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Kenya - A Natural Outlook

Kenya - A Natural Outlook
  • Author : Paolo Paron
  • Publisher :Unknown
  • Release Date :2013
  • Total pages :374
  • ISBN : 0444595597
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Summary : Kenya is a thriving country in East Africa: its economy is largely based on the natural environment that frames the tourism sector, mainly through safaris and holidays on the coast. The natural environment also underpins the second largest industry: agriculture. Kenya's social, technological, and industrial developments are a reference for many neighboring countries. Kenya plays a leading role in Africa and attracts huge amounts of investments. Furthermore, the humanitarian community has made Nairobi its base for international headquarters and regional offices. This makes Kenya a possible model for development and investment in its widest sense. This book aims at updating the holistic view on Kenya's natural environment and resources. It provides a sound scientific introduction to this country's physical and socioeconomic setting and its evolution through time and will appeal to a broad audience of students - in Kenya and abroad - as well as those working in the development and humanitarian sectors and to international donors looking for a scientific compendium on Kenya's environment. Its structure and references allow the reader to deepen his or her knowledge of every theme touched on in the book. Combines different aspects of physical geography, water and soil resources and their management strategies Written by a blend of international and national experts Includes specific case studies

Kenya: A Natural Outlook

Kenya: A Natural Outlook
  • Author : Anonim
  • Publisher :Unknown
  • Release Date :2013-10-22
  • Total pages :402
  • ISBN : 9780444595478
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Summary : Kenya is a thriving country in East Africa: its economy is largely based on the natural environment that frames the tourism sector, mainly through safaris and holidays on the coast. The natural environment also underpins the second largest industry: agriculture. Kenya’s social, technological, and industrial developments are a reference for many neighboring countries. Kenya plays a leading role in Africa and attracts huge amounts of investments. Furthermore, the humanitarian community has made Nairobi its base for international headquarters and regional offices. This makes Kenya a possible model for development and investment in its widest sense. This book aims at updating the holistic view on Kenya’s natural environment and resources. It provides a sound scientific introduction to this country’s physical and socioeconomic setting and its evolution through time and will appeal to a broad audience of students – in Kenya and abroad – as well as those working in the development and humanitarian sectors and to international donors looking for a scientific compendium on Kenya’s environment. Its structure and references allow the reader to deepen his or her knowledge of every theme touched on in the book. Combines different aspects of physical geography, water and soil resources and their management strategies Written by a blend of international and national experts Includes specific case studies

Kenya: A Natural Outlook

Kenya: A Natural Outlook
  • Author : Charles Maina-Gichaba,Enoch K. Kipseba,Moses Masibo
  • Publisher :Unknown
  • Release Date :2013-10-22
  • Total pages :402
  • ISBN : 9780128083987
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Summary : Natural disasters disrupt people's lives through displacements, destruction of livelihoods and property, deaths, and injuries. Consequently, they take back years of development, thus posing a major challenge to the achievement of the Millennium Development Goals especially the target of halving extreme poverty by 2015 and Kenya's set development goals as contained in Vision 2030. The nature of natural disasters in Kenya especially landslides has constantly eroded the recovery capacity of communities especially in the affected areas, hence affecting their economic development year in year out. This requires more vigorous attention and planning to mitigate the effects as they have impacted greatly on the country's fight against poverty and efforts to reduce the number of people living below the poverty line. The economic cost of the impact of landslides in the past has been estimated in millions of shillings. This chapter provides a background on landslides in Kenya, the most common locations/areas affected by landslides in Kenya, factors contributing to vulnerability to landslides in Kenya, and economic and social impacts of landslides in Kenya. The impact of such hazards is compounded by poverty and lack of adequate resources to develop the affected areas, rendering the populations more vulnerable. The chapter highlights on the need to take up a proactive strategy in the management of natural disasters in Kenya, which would improve the coping capacity of communities, lessen the impact, and therefore improve the lives of Kenyans in the areas prone to harsh weather conditions. A clear vision for future actions is inevitably necessary to set the pace for development aimed at mitigating the impact of landslides in Kenya, thereby improving the lives of communities in Kenya.

Kenya: A Natural Outlook

Kenya: A Natural Outlook
  • Author : Dorothy Wanja Nyingi,Nathan Gichuki,Mordecai O. Ogada
  • Publisher :Unknown
  • Release Date :2013-10-22
  • Total pages :402
  • ISBN : 9780128083949
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Summary : Freshwater ecosystems of Kenya are the lifeline of economic and social development; however, most of these are threatened or on the verge of collapse. The need to maintain them in their natural condition, reduce disturbance and conserve their biodiversity has been stressed in the face of severe drought, food insecurity and water stress conditions including inability to maintain constant hydroelectric power. However, without a clear picture of how many freshwater rivers, wetlands and lakes exist and their precise locality, size, sources and uses, it would be impossible for the authorities charged with their protection to put in place management or mitigation measures. Highland freshwater ecosystems of Kenya include Mount Kenya, Aberdares, Mau Forest, Mount Elgon and Cherangani Hills, which are referred to Kenya's water towers since they jointly supply most of the freshwater resources of the country. They are fragile ecosystems with streams flowing through montane forest belts and are critical reservoirs of biodiversity. They are characterized by high rainfall; steep slopes and erodible soils induce severe surface runoff, soil erosion and landslides. Sediments from erosion cause pollution of water in the streams. In countries with limited resources such as Kenya only small portions of rivers can be effectively conserved. It is imperative that significant effort is targeted at the upper reaches, because any conservation effort in the lower reaches of the river are easily negated by upstream disturbances. Their importance is primarily due to their ability to store and distribute water to lowlands and for ground water recharge. For example, 90% of dry season flow of the Northern Ewaso Ng'iro River is derived from the Mount Kenya. Montane areas in Kenya are also often associated with sacred sites and areas of cultural and social importance to the communities around them. Kenya's highland ecosystems face great anthropogenic threats due to deforestation and agricultural pressure. These areas have been ideal for tea and coffee plantations and human settlements. The Mau Forest, which is the largest indigenous forest in Kenya, has had vast areas cleared for settlements by immigrants, which in turn has caused reduction of flows of the Sondu Miriu River, which is dammed downstream for hydroelectric power. Even though sections of the Aberdares and Mount Kenya occur in protected areas, the lack of management and inability to patrol large areas has had led to various conflicts over land and water uses. Lowland freshwater ecosystems include those occurring on the lower sections of the eastwards-flowing rivers of Kenya including Rivers Tana, Athi, Northern Ewaso Ng'iro and the Ramisi. These are areas of low altitude and the rivers are slow moving and characterized by high sediment load, which is rich in nutrients and important for agriculture along the banks of these rivers. However, reductions and changes in flow regimes in the lowlands are more recently becoming a reason for concern. In the Tana River Delta, a large number of communities and biodiversity rely on the water for agriculture, pastoralism, fishing and other socioeconomic uses related to ecosystem services. The two main factors affecting river flows in lowlands are water abstractions and land-use change and intensification, both related to growing human populations. Climate change poses a further complication to both highland and lowland ecosystems due to changes in rainfall patterns reducing not only river flows but also the high rainfall events that cause unprecedented floods.

Kenya: A Natural Outlook

Kenya: A Natural Outlook
  • Author : Bernard K. Kirui
  • Publisher :Unknown
  • Release Date :2013-10-22
  • Total pages :402
  • ISBN : 9780128083932
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Summary : Mangroves are important ecosystems in Kenya, producing goods and services of immense importance to the communities living adjacent to them. Their coverage is estimated at 46,590 hectares and is found along the 536km coastline which extends over 3° latitude from 1°42′ south to 4°40′ south. Mangroves are common features in protected bays, creeks, estuaries and river deltas spread all along the Kenya coast. Two communities of mangroves (fringe and creek) formations occur along the Kenya coast. The largest formations occur in the north coast around the Lamu area and at the River Tana delta. Nine species of mangroves are found in Kenya with Rhizophora mucronata and Avicennia marina being the dominant species. The mangrove management in Kenya is contained in the Forest Act of 2005 where it is treated as part of the natural environment (forests/flora). The act created Kenya Forest Service with the mandate of managing forests in Kenya including mangroves. The legislation also provides for comprehensive community involvement in forest management through creation of community forests associations. Through its licencing system, the service regulates the harvesting mangroves. However, due to lack of comprehensive management plans, coupled with lack of resources to monitor harvesting system used by mangrove cutters, mangrove cutting is unregulated in all areas. Participatory management is also at its infancy stages. In this chapter, the status of mangroves in Kenya, their uses, dynamics and threats (anthropogenic and natural) are discussed and suggestions made on their wise use.

Kenya: A Natural Outlook

Kenya: A Natural Outlook
  • Author : Petri K.E. Pellikka,Barnaby J.F. Clark,Alemu Gonsamo Gosa,Nina Himberg,Pekka Hurskainen,Eduardo Maeda,James Mwang’ombe,Loice M.A. Omoro,Mika Siljander
  • Publisher :Unknown
  • Release Date :2013-10-22
  • Total pages :402
  • ISBN : 9780128083918
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Summary : The indigenous cloud forests in the Taita Hills have suffered substantial degradation for several centuries due to agricultural expansion. Additionally, climate change imposes an imminent threat for local economy and environmental sustainability. In such circumstances, elaborating tools to conciliate socioeconomic growth and natural resources conservation is an enormous challenge. This chapter describes applications of remote sensing and geographic information systems for assessing land-cover changes in the Taita Hills and its surrounding lowlands. Furthermore, it provides an overall assessment on the consequences of land-cover changes to water resources, biodiversity and livelihoods. The analyses presented in this study were undertaken at multiple spatial scales, using field data, airborne digital images and satellite imagery. Furthermore, a modelling framework was designed to delineate agricultural expansion projections and evaluate the future impacts of agriculture on soil erosion and irrigation water demand.

Kenya: A Natural Outlook

Kenya: A Natural Outlook
  • Author : Zoltan Balint,Francis Mutua,Peris Muchiri,Christian T. Omuto
  • Publisher :Unknown
  • Release Date :2013-10-22
  • Total pages :402
  • ISBN : 9780128084014
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Summary : A first step in any drought management system is to monitor the state and the evolution of the drought. This study addresses the problem of nonexistent operational drought monitoring systems and presents a new methodology for monitoring the evolution and severity of drought with the new, Combined Drought Index (CDI). It is based on the fact that drought is a natural phenomenon created by a combination of several factors, such as deficiency in rainfall amount, persistence of below average rainfall, temperature excess and soil moisture characteristics. By combining the factors in the preceding text, the CDI compares present conditions with multiyear average (normal) conditions for the same time period. The methodology was applied at selected locations of different climate zones in Kenya. The results were compared with available official records of drought events (impacts), showing a very good positive relationship between the two. An attempt to detect the long-term trends of drought events using the CDI indicates that there is an increasing trend of drought events in the country, while the drought severity is not necessarily getting worse in all stations. The CDI method also revealed the possibility of drought early warning and drought-related climate change analysis in Kenya.

Kenya: A Natural Outlook

Kenya: A Natural Outlook
  • Author : John B. Kyalo Kiema
  • Publisher :Unknown
  • Release Date :2013-10-22
  • Total pages :402
  • ISBN : 9780128083840
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Summary : This chapter begins with a synopsis of the basic concept of remote sensing with the various stages and interactions that characterize the entire remote sensing process described. A brief recapitulation of the status of stored water in Kenya is then presented. The monumental challenge facing many poor Kenyan households in accessing clean and safe water in sufficient quantities is reiterated. The chapter underscores the critical value of accurate and timely geospatial and hydro-meteorological datasets in supporting integrated water resources management. It is argued that the availability of techniques that deliver information on the changes in stored water at a more local scale is the first step towards realizing an efficient water society. Finally, two case studies that employ diverse remote sensing datasets to provide an evidence based explanation of the decline in stored water in Lakes Victoria and Naivasha are elucidated.

Kenya: A Natural Outlook

Kenya: A Natural Outlook
  • Author : Alfred Opere
  • Publisher :Unknown
  • Release Date :2013-10-22
  • Total pages :402
  • ISBN : 9780128083994
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Summary : The vulnerability of a water resource system to climate change is a function of a number of physical features and social characteristics. The physical features associated with maximum vulnerability of water resources in a region include the marginal hydrologic and climatic regime; high rates of sedimentation leading to reduction of reservoir storage; topography and land-use practices that promote soil erosion and flash flooding conditions; and deforestation, which allows increased surface run-off, increased soil erosion and more frequent significant flooding. Coupled with these factors, the social characteristics that increase vulnerability of water resources include poverty and low income levels that prevent long-term planning and provision at the household level, lack of water control infrastructures, inadequate maintenance and deterioration of existing infrastructure, lack of human capital skills for system planning and management, lack of appropriate and empowered institutions, absence of appropriate land-use planning and management, and high population densities and other factors that inhibit population mobility. Of all the relevant factors in climate, precipitation is the main cause of disasters in flooding, water pollution, soil erosion, dam breaks and water-related disease outbreaks among others. Floods increase vulnerability of society and thereby perpetuate and increase the incidence of poverty.

Kenya: A Natural Outlook

Kenya: A Natural Outlook
  • Author : Norbert Opiyo Akech,Christine A. Omuombo,Moses Masibo
  • Publisher :Unknown
  • Release Date :2013-10-22
  • Total pages :402
  • ISBN : 9780128083796
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Summary : The oldest supracrustal rocks in Kenya are the Archaean Nyanzian meta-volcanics and the Kavirondian meta-sediments. These rocks are found to the west of the country in the areas adjacent to Lake Victoria. The Neo-Proterozoic Mozambique belt rocks occupy the central parts of Kenya. These are in most parts separated from the Archaean rocks by the Tertiary volcanics associated with the East African Rift System. The eastern parts of Kenya from the north to the south are dominated by sedimentary rock sequences ranging in age from the Jurassic to Recent. Large volumes of sediments are also found within the rift floor. Faulting and rifting characterizes the Mesozoic and Quaternary rocks and sediments. Sedimentary deposits of the Permo-Triassic are as a consequence of faulting and subsequent rifting during the break-up of Gondwanaland leading to the distribution of Karoo-like sediments in an intracratonic basin to the east along the Kenyan coast. These sediments are extensively exposed in the south-eastern coastal region and are locally referred to as the Duruma Group, while the small exposures to the northeast are referred to as the Mansa Guda Formation. Notably, Jurassic shales and limestones associated with shallow to deep marine environments are present alongside the Permo-Triassic sediments. The development of the East African Rift System led to the distribution of the Quaternary volcanics and sediments on the floor of the tectonic rift valley trough. Evidence of the Cenozoic history that is characterized by relict erosion surfaces is seen on certain areas of the coastal zone. Quaternary sediments are widely distributed in the country with extensive deposits in the eastern region (east of the Rift Valley) with limited exposures to the northwest.

Kenya: A Natural Outlook

Kenya: A Natural Outlook
  • Author : Christian T. Omuto
  • Publisher :Unknown
  • Release Date :2013-10-22
  • Total pages :402
  • ISBN : 9780128083895
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Summary : Soil is a natural resource that supports food production and numerous types of support to life on earth. It occurs on the earth’s surface as groups or types, which have special capabilities. To identify these capabilities, soil scientists have developed tools for mapping soil types in the landscape so that their potential uses can be maximised. However, the mapping tool needs sufficient input data that many countries in the world do not have. In Kenya, the input data for soil mapping can be found from several governmental and nongovernmental organisations. This study identified and described publicly available soil data and new tools that can be used to produce high-resolution soil map of Kenya. The spatial distribution of the locations of these soil information sources showed that the northeastern parts of the country have been poorly represented in soil information development. Furthermore, using the available soil data, this study developed a new soil map of Kenya at a higher scale than the currently available area-class map. This soil map depicts the country as consisting of 22 main soil groups according to the FAO-UNESCO classification. These groups are dominated by soil types that have strong crop production limitations under rain-fed agriculture but are good for the development of pastoral resources. This implies that rain-fed crop production in the country cannot adequately sustain the consumptive demand of over 40 million people unless improved farming methods are applied.

Kenya: A Natural Outlook

Kenya: A Natural Outlook
  • Author : Zachariah Kuria
  • Publisher :Unknown
  • Release Date :2013-10-22
  • Total pages :402
  • ISBN : 9780128083864
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Summary : Comprehensive hydrogeological investigations of Kenya as country have been carried out within various geological settings that range from volcanic terrains and associated quaternary sediments, through sedimentary terrains of northern and coastal Kenya to areas underlain by metamorphic rocks. The objective of the study was to establish groundwater occurrence and distribution in country including characterization of the aquifer properties. The aspects considered in this study of groundwater include: underlying geology, aquifer geometry, groundwater levels in the aquifer, groundwater flow and recharge, specific capacity and transmissivity of the aquifer. The study commences with a systematic analysis of over 13,000 borehole data in relation to geomorphological and geological setting from a regional conceptualization to more specific areas with distinct hydrogeological features. The results reveal that the aquifer within the sedimentary terrains (northern Kenya-Kenya coast) stretches over a distance of 740km in NW-SE direction as a continuum all the way from the Marsabit through Garissa and terminates at Lamu within the Kenyan Coast. Merti aquifer is part of this large aquifer system. The estimated average transmissivity indicate that a net flux of some 75,000m3. The main aquifer within the sedimentary setting of southern Kenya include Sabaki aquifer (at Baricho area), Tiwi Aquifer and Msambweni. The aquifer zone is marked by saturated sandy layers within the Kilindini Formation. The total storage in the northern and central parts of the sandy facies of the Kilindini Formation, assuming an effective porosity of 30%, is in the order of 112 million m3. Within the Rift Valley ground water is confined within lacustrine sediments, weathered and/or fractured zones in the volcanic rocks, and sediments interbedded between volcanic rocks. The aquifers within rift valley include: Turkana aquifer, Baringo-Bogoria aquifer, Nakuru aquifer, and Magadi aquifer. In the areas covered by the basement rocks there is no single identified aquifer with significant amount of groundwater. According to the peizometric map, the aquifer within the basement rocks are localized; examples of these aquifers occur around Isiolo, Meru, Embu, Wote and Kitui areas. Under the geological conditions of the Basement terrains, the ground­water occurs in weathered zones above the crystalline Basement rocks, fractured zones within the crystalline bedrock, and alluvial deposits along the main drainage channels.

Kenya: A Natural Outlook

Kenya: A Natural Outlook
  • Author : Christopher Oludhe
  • Publisher :Unknown
  • Release Date :2013-10-22
  • Total pages :402
  • ISBN : 9780128083888
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Summary : Energy is an important input in a country's development process since it provides the stimulus, drive and momentum for socioeconomic development. It forms one of the foundations on which the three key pillars of the Kenya Vision 2030 (Economic, Social and Political Governance) are anchored on. The country therefore needs to generate more energy and increase efficiency in energy consumption in order to realize Vision 2030 and the overall socioeconomic growth in the country. Kenya is endowed with significant amounts of renewable energy resources such as wind, solar, geothermal, small hydro and biomass. However, few renewable energy resources in the country have been fully assessed, mapped and appraised for their technical and economic viability. If harnessed, these resources can play a significant role in the country's energy supply mix. Kenya has made a significant effort to assess wind, solar and small-hydro potential in the country. However, comprehensive assessment, mapping and appraisal of all the renewable energy resources in the country have not been fully done in order to determine their technical and economic viability. The sections below present the renewable energy situation in Kenya.

Kenya: A Natural Outlook

Kenya: A Natural Outlook
  • Author : Mordecai O. Ogada,Dorothy Wanja Nyingi
  • Publisher :Unknown
  • Release Date :2013-10-22
  • Total pages :402
  • ISBN : 9780128083956
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Summary : This chapter examines the challenges facing the management of wildlife and fisheries in Kenya using the historical perspectives of the current systemic weaknesses therein. Statutory institutions managing wildlife and fisheries resources in Kenya still operate under the colonial ‘policing’ model that presumed absence of any local management capacity in situ. Examples are given of unsuccessful attempts to manage wildlife and fisheries resources over the years using interventions that failed to include local human dimensions. The colonial model is thus demonstrated to be still in place but inapplicable to address the current challenges in Kenya. The chapter finally recommends the deliberate inclusion of local communities as intellectual participants to ensure socially and environmentally sustainable management of wildlife and fisheries resources in Kenya.

Kenya: A Natural Outlook

Kenya: A Natural Outlook
  • Author : Elijah K. Biamah,Jacqueline Kiio,Benjamin Kogo
  • Publisher :Unknown
  • Release Date :2013-10-22
  • Total pages :402
  • ISBN : 9780128083963
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Summary : In Kenya, environmental impact assessment (EIA) has been used to ensure that environmental management is integrated into project planning and decision-making with a view of achieving ecologically sustainable development. Best-practice EIA identifies environmental risks, lessens resource use conflicts by promoting community participation, minimizes adverse environmental effects, informs decision-makers, and helps lay the base for environmentally sound projects. In the integration of an EIA, due considerations are made in all stages of a project, from exploration and planning through construction, operations, decommissioning, and beyond site closure. Therefore, this chapter brings out an in-depth understanding of the EIA in the Kenyan context. Some of the key issues looked into are the goals and principles of the EIA, the EIA process, public consultation and participation in environmental assessment, social dimensions in environmental assessment, and the legislative and regulatory framework for environmental management in Kenya.

Kenya: A Natural Outlook

Kenya: A Natural Outlook
  • Author : Michael E. McClain,Amanda L. Subalusky
  • Publisher :Unknown
  • Release Date :2013-10-22
  • Total pages :402
  • ISBN : 9780128083857
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Summary : Freshwater is key to Kenya’s socioeconomic development but also essential for maintaining environmental integrity and human welfare. Here, we report the results of a comprehensive and collaborative assessment of the ecological status of the Mara River and the environmental flow regime needed to sustain the ecological function of the river and related systems in the Mara/Serengeti Ecoregion. Field surveys indicate only modest evidence of degradation based on the geomorphology of the river channel and the presence and vitality of select indicator riparian plants, fish, and macroinvertebrates. Environmental flow recommendations were based on hydraulic modelling and field observations and were determined through a consensus building process involving members of the research team. During normal rainfall years, recommendations range from average monthly values of 1.3 to 15.0m3 s−1. During drought years, the respective recommended flows are 0.3 to 6.0m3 s−1. These recommendations fall between the 45th percentile of monthly flow durations curve during wet months of normal years and the 98th percentile of the annual flow duration curves during drought years. Recommended floods range from 2-day events of 12m3 s−1 to an annual 3-day flood of 90m3 s−1. Results of the assessment suggest that during years of normal rainfall there is sufficient flow in the river to allow additional water extractions and still meet environmental requirements, but environmentally friendly storage is needed and uncontrolled abstractions could easily exhaust the available resource. During drought years, however, the river may already drop to flows incapable of simultaneously meeting both extractive water demands and environmental flow recommendations.

Kenya: A Natural Outlook

Kenya: A Natural Outlook
  • Author : Christine A. Omuombo,Daniel O. Olago,Eric O. Odada
  • Publisher :Unknown
  • Release Date :2013-10-22
  • Total pages :402
  • ISBN : 9780128083871
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Summary : The Indian Ocean waters off the Kenyan coast is stratified due to temperature, salinity and pressure differences between the warm less saline less dense surface waters and the deep saline cooler waters. This stratification displays local variations influenced by rainfall or heavy water discharges of the deltas of Tana and Sabaki as well as the monsoon with maximum temperatures during the transition periods of the monsoons when the winds are light and the solar insolation is high. Turbidity increases due to sediment discharges at the mouths of the Tana and Sabaki deltas has been noted with high turbidity during the long rains in April–May and short rains in October–November, the East African Coastal Current transports the sediment northwards to the northern banks with a minimum influence on the water quality south of the coast. Sedimentation rates of 3–4 mg/cm2/day have been recorded from the Galana and Tana deltas where increased concentrations of elements such as Co, Cr, Cu, Ni, Pb, V and Zn have been reported. The semidiurnal tidal regime is influenced by the monsoon winds with the larger waves (>1.5 m) during the southeast monsoons and the lower waves (

Kenya: A Natural Outlook

Kenya: A Natural Outlook
  • Author : Josphat K. Mulwa,Fumiaki Kimata,Nguyen Anh Duong
  • Publisher :Unknown
  • Release Date :2013-10-22
  • Total pages :402
  • ISBN : 9780128083970
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Summary : The East African Rift System (EARS) and by extension the Davie Ridge, which is considered as the seaward extension of eastern branch (Kenya Rift Valley) of the East African Rift Valley (), are characterized by divergence whose maximum rate is estimated to be about 7mm/year (). This rate of divergence is somewhat much slower than that found at most active mid-ocean ridges or even the convergence of India–Burma plates or that between the Australian and Sunda plates (). Despite this slow rate of divergence, the East African Rift Valley and the Davie Ridge are characterized by frequent seismicity with large and shallow earthquakes occurring occasionally. Seismic reflection, gravity, and magnetic data from offshore East Africa allow the Davie Fracture Zone to be traced from 11oS to its intersection with the Kenyan coast at 2oS, constraining the relative motion of Madagascar and Africa (). Further, numerous faults and fractures probably associated with the Davie Fracture have been mapped using recent gravity and magnetic data between latitudes 2o21′S and 3o03′S and longitudes 40o08′E and 40o45′E by . Seasat-derived free-air gravity anomalies and slope/rise positive magnetic anomalies observed in shipboard data help to locate the continent–ocean boundaries (COB) off the shore of East Africa and Madagascar. Furthermore, the EARS, and precisely the Kenya Rift Valley, is characterized by ~3-km-thick sediments and normal-faulting mechanism. Deformation has been active along the Kenya Rift Valley as evidenced by high seismic activity. Surface deformation studies from SAR interferometry in the southern sector of the Kenya Rift Valley in Magadi show that it is characterized by 14cm of deformation over 10-km-long stretches (). If the Davie Ridge is an extension of the East African Rift Valley, we cannot rule out the occurrence of tsunami-generating earthquakes, which are bound to have devastating consequences on the eastern coast of Africa. Earthquakes as deep as 40km have been recorded below Davie Ridge (). However, evaluation of recent seismic data shows that magnitude 6.0–7.2 earthquakes at relatively shallow depths of 10–30km are a common occurrence along the Kenya Rift Valley and the Davie Ridge in the Mozambique Channel. The focal mechanism of these earthquakes supports what has previously been proposed that the Davie Ridge is a southward extension of the eastern arm of the EARS. The earthquake focal mechanism indicates that the Davie Ridge is characterized by predominantly normal faulting with occasional oblique faulting. Consequently, Kenya and generally the East African coast are prone to both seismic hazards on land and tsunami-generating earthquakes. This chapter begins with general overview of the seismicity in Kenya from the 1900s to the present. Seismicity in Kenya up to 1963 is mainly based on macroseismic data while that from 1963 to the present is based on data from instrumental recordings. In the past, a number of microseismic and seismicity studies in Kenya have previously been undertaken and the results from these studies are rather disjointed. In this chapter, we have made an attempt to merge all the existing results into one database from which the general seismicity, and subsequently seismic hazard in Kenya has been evaluated. The main goal of this chapter is to bring into focus the area(s) in Kenya more prone to seismic hazards either due to ground shaking occasioned by an earthquake or due to tsunami as a result of earthquakes occurring along the Davie Ridge.

Kenya: A Natural Outlook

Kenya: A Natural Outlook
  • Author : Ilaria Palumbo
  • Publisher :Unknown
  • Release Date :2013-10-22
  • Total pages :402
  • ISBN : 9780128083925
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Summary : In this chapter, we discuss the ecological role of fire and how this is relevant to biodiversity and park management. We summarize the role fire has in different types of ecosystems and why conservation programmes would benefit from including fire plans. We present the fire activity in the Kenyan protected areas between the years 2002 and 2012. The information is derived from satellite observations and processed to show the fire seasonality and how fire occurrence is distributed in different vegetation classes. We also provide insights about how fire can contribute to land-cover change looking at long time series of data.

Kenya: A Natural Outlook

Kenya: A Natural Outlook
  • Author : John P.O. Obiero,Japheth O. Onyando
  • Publisher :Unknown
  • Release Date :2013-10-22
  • Total pages :402
  • ISBN : 9780128083833
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Summary : Climatic characteristics, factors influencing them and effects on agro-climatic zonation and crop productions is discussed. It is recognized that climate plays a key role in agricultural production which is the mainstay of the Kenyan economy. Factors influencing climatic characteristics are notably latitude, altitude, characteristics of prevailing winds, distance from water body, topography, vegetal cover and pressure belts. Air masses, their sources and influence on dry and rainy seasons for various regions of the country are described. Rainfall and temperature distribution in various parts of the country are observed to have significant influence on agricultural practices. Variations in rainfall and temperatures are attributed to differences in characteristics that influence these climate variables. Subsequently, seven climatic regions are identified as residing in various sections of the country. Based on rainfall and temperature which determine moisture availability and evaporation rates, distinct agro-climatic zones are have been established and which play a significant role in determining appropriate land use practices for various regions of the country as well as serving as a tool for assessing suitable crops to be grown in these distinct zones. The effects of climate extremes resulting into natural disasters like floods and droughts are further discussed and strategies for their management proposed to minimize their effects on agricultural production. The role of meteorological network in monitoring weather information is noted to be important for predicting weather related disasters.

Kenya: A Natural Outlook

Kenya: A Natural Outlook
  • Author : Daniel O. Olago
  • Publisher :Unknown
  • Release Date :2013-10-22
  • Total pages :402
  • ISBN : 9780128083826
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Summary : The Quaternary evolution of Kenya is set in a dynamic climatic, environmental, volcanic and tectonic context. Climate has been controlled by orbital forcing with a dominant precessional cycle of 23,000 years driving hydrological changes that have had dramatic impacts on lake levels. Climate has interacted with tectonism and volcanism to continually modify the landscapes and environments, partly influencing hominin, animal and plant evolution. The most prominent feature is the Rift Valley, whose evolution was associated with flood volcanism, rift deformation and migration, formation of caldera volcanoes and the rise and establishment of many lakes, up to about 0.3 Ma. In the western part of the country, Lake Victoria arose in the Middle Pleistocene as a consequence of rift margin uplift and resulting river reversal and ponding. In the eastern part of the country, the landscape is dominated by the Plio-Pleistocene evolution of Mount Kenya and the Nyambeni Volcanic Series which comprises of a large field of basaltic cones and vents that extend to the arid to semi-arid northern part of the country. Several factors such as the tectonic evolution, climate, wave and tidal regime, marine transgressions and regressions, sedimentation and river discharge control the geomorphology of the Kenyan coast. Geomorphological features include dune sands, coral reefs and terraces which indicate that sea level was above present levels at least four times during the Pleistocene.