PHD-Department of Geography

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Browsing PHD-Department of Geography by Subject "Kenya"

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    Climate Variability and Malaria Transmission Trends in Different Altitudes of Lower Lake Victoria Basin, Kenya.
    (Kenyatta University, 2023-11) Odhiambo, Samwel Olela; George L. Makokha; Kennedy Obiero
    Consequences of global climate variability and change are some of the biggest environmental challenges the world is facing. Impacts include increased frequency of extreme weather events. The impacts vary, Africa being the most vulnerable due to her high dependence on natural resources. One of the issues most associated with the challenges is malaria prevalence. Half of the world’s population, (3.4 billion people in 92 countries), is at risk, 1.1 billion at high risk. Malaria burden is greatest in the developing countries of the tropics such as Africa which has 91% of the related deaths, 60% being children under five years. Climate extremes have increased in East Africa, which is predicted to add 75.9 million people to the risk bracket. In Kenya, malaria is blamed on high rainfall, temperature and relative humidity. This study evaluated climate variability and malaria transmission trends in different altitudes of Lower Lake Victoria Basin (LLVB), Kenya where malaria prevalence rate was 27% despite varying between 4% - 8% in other parts of the country. Descriptive and correlational designs with quantitative methods were used to analyze spatiotemporal variability of selected climate elements and malaria transmission trends. Target population was flooded malaria morbidity cases recorded at Sub – County Hospitals. Meteorological data was obtained per sampled county and sub - county i.e. Migori - SONY Central Meteorological Station, Kisumu - Kisumu Airport Meteorological Station and Kakamega -MSC Meteorological Station. Data for the selected climate parameters were collected for twenty years except Relative Humidity from Kisumu Airport which was only available for 12 years (2009-2020). Health data was obtained from the Kenya Health Information System (KHIS) for ten years (2011 to 2020) through sampled Sub-County Level 4 Hospitals. ANOVA was used to analyze variability among climate and malaria transmission variables, Pearson’s Correlation Coefficient tested relationships while Descriptive Time Series and “ARIMA regression models” were respectively used to give trends and to predict future climate and malaria scenarios. Results revealed that Malaria transmission and climatic variables significantly varied in space and time. Mean annual malaria transmission in Kisumu was 3902.87, Kakamega 3385.53 and Migori 2130.33. Mean annual temperature was 23.770C in Kisumu, 22.610C in Kakamega and 22.520C in Migori. The two had insignificant monthly and annual correlations. However, climate elements insignificantly defined transmission differently at different altitudes. In a further analysis, stepwise linear regression dropped all climatic variables and left only altitude as the significant determinant of malaria transmission variability in the LLVB. This made the study use altitude and transmission levels to zone LLVB as follows: 1001m to 1200m – high transmission; 1201 to 1400 - medium transmission; 1401 to 1600 – low transmission. The study predicted that malaria transmission would increase in high and medium transmission zones while decreasing in low transmission zones. This meant that malaria prevalence would still vary depending on altitude. The revelations were used to inform experts in policy decision making on reduction of malaria transmission. This was to enhance malaria eradication processes in the LLVB, Kenya, and hence promote the realization of Kenya’s vision 2030.
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    Effects of Land Use/Land Cover Change and Rainfall Variability on Hydrological Characteristics of River Ruiru Watershed, Kiambu County, Kenya
    (Kenyatta University, 2021) Waithaka, Ann; Shadrack K. Murimi; Kennedy Obiero
    Watersheds and their water resources are highly vulnerable to land use/land cover changes and seasonal rainfall variability as they directly influence basin hydrological characteristics in terms of water quantity and quality. This study assessed the effects of land use/land cover change and rainfall variability on hydrological characteristics of River Ruiru watershed in Kiambu County. The study integrated the use of remote sensing, Geographic Information System (GIS), water quality sampling, hydrological modelling and statistical methods to collect and analyse the collected data. Results of land use/land cover change analysis indicated that built-up areas, annual crops and perennial crops (tea and coffee) increased by 3.068%, 35.848% and 11.493% respectively between 1976 and 2017. However, it was observed that perennial crops increased gradually between 1976 and 1995 but declined by 1.94% between 1995 and 2017. Grassland, shrubland and forestland declined by 7.48%, 13.25% and 29.79% respectively between 1976 and 2017. Consequently, Soil and Water Assessment Tool (SWAT) model simulation results indicated that the land use/land cover changes that occurred in River Ruiru watershed between 1984 and 2017 had effects on the quantity of river discharge and water quality for drinking purposes. Surface runoff (SURQ), lateral flow (LATQ) and groundwater contribution to discharge (GWQ) increased from 30.25mm/yr, 8.48mm/yr and 9.95mm/yr to 181.25mm/yr, 11.44mm/yr and 10.66mm/yr respectively. Moreover, the nitrates in surface runoff (NO3SURQ), nitrates in lateral runoff (NO3LATQ), Organic Nitrogen (N.ORG) and Organic Phosphorus (P.ORG) increased from 0.05kgN/ha/yr, 0.06kgN/ha/yr, 5.77kgN/ha/yr and 0.87kgP/ha/yr to 1.47kgN/ha/yr, 0.19kgN/ha/yr, 70.60kgN/ha/yr and 8.86kgP/ha/yr respectively. In additions, findings from the study indicated that temporal rainfall variability had effects on the quantity of river discharge and water quality of River Ruiru. Based on regression analysis, the correlation between the observed and predicted value of dependent variable indicated an association of R=0.972 between temporal rainfall variability and quantity of river discharge hence showing a strong positive linear relationship. Similarly, Pearson’s correlation analysis results showed that temporal rainfall variability was strongly and positively correlated to NO3, N.ORG and P.ORG with R=.695, p<.001; R=.781, p<.001 and R=-.780, p<.001. Furthermore, results from a paired sample t-test indicated that pH, turbidity, Dissolved Oxygen (DO), electrical conductivity and Total Dissolved Solids (TDS) had higher mean during wet season (M=8.40, M=79.00, M=51.20, M=87.00 and M=54.20) than in dry season (M=6.80, M=11.60, M=43.40, M=73.00, and M=45.40). The difference for these water quality parameters between dry and wet seasons was significant (P=0.003, P=0.034, P=0.005, P=0.013 and P=0.014). Moreover, findings from the study indicated that DO, TDS, electrical conductivity, total phosphorus and total nitrogen values were within World Health Organization (WHO) and National Environment Management Authority (NEMA) recommended values. However, the results for the total coliforms and E. coli indicated that River Ruiru was severely polluted with faecal organisms. In conclusion, land use and land cover changes and temporal rainfall variability have affected the quantity of river discharge and water quality in River Ruiru watershed. As such, remedial actions to address the hydrological effects of land use/land cover change and temporal rainfall variability both by national and county governments are required.
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    Examining the Poverty-Land Degradation Nexus in Kitui County, Kenya through a Political Ecology Lens
    (Kenyatta University, 2022) Mutiso, Mary N.; Calvine Kayi; Mary Kinyanjui
    The twin problems of poverty and landdegradation have persistently plagued Kenya in general and Kitui county in particular. Colonial and post-independence governments devised state policies and interventions to address these problems without much success. The overall aim of this study was to examine the nexus between poverty and land degradation. The specific objectives of the study were first, to examine the role played by colonial economic policies in the development of poverty and land degradationin Kitui, second, to analyze the relationship between the assets owned by households and their poverty levels, third, to assess the effect of the land management practices adopted by households in Kitui on the Land management outcomes and fourth, to evaluate the relationship between the assets owned by households in Kitui and their choice of land management practices. The study employed political ecology and the the investment poverty frameworks respectivelyto analyse,first, the the role of colonial policies in the development of poverty and land degradation and, second, the link between poverty, land management practices, and land management outcomes. The study used a mixed-methods analytical study design. Cross sectional data was collected using aquestionnaire while historical data was collected from archival and secondary sources. Three hundred and eighty-three households were sampled using the population proportional to size sampling method. This study used assets that a household had as measures of poverty and farmers’ perceptions of environmental problems as measures of land management outcomesIt analysed the data as follows; First, a historical analysis of the dynamics of poverty and land degradation in Kitui was undertaken to examine the influence of colonial economic policies on the development of poverty and land degradation. Second, the assets influencing household consumption (poverty) were identified through a regression between household consumption and household assets. Third, the study identified the land management practices practices influencing land management outcomes using Chi-square statistics. Finally, a regression of the determinants of poverty with the determinants of land management practices practices yielded the determinants of land management practices practices. This study identified four determinants of poverty levels namely: education, the number of active household members, land size and access to extension services. It associated crop failure, soil erosion, and vegetation cover depletion with land management practices. Finally, three assets, namely education, the number of household members between twenty and sixty (out of how many) and advice from extension officers influenced land management practices households in Kitui adopted. Since the factors that influenced poverty also influencedland management outcomes, the study concluded that poverty and land degradation are outcomes of the same causes and processes and therefore not necessarily mutually reinforcing phenomena. It therefore refuted the Vicious Circle hypothesis. Policy interventions to eradicate poverty and land degradation should therefore be on education, labour and extension services.