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Sample records for mekhanizmy radiatsionnoi gibeli

  1. Characterization of the regional variability of flood regimes within the Omo-Gibe River Basin, Ethiopia

    NASA Astrophysics Data System (ADS)

    Yared, Adanech; Demissie, Solomon S.; Sivapalan, Murugesu; Viglione, Alberto; MacAlister, Charlotte

    2014-05-01

    Hydrological variability and seasonality is one of the Ethiopia's primary water resource management challenges. Variability is most obviously manifest in endemic, devastating droughts and floods. While the level of flooding is quite often extremely high and destroys human beings and property, in many cases flooding is of vital importance because the community benefits from flood recession agriculture. This is the case of the lower Omo plain whose agriculture is based on the regularity of the inundations due to flooding of the Omo Gibe River. The big flood in 2006, which caused death for more than 300 people and 2000 cattle, poses a dilemma. Flooding must be controlled and regulated in a way that the damages are reduced as much as possible but the flooding-related benefits are not lost. To this aim, characterization and understanding of hydrological variability of the Omo Gibe River basin is fundamental. The goal of this work is to extract the maximal amount of information on the hydrological variability and specially on the flooding regime from the few data available in the region. Because most of the basin is ungauged, hydrological information is reconstructed using the data from 9 gauged catchments. A daily water balance model has been developed, calibrated and validated for 9 gauged catchments and, subsequently, the parameters have been correlated to catchment characteristics in order to establish a functional relationship that allows to apply the model to ungauged catchments. Daily streamflow has been predicted for 15 ungauged catchments, which are assumed to comprehensively represent the hydrological variability of the Omo-Gibe River Basin. Even though both northern and southern catchments are affected by a strong seasonality of precipitation, with most of the rain falling in less than 3 months, most of the northern catchments are humid, while in the southern part of the Omo-Gibe River basin, the catchments are either humid, dry sub humid, semiarid or arid. As

  2. Anaemia and associated risk factors among pregnant women in Gilgel Gibe dam area, Southwest Ethiopia

    PubMed Central

    2012-01-01

    Background Anaemia is known to be one of the outcomes of parasitic infection and it may result in impaired cognitive development, reduced physical work capacity and in severe cases increased risk of mortality, particularly during the prenatal period. The aim of this study was to determine the prevalence and associated risk factors of anaemia among pregnant women in Gilgel-Gibe dam area, southwestern Ethiopia. Methods A cross-sectional community based study was conducted on 388 pregnant women living in three districts around Gilgel Gibe Dam area, southwestern Ethiopia. Socio-demographic and socio-economic data were collected from each participant. A single stool sample was also collected from each selected pregnant woman. Haemoglobin concentration was determined by the cyanmethemoglobin method. Plasmodium infection prevalence and intensity were assessed with thin and thick blood film examination. Results Of the total 388 study participants, 209 (53.9%) were anaemic. Pregnant woman who were rural residents (Adjusted odds ratio (AOR) = 1.62, 95% C.I: 1.02-2.62, P= 0.042), not using insecticide treated nets (ITNs) during the study period (AOR = 2.84, 95% C.I: 1.33-6.05, p = 0.007), those who were Plasmodium malaria infected (AOR = 11.19, 95% C.I: 3.31-37.7, p= 0.01) and those with Soil Transmitted Helminth (STH) infections (AOR=1.82, 95% C.I: 1.16-2.87, p=0.001) had higher odds of being anaemic than those who were urban residents, using ITNs, free of Plasmodium malaria and Soil transmitted helminth infection, respectively. There was a significant correlation between increasing hookworm parasite load (r = −.110, P< 0.001), Ascaris lumbricoides (r = −.122, P < 0.001) and Trichuris trichiura (r = −.025, P < 0.001) and decreasing hematocrit values. Conclusion The high prevalence of anaemia indicates it is currently a serious health problem of pregnant women living in Gilgel Gibe Dam area. Plasmodium malaria and soil transmitted helminth infections were significantly

  3. Assessing the potential hydrological impact of the Gibe III Dam on Lake Turkana water level using multi-source satellite data

    NASA Astrophysics Data System (ADS)

    Velpuri, N. M.; Senay, G. B.

    2012-10-01

    Lake Turkana, the largest desert lake in the world, is fed by ungauged or poorly gauged river systems. To meet the demand of electricity in the East African region, Ethiopia is currently building the Gibe III hydroelectric dam on the Omo River, which supplies more than 80% of the inflows to Lake Turkana. On completion, the Gibe III dam will be the tallest dam in Africa with a height of 241 m. However, the nature of interactions and potential impacts of regulated inflows to Lake Turkana are not well understood due to its remote location and unavailability of reliable in situ datasets. In this study, we used 12 yr (1998-2009) of existing multi-source satellite and model-assimilated global weather data. We used a calibrated multi-source satellite data-driven water balance model for Lake Turkana that takes into account model routed runoff, lake/reservoir evapotranspiration, direct rain on lakes/reservoirs and releases from the dam to compute lake water levels. The model evaluates the impact of the Gibe III dam using three different approaches - a historical approach, a rainfall based approach, and a statistical approach to generate rainfall-runoff scenarios. All the approaches provided comparable and consistent results. Model results indicated that the hydrological impact of the Gibe III dam on Lake Turkana would vary with the magnitude and distribution of rainfall post-dam commencement. On average, the reservoir would take up to 8-10 months, after commencement, to reach a minimum operation level of 201 m depth of water. During the dam filling period, the lake level would drop up to 1-2 m (95% confidence) compared to the lake level modeled without the dam. The lake level variability caused by regulated inflows after the dam commissioning were found to be within the natural variability of the lake of 4.8 m. Moreover, modeling results indicated that the hydrological impact of the Gibe III dam would depend on the initial lake level at the time of dam commencement. Areas

  4. Phosphorus contents and phosphorous sorption in soils of the Gilgel Gibe catchment, SW Ethiopia

    NASA Astrophysics Data System (ADS)

    Behn, Christian; Janssen, Manon; Geda Adela, Yalemsew; Lennartz, Bernd

    2013-04-01

    The Gilgel Gibe reservoir, located on the edge of the Ethiopian Plateau, is threatened by siltation and nutrient imports, with phosphate concentrations being more than 50-fold higher than WHO guidelines. Phosphorus reaches the reservoir mainly adsorbed to eroded soil particles. At the same time, P availability for plant production is generally limited in strongly weathered volcanic soils due to their high P sorption capacity. The objectives of this study are therefore to determine the P contents and the P sorption capacity of the soils in the catchment, and to evaluate the influence of slope position and land use. Six catenas surrounding the reservoir (120 to 440 m long), either used as pasture or as arable land, were investigated. Topsoil samples were taken at three slope positions. Parent materials were basalt and rhyolite. Soil texture was clay, the clay content ranged between 41 and 88 %. The soils were moderately to very strongly acid with pH values of 4.6 to 5.9. Plant-available P (double lactate method), total P, Fe and Al (aqua regia digestion) as well as dithionite and oxalate extractable P, Al and Fe contents were determined. Batch experiments were conducted with 7 P concentrations ranging from 0 to 500 mg/l, and the adsorption isotherms will be evaluated using Freundlich and Langmuir models. First results showed that total P contents ranged between 0.2 and 0.5 g/kg soil. Total Fe and Al contents were extremely high with values of 36 to 85 and 29 to 80 g/kg soil, respectively. P contents were significantly correlated with Fe (r=0.68) and clay (r=0.65) contents (P<0.01), which highlights the effect of the parent material. No plant-available P, however, was found in any of the soils, demonstrating the poor growth conditions. P sorption also mainly depended on the soil's Fe content. An influence of slope position or land use on either P content or P sorption capacity could not be detected.

  5. Modeling Lake Turkana Hydrology: Evaluating the potential hydrological impact of Gibe III reservoir on the Lake Turkana water levels using multi-source satellite data

    NASA Astrophysics Data System (ADS)

    Velpuri, N.; Senay, G. B.

    2012-12-01

    Ethiopia is currently building the Gibe III hydroelectric dam on the Omo River, which supplies >80% of the inflows to Lake Turkana, Kenya. On completion, the Gibe III dam will be the tallest dam in Africa (height of 241 m) with a storage capacity of 14.5 billion m3. Arguably, this is one of the most controversial hydro-power projects in the region because the nature of interactions and potential impacts of the dam regulated flows on Lake Turkana are not well understood due to its remote location and unavailability of reliable in situ hydrological datasets. In this research, we used a calibrated multi-source satellite data-driven water balance model for Lake Turkana that takes into account 12 years (1998-2009) of satellite rainfall, model routed runoff, lake/reservoir evapotranspiration, direct rain on lakes/reservoirs and releases from the dam to compute lake water levels. The model was used to evaluate the impact of the Gibe III dam using three different simple but robust approaches - a historical approach; a rainfall based sampling approach; and a non-parametric bootstrap resampling approach to generate rainfall-runoff scenarios. Modelling results indicate that, on average, the reservoir would take up to 8-10 months to reach minimum operation level of 201 m (initial impoundment period). During this period, the dam would regulate the lake inflows up to 50% and as a result the lake level would drop up to 2 m. However, after the initial impoundment period, due to releases from the dam, the rate of lake inflows would be around 10 m3/s less when compared to the rate without Gibe III (650 m3/s). Due to this, the lake levels will decline on average 1.5 m (<1 m to >3 m). Over the entire modeling period including the initial period of impoundment, the average rate of lake inflows due to Gibe III dam was estimated to be 500 m3/s. Results indicated that dam would also moderate the seasonal fluctuations in the lake. Areas along the Lake Turkana shoreline that are vulnerable

  6. Assessing the potential hydrological impact of the Gibe III Dam on Lake Turkana water level using multi-source satellite data

    NASA Astrophysics Data System (ADS)

    Velpuri, N. M.; Senay, G. B.

    2012-03-01

    Lake Turkana, the largest desert lake in the world, is fed by ungauged or poorly gauged river systems. To meet the demand of electricity in the East African region, Ethiopia is currently building the Gibe III hydroelectric dam on the Omo River, which supplies more than 80% of the inflows to Lake Turkana. On completion, the Gibe III dam will be the tallest dam in Africa with a height of 241 m. However, the nature of interactions and potential impacts of regulated inflows to Lake Turkana are not well understood due to its remote location and unavailability of reliable in-situ datasets. In this study, we used 12 years (1998-2009) of existing multi-source satellite and model-assimilated global weather data. We use calibrated multi-source satellite data-driven water balance model for Lake Turkana that takes into account model routed runoff, lake/reservoir evapotranspiration, direct rain on lakes/reservoirs and releases from the dam to compute lake water levels. The model evaluates the impact of Gibe III dam using three different approaches such as (a historical approach, a knowledge-based approach, and a nonparametric bootstrap resampling approach) to generate rainfall-runoff scenarios. All the approaches provided comparable and consistent results. Model results indicated that the hydrological impact of the dam on Lake Turkana would vary with the magnitude and distribution of rainfall post-dam commencement. On average, the reservoir would take up to 8-10 months, after commencement, to reach a minimum operation level of 201 m depth of water. During the dam filling period, the lake level would drop up to 2 m (95% confidence) compared to the lake level modelled without the dam. The lake level variability caused by regulated inflows after the dam commissioning were found to be within the natural variability of the lake of 4.8 m. Moreover, modelling results indicated that the hydrological impact of the Gibe III dam would depend on the initial lake level at the time of dam

  7. Assessing the Potential Hydrological Impact of the Gibe III Dam on Lake Turkana Water Level Using Multi-Source Satellite Data

    USGS Publications Warehouse

    Naga Manohar Velpuri; Senai, G.B.

    2012-01-01

    Lake Turkana, the largest desert lake in the world, is fed by ungauged or poorly gauged river systems. To meet the demand of electricity in the East African region, Ethiopia is currently building the Gibe III hydroelectric dam on the Omo River, which supplies more than 80% of the inflows to Lake Turkana. On completion, the Gibe III dam will be the tallest dam in Africa with a height of 241 m. However, the nature of interactions and potential impacts of regulated inflows to Lake Turkana are not well understood due to its remote location and unavailability of reliable in-situ datasets. In this study, we used 12 years (1998–2009) of existing multi-source satellite and model-assimilated global weather data. We use calibrated multi-source satellite data-driven water balance model for Lake Turkana that takes into account model routed runoff, lake/reservoir evapotranspiration, direct rain on lakes/reservoirs and releases from the dam to compute lake water levels. The model evaluates the impact of Gibe III dam using three different approaches such as (a historical approach, a knowledge-based approach, and a nonparametric bootstrap resampling approach) to generate rainfall-runoff scenarios. All the approaches provided comparable and consistent results. Model results indicated that the hydrological impact of the dam on Lake Turkana would vary with the magnitude and distribution of rainfall post-dam commencement. On average, the reservoir would take up to 8–10 months, after commencement, to reach a minimum operation level of 201 m depth of water. During the dam filling period, the lake level would drop up to 2 m (95% confidence) compared to the lake level modelled without the dam. The lake level variability caused by regulated inflows after the dam commissioning were found to be within the natural variability of the lake of 4.8 m. Moreover, modelling results indicated that the hydrological impact of the Gibe III dam would depend on the initial lake level at the time of

  8. Determinants of infant mortality in community of Gilgel Gibe Field Research Center, Southwest Ethiopia: a matched case control study

    PubMed Central

    2013-01-01

    Background Infant mortality accounts for almost 67 percent of under-five child mortality that occurs globally. An understanding of factors related to infant mortality is important to guide the development of focused and evidence-based health interventions to reduce infant deaths. But no community based studies have been conducted to identify determinants of infant mortality in Ethiopia for the past two decades. The purpose of this study is to identify determinants of infant mortality in community of Gilgel Gibe Field Research Center, Southwest Ethiopia. Methods A community based matched case–control study was conducted. The study covered 133 infants who died during infancy between January 2010 and February 2011 in the study area. For each case, a control with approximately same date of birth and survived his/her first year of live and alive at time data collection was selected. Conditional logistic regression method was used to identify determinant factors of infant mortality using Epi-info 3.5.1 statistical software. Results According to the final logistic regression model, not attending antenatal care follow-up [AOR=2.04, 95% CI:(1.04,4.02)], not using soap for hand washing before feeding child [AOR=2.50, 95% CI: (1.32,4.76)], negative perceived benefits of mother to modern treatment and prevention [AOR=2.76, 95% CI: (1.21,6.09)], small birth size [AOR=2.91, 95% CI: (1.01,8.46)] and high birth order with short birth interval [AOR=3.80, 95% CI: (1.20,11.98)] were found to be independent determinants of infant mortality. Conclusions Antenatal care follow-up, hand washing habit with soap before feeding child, birth size, perceived benefits of mothers to modern treatment, birth order and preceding birth interval were determinants of infant mortality. PMID:23621915

  9. Evaluating the Impact of Gilgel Gibe Dam on the Lake Turkana Water Levels: An Illustration from an Endorheic Lake in Africa

    NASA Astrophysics Data System (ADS)

    Velpuri, N.; Senay, G. B.

    2010-12-01

    Lake Turkana is one of the lakes in the Great Rift Valley, Africa. This lake has no outlet hence it is considered as closed or endorheic lake. To meet the demand of electricity in the east African region, Ethiopia is currently building Gilgel Gibe-III dam on the Omo River, which supplies up to 80% of the inflows to the Lake Turkana. On completion, this dam would be the tallest dam in Africa with a height of 241 m. As Lake Turkana is highly dependent on the inflows from the Omo River, the construction of this dam could potentially pose a threat to the downstream river valley and to Lake Turkana. This hydroelectric project is arguably one of the most controversial projects in the region. The impact of the dam on the lake is evaluated using Remote Sensing datasets and hydrologic modeling. First, lake water levels (1998-2007) were estimated using the Simplified Lake Water Balance (SLAB) approach which takes in satellite based rainfall estimates, modeled runoff and evapotranspiration data over the Turkana basin. Modeled lake levels were validated against TOPEX/POSIEDON/Jason-1 satellite altimeter data. Validation results showed that the model could capture observed trends and seasonal variations in lake levels. The fact that the lake is endorheic makes it easy to model the lake levels. Using satellite based estimates for the years 1998-2009, future scenarios for rainfall and evapotranspiration were generated using the Monte Carlo simulation approach and the impact of Gilgel Gibe-III dam on the Lake Turkana water levels is evaluated using SLAB approach. Preliminary results indicate that the impact of the dam on the lake would vary with the initial water level in the lake at the time of dam commissioning. It was found that during the initial period of dam/reservoir filling the lake level would drop up to 2-3 m (95% confidence interval). However, on average the lake would stabilize within 10 years from the date of commissioning. The variability within the lake levels due

  10. The Application of Predictive Modelling for Determining Bio-Environmental Factors Affecting the Distribution of Blackflies (Diptera: Simuliidae) in the Gilgel Gibe Watershed in Southwest Ethiopia

    PubMed Central

    Ambelu, Argaw; Mekonen, Seblework; Koch, Magaly; Addis, Taffere; Boets, Pieter; Everaert, Gert; Goethals, Peter

    2014-01-01

    Blackflies are important macroinvertebrate groups from a public health as well as ecological point of view. Determining the biological and environmental factors favouring or inhibiting the existence of blackflies could facilitate biomonitoring of rivers as well as control of disease vectors. The combined use of different predictive modelling techniques is known to improve identification of presence/absence and abundance of taxa in a given habitat. This approach enables better identification of the suitable habitat conditions or environmental constraints of a given taxon. Simuliidae larvae are important biological indicators as they are abundant in tropical aquatic ecosystems. Some of the blackfly groups are also important disease vectors in poor tropical countries. Our investigations aim to establish a combination of models able to identify the environmental factors and macroinvertebrate organisms that are favourable or inhibiting blackfly larvae existence in aquatic ecosystems. The models developed using macroinvertebrate predictors showed better performance than those based on environmental predictors. The identified environmental and macroinvertebrate parameters can be used to determine the distribution of blackflies, which in turn can help control river blindness in endemic tropical places. Through a combination of modelling techniques, a reliable method has been developed that explains environmental and biological relationships with the target organism, and, thus, can serve as a decision support tool for ecological management strategies. PMID:25372843

  11. Grazing incidence beam expander

    SciTech Connect

    Akkapeddi, P.R.; Glenn, P.; Fuschetto, A.; Appert, Q.; Viswanathan, V.K.

    1985-01-01

    A Grazing Incidence Beam Expander (GIBE) telescope is being designed and fabricated to be used as an equivalent end mirror in a long laser resonator cavity. The design requirements for this GIBE flow down from a generic Free Electron Laser (FEL) resonator. The nature of the FEL gain volume (a thin, pencil-like, on-axis region) dictates that the output beam be very small. Such a thin beam with the high power levels characteristic of FELs would have to travel perhaps hundreds of meters or more before expanding enough to allow reflection from cooled mirrors. A GIBE, on the other hand, would allow placing these optics closer to the gain region and thus reduces the cavity lengths substantially. Results are presented relating to optical and mechanical design, alignment sensitivity analysis, radius of curvature analysis, laser cavity stability analysis of a linear stable concentric laser cavity with a GIBE. Fabrication details of the GIBE are also given.

  12. Earthshots: Satellite images of environmental change – Lake Turkana, Kenya and Ethiopia

    USGS Publications Warehouse

    U.S. Geological Survey

    2013-01-01

    Ethiopia is constructing a series of dams on the Omo River. The Gibe I and Gibe II dams are completed, and the Gibe III dam began filling its reservoir in 2015. Studies are ongoing to understand the interactions between regulated flows as a result of the dams and rainfall on the water levels of Lake Turkana. Scientists use many years’ worth of data to get a better understanding of the lake’s natural variability and how that variability might be affected by dams, irrigation, and rainfall.

  13. Acute effects of ginger extract on biochemical and functional symptoms of delayed onset muscle soreness

    PubMed Central

    Hoseinzadeh, Khadijeh; Daryanoosh, Farhad; Baghdasar, Parvin Javad; Alizadeh, Hamid

    2015-01-01

    Background: Inflammation and pain induced by delayed onset muscle soreness (DOMS) as a result of eccentric exercise (EE) or unaccustomed activity cause some difficulties in exercise for athletes. The purpose of this study was to survey the effect of ginger extract on biochemical and functional symptom of delayed onset muscle soreness. Methods: In a quasi-experimental study, 36 healthy female subjects, who were recruited by intra dormitory calls, randomly divided into 3 groups, including: ginger intake 1 hour before exercise (GIBE), ginger intake immediately after exercise (GIAE) and placebo group (PL). Subjects consumed capsules contain 60 mg of ginger extract (equivalent of 2 g dried ginger powder) or placebo before and after exercise. The exercise protocol consisted of a 20 minute step test using a 46cm step at a rate of 15 steps per minute. The blood samples were taken before, 1, 24 and 48 hour after exercise to assay creatine kinase (CK) and interleukin-6 (IL-6). Muscle pain scores, isometric strength and circumference of thigh muscle, and hip range of motion were recorded at mentioned times. The analysis of variance (ANOVA) with repeated measure was used to determine the differences between groups. Results: The results showed a significant reduction of pain in GIBE compared to GIAE after 24 and 48h of EE and GIAE compared to PL (p<0.05). IL-6 changed significantly in GIBE compared to PL (p<0.05) after 1, 24, and 48h after EE. The other factors didn’t change meaningfully. Conclusion: The finding of this study suggests that 2 grams of ginger may have anti-inflammation and analgesic effect on DOMS. PMID:26793652

  14. Monitoring climate and man-made induced variations in terrestrial water storage (TWS) across Africa using GRACE data

    NASA Astrophysics Data System (ADS)

    Ahmed, M. E.; Sultan, M.; Wahr, J. M.; Yan, E.; Bonin, J. A.; Chouinard, K.

    2012-12-01

    northwest Africa; (5) deforestation in the Congo Basin and southern Tanzania decreased TWS and (6) the construction of dams (e.g., Merowe High Dam, Tekezé, Amerti-Neshi, Beles, Gilgel Gibe I, Gilgel Gibe II, and Karadobi) throughout the GRACE period increased TWS in upstream Nile Valley countries. Given the 10-year monthly GRACE record of water availability data (represented by GRACE TWS) acquired on the sub-basin scale across the globe, and the plans underway for deployment of a GRACE follow-up (2016-2026), consideration should be given to using GRACE TWS data as an alternative, viable drought index, and for monitoring the impacts of human interventions on hydrologic systems.

  15. My Philosophy

    NASA Astrophysics Data System (ADS)

    Lodge, Oliver

    2012-08-01

    Foreword; Part I. An Elementary Survey of Physical Existence: 1. The constitution of things around us; 2. The progress of physical science; 3. Design and purpose in the universe; 4. Religion and science; 5. The organism and the control; 6. The property of inertia; 7. Summary of new knowledge; 8. Machinery of guidance; Part II. Evidence for and Controversies Concerning the Ether: 9. Matter, energy and the ether; 10. The ether and the forms of energy; 11. Faraday's conception of the ether; 12. Modern gibes at the ether; 13. The physical aspect of the universe; 14. Views of Thomas Young, Newton and Fresnel; 15. The ether and relativity; 16. Magnetism and the ether, with suggestions for experiment; 17. Summary of our present knowledge about the ether; Part III. Introduction of Life and Mind: 18. The interaction of the psychical with the physical; 19. Life and mechanism; 20. A psychical function suggested for the ether of space; 21. Ether and the soul; Part IV. The Evidence for Survival and its Mechanism: 22. Evidence for and mechanism of survival; 23. On the difficulty of proving individual survival; 24. On the reasons for the non-recognition of psychical research by the majority of the scientific world; 25. On the apparent element of caprice introduced by the spiritistic hypothesis; 26. The whole organically considered; 27. The spiritistic hypothesis; 28. The bearing of the theory upon religions; Index.

  16. The Need for Direct High-Energy Cosmic-Ray Measurements

    NASA Technical Reports Server (NTRS)

    Jones, Frank C.; Streitmatter, Robert

    2004-01-01

    Measuring the chemical composition of the cosmic rays in the energy region of greater than or equal to 10(exp 12)eV would be highly useful in settling several nagging questions concerning the propagation of cosmic rays in the galaxy. In particular an accurate measurement of secondary to primary ratios such as Boron to Carbon would gibe clear evidence as to whether the propagation of cosmic rays is determined by a diffusion coefficient that varies with the particle's energy as E(sup 0.5) or E(sup 0.3). This would go a long ways in helping us to understand the anistropy (or lack thereof) of the highest energy cosmic rays and the power requirements for producing those particles at approximately equal to 10(exp 18) eV which are believed to be highest energy particles produced in the Galaxy. This would be only one of the benefits of a mission such as ACCESS to perform direct particle measurements on very high energy cosmic rays.

  17. Analysis of trend of malaria prevalence in south-west Ethiopia: a retrospective comparative study

    PubMed Central

    2014-01-01

    Background The temporal analysis of pertinent malaria data on the health care system is crucially important to measure success or failure of malaria programmes and identify remaining malaria hot spots. The objectives of this study were to analyse and compare trends of malaria prevalence around Gilgel-Gibe Hydroelectric Dam (GGHD), and a control site over an eight-year period. Methods A retrospective record review of health care services was conducted in southwest Ethiopia. Records of malaria cases over an eight-year period in primary health care units of two localities were reviewed. One study site was selected from villages around a man-made lake, GGHD, within a distance of 10 km, and a control site with similar geographic features was identified. Data were summarized in tables; prevalence of malaria was analysed and described by person, place and time using line graphs. Odds ratio was used to examine significant difference of malaria occurrence in the two sites. Results Records of 163,918 malaria cases registered over eight years (September 2003 to August 2011) were explored. Close to one thirds (32.7%) of these cases were from GGHD site and two-thirds (67.3%) of them were from the control site. Among the confirmed cases, Plasmodium falciparum constituted 54.6%, Plasmodium vivax accounted for 41.6%, and mixed infection was 3.8%. There were three peaks of malaria prevalence in the control site whereas only one major peak was identified during the eight-year period in GGHD site; and prevalence of malaria in GGHD site was lower than control site. Children in the age range ten to 14 years were the most affected by the disease, followed by children below the age group five to nine years, which demands due consideration in the effort of malaria control. Conclusions More malaria prevalence was observed in the control site compared to GGHD site almost throughout the time period considered. The present finding did not show evidence of the excess malaria burden in the