http://erepository.uonbi.ac.ke/handle/11295/8014 2026-06-08T00:49:38Z 2026-06-08T00:49:38Z Mbae, Loise K http://erepository.uonbi.ac.ke/handle/11295/168220 2026-03-24T07:12:09Z 2024-01-01T00:00:00Z

Tracing Sediment Provenance in Kilindini Harbour, Mombasa Using Heavy Minerals and Natural Radionuclides Mbae, Loise K Harbours are essential gateways for trade, but they often face challenges like sedimentation, which can obstruct navigation channels and hinder ship movement. Understanding sediment dynamics is crucial to managing this issue. Various methods, such as using Rare Earth Elements (REEs), artificial radionuclides, and exotic particles, have been explored globally. However, these methods can be costly, pose safety risks, or are impractical for large-scale studies. This study applied sediment fingerprinting using selected elements and natural radionuclides to trace sediment transport and sources in Kilindini Harbour, Mombasa. Samples were collected from River Mwache, Mteza Creek, and Port Reitz, about 10 km from the harbour's main channel, and analyzed using EDXRF and gamma spectroscopy. The analysis showed that elemental concentrations generally decrease as sediments move through the system, with the lowest levels found in Port Reitz. This was a clear indicator of sediments being transported downstream from River Mwache and into Kilindini Harbour through Port Reitz. Zircon (Zr) behaved differently due to its resistance to weathering, remaining consistent throughout the transport. This proved that Zr would be an essential tracer element for future studies. Radionuclide activity patterns revealed regions of sediment accumulation, particularly along River Mwache and its banks. Natural radionuclides were therefore proven as an effective, cheap and safe method to determine sediment deposition areas. In conclusion, the study determined a major source of sediments in Kilindini harbour to be Mwache River and Mteza creek. Future research can refine these methods for more accurate quantification of sediment sources

2024-01-01T00:00:00Z Ochieng', Fredrick O http://erepository.uonbi.ac.ke/handle/11295/168216 2026-03-17T09:09:22Z 2024-01-01T00:00:00Z

Land Use Changes and Their Implication on Wildlife Dispersal Areas. A Case of Merrueshi Location, Kajiado County Ochieng', Fredrick O Conservation of wildlife in Kenya primarily involves the establishment and maintenance of protected areas, such as national parks and reserves. These areas are managed with strict land use regulations to ensure the protection of wild fauna, flora, and their habitats. In addition to these protected areas, there are surrounding lands that do not enjoy the same level of protection, but they serve as crucial wildlife habitats essential for the sustainability of wildlife and the protected regions. Historically, land use in the wildlife dispersal areas was compatible with conservation efforts. However, these areas are now facing significant pressures due to land use changes that pose a serious threat to the viability of wildlife conservation in Kenya. Despite the importance of wildlife dispersal corridors, existing studies on wildlife conservation have largely overlooked the impact of land use changes on these areas. This study examined land use change in Merrueshi Location and how the change affects the wildlife dispersal areas; it determined the drivers of land use change in the study area, evaluated the roles, behaviour and perceptions of stakeholders on land use change and wildlife dispersal areas within the location and has proposed strategies that can address land use change in relation to wildlife dispersal areas. The study adopted a descriptive survey design. The target population was all the households living in the former Merrueshi Group Ranch, in Kajiado County and other stakeholders who included the physical planner, local chief, and the Nasaru Olosho Conservancy officials. A total of 60 randomly sampled households were interviewed using a household questionnaire. Three groups of men, women, and youth were interviewed using customized focus group discussion guides. Observations were also done using an observation checklist. Photographs of relevant features were taken to amplify evidence of the data. The findings revealed that the main causes of land use change in the location were: (i) high population growth due to natural increase and immigration and the need for land by all heirs and immigrants. In 1987, each registered member was allocated a minimum of 141 ha. (350 acres) that has reduced to the current majority owning less than 100 acres. (ii) The change from communal tenure to private freehold landholding. Under communal tenure, communities were involved in decision-making and benefit sharing, and there was more support for conservation efforts. (iv) The fourth cause is increasing poverty and loss of livelihood for Indigenous people, which has driven them to sell land without consideration of conservation objectives. The impacts of land use change to wildlife corridors and dispersal areas were identified as loss of biodiversity, increased human-wildlife conflict, and environmental degradation. The key stakeholders are the immigrants who, once they move into the area, fence their farms and practice crop farming, mainly onions and tomatoes. The findings highlight the urgent need to address the pressures from changing land tenure systems, population growth, and the expansion of agricultural and residential land use areas, which are rapidly transforming landscapes crucial for wildlife movement and survival. Maintaining the ecological integrity of these corridors and dispersal areas is essential for the long-term viability of wildlife populations within protected areas. Effective conservation strategies must extend beyond national parks and reserves to include these surrounding lands, employing a comprehensive approach to ensure successful wildlife conservation. The study recommends the development of wildlife corridors as special planning areas, the formulation of specific planning guidelines for wildlife conservation areas and adherence to the land use development guidelines. Others include the enhancement of community-based approaches in the management of wildlife conservation areas and the promotion of the Public Private Partnership resource management model.

2024-01-01T00:00:00Z Nguca, Ann W http://erepository.uonbi.ac.ke/handle/11295/168200 2026-03-17T07:07:22Z 2024-01-01T00:00:00Z

Evaluating the Potential Impact of Variable Frequency Drive Technology in Pumping Operations of Refined Petroleum Products in Kenya. A Case Study of Kenya Pipeline Company Nguca, Ann W The research investigates the energy consumption patterns and potential for energy efficiency improvements within the Kenya Pipeline Company, focusing on the mainline pumping operations. With rising energy costs significantly impacting the company's operations, an analysis was conducted to evaluate the effectiveness of implementing variable frequency drives as an alternative to the current autotransformer, direct online, and soft starters used in pumps. The research highlights the energy consumption for pump stations on the eastern line, evaluates the current motor starters' energy efficiency, and calculates the potential economic benefits of transitioning to variable frequency drive technology. The research involved auditing the company’s major loads, distributing questionnaires, and reviewing electricity bills and throughput data for three years. The energy audit findings indicate that pumps are the main energy consumers, representing a significant portion of Kenya Pipeline Company's total energy expenses. The use of auto-transformer starters, though common, has been identified as inefficient due to high inrush currents and low power factors, resulting in significant energy losses and high operational costs. By replacing these starters with variable frequency drives, the company can modulate pump speeds based on real-time demand, significantly reducing equipment energy consumption and mechanical stress. The research presents a detailed techno-economic evaluation showing that implementing variable frequency drives could save approximately Ksh. 1,101,299,377 for the three years, with an average payback period of 5 months and energy consumption would reduce by 54,585,211 kWh. The study concludes that upgrading to variable frequency drives would align with national energy conservation goals and enhance the operational efficiency and economic viability of the Kenya Pipeline Company. Kenya Pipeline Company is recommended to prioritize this upgrade to mitigate the high energy costs and contribute to more sustainable energy management practices in the region. Further research is suggested to optimize variable frequency drive technology use and monitor its long-term benefits accurately. Keywords: Energy efficiency, motor starters, variable frequency drives,

2024-01-01T00:00:00Z Muthuri, Lee M http://erepository.uonbi.ac.ke/handle/11295/168149 2026-03-16T06:12:36Z 2024-01-01T00:00:00Z

Use of Geospatial Technologies in Assessment of Land Use Land Cover Changes for Land Use Planning, a Case Study of Meru County Muthuri, Lee M Land use Land Cover change is a major phenomenon today across the globe. In Kenya, there have been tremendous changes in land use land cover over the years due to human activities. These include the need for land for settlement, agriculture, charcoal burning, and illegal logging among others. Population in Meru has increased tremendously over the years; this has led to the conversion of lands from their original use to other uses. These changes have further led to unplanned growth and strain on natural resources as well as changes in the natural landscape. Remote sensing is a technology that is useful in assessing changes in land use and land cover trends over large tracts of land over time using satellite imagery. This study therefore assessed these changes in land use and land cover using Remote sensing and Geographic information systems. The objectives included identifying the prominent land cover classes in the county, collecting suitable data, mapping out the land use land cover changes, and lastly identifying the causes of these changes. Using satellite images, land cover changes were mapped out for these classes for the years 1995, 2002, 2009, 2016, and 2023. A collection of Ground truth coordinates was used to validate the changes. Causes of land use land cover changes were identified using a literature review and a ground-truthing exercise. The tools used were the ArcGIS software and a GPS-enabled phone. The results of this study were Land use Land cover maps and how they changed over time in the Meru County landscape. The maps displayed the six major land use land cover maps in the county which include; Forest, Cropland, Woody Grassland, Grassland, and Bare land. The causes of the changes were also highlighted. Cropland emerged as the land cover that appreciated at a high rate. Forest cover decreased from 1995 to 2009 but increased onwards to 2023. These will consequently inform the County Government in the future in respect of sustainable land use planning. The research depicted that remotely sensed data is very effective in monitoring land use land cover changes, thus saving time and costs. The change detection was able to identify the specific areas where rapid change occurred and thus could inform the county government administration on sustainable planning.

2024-01-01T00:00:00Z