The model showed sensitivity primarily to surface roughness but also to root zone uptake. This study indicates that land cover type, as well as spatial relations to breeding habitats, plays an important role in determining the formation and persistence of successful breeding habitats in water-limited environments, and thereby has an impact on mosquito abundance and malaria transmission. This study suggests that a more detailed representation of the role of vegetation in soil moisture variability and runoff generation would improve both regional malaria risk models and models that focus on smaller scale hydrological processes. This modeling approach can be applied to assess relative risk of malaria transmission as it is affected by expected and observed changes in land use and climate.
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.
Agricultural productivity in the highlands of Ethiopia is threatened by severe land degradation, resulting in significant reductions in agricultural GDP. In order to mitigate ongoing erosion and soil nutrient loss in the productive agricultural highlands of the country, the government of Ethiopia initiated a Sustainable Land Management Program (SLMP) targeting 209 woredas (districts) in six regions of the country. This study evaluates the impact of SLMP on the value of agricultural production in select woredas by using a panel survey from 2010 to 2014. Whereas previous studies have used cross-sectional data and short timeframe field trials to measure sustainable land management (SLM) effects on agricultural productivity, this analysis exploits data collected over four years to assess impact. The results of this analysis show that participation by farmers in SLMP, regardless of the number of years of participation in the program, is not associated with significant increases in value of production. This may be due to several reasons. First, similar to previous studies, it is possible that longer term maintenance is necessary in order to experience significant benefits. For example, Schmidt and Tadesse (2014) report that farmers must maintain SLM for a minimum of seven years to reap benefits in value of production. Second, this analysis finds that value of production, as well as SLM investments, increased significantly in both treatment and non-treatment areas over the study period. Previous research has found that non-treatment neighbors learn from nearby program areas, and adopt technologies similar to programmed areas, which would dilute the impact measurement of program effects (Bernard et al. 2007; Angelucci and DiMaro 2010). Finally, it is important to note that kebeles that were not selected in the SLMP, but are downstream relative to a targeted kebele may receive indirect benefits through reduced flooding, increased water tables, etc. Thus, the impact of the SLMP may be underestimated in this analysis if non-program kebeles are benefiting indirectly from the program.
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.
A primary means of increasing agricultural productivity to reduce global food insecurity is through intensification, including scaling irrigation measures (USAID, 2014). Aid agencies have strongly promoted agricultural intensification efforts to increase productivity and improve overall livelihoods. While scaling of irrigated agriculture has demonstrated significant boosts in productivity (ADB, 2013; Melaine & Nonvide, 2017), agrarian transformation of the landscape through irrigated agricultural practices is associated with a number of water-related diseases (Hunter et al., 1993; Lacey & Lacey, 1990; Mather & That, 1984) including malaria (Ghebreyesus et al., 1999; Koudou et al., 2005; Oomen, De Wolf, & Jobin, 1988). The government of Malawi established through the Green Belt Initiative (GBI) a long-term program aimed at land use modifications for the development of small and large-scale irrigation. While Malawians continue to face challenges directly related to food insecurity, the country is simultaneously holoendemic for malaria, wherein the disease is found in essentially all members of the population.This research investigates changes in disease dynamics of seasonal malaria cycles as a result of land transformation for irrigated agriculture using remote sensing and spatial analytical approaches. It is conducted against a backdrop of scaling up irrigated agricultural solutions across varying sectors, and myriad actors. To that end, the meaning of 'scaling up' is analyzed across Research and Development (R&D) institutions and a conceptual framework of scaling up was constructed to promote ontological agreement of scaling up from defining programs through to final evaluation of success. Three scenarios for estimated spatio-temporal distribution of suitablearea for mosquito breeding pool formation and persistence were produced for the Bwanje Valley Irrigation Scheme (BVIS) using remotely sensed and field-based data. In addition, an estimation of habitat suitability during the dry season was produced for the 8-km area surrounding BVIS, the Bwanje Valley. Potential malaria transmission at the national scale driven by the GBI is presented through analysis of the current extent of irrigated agriculture, proposed expansion, and historic malaria prevalence data assessed by the 2012, 2014, and 2017 Demographic Health Survey (DHS) in combination with the results of a habitat suitability model generated in Google Earth Engine. The conclusions from this study provide a strong foundation for agricultural land use decision making with respect to malaria transmission across Malawi.
Ending poverty and stabilizing climate change will be two unprecedented global achievements and two major steps toward sustainable development. But the two objectives cannot be considered in isolation: they need to be jointly tackled through an integrated strategy. This report brings together those two objectives and explores how they can more easily be achieved if considered together. It examines the potential impact of climate change and climate policies on poverty reduction. It also provides guidance on how to create a “win-win†? situation so that climate change policies contribute to poverty reduction and poverty-reduction policies contribute to climate change mitigation and resilience building. The key finding of the report is that climate change represents a significant obstacle to the sustained eradication of poverty, but future impacts on poverty are determined by policy choices: rapid, inclusive, and climate-informed development can prevent most short-term impacts whereas immediate pro-poor, emissions-reduction policies can drastically limit long-term ones.
In a rapidly changing world, there is an ever-increasing need to monitor the Earth’s resources and manage it sustainably for future generations. Earth observation from satellites is critical to provide information required for informed and timely decision making in this regard. Satellite-based earth observation has advanced rapidly over the last 50 years, and there is a plethora of satellite sensors imaging the Earth at finer spatial and spectral resolutions as well as high temporal resolutions. The amount of data available for any single location on the Earth is now at the petabyte-scale. An ever-increasing capacity and computing power is needed to handle such large datasets. The Google Earth Engine (GEE) is a cloud-based computing platform that was established by Google to support such data processing. This facility allows for the storage, processing and analysis of spatial data using centralized high-power computing resources, allowing scientists, researchers, hobbyists and anyone else interested in such fields to mine this data and understand the changes occurring on the Earth’s surface. This book presents research that applies the Google Earth Engine in mining, storing, retrieving and processing spatial data for a variety of applications that include vegetation monitoring, cropland mapping, ecosystem assessment, and gross primary productivity, among others. Datasets used range from coarse spatial resolution data, such as MODIS, to medium resolution datasets (Worldview -2), and the studies cover the entire globe at varying spatial and temporal scales.
"Neglected tropical diseases (NTDs) blight the lives of a billion people worldwide and threaten the health of millions more. These ancient companions of poverty weaken impoverished populations, frustrate the achievement of health in the Millennium Development Goals and impede global health and economies has convinced governments, donors, the pharmaceutical industry and other agencies, including nongovernmental organizations (NGOs), to invest in preventing and controlling this diverse group of diseases. Global efforts to control "hidden" diseases, such as dracunculiasis (guinea-worm disease), leprosy, gains including the imminent eradication of dracunculiasis. Since 1989 (when most endemic countries began reporting monthly from each endemic village), the number of new dracunculiasis cases has fallen from 892 055 in 12 endemic countries to 3190 in 4 countries in 2009, a decrease of more than 99%. The World Health Organization (WHO) recommends five public-health strategies for the prevention and control of NTDs: preventive chemotherapy; intensified case-management; vector control; the provision of safe water, sanitation and hygiene; and veterinary public health (that is, applying veterinary sciences to ensure the health and well-being of humans). Although one approach and delivered locally." - p. vii
