The construction of dams in Africa is often associated with adverse malaria impacts in surrounding communities. However, the degree and nature of these impacts are rarely quantified and the feasibility of manipulating reservoir water levels to control mosquito breeding has not been previously investigated in Africa. This report describes entomological and epidemiological studies conducted around the Koka Dam and Reservoir in Ethiopia. The research findings confirm the role of the reservoir in increasing malaria transmission and provide evidence that there is potential to use dam operation in integrated malaria control strategies.
New dam construction is likely to exacerbate malaria transmission in Africa. The vectors of malaria - Anopheles mosquitoes - use bodies of water as breeding sites. Thus, dams and their reservoirs are associated with elevated risks of malaria. In Africa, more than 150 dams are currently under construction or proposed, and most of them are designed without satisfactory considerations for the potential of enhancing malaria transmission. Precise environmental mechanisms of malaria transmission around reservoirs are yet to be identified. Understanding of these mechanisms should lead to a better assessment of the impacts of dam construction. Moreover, incorporation of such understanding into environmental management approaches can sustainably and cost-effectively prevent malaria transmission. This thesis first develops a malaria transmission model around a typical reservoir in Africa based on extensive multi-year field surveys around the Koka Reservoir in Ethiopia. A mechanistic malaria transmission model, HYDREMATS (Hydrology, Entomology, and Malaria Transmission Simulator), was extended to simulate the hydrology influenced by a reservoir system and to represent the associated behaviors of Anopheles mosquitoes in such environment. The model was calibrated and tested against various observational data on hydrology around the reservoir, and entomology of Anopheles mosquitoes. Three distinct environmental mechanisms of malaria transmission around water resource reservoirs were identified: faster parasite development during warmer seasons; amplification of reproductive activities at closer shoreline-to-house distances; enhancement of Anopheles populations under favorable wind conditions. The effect of temperature and the associated impact of global warming over the Ethiopian Highlands were analyzed. This region is particularly susceptible to the future risk of malaria transmission, because of the high sensitivity to warming and also the ephemeral immunity of the inhabitants. Specific areas expected to have high malaria risk towards the end of the 21st century were identified, including 12% of the land area and a third of the population in Ethiopia. House-to-reservoir distance and the wind direction were identified as important factors in the design of malaria-resistant villages. Keeping houses further away than certain critical distances from the shoreline was demonstrated to decrease malaria transmission. Beyond these critical distances, malaria transmission can no longer be sustained. If houses cannot not be built further away than the critical distances for malaria transmission, then extra control measures should be targeted towards such houses. The critical distances to prevent malaria are defined based on environmental and biological conditions. Malaria can also be mitigated if a village location is planned carefully. In order to effectively mitigate malaria, a village should not be located upwind of a reservoir, in general, because such location will have favorable breeding conditions with small waves and enhanced host-seeking activities through CO2 attraction from human settlements upwind. Given seasonality of wind directions and other weather conditions, wind direction during periods of high temperature, low wind speed, and low reservoir water levels are critical in deciding where to locate villages around new reservoirs. By shedding light on the precise environmental mechanisms of malaria transmission around reservoirs, the findings in this thesis are presented to inform environmental policy on how to prevent enhancement of malaria transmission around dams and reservoirs.
This thesis applies the HYDRology, Entomology and MAlaria Transmission Simulator (HYDREMATS) to the environment around a water resources reservoir in Ethiopia. HYDREMATS was modified to simulate the local hydrology and the mosquito population dynamics influenced by the reservoir system. The hydrology component of HYDREMATS including a representation of the groundwater was coupled with a reservoir model to describe the spatiotemporal variability of the groundwater table, and the variability in shoreline locations. The entomology component was modified to match the relatively humid environment. HYDREMATS was applied to two villages around the Koka Reservoir in Ethiopia, one adjacent to the reservoir, Ejersa, and the other located 12 km away from it, Gudedo. Meteorological data were collected from July 2011 to February 2013. Entomological data collection started in July 2012 and continued until February 2013. Adult mosquitoes were sampled from the two field sites and classified at the genus level, i.e., Anopheles or Culex. Because of their geographical proximity, the climatology in Ejersa and the climatology in Gudedo were comparable; however, entomological conditions in the two villages were distinct. Ejersa experienced an enhanced and prolonged mosquito season. HYDREMATS was able to simulate the hydrology and the population dynamics of Anopheles mosquitoes at both sites for the period, from January 2012 to February 2013. The model applied to Ejersa simulated a large mosquito population and a prolonged mosquito breeding season because of the existence of the reservoir, in agreement with observations. Especially, a large mosquito population in the post-rainy season was sustained in the simulation due to a large shoreline breeding area. The model applied to Gudedo simulated smaller mosquito population, but it failed to reproduce observed adult mosquito population dynamics correctly. However, the simulated adult mosquito population dynamics in Gudedo resembled those of the observed larvae samples. Further model calibration and validation will be conducted as more data become available. This study demonstrates that HYDREMATS can serve as an effective tool to simulate local hydrology and mosquito population dynamics at a reservoir environment, given hydrological and entomological parameters specified for the given field site.
This book is open access under a CC BY-NC 2.5 license. This book offers a devastating look at deeply flawed development processes driven by international finance, African governments and the global consulting industry. It examines major river basin development underway in the semi-arid borderlands of Ethiopia, Kenya and South Sudan and its disastrous human rights consequences for a half-million indigenous people. The volume traces the historical origins of Gibe III megadam construction along the Omo River in Ethiopia—in turn, enabling irrigation for commercial-scale agricultural development and causing radical reduction of downstream Omo and (Kenya's) Lake Turkana waters. Presenting case studies of indigenous Dasanech and northernmost Turkana livelihood systems and Gibe III linked impacts on them, the author predicts agropastoral and fishing economic collapse, region-wide hunger with exposure to disease epidemics, irreversible natural resource destruction and cross-border interethnic armed conflict spilling into South Sudan. The book identifies fundamental failings of government and development bank impact assessments, including their distortion or omission of mandated transboundary assessment, cumulative effects of the Gibe III dam and its linked Ethiopia-Kenya energy transmission 'highway' project, key hydrologic and human ecological characteristics, major earthquake threat in the dam region and widespread expropriation and political repression. Violations of internationally recognized human rights, especially by the Ethiopian government but also the Kenyan government, are extensive and on the increase—with collaboration by the development banks, in breach of their own internal operational procedures. A policy crossroads has now emerged. The author presents the alternative to the present looming catastrophe—consideration of development suspension in order to undertake genuinely independent transboundary assessment and a plan for continued development action within a human rights framework—forging a sustainable future for the indigenous peoples now directly threatened and for their respective eastern Africa states. Claudia Carr’s book is a treasure of detailed information gathered over many years concerning river basin development of the Omo River in Ethiopia and its impact on the peoples of the lower Omo Basin and the Lake Turkana region in Kenya. It contains numerous maps, charts, and photographs not previously available to the public. The book is highly critical of the environmental and human rights implications of the Omo River hydropower projects on both the local ethnic communities in Ethiopia and on the downstream Turkana in Kenya. David Shinn Former Ambassador to Ethiopia and to Burkina Faso Adjust Professor of International Affairs, The George Washington University, Washington D.C.
The book addresses the interactions between wetlands and human health and well-being. A key feature is the linking of ecology-health and the targeting of practitioners and researchers. The environmental health problems of the 21st Century cannot be addressed by the traditional tools of ecologists or epidemiologists working in their respective disciplinary silos; this is clear from the emergence and re-emergence of public health and human well-being problems such as cholera pandemics, mosquito borne disease, and episodic events and disasters (e.g. hurricanes). To tackle these problems requires genuine cross-disciplinary collaboration; a key finding of the recently concluded Millennium Ecosystem Assessment when looking at human well-being and ecosystem health. This book brings the disciplines of ecology and health sciences closer to such a synthesis for researchers, teachers and policy makers interested in or needing information to manage wetlands and human health and well-being issues.
Conservation Biology in Sub-Saharan Africa comprehensively explores the challenges and potential solutions to key conservation issues in Sub-Saharan Africa. Easy to read, this lucid and accessible textbook includes fifteen chapters that cover a full range of conservation topics, including threats to biodiversity, environmental laws, and protected areas management, as well as related topics such as sustainability, poverty, and human-wildlife conflict. This rich resource also includes a background discussion of what conservation biology is, a wide range of theoretical approaches to the subject, and concrete examples of conservation practice in specific African contexts. Strategies are outlined to protect biodiversity whilst promoting economic development in the region. Boxes covering specific themes written by scientists who live and work throughout the region are included in each chapter, together with recommended readings and suggested discussion topics. Each chapter also includes an extensive bibliography. Conservation Biology in Sub-Saharan Africa provides the most up-to-date study in the field. It is an essential resource, available on-line without charge, for undergraduate and graduate students, as well as a handy guide for professionals working to stop the rapid loss of biodiversity in Sub-Saharan Africa and elsewhere.
Water may seem innocuous, but as a universal necessity, it inevitably intersects with politics when it comes to acquisition, control, and associated technologies. While we know a great deal about the socioecological costs and benefits of modern dams, we know far less about their political origins and ramifications. In Concrete Revolution, Christopher Sneddon offers a corrective: a compelling historical account of the US Bureau of Reclamation’s contributions to dam technology, Cold War politics, and the social and environmental adversity perpetuated by the US government in its pursuit of economic growth and geopolitical power. Founded in 1902, the Bureau became enmeshed in the US State Department’s push for geopolitical power following World War II, a response to the Soviet Union’s increasing global sway. By offering technical and water resource management advice to the world’s underdeveloped regions, the Bureau found that it could not only provide them with economic assistance and the United States with investment opportunities, but also forge alliances and shore up a country’s global standing in the face of burgeoning communist influence. Drawing on a number of international case studies—from the Bureau’s early forays into overseas development and the launch of its Foreign Activities Office in 1950 to the Blue Nile investigation in Ethiopia—Concrete Revolution offers insights into this historic damming boom, with vital implications for the present. If, Sneddon argues, we can understand dams as both technical and political objects rather than instruments of impartial science, we can better participate in current debates about large dams and river basin planning.
