services. Vulnerable individuals (children, urban poor, elderly, ill) are merged into household data and are thus largely invisible or ignored. With increasing water security risks there is a need for 'climate services', whereby scientists work with decision makers to explore the resilience of their decisions to climate variability and change. Current gaps include lack of data about rainfall variability, extremes and future changes, which are relevant both for short-term operational decisions and for long-term strategic planning. These data needs to be presented considering impactrelevant water security metrics with user defined thresholds and decision-relevant spatial scales. This knowledge will help establish whether strategies put in place for current water security will survive the near-term manifestation of climate change. Kenya's advances in mobile ecosystems are one response to its water security and poverty challenges. Mobile technologies offer 'accidental infrastructure' to provide high quality, low cost and remote data to support decision-making. Mobile platforms narrow the distance between data and decision-making. Political accountability can be enhanced with electoral cycles and physical proximity recalibrating decision-making processes and priorities. The University of Oxford is building sciencepractitioner partnerships with county governments, the Ministry of Water and Irrigation, the Water Services Regulatory Board, UNICEF, the University of Nairobi to establish Water Security Observatories for 'small towns and fragile lands' in Turkana County and 'build water secure institutions' in Kitui County. Impacts and implications of the work will support wider regional initiatives to improve water security for millions of poor people.

Journal of Water Resource and Protection, 2019

This study aimed at identifying the most preferred water quality tracking system (WQTS) for adopt... more This study aimed at identifying the most preferred water quality tracking system (WQTS) for adoption and the determining factors for the same among the Langata sub County households in Nairobi city, Kenya. Perrenial municipal water shortage in this neighborhood has forced the residents to depend on vended water supplication but whose quality is not possible to verify at the moment. Accordingly, a mobile phone quality tracing application running on blockchain technology platform was developed to fill the gap of provenance tracking. A non-market discrete choice experiments (DCEs) model was deployed in which four-option attribute bundles; with one being the "status quo" choice were presented to each of the 382 randomly sampled respondents from the five wards within the area. Results indicated that Option 2; the communally managed WQTS emerged as the most preferred choice at 53.9%. Secondly, the male factor was identified as the major determinant to this decision. In conclusion, the study proposes for the installation of this new WQTS which will trigger a 12% adjustment of the average household's monthly water bill. In addition, this paper recommends for a city-wide assessment of residents' willingness to pay (WTP) for this WQTS, which it deems as an improved response to water shortage problem. Finally, the study contributes to the application of DCEs model in technology adoption literature.

Journal of Science and Technology (Ghana), 2011

The daily meteorological data of relative humidity, maximum, minimum, and average temperatures ob... more The daily meteorological data of relative humidity, maximum, minimum, and average temperatures obtained from five stations of the Kenya Meteorological Department over the period 1986 to 2005 were filtered and reduced to monthly means. Monthly data of solar indices: Sunspot number, F10.7 cm solar radio flux and Mg II core-towing ratio covering the same period were employed to model the meteorological variables using the linear multivariate model and applying least square fittings. Validity of the models was tested using Mean Bias Error (MBE) and Root Mean Square Error (RMSE) statistical indicators. The correlations between the observed and predicted values from the models were significant at above 95% level of confidence. The models show the effect of solar forcing on the climatic parameters at different locations in Kenya. Solar forcing of climate is evident in Kenya.

Contribution of Agricultural …, 2010

to investigate the ethnobotanical and chemical characterization of selected medicinal plants grow... more to investigate the ethnobotanical and chemical characterization of selected medicinal plants growing in South Nandi District in the year 2004 and 2005. Subsequently, propagation studies were carried out on the identified endangered medicinal plants. Local communities who use medicinal plants were interviewed. Ethnobotanical data on families, plant species, botanical name, local name, part (s) used, popular ethnobotanical medicinal use, forms of preparation and applications of the herbal remedies were collected. Plants were collected, pressed, dried, preserved, mounted and identified through available literature and voucher specimens at the University of Nairobi and National Museum Laboratories. From the surveys carried out it was observed that the endangered plants were Asystasia schimperi, Carissa edulis, Toddalia asiatica .These were propagated using stem cuttings subjected to different concentrations of auxin in a polypropagator in a completely randomized design experiment. It was found that as auxin concentration increased from 100 ppm to 500 ppm, there was increase in rooting and growth in the decreasing order of Asystasia schimperi, Carissa edulis and T. asiastica. The treated cuttings were planted in polythene pots, which were placed in a non-mist propagator. The duration of the experiment on propagation was four months and the data taken were number of rooted plants, plant height, and number of leaves. The data on propagation was subjected to analysis of variance and Least Significant Difference (LSD = P< 0.05) separation of means. The results showed that hormone concentration, species and date of sampling significantly (P< 0.05) affected the number of leaves, plant height, and number of rooted cuttings. A. schimperi had the best rooting and subsequent growth followed by Carissa edulis and lastly Toddalia asiastica. It is concluded that Asystasia schimperi and C. edulis can be easily propagated by stem cuttings hence introduced to the farmers of South Nandi District. 2 INTRODUCTION: Man uses plants in many different ways to meet his basic needs food, clothing and shelter. Wild plants supply medicine, crafts and cosmetics to rural and urban communities.. In addition, wild

Bulletin of the American Meteorological Society

The Turkana Low-level Jet (LLJ) is an intrinsic part of the African climate system. It is the pri... more The Turkana Low-level Jet (LLJ) is an intrinsic part of the African climate system. It is the principle conduit for water vapour transport to the African interior from the Indian Ocean, and droughts in East Africa tend to occur when the jet is strong. The only direct observations of the Turkana Jet come from manual tracking of pilot balloons in the 1980s. Now, modern reanalysis datasets disagree with one another over the strength of jet winds and underestimate the strength of the jet by 25-75% compared to the pilot balloon data. This article gives an overview of a month-long field campaign based in northwest Kenya - the Radiosonde Investigation For the Turkana Jet (RIFTJet) - which measured the Turkana Jet for the first time in forty years using modern technologies. Radiosonde data reveal a persistent low-level jet, which formed on every night of the campaign, with an average low-level maximum wind speed of 16.8 m.s-1 at 0300LT. One of the latest reanalysis datasets (ERA5) underesti...

Encyclopedia of the UN Sustainable Development Goals, 2019

Journal of Water Resource and Protection, 2019

Interest on the investigation of groundwater depletion threat is growing globally and Langata sub... more Interest on the investigation of groundwater depletion threat is growing globally and Langata sub County in Nairobi, the capital city of the Republic of Kenya, is not an exception. Because of drought-induced water shortage, households in Langata do rely on borehole water to augment their intermittent municipal water supply system. Consequently, there is an upsurge of borehole developments as drought events unfold. Previous studies here have focused on impact of borehole depths and density yet little seems to have been done to compute the correlation coefficient between drought events data and historical borehole development records as an assessment for groundwater "grab" syndrome. This study used drought index computation method (SPI) alongside other statistical methods to seek the answer to the problem. Using 57 years of monthly rainfall data and 26 years of borehole development data, the study established that, there is a positive correlation coefficient. Similarly, a trend analysis of borehole drilling and struck water level depths indicated a positive parallel rising trend on both. Further, when the borehole distribution map and struck water level contour maps were plotted, a sign of a probable well interference during pumping was detected, which however, requires a new investigation to confirm the syndrome of groundwater depletion threat. The study has contributed to the groundwater depletion research by deploying statistical research methods for risk detection. Finally, the study has proposed for a new groundwater management policy that will encourage initiation of artificial recharge schemes for the study site and beyond.

Applied Physics Research, 2016

In this study, a statistical analysis between three solar activity indices (SAI) namely; sunspot ... more In this study, a statistical analysis between three solar activity indices (SAI) namely; sunspot number (ssn), F10.7 index (sf) and Mg II index (mg) and total column ozone (TCO) time series over three cities in Kenya namely; Nairobi (1.17º S; 36.46º E), Kisumu (0.03º S; 34.45º E) and Mombasa (4.02º S; 39.43º E) for the period 1985 - 2011 are considered. Pearson and cross correlations, linear and multiple regression analyses are performed. All the statistical analyses are based on 95% confidence level. SAI show decreasing trend at significant levels with highest decrease in international sunspot number and least in Mg II index. TCO are highly correlated with each other at (0.936< r < 0.955, p < 0.001). SAI are also highly correlated with each other at (0.941< r < 0.976, p < 0.001) and are significantly positively correlated with TCO over the study period except Mg II index at Kisumu. TCO and SAI have correlations at both long and short lags. At all the cities, F10.7...

Keziya Magawa, a farmer with Nazareti Womens' Group, tends maize in a field school in Chibel... more Keziya Magawa, a farmer with Nazareti Womens' Group, tends maize in a field school in Chibelela, Tanzania. Photo: IDRC/ F. Nzema ... Lessons from participatory action research in sub-Saharan Africa ... Contributing authors: Ignitius Chagonda Jacob Churi Amadou ...

Many pilot-based initiatives have been developed to promote awareness and use of climate informat... more Many pilot-based initiatives have been developed to promote awareness and use of climate information services among vulnerable smallholder farmers in Africa through million-dollar investments. However, despite their experimental nature, these pilot projects have been successful in raising participating farmers' awareness and use of climate information services and they can inform transferrable good practices. Through a systematic literature review approach, this review sought to understand ways in which these past pilot projects have contributed to climate risk management in the context of smallholder farming and the factors that led to their success. Results showed that climate information services main contribution to climate risk management has been through facilitating farm level decision making. Factors that led to success of the pilots include: use of downscaled information; building institutional partnerships to add value to climate information; involving farmers through the co-designing and co-developing process; face-to-face way of communication; embedding pre-seasonal workshops in the activities of local institutions for sustainability; using diversity of communication channels to enhance reach among others. These factors can be borrowed as good practices to inform future efforts focused on increasing adoption of climate information services among a wider population beyond pilot project reach.