Kenya: A Natural Outlook
Title | Kenya: A Natural Outlook PDF eBook |
Author | |
Publisher | Newnes |
Pages | 403 |
Release | 2013-10-22 |
Genre | Technology & Engineering |
ISBN | 0444595473 |
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
Title | Kenya: A Natural Outlook PDF eBook |
Author | Michael E. McClain |
Publisher | Elsevier Inc. Chapters |
Pages | 23 |
Release | 2013-10-22 |
Genre | Science |
ISBN | 0128083859 |
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
Title | Kenya: A Natural Outlook PDF eBook |
Author | Andreas B. Brink |
Publisher | Elsevier Inc. Chapters |
Pages | 40 |
Release | 2013-10-22 |
Genre | Science |
ISBN | 0128083905 |
Monitoring vegetation dynamics and land cover change in Kenya are essential for the sustainable management of natural resources and biodiversity conservation. However, accurate status of seasonal variation in vegetation and long-term land cover change data valid at the regional and country level generally do not exist or are hard to obtain. Here, we describe the various ecological regions of Kenya and the associated rainfall and land cover patterns of each ecological zone. This includes the use of low-resolution satellite data time series to characterise for each ecoregion and land cover type the interannual variability of the vegetation cycle, including the start-, mid- and end of the growing season. Seasonal variation in vegetation phenology is mapped to highlight the areas of greatest interannual variation and compared to rainfall patterns over the focal study period. Statistical estimates of land cover change are produced for six broad classes for the years 1990, 2000 and 2010, based on detailed land cover change assessed by a systematic sampling of high-resolution satellite imagery. Rates of change for Kenya are presented and discussed in light of the low-resolution time series analysis. Results highlight information on land cover change processes such as vegetation dynamics and deforestation. These are discussed within the context of the drivers of changes to the natural ecosystem—their potential impact on land availability for human activities such as agriculture and logging for timber and fire wood production on the one side and habitat and biodiversity conservation on the other side. Finally, biodiversity and habitat value, ecosystems and threats are analysed for Kenya’s conservation and protected areas so as to identify the status of and pressures on the country’s protected areas. Six indicators of species irreplaceability, habitat irreplaceability and the level of perceived threat to a protected area’s habitat and species from agriculture and human population are analysed. In addition, high-resolution satellite images taken over conservation areas are used for assessing land cover changes inside protected areas and in the surrounding 20km buffer zone. The results show the importance and effectiveness of protected areas in reducing the loss of natural vegetation and hence protecting the habitats and biodiversity.
Kenya: A Natural Outlook
Title | Kenya: A Natural Outlook PDF eBook |
Author | Charles Maina-Gichaba |
Publisher | Elsevier Inc. Chapters |
Pages | 15 |
Release | 2013-10-22 |
Genre | Science |
ISBN | 0128083816 |
Kenya's relief stretches from sea level to just over 5000m at the peak of Mt. Kenya. Combined with its tropical latitudinal location, this relief range creates varied physical environment with characteristics that are almost equatorial sharply contrasting with semi-arid and arid environments. Topography is described as both simple and diverse. Its simplistic form is shown by the fact that the relief can easily be separated into lowlands and uplands while diversity is exemplified by the presence of varied landform types which include Equatorial, Savannah, Aeolian, Glacial, Volcanic and Tectonic. The Kenyan landscape, with its wide variety of forms, is closely linked with such factors as climate, micro-climate, water supply, soils, vegetation and agricultural potential. Some of the sharp contrasts in Kenya’s landscape result from the considerable differences in age of the component landforms. These are now warped and broken by faults in many areas while elsewhere volcanic activity has produced further modifications. Earth movements particularly in late Tertiary, Pleistocene and recent times, have resulted in the formation of the major mountain blocks and Rift Valley systems. These were accompanied by extensive volcanic lava emissions, which cover a significant percentage of the country's land surface. As a consequence of volcanism and earth movements, the drainage has been dislocated, interrupted and modified, and there is hardly a river that has not been affected. Many lakes have been formed in downwarped or downfaulted areas. In coastal regions, the history has been further complicated by Pleistocene changes of sea level. Major physiographic regions seems to be associated with the drainage patterns of the country. A combination of the relief, drainage systems and physiographic regions seem to influence the management and planning of the country’s development strategy. The policy makers must therefore design projects and programs for information gathering, analysis and dissemination on the basis of physical geographic factors as well as the man-made innovative improvements of nature. A superimposition of these attributes through Geographic Information System may show areas that are likely to give the greatest production-increasing effects on the basis of a combination of all the resident attributes.
Kenya: A Natural Outlook
Title | Kenya: A Natural Outlook PDF eBook |
Author | Mordecai O. Ogada |
Publisher | Elsevier Inc. Chapters |
Pages | 25 |
Release | 2013-10-22 |
Genre | Science |
ISBN | 0128083956 |
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
Title | Kenya: A Natural Outlook PDF eBook |
Author | John B. Kyalo Kiema |
Publisher | Elsevier Inc. Chapters |
Pages | 23 |
Release | 2013-10-22 |
Genre | Science |
ISBN | 0128083840 |
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
Title | Kenya: A Natural Outlook PDF eBook |
Author | Josphat K. Mulwa |
Publisher | Elsevier Inc. Chapters |
Pages | 36 |
Release | 2013-10-22 |
Genre | Science |
ISBN | 0128083972 |
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.