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Sample records for lake tana ethiopia

  1. The geomorphological map of Lake Tana basin (Ethiopia)

    NASA Astrophysics Data System (ADS)

    Poppe, Ludwin; Nyssen, Jan; Poesen, Jean; Admasu, Teshager; Dessie, Mekete; Adgo, Enyew; Deckers, Jozef; Frankl, Amaury

    2013-04-01

    The geomorphological map of Lake Tana basin (15 077 km², Nile basin, Ethiopia) was prepared from fieldwork data, maps and satellite data that were processed in a GIS system. It contains four major components: (i) hydrography, (ii) morphology and -metry, (iii) materials and (iv) processes. The scale is 1:500 000. The geomorphological setting of the basin consists of lavas that erupted from fissures or (shield) volcanoes during the Tertiary and Quaternary eras, were uplifted and ultimately sculpted by (mainly water) erosion. Lake Tana emerged by the combination of a lava barrier blocking the Blue Nile to the south and by epirogenetic subsidence. Since the time that the lake reached its maximum extent, extensive floodplains were created, river valleys have been filled with sediment and higher laying topography has been eroded. Today, the lake plays a lesser role in landscape formation because of a decreased lake extent (3041 km² now) as compared to the ancient maximum (6602 km²). Dominant processes today are merely fluvial and denudative. Recent (1886-2010) changes in lake coast are small with exception of the delta of the major feeding river, Gilgel Abay, which increased disproportionally the last 15 years. This indicates a large input of sediment which is mainly due to rivers flowing through Quaternary lavas. The recent sediment input increase is most probably related to human induced land-use changes.

  2. Water balance of a lake with floodplain buffering: Lake Tana, Blue Nile Basin, Ethiopia

    NASA Astrophysics Data System (ADS)

    Dessie, Mekete; Verhoest, Niko E. C.; Pauwels, Valentijn R. N.; Adgo, Enyew; Deckers, Jozef; Poesen, Jean; Nyssen, Jan

    2015-03-01

    Lakes are very important components of the earth's hydrological cycle, providing a variety of services for humans and ecosystem functioning. For a sustainable use of lakes, a substantial body of knowledge on their water balance is vital. We present here a detailed daily water balance analysis for Lake Tana, the largest lake in Ethiopia and the source of the Blue Nile. Rainfall on the lake is determined by Thiessen polygon procedure, open water evaporation is estimated by the Penman-combination equation and observed inflows for the gauged catchments as well as outflow data at the two lake outlets are directly used. Runoff from ungauged catchments is estimated using a simple rainfall-runoff model and runoff coefficients. Hillslope catchments and floodplains are treated separately, which makes this study unique compared to previous water balance studies. Impact of the floodplain on the lake water balance is analyzed by conducting scenario-based studies. We found an average yearly abstraction of 420 × 106 m3 or 6% of river inflows to the lake by the floodplain in 2012 and 2013. Nearly 60% of the inflow to the lake is from the Gilgel Abay River. Simulated lake levels compare well with the observed lake levels (R2 = 0.95) and the water balance can be closed with a closure error of 82 mm/year (3.5% of the total lake inflow). This study demonstrates the importance of floodplains and their influence on the water balance of the lake and the need of incorporating the effects of floodplains and water abstraction for irrigation to improve predictions.

  3. Sediment budget including the role of floodplains: the case of Lake Tana Basin (Ethiopia)

    NASA Astrophysics Data System (ADS)

    Lemma, Hanibal; Admasu, Teshager; Dessie, Mekete; Fentie, Derbew; Poesen, Jean; Lanckriet, Sil; Adgo, Enyew; Nyssen, Jan

    2016-04-01

    Based on the collection of a large new dataset, we quantify the sediment 1) mobilized on the hillslopes surrounding Lake Tana (Ethiopia), 2) stored on the floodplains, 3) transported into the lake, 4) deposited in the lake and 5) delivered out of the lake so as to establish a sediment budget. In 2012 and 2013, suspended sediment concentration (SSC) and discharge measurements were made at 13 monitoring stations, including two lake outlets. 4635 SSC samples were collected and sediment rating curves that account for land cover conditions and rainfall seasonality were established for the 11 river stations, and mean monthly SSC was calculated for the outlets. Effects of the floodplain on rivers' sediment yield (SY) were investigated using the measurements at the upper and lower stations of Gilgel Abay, Gumara, Megech and Rib Rivers. SY from ungauged rivers was assessed using a model that includes catchment area and rainfall, whereas bedload and direct sediment input from lake shores were estimated. As a result, the gross annual SY from both gauged and ungauged rivers, bedload and lake shores was ca. 3.14 million tons, dominantly from Gilgel Abay and Gumara Rivers. The 0.48 million tons sedimentation in floodplains indicate that the floodplains serve as sediment sink. Moreover, annually about 1.09 million tons of sediment leaves the lake through the two outlets. Annual deposition in Lake Tana was about 1.56 million tons with a trapping efficiency of 60%. Furthermore, SSC and SY are generally higher at the beginning of the rainy season because soil in cultivated fields is bare and loose due to frequent ploughing and seedbed preparation. Later on in the season, increased crop and vegetation cover lead to a decrease in sediment supplies. Based on the established sediment budget and its calculated components, one can conclude that the expected lifetime of Lake Tana (20,396 years) is longer than what was anticipated in earlier studies.

  4. Preliminary insight into the age and origin of the Labeobarbus fish species flock from Lake Tana (Ethiopia) using the mtDNA cytochrome b gene.

    PubMed

    de Graaf, Martin; Megens, Hendrik-Jan; Samallo, Johannis; Sibbing, Ferdinand

    2010-02-01

    The high diversity of Cyprinid fish in Ethiopia's Lake Tana appears to be an example of ecological differentiation and assortative mating leading to rapid sympatric speciation. Lake Tana's Labeobarbus species flock consists of 15 morphological and ecological distinct species. This is the first attempt to determine the age and origin and inter-species relationships of Lake Tana's Labeobarbus species using the mtDNA cytochrome b gene. Analysis of cytchrome b sequences shows that Lake Tana's species flock appears to be young but the present dataset did not unequivocally support monophyly of Lake Tana's species. Additional markers are needed to determine whether Lake Tana's labeobarbs originated from a single or multiple incursion(s) of ancestral L. intermedius in the Lake Tana drainage basin, or the disruption of an ancient continuous riverine population by the emergence of the Tissisat waterfalls. Adaptive radiation and speciation within Lake Tana's Labeobarbus species flock may have occurred in the last 10,000-25,000years, following the desiccation of Lake Tana around 17,000years ago, at the same time as Lake Victoria, however, obtaining more data using other (nuclear) markers is urgently required. PMID:19878730

  5. Climatic variability, plasticity, and dispersal: A case study from Lake Tana, Ethiopia.

    PubMed

    Grove, Matt; Lamb, Henry; Roberts, Helen; Davies, Sarah; Marshall, Mike; Bates, Richard; Huws, Dei

    2015-10-01

    The numerous dispersal events that have occurred during the prehistory of hominin lineages are the subject of longstanding and increasingly active debate in evolutionary anthropology. As well as research into the dating and geographic extent of such dispersals, there is an increasing focus on the factors that may have been responsible for dispersal. The growing body of detailed regional palaeoclimatic data is invaluable in demonstrating the often close relationship between changes in prehistoric environments and the movements of hominin populations. The scenarios constructed from such data are often overly simplistic, however, concentrating on the dynamics of cyclical contraction and expansion during severe and ameliorated conditions respectively. This contribution proposes a two-stage hypothesis of hominin dispersal in which populations (1) accumulate high levels of climatic tolerance during highly variable climatic phases, and (2) express such heightened tolerance via dispersal in subsequent low-variability phases. Likely dispersal phases are thus proposed to occur during stable climatic phases that immediately follow phases of high climatic variability. Employing high resolution palaeoclimatic data from Lake Tana, Ethiopia, the hypothesis is examined in relation to the early dispersal of Homo sapiens out of East Africa and into the Levant. A dispersal phase is identified in the Lake Tana record between c. 112,550 and c. 96,975 years ago, a date bracket that accords well with the dating evidence for H. sapiens occupation at the sites of Qafzeh and Skhul. Results are discussed in relation to the complex pattern of H. sapiens dispersal out of East Africa, with particular attention paid to the implications of recent genetic chronologies for the origin of non-African modern humans. PMID:26472274

  6. Isolation and characterization of potential antibiotic producing actinomycetes from water and sediments of Lake Tana, Ethiopia

    PubMed Central

    Gebreyohannes, Gebreselema; Moges, Feleke; Sahile, Samuel; Raja, Nagappan

    2013-01-01

    Objective To isolate, evaluate and characterize potential antibiotic producing actinomycetes from water and sediments of Lake Tana, Ethiopia. Methods A total of 31 strains of actinomycetes were isolated and tested against Gram positive and Gram negative bacterial strains by primary screening. In the primary screening, 11 promising isolates were identified and subjected to solid state and submerged state fermentation methods to produce crude extracts. The fermented biomass was extracted by organic solvent extraction method and tested against bacterial strains by disc and agar well diffusion methods. The isolates were characterized by using morphological, physiological and biochemical methods. Results The result obtained from agar well diffusion method was better than disc diffusion method. The crude extract showed higher inhibition zone against Gram positive bacteria than Gram negative bacteria. One-way analysis of variance confirmed most of the crude extracts were statistically significant at 95% confidence interval. The minimum inhibitory concentration and minimum bactericidal concentration of crude extracts were 1.65 mg/mL and 3.30 mg/mL against Staphylococcus aureus, and 1.84 mg/mL and 3.80 mg/mL against Escherichia coli respectively. The growth of aerial and substrate mycelium varied in different culture media used. Most of the isolates were able to hydrolysis starch and urea; able to survive at 5% concentration of sodium chloride; optimum temperature for their growth was 30 °C. Conclusions The results of the present study revealed that freshwater actinomycetes of Lake Tana appear to have immense potential as a source of antibacterial compounds. PMID:23730554

  7. [Ontogenetic Mechanisms of Explosive Morphological Divergence in the Lake Tana (Ethiopia) Species Flock of Large African Barbs (Labeobarbus; Cyprinidae; Teleostei)].

    PubMed

    Shkila, F N; Lazebny, O E; Kapitanova, D V; Abdissa, Belay; Borisov, V B; Smirnov, S V

    2015-01-01

    Species flock of Lake Tana (Ethiopia) large African barbs (Labeobarbus; Cyprinidae; Teleostei) was studied as a model system for investigating ontogenetic mechanisms of the explosive morphological divergence often accompanying sympatric speciation in bony fishes. Comparative morphological analysis carried out with the use ofgeometric morphometric techniques revealed quantitative differences in the head shapes of species under study. Comparative analysis of skull development revealed significant interspecies differences in the temporal characteristics of craniogenesis in these species. These two lines of evidence suggest that heterochronies in craniogenesis underlie divergence in the head shapes of adult Tana barbs. This prediction was verified via experimental changes of temporal characteristics of craniogenesis in L. intermedius, a putative ancestor for the Lake Tana species flock. For this aim, timing and rate of skull development were changed by artificial manipulation of thyroid hormone levels. In sum, it was shown that it is heterochronies that underlie an explosive morphological divergence of the Lake Tana barbs species flock. Our findings together with those reported in the literature suggest variability in the activity of the hypothalamic-pituitary-thyroid axis to contribute to these heterochronies. PMID:26606829

  8. Comparison of TRMM, MPEG and CFSR rainfall estimation with the ground observed data for the Lake Tana Basin, Ethiopia

    NASA Astrophysics Data System (ADS)

    Worqlul, A. W.; Maathuis, B.; Adem, A. A.; Demissie, S. S.; Langan, S.; Steenhuis, T. S.

    2014-07-01

    Planning of drought relief and floods in developing countries is greatly hampered by lack of a sufficiently dense network of weather station measuring precipitation. In this paper we test the utility of three satellite products to augment the ground based precipitation measurement to provide improved spatial estimates of rainfall. The three products are: Tropical Rainfall Measuring Mission (TRMM) product (3B42), Multi-Sensor Precipitation Estimate-Geostationary (MPEG) and Climate Forecast System Reanalysis (CFSR). The accuracy of three products is tested in the Lake Tana Basin in Ethiopia where in 2010 38 weather stations were available with a full record of daily precipitation amounts. Daily grid satellite based rainfall estimates were compared to: (1) point observed ground rainfall (2) areal rainfall in the major river sub-basins of Lake Tana. The result shows that, the MPEG and CFSR satellite provided most accurate rainfall estimates. On the average for 38 stations 78 and 86% of the observed rainfall variation is explained by MPEG and CFSR data respectively while TRIMM explained only 17% of the variation. Similarly, the areal comparison indicated a better performance for both MPEG and CFSR data in capturing the pattern and amount of rainfall. MPEG and CFSR have also a lower RMSE compared to the TRMM satellite rainfall. The Bias indicated that, the MPEG is consistent in underestimating the observed rainfall while the TRMM and CFSR were not consistent; they overestimated for some and underestimated for the others.

  9. Comparison of rainfall estimations by TRMM 3B42, MPEG and CFSR with ground-observed data for the Lake Tana basin in Ethiopia

    NASA Astrophysics Data System (ADS)

    Worqlul, A. W.; Maathuis, B.; Adem, A. A.; Demissie, S. S.; Langan, S.; Steenhuis, T. S.

    2014-12-01

    Planning for drought relief and floods in developing countries is greatly hampered by the lack of a sufficiently dense network of weather stations measuring precipitation. In this paper, we test the utility of three satellite products to augment the ground-based precipitation measurement to provide improved spatial estimates of rainfall. The three products are the Tropical Rainfall Measuring Mission (TRMM) product (3B42), Multi-Sensor Precipitation Estimate-Geostationary (MPEG) and the Climate Forecast System Reanalysis (CFSR). The accuracy of the three products is tested in the Lake Tana basin in Ethiopia, where 38 weather stations were available in 2010 with a full record of daily precipitation amounts. Daily gridded satellite-based rainfall estimates were compared to (1) point-observed ground rainfall and (2) areal rainfall in the major river sub-basins of Lake Tana. The result shows that the MPEG and CFSR satellites provided the most accurate rainfall estimates. On average, for 38 stations, 78 and 86% of the observed rainfall variation is explained by MPEG and CFSR data, respectively, while TRMM explained only 17% of the variation. Similarly, the areal comparison indicated a better performance for both MPEG and CFSR data in capturing the pattern and amount of rainfall. MPEG and CFSR also have a lower root mean square error (RMSE) compared to the TRMM 3B42 satellite rainfall. The bias indicated that TRMM 3B42 was, on average, unbiased, whereas MPEG consistently underestimated the observed rainfall. CFSR often produced large overestimates.

  10. Evaluating suitability of MODIS-Terra images for reproducing historic sediment concentrations in water bodies: Lake Tana, Ethiopia

    NASA Astrophysics Data System (ADS)

    Kaba, Essayas; Philpot, William; Steenhuis, Tammo

    2014-02-01

    Government and NGO funded conservation programs are being implemented in developing countries with the potential benefit of reduced sediment inflow into fresh water lakes. However, these claims are difficult to verify due to limited historical sediment concentration data in lakes and rivers. Remote sensing can potentially aid in monitoring sediment concentration. With almost daily availability over the past ten years and consistent atmospheric correction applied to the images, Moderate Resolution Imaging Spectroradiometer (MODIS) 250 meter images are potential resources capable of monitoring future concentrations and reconstructing historical sediment concentration records. In this paper, site-specific relationships are developed between reflectance in near-infrared (NIR) images and three factors: total suspended solids (TSS), turbidity and Secchi depth for Lake Tana near the mouth of the Gumara River. The first two sampling campaigns on November 27, 2010 and May 13, 2011 are used in calibration. Reflectance in the NIR varies linearly with turbidity (R2 = 0.89) and TSS (R2 = 0.95). Secchi depth fit best to an exponential relation with R2 of 0.74. The relationships are validated using a third sample set collected on November 7, 2011 with RMSE of 11 Nephelometric Turbidity Units (NTU) for Turbidity, 16.5 mg l-1 for TSS and 0.12 meters for Secchi depth. The MAE was 10% for TSS, 14% for turbidity and 0.1% for Secchi depth. Using the relationship for TSS, a 10-year time series of sediment concentration in Lake Tana near the Gumara River was plotted. It was found that after the severe drought of 2002 and 2003 the concentration in the lake increased significantly. The results showed that MODIS images are potential cost effective tools to monitor suspended sediment concentration and obtain a past history of concentration for evaluating the effect of best management practices.

  11. Assessment of hydrological controls on gully formation near Lake Tana, Northern Highlands of Ethiopia

    NASA Astrophysics Data System (ADS)

    Tebebu, T. Y.; Abiy, A. Z.; Dahlke, H. E.; White, E. D.; Collick, A. S.; Steenhuis, T. S.

    2008-12-01

    For the past five decades, gully erosion has been one of the dominant degradation processes in the Ethiopian Highlands. Gully erosion negatively affects soil resources, lowers soil fertility in intergully areas, reduces the pastureland available for livestock, and aggravates siltation of reservoirs. Assessing the location and rate of gully development and changes in the controlling factors (climate, soil, hydrology and land cover) of gully erosion will help explain the faced acceleration in land degradation. The study was performed in a gully system in the 800 ha Debre-Mewi watershed south of Bahir Dar, Amhara region, Ethiopia. Analyses comprised monitoring gully development through profile measurements, air photograph interpretations, and semi-structured interview techniques. Gully hydrological processes were investigated based on measurements of gully runoff and water levels in 24 piezometers in the gully contributing area. The Debre-Mewi gully is a still actively eroding gully system. A comparison of the gully area estimated from a 0.5 m resolution Quickbird image with the current gully area, walked with a Garmin GPS, showed that the eroded gully area increased by 30% from 0.51 ha in 2005 to 0.735 ha in 2008. Based on measurements of several gully cross-sections an approximate gully volume of 7985 m3 could be estimated. Using the watershed area of the gully system of 14.29 ha and an average gully erosion rate of 24.8 t ha-1 a- 1 could be estimated. Gully erosion rates accelerated since 1991 through the increased degradation of the vegetation cover and clearance of the indigenous vegetation on the hillsides, leading to an increase of surface and subsurface runoff from the hillsides to the wet valley bottoms. Gully heads retreat into the hillslope through concentrated runoff during the rainy season erodes existing soil pipes and cracks in the vicinity of the gully head and banks. The formation of subsurface soil pipes is likely triggered through abrupt changes in

  12. Hydrological Response to Climate Change for Gilgel Abay River, in the Lake Tana Basin - Upper Blue Nile Basin of Ethiopia

    PubMed Central

    Dile, Yihun Taddele; Berndtsson, Ronny; Setegn, Shimelis G.

    2013-01-01

    Climate change is likely to have severe effects on water availability in Ethiopia. The aim of the present study was to assess the impact of climate change on the Gilgel Abay River, Upper Blue Nile Basin. The Statistical Downscaling Tool (SDSM) was used to downscale the HadCM3 (Hadley centre Climate Model 3) Global Circulation Model (GCM) scenario data into finer scale resolution. The Soil and Water Assessment Tool (SWAT) was set up, calibrated, and validated. SDSM downscaled climate outputs were used as an input to the SWAT model. The climate projection analysis was done by dividing the period 2010-2100 into three time windows with each 30 years of data. The period 1990-2001 was taken as the baseline period against which comparison was made. Results showed that annual mean precipitation may decrease in the first 30-year period but increase in the following two 30-year periods. The decrease in mean monthly precipitation may be as much as about -30% during 2010-2040 but the increase may be more than +30% in 2070-2100. The impact of climate change may cause a decrease in mean monthly flow volume between -40% to -50% during 2010-2040 but may increase by more than the double during 2070-2100. Climate change appears to have negligible effect on low flow conditions of the river. Seasonal mean flow volume, however, may increase by more than the double and +30% to +40% for the Belg (small rainy season) and Kiremit (main rainy season) periods, respectively. Overall, it appears that climate change will result in an annual increase in flow volume for the Gilgel Abay River. The increase in flow is likely to have considerable importance for local small scale irrigation activities. Moreover, it will help harnessing a significant amount of water for ongoing dam projects in the Gilgel Abay River Basin. PMID:24250755

  13. Late Pleistocene and Holocene drought events at Lake Tana, the source of the Blue Nile

    NASA Astrophysics Data System (ADS)

    Marshall, Michael H.; Lamb, Henry F.; Huws, Dei; Davies, Sarah J.; Bates, Richard; Bloemendal, Jan; Boyle, John; Leng, Melanie J.; Umer, Mohammed; Bryant, Charlotte

    2011-08-01

    Magnetic and geochemical core data spanning the last 17,000 years are correlated with new seismic stratigraphy from Lake Tana, Ethiopia, to infer past lake-level change and hence effective precipitation. The data confirm that low lake-level coincides with Heinrich Event 1 (H1) in the North Atlantic, as previously shown from diatom and pollen evidence (Lamb et al., 2007). The lake deepened at 15.3 cal kyr BP and abruptly returned to freshwater conditions, when the lake overflowed into the Blue Nile. Low runoff and lake levels and therefore rainfall are inferred between 13.0 and 12.5 cal kyr BP and may represent southerly suppression of the ITCZ and the associated monsoon front at the time of the Younger Dryas. Two drought episodes occurred at 8.4 and 7.5 cal kyr BP, and are also interpreted as a southward shift in the monsoon front. The first of these events appears to have preceded and been more significant than the 8.2 cal kyr BP. Precipitation declined after 6.8 cal kyr BP, although we do not see an abrupt end to the African Humid Period. This period culminated in a dry episode at ~ 4.2 cal kyr BP, supporting the view that reduced Nile flow was a contributing factor to the demise of the Egyptian Old Kingdom.

  14. The water balance of Lake Tana and the surrounding catchments using satellite data and routine weather data

    NASA Astrophysics Data System (ADS)

    Duan, Zheng; Bastiaanssen, Wim

    2014-05-01

    Lake Tana is the largest lake in Ethiopia. The outflow is the source of the Blue Nile and this water is fundamental for many livelihoods and delivers ecosystem services to downstream - international - stakeholders. It is essential to estimate the major hydrological flow processes of the Lake Tana Basin, including the runoff from ungauged catchments that feed the lake as well as the outflow through weirs and turbines. Flow releases from many lakes and reservoirs in the world are often kept tight by responsible agencies, and this abstract shows how smart hydroinformatics based on freely accessible earth observation data can be explored to inform stakeholders. Routine weather data were added for calibration of rainfall and for the computation of evapotranspiration rates. The monthly inflow from catchments draining into Lake Tana was computed from the difference in rainfall and land evapotranspiration, including a minor correction term for storage changes in the unsaturated/saturated zone. The large majority of the inflow is ungauged, so this provides more information on the total water yield. The rainfall map at 1 km resolution was obtained from Version 7 TRMM 3B43 product using a new published downscaling-calibration procedure with measured rainfall from 20 rain gauges. The 1 km resolution evapotranspiration map was modeled from newly developed ETLook model using data from MODIS, AMSR-E and Meteosat systems. The water balance of the lake area was computed from rainfall, lake evaporation and the changes in water volumes. The rainfall over the lake area was estimated from TRMM 3B43 product with a calibration factor. The De Bruin-Keijman model was used to compute lake evaporation. Monthly heat storage changes were modeled using a newly developed hysteresis model using monthly MODIS surface temperature data. The water volume changes in the lake were estimated using Landsat TM/ETM imagery and satellite altimetry data. The satellite altimetry data were obtained from

  15. Accuracy of the CMORPH satellite-rainfall product over Lake Tana Basin in Eastern Africa

    NASA Astrophysics Data System (ADS)

    Haile, Alemseged Tamiru; Yan, Fang; Habib, Emad

    2015-09-01

    In this study, we assessed the accuracy of rainfall occurrence, amount and distribution over the Lake Tana basin in Ethiopia, Eastern Africa, as represented in the NOAA satellite-based Climate Prediction Center Morphing technique (CMORPH) rainfall product. This analysis is carried out at high spatial and temporal resolutions (8 × 8 km2 and daily) using observations from rain gauges as a reference for the period covering January 2003 to December 2006. Graphical comparisons and several statistical metrics such as bias, correlation coefficient, and standard deviation of rainfall differences are used to perform the evaluation analysis. Spatial maps of these statistical metrics were developed to assess the spatial dependency in the CMORPH accuracy. The bias is decomposed into different components, hit, missed, and false, in order to gain additional insight into the possible sources of systematic deviations in CMORPH. Overall, CMORPH was able to capture the seasonal and spatial patterns of rainfall over the basin, but with varying degrees of accuracy that depend on topography, latitude and lake-versus-land conditions within the basin. The results show that CMORPH captured rain occurrence relatively well in both wet and dry seasons over the southern part of the basin but it significantly overestimated those over the lake and its southern shore. The bias of CMORPH in the study area is characterized by seasonal and spatial variations (- 25 to 30% in wet season and - 40 to 60% in dry season). False as well as missed rains contribute significantly to the total rainfall amounts over the basin. Significant levels of the differences are observed at the daily resolution of CMORPH. The relation between CMORPH and gauge rainfall amounts is stronger (correlation mostly > 0.4) in the wet season than in the dry (mostly < 0.4).

  16. Water Resources in Lake Tana Basin: Statistical Analysis of Hydrological and Meteorological Time Series

    NASA Astrophysics Data System (ADS)

    Tigabu, T. B.; Hörmann, G.; Fohrer, N.

    2015-12-01

    Nowadays, time series environmental flow analysis is becoming one of the most important tasks in ecohydrology in order to design process based system solutions. Thus, the purpose of this research paper was to understand temporal and spatial variability of stream flows, rainfall, and inflows and outflows to and from the Lake Tana basin. Autocorrelation and cross correlation tests were applied for the long years' daily stream flows and rainfall using R languages. These methods were used to see how the stream flow or rainfall data were serially correlated and rainfall, stream flow and lake level time series data were cross correlated with each other. Autocorrelation tests of daily rainfall were carried out for many rainfall stations and the outputs indicate that there are no spikes showing significant seasonal signals. The annual rainfall map was produced for the whole catchment based on long years' records at different stations inside the catchment using inverse distance weighted interpolation (IDW) method in the GIS environment. Based on this map there is high spatial variability of annual rainfall in the catchment. The average maximum, minimum and mean annual rainfall values are 1506.4, 798.7, and 1238.1 mm respectively. According to the cross correlation tests done for stream flow & rainfall, better correlations were observed after 15 to 30 days lag time due to late response of the catchment for runoff generation. The study also prevailed that the Lake Tana water level and Blue Nile discharge at Bahir Dar station have positive cross correlation with maximum value at time lag of zero. There is a dramatic drop in the lake level and stream flow volume at the same location since 2000 due to human induced local climate forcing. In general, this research indicates that there is high temporal and spatial variability in rainfall, Lake water level and stream flows.

  17. Geology and geochronology of the Tana Basin, Ethiopia: LIP volcanism, super eruptions and Eocene-Oligocene environmental change

    NASA Astrophysics Data System (ADS)

    Prave, A. R.; Bates, C. R.; Donaldson, C. H.; Toland, H.; Condon, D. J.; Mark, D.; Raub, T. D.

    2016-06-01

    New geological and geochronological data define four episodes of volcanism for the Lake Tana region in the northern Ethiopian portion of the Afro-Arabian Large Igneous Province (LIP): pre-31 Ma flood basalt that yielded a single 40Ar/39Ar age of 34.05 ± 0.54 / 0.56 Ma; thick and extensive felsic ignimbrites and rhyolites (minimum volume of 2- 3 ×103 km3) erupted between 31.108 ± 0.020 / 0.041 Ma and 30.844 ± 0.027 / 0.046 Ma (U-Pb CA-ID-TIMS zircon ages); mafic volcanism bracketed by 40Ar/39Ar ages of 28.90 ± 0.12 / 0.14 Ma and 23.75 ± 0.02 / 0.04 Ma; and localised scoraceous basalt with an 40Ar/39Ar age of 0.033 ± 0.005 / 0.005 Ma. The felsic volcanism was the product of super eruptions that created a 60-80 km diameter caldera marked by km-scale caldera-collapse fault blocks and a steep-sided basin filled with a minimum of 180 m of sediment and the present-day Lake Tana. These new data enable mapping, with a finer resolution than previously possible, Afro-Arabian LIP volcanism onto the timeline of the Eocene-Oligocene transition and show that neither the mafic nor silicic volcanism coincides directly with perturbations in the geochemical records that span that transition. Our results reinforce the view that it is not the development of a LIP alone but its rate of effusion that contributes to inducing global-scale environmental change.

  18. Assessing the implications of water harvesting intensification on upstream-downstream ecosystem services: A case study in the Lake Tana basin.

    PubMed

    Dile, Yihun Taddele; Karlberg, Louise; Daggupati, Prasad; Srinivasan, Raghavan; Wiberg, David; Rockström, Johan

    2016-01-15

    Water harvesting systems have improved productivity in various regions in sub-Saharan Africa. Similarly, they can help retain water in landscapes, build resilience against droughts and dry spells, and thereby contribute to sustainable agricultural intensification. However, there is no strong empirical evidence that shows the effects of intensification of water harvesting on upstream-downstream social-ecological systems at a landscape scale. In this paper we develop a decision support system (DSS) for locating and sizing water harvesting ponds in a hydrological model, which enables assessments of water harvesting intensification on upstream-downstream ecosystem services in meso-scale watersheds. The DSS was used with the Soil and Water Assessment Tool (SWAT) for a case-study area located in the Lake Tana basin, Ethiopia. We found that supplementary irrigation in combination with nutrient application increased simulated teff (Eragrostis tef, staple crop in Ethiopia) production up to three times, compared to the current practice. Moreover, after supplemental irrigation of teff, the excess water was used for dry season onion production of 7.66 t/ha (median). Water harvesting, therefore, can play an important role in increasing local- to regional-scale food security through increased and more stable food production and generation of extra income from the sale of cash crops. The annual total irrigation water consumption was ~4%-30% of the annual water yield from the entire watershed. In general, water harvesting resulted in a reduction in peak flows and an increase in low flows. Water harvesting substantially reduced sediment yield leaving the watershed. The beneficiaries of water harvesting ponds may benefit from increases in agricultural production. The downstream social-ecological systems may benefit from reduced food prices, reduced flooding damages, and reduced sediment influxes, as well as enhancements in low flows and water quality. The benefits of water

  19. Seroepidemiology of Selected Arboviruses in Febrile Patients Visiting Selected Health Facilities in the Lake/River Basin Areas of Lake Baringo, Lake Naivasha, and Tana River, Kenya

    PubMed Central

    Lwande, Olivia; Orindi, Benedict; Irura, Zephania; Ongus, Juliette; Sang, Rosemary

    2015-01-01

    Abstract Introduction: Arboviruses cause emerging and re-emerging infections affecting humans and animals. They are spread primarily by blood-sucking insects such as mosquitoes, ticks, midges, and sandflies. Changes in climate, ecology, demographic, land-use patterns, and increasing global travel have been linked to an upsurge in arboviral disease. Outbreaks occur periodically followed by persistent low-level circulation. Aim: This study was undertaken to determine the seroepidemiology of selected arboviruses among febrile patients in selected lake/river basins of Kenya. Methods: Using a hospital-based cross-sectional descriptive survey, febrile patients were recruited and their serum samples tested for exposure to immunoglobulin M (IgM) and IgG antibodies against Crimean–Congo hemorrhagic fever virus (CCHFV), Rift Valley fever virus (RVFV), West Nile virus (WNV), and chikungunya virus (CHIKV). Samples positive for CHIKV and WNV were further confirmed by the plaque reduction neutralization test (PRNT). Results: Of the 379 samples examined, 176 were IgG positive for at least one of these arboviruses (46.4%, 95% confidence interval [CI] 41.4–51.5%). Virus-specific prevalence for CCHF, RVF, WN, and CHIK was 25.6%, 19.5%, 12.4%, and 2.6%, respectively. These prevalences varied significantly with geographical site (p<0.001), with Tana recording the highest overall arboviral seropositivity. PRNT results for Alphaviruses confirmed that the actual viruses circulating in Baringo were Semliki Forest virus (SFV) and CHIKV, o'nyong nyong virus (ONNV) in Naivasha, and SFV and Sindbis virus (SINDV) in Tana delta. Among the flaviviruses tested, WNV was circulating in all the three sites. Conclusion: There is a high burden of febrile illness in humans due to CCHFV, RVFV, WNV, and CHIKV infection in the river/lake basin regions of Kenya. PMID:25700043

  20. Paleomagnetism of Lake Sediments, Chew Bahir, Ethiopia

    NASA Astrophysics Data System (ADS)

    Frank, U.; Brown, M. C.; Foerster, V. E.; Schäbitz, F.

    2011-12-01

    Quasi-continuous variations of the Earth's magnetic field recorded in lake sediments can provide detailed time series describing the evolution of the geomagnetic field. To make robust conclusions about underlying geodynamo processes an improvement in the global coverage of recording sites is required. Current lake data for the late Brunhes are biased towards Europe and North America with only five studies reporting paleomagnetic results from equatorial Africa. We present inclination and relative paleointensity from Chew Bahir, southern Ethiopia; a saline mudflat located in the East African Ridge System, previously covered by a ~2000 km2 lake. Discrete measurements were made on two ten meter cores, which we continuously sub-sampled at 2 cm intervals. Calibrated AMS radiocarbon ages constrain the base of the cores to ~45 ka. NRM was demagnetized in ten steps up to 100 mT and well defined characteristic remanence directions, with MAD < 3°, were determined for the majority of specimens. Secondary components of magnetization were generally removed after alternating field demagnetization to 15 mT. Inclination is compared with previously obtained directional records from Lake Turkana, northern Kenya (~60 km to the southwest of Chew Bahir), and we discuss differences between these records. The ratio of NRM to ARM intensity at 20 mT was used as a proxy for relative paleointensity. Broad similarities in variations in relative paleointensity are seen between Chew Bahir and other globally distributed sites; most evidently through the Holocene. The magnetic mineralogy of the cores has been determined using a number of rock magnetic methods and has been used to assess the fidelity of the paleomagnetic records.

  1. Field temperature measurements at Erta'Ale Lava Lake, Ethiopia

    NASA Astrophysics Data System (ADS)

    Burgi, Pierre-Yves; Caillet, Marc; Haefeli, Steven

    2002-06-01

    The shield volcano Erta'Ale, situated in the Danakil Depression, Ethiopia, is known for its active lava lake. In February 2001, our team visited this lake, located inside an 80-m-deep pit, to perform field temperature measurements. The distribution and variation of temperature inside the lake were obtained on the basis of infrared radiation measurements performed from the rim of the pit and from the lake shores. The crust temperature was also determined from the lake shores with a thermocouple to calibrate the pyrometer. We estimated an emissivity of the basalt of 0.74 from this experiment. Through the application of the Stefan-Boltzmann law, we then obtained an estimate of the total radiative heat flux, constrained by pyrometer measurements of the pit, and visual observations of the lake activity. Taking into account the atmospheric convective heat flux, the convected magma mass flux needed to balance the energy budget was subsequently derived and found to represent between 510 and 580 kg s-1. The surface circulation of this mass flux was also analyzed through motion processing techniques applied to video images of the lake. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s00445-002-0224-3.

  2. Change Detection of Lake Aba Samuel in Ethiopia

    NASA Astrophysics Data System (ADS)

    Kaczynski, R.; Rylko, A.

    2016-06-01

    Old topographic map published in 1975 elaborated from aerial photographs taken in 1972, Landsat TM data acquired in May 1986 and Landsat ETM+ from June 2002 have been used to assess the changes of the lake Aba Samuel in Ethiopia. First map of the lake has been done in the framework of UNDP project running in 1988-90 in the Ethiopian Mapping Authority. The second classification map has been done as M.Sc. thesis in the MUT in 2015. Supervised classification methods with the use of ground truth data have been used for elaboration of the Landsat TM data. From the year 1972 up to 1986 the area of the lake has decreased by 23%. From 1986 up to 2002 the area of the lake has decreased by 20%. Therefore, after 30 years the lake was smaller by 43%. This have had very bad influence on the lives of the local population. From other recent data in the period from 2002-2015 the lake has practically disappeared and now it is only a small part of the river Akaki. ENVI 5.2 and ERDAS IMAGINE 9.2 have been used for Radiometric Calibration, Quick Atmospheric Correction (QUAC) and supervised classification of Landsat ETM+ data. The Optimum Index Factor shows the best combination of Landsat TM and ETM+ bands for color composite as 1,4,5 in the color filters: B, G, R for the signature development. Methodology and final maps are enclosed in the paper.

  3. Thermal imaging of Erta 'Ale active lava lake (Ethiopia)

    NASA Astrophysics Data System (ADS)

    Spampinato, L.; Oppenheimer, C.; Calvari, S.; Cannata, A.; Montalto, P.

    2009-04-01

    Active lava lakes represent the uppermost portion of a volume of convective magma exposed to the atmosphere, and provide open windows on magma dynamics within shallow reservoirs. Erta ‘Ale volcano located within the Danakil Depression in Ethiopia, hosts one of the few permanent convecting lava lakes, active at least since the last century. We report here the main features of Erta ‘Ale lake surface investigated using a hand-held infrared thermal camera between 11 and 12 November 2006. In both days, the lake surface was mainly characterized by efficient magma circulation reflecting in the formation of well-marked incandescent cracks and wide crust plates. These crossed the lake from the upwelling to the downwelling margin with mean speeds ranging between 0.01 and 0.15 m s-1. Hot spots opened eventually in the middle of crust plates and/or along cracks. These produced explosive activity lasting commonly between ~10 and 200 sec. Apparent temperatures at cracks ranged between ~700 and 1070˚C, and between ~300 and 500˚C at crust plates. Radiant power output of the lake varied between ~45 and 76 MW according to the superficial activity and continuous resurfacing of the lake. Time series analysis of the radiant power output data reveals cyclicity with a period of ~10 min. The combination of visual and thermal observations with apparent mean temperatures and convection rates allows us to interpret these signals as the periodic release of hot overpressured gas bubbles at the lake surface.

  4. Lake evaporation estimates in tropical Africa (Lake Ziway, Ethiopia)

    NASA Astrophysics Data System (ADS)

    Vallet-Coulomb, Christine; Legesse, Dagnachew; Gasse, Françoise; Travi, Yves; Chernet, Tesfaye

    2001-05-01

    Estimates of evaporation from an open shallow lake in tropical Africa (Lake Ziway, Main Ethiopian Rift) are made by using monthly hydrometeorological data available for the past three decades. On the one hand, annual average estimates are inferred from three climatic approaches, which can be applied in areas with limited meteorological data. The lake energy balance yields an evaporation rate of 1780 mm yr -1, assuming a Bowen ratio of 0.15 (that of Lake Victoria). The Penman method gives an annual evaporation rate of 1870 mm. The complementary relationship lake evaporation model (CRLE) applied on monthly averaged values of air temperature, air humidity and sunshine duration gives 1730 mm yr -1. The sensitivity of each method to changes in input variables is analyzed in order to test the stability of the resulting estimates. This helps discuss uncertainties and possible inter-annual variations of the evaporation rate. On the other hand, the monthly lake level records together with precipitation and river discharge data between 1969 and 1990, allow us to estimate the water balance, providing an annual rate of 1937 mm for the combined evaporation and groundwater losses. The chloride budget is used to discriminate the groundwater from the evaporation loss. It gives us an annual evaporation rate of 1740 mm and a corresponding groundwater loss of 200 mm yr -1. The groundwater loss estimate is of the same order of magnitude as the surface outflow, but the associated error in the former is significant because the result is sensitive to the poorly known chloride content of river inflows. Our results can be used to forecast the impact of increased water consumption in the basin.

  5. Soil-Transmitted Helminths and Schistosoma mansoni Infections in Ethiopian Orthodox Church Students around Lake Tana, Northwest Ethiopia

    PubMed Central

    Afework Bitew, Aschalew; Abera, Bayeh; Seyoum, Walle; Endale, Befekadu; Kiber, Tibebu; Goshu, Girma; Admass, Addiss

    2016-01-01

    Background Soil-transmitted helminths (STH) and Schistosoma mansoni infections are the major neglected tropical diseases that result in serious consequences on health, education and nutrition in children in developing countries. The Ethiopian Orthodox church students, who are called Yekolotemari in Amharic, live in areas with poor sanitation and hygiene. Moreover, they are not included in the national STH control programs. Thus, STH and S. mansoni infections prevalence is unknown. Methods A cross-sectional study was conducted on 384 students in June 2014 to determine STH and S. mansoni infections prevalence. Moreover, the knowledge of students about STH and S. mansoni was assessed. Data on knowledge and clinical symptoms were collected using structured questionnaires via face to face interview. Stool specimens were examined by formol-ether concentration method. Results The overall prevalence of intestinal helminths infections was 85.9% (95% confidence interval (CI): 82.1–89%). STHs infections prevalence was 65.6% (95% CI: 60.7–70.2%). The prevalence of hookworm, Ascaris lumbricoides and Trichuris trichiura were 31.8% (95% CI: 27.3–36.6%), 29.4% (25–31%) and 3.1% (1.8–5.4%), respectively. On the other hand, S. mansoni prevalence was 14.3% (95% CI: 11.1–18.1%). Majority of students infected with S. mansoni had bloody stool with crud odds-ratio of 2.9 (95% CI: 1.5–5.5). Knowledge assessment showed that 50 (13%) and 18 (4.9%) of the respondents knew about transmission of STH and S. mansoni, respectively. Conclusions The prevalence of STH and S. mansoni infections were high thus de-worming program should include the students of Ethiopian Orthodox churches. Furthermore, provision and use of sanitary facilities, health education for students to create awareness of parasitic infections and improved personal hygiene should be in place. PMID:27203749

  6. Stock assessment of fishery target species in Lake Koka, Ethiopia.

    PubMed

    Tesfaye, Gashaw; Wolff, Matthias

    2015-09-01

    Effective management is essential for small-scale fisheries to continue providing food and livelihoods for households, particularly in developing countries where other options are often limited. Studies on the population dynamics and stock assessment on fishery target species are thus imperative to sustain their fisheries and the benefits for the society. In Lake Koka (Ethiopia), very little is known about the vital population parameters and exploitation status of the fishery target species: tilapia Oreochromis niloticus, common carp Cyprinus carpio and catfish Clarias gariepinus. Our study, therefore, aimed at determining the vital population parameters and assessing the status of these target species in Lake Koka using length frequency data collected quarterly from commercial catches from 2007-2012. A total of 20,097 fish specimens (distributed as 7,933 tilapia, 6,025 catfish and 6,139 common carp) were measured for the analysis. Von Bertalarffy growth parameters and their confidence intervals were determined from modal progression analysis using ELEFAN I and applying the jackknife technique. Mortality parameters were determined from length-converted catch curves and empirical models. The exploitation status of these target species were then assessed by computing exploitation rates (E) from mortality parameters as well as from size indicators i.e., assessing the size distribution of fish catches relative to the size at maturity (Lm), the size that provides maximum cohort biomass (Lopt) and the abundance of mega-spawners. The mean value of growth parameters L∞, K and the growth performance index ø' were 44.5 cm, 0.41/year and 2.90 for O. niloticus, 74.1 cm, 0.28/year and 3.19 for C. carpio and 121.9 cm, 0.16/year and 3.36 for C. gariepinus, respectively. The 95 % confidence intervals of the estimates were also computed. Total mortality (Z) estimates were 1.47, 0.83 and 0.72/year for O. niloticus, C. carpio and C. gariepinus, respectively. Our study suggest that

  7. Ethiopia.

    ERIC Educational Resources Information Center

    Semaan, Leslie

    This document is a text dealing mainly with Ethiopia's rich cultural heritage and current lifestyles. It gives students the opportunity to go beyond the media coverage that has led to the perception of the whole of Ethiopia as a famine stricken land, and to discover the realities of this new nation, that about 15 percent of the population, mainly…

  8. Distribution of polycyclic aromatic hydrocarbons in sediments of Akaki River, Lake Awassa, and Lake Ziway, Ethiopia.

    PubMed

    Mekonnen, Kebede Nigussie; Chandravanshi, Bhagwan Singh; Redi-Abshiro, Mesfin; Ambushe, Abayneh Ataro; McCrindle, Robert Ian; Moyo, Stanley

    2015-07-01

    The quantification of 14 polycyclic aromatic hydrocarbons (PAHs) was carried out in sediment samples collected from Akaki River, Lake Awassa, and Lake Ziway, Ethiopia. The concentration of PAHs in the samples was determined using gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring (SIM) mode, after microwave-assisted extraction (MAE), using acetone/n-hexane (1:1, v/v) mixture. The accuracy of the method was determined by extracting and analyzing New York/New Jersey waterway sediment standard reference material (SRM 1944). The measured concentrations of PAHs in SRM 1944 agreed well with the certified values. In samples from Akaki River, Lake Awassa, and Lake Ziway, the total content of PAHs determined ranged from 0 to 3070 ng/g (average 534 ng/g), 24.9 to 413 ng/g (average 169 ng/g), and 15.0 to 305 ng/g (average 175 ng/g), respectively. Source ratios indicated that the PAHs were mainly from petrogenic origin. Sediments from all sampling sites indicated negligible levels of toxicity with no risk of adverse biological effects. PMID:26122125

  9. Ethiopia.

    PubMed

    1988-07-01

    Ethiopia lies in the Horn of Africa at the southern end of the Red Sea. It has the distinction of being the oldest independent country in Africa. In 1936, fascist Italy invaded and occupied Ethiopia, but Ethiopia regained its independence 5 years later with the help of colonial British forces. In 1974, civil unrest led to a coup and the armed forces deposed Emperor Haile Selassie. Today, the socialist government has a national legislature and a new constitution, both of which were created 13 years after the revolution. This government is faced with armed separatist movements in the autonomous regions of Eritrea and Tigre and also with periodic border conflicts with Somali forces. These conflicts combined with a massive drought in 1983-1985 and another in 1987 led to widespread famine in which an estimated 7.9 million people faced starvation and up to 1 million people died. Ethiopia has the potential for self-sufficiency in grains, livestock, vegetables, and fruits. Yet it's agriculture has been plagued not only with drought; but also soil degradation caused by overgrazing, deforestation, and high population density; dislocation due to the economy's rapid centralization; and government policies that do not provide incentives to producers. Still agriculture provides the basis of the nation's economy. Ethiopia has good relations with the Soviet Union, and the foreign policy of Ethiopia generally supports and parallels that of the USSR. After the revolution, the United States' relationship with Ethiopia has cooled because of differences over human rights. The US does assist with drought relief, however. PMID:12177998

  10. STS-65 Earth observation of Omo River Delta, Lake Turkana in Ethiopia / Kenya

    NASA Technical Reports Server (NTRS)

    1994-01-01

    STS-65 Earth observation taken aboard Columbia, Orbiter Vehicle (OV) 102, is of Omo River Delta and Lake Turkana in Ethiopia / Kenya. The Omo Delta at the north end of Lake Turkana (Rudolph) is one of the long-term environmental study sites of the Space Shuttle program. The environmental interest in this instance is the documentation of the delta's extension into the lake. This delta extension, or aggradation, is felt to be the result of large-scale soil erosion in the recently deforested areas of Ethiopia in the watershed of the Omo River. Using digitized, rectified, machine-classified, and mensurated NASA photography, it has been determined that the Omo Delta has increased in area by approximately 400% to about 1,800 square kilometers since it was first photographed during the Gemini program in 1965. This photograph documents the long-term and increasing turbidity of Lake Turkana and the continuing delta extension southward by both the northwest and northeast distributaries of the Om

  11. Ethiopia.

    PubMed

    1984-03-01

    This discussion of Ethiopia reviews the history of the country's demographic situation and reports on the government's overall approach to population problems; the population data systems and development planning; institutional arrangements for the integration of population with development planning; the government's view of the importance of population policy in realizing development objectives; population size, growth, and natural increase; morbidity and mortality; fertility; international migration; and spatial distribution. Ethiopia is 1 of the few remaining countries in the world that has never conducted a population census. The prevailing demographic data come from sample surveys, none of which had a complete national coverage. UN estimates indicate a crude birthrate of 51.8/1000 for the 1950s, with a slight decline to 49.6/1000 by 1970-75. The crude death rate was estimated to have dropped from 30.6/1000 in the early 1950s to 23.2/1000 in the early 1970s. Infant mortality is reported to have declined from 208/1000 in the early 1950s to 155/1000 during 1970-75. and life expectancy increased from 32.9 years in 1950-55 to 40.9 in 1970-75. Historically, Ethiopia is not known to have experienced any serious migration problems except for the massive exodus of refugees into neighboring countries in recent years due to continuous military operations. The government has no explicit policy to modify fertility or population growth, although in recent years it has acknowledged that these rates are too high. The most pressing concern is the improvement of the health situation through a primary health care approach. Institutional arrangements in the area of population remain at an early stage of development. The government explicitly recognizes the interrelationships between population and socioeconomic development. The Central Statistical Office estimated the population size at 24.1 million in January 1970, and the annual rate of population growth at 2.2% for the early

  12. Lava lake surface characterization by thermal imaging: Erta 'Ale volcano (Ethiopia)

    NASA Astrophysics Data System (ADS)

    Spampinato, L.; Oppenheimer, C.; Calvari, S.; Cannata, A.; Montalto, P.

    2008-12-01

    Active lava lakes represent the exposed, uppermost part of convecting magma systems and provide windows into the dynamics of magma transport and degassing. Erta 'Ale volcano located within the Danakil Depression in Ethiopia hosts one of the few permanent convecting lava lakes, probably active for a century or more. We report here on the main features of the lava lake surface based on observations from an infrared thermal camera made on 11 November 2006. Efficient magma circulation was reflected in the sustained transport of the surface, which was composed of pronounced incandescent cracks that separated wide plates of cooler crust. These crossed the lake from the upwelling to the downwelling margin with mean speeds ranging between 0.01 and 0.15 m s-1. Hot spots eventually opened in the middle of crust plates and/or along cracks. These produced mild explosive activity lasting commonly between ˜10 and ˜200 s. Apparent temperatures of cracks ranged between ˜700 and 1070°C, and of crust between ˜300 and 500°C. Radiant power output of the lake varied between ˜45 and 76 MW according to the superficial activity and continuous resurfacing of the lake. Time series analysis of the radiant power output data reveals cyclicity with a period of ˜10 min. The combination of visual and thermal observations with apparent mean temperatures and convection rates allows us to interpret these signals as the periodic release of hot overpressured gas bubbles at the lake surface.

  13. 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.

  14. Occurrence, distribution, and ecological risk assessment of potentially toxic elements in surface sediments of Lake Awassa and Lake Ziway, Ethiopia.

    PubMed

    Mekonnen, Kebede N; Ambushe, Abayneh A; Chandravanshi, Bhagwan S; Redi-Abshiro, Mesfin; McCrindle, Robert I

    2015-01-01

    Microwave-assisted acid digestion and modified aqua regia (HNO3:HCl:HF:H3BO3) leaching techniques were used for the determination of 15 potentially toxic elements (V, Cr, Fe, Mn, Co, Ni, Cu, Zn, As, Se, Ag, Cd, Sn, Hg and Pb) in sediment samples from Lake Awassa and Lake Ziway, Ethiopia. The digests were subsequently analyzed by inductively coupled plasma-mass spectrometry (ICP-MS) and inductively coupled plasma-optical emission spectrometry (ICP-OES). Mercury was directly determined in the solid samples using an elemental mercury analyzer. The precision and accuracy of the digestion procedures were verified using certified reference materials. The experimental results were in good agreement with the certified values (P < 0.05) and the recoveries were quantitative (>90%). The average relative standard deviations were below 10%. There is significant correlation between the two lakes at the 0.01 level (2-tailed). Using the sediment quality guidelines, both lakes are heavily polluted with Zn and some of the sites are heavily polluted with Cu, Ni and Pb. Based on effect range low (ERL) - effect range medium (ERM), in both lakes for Ag were greater than the ERM, indicating that the areas could be toxic to aquatic organisms, while for Cr, Cu, As and Hg the values were less than ERL. PMID:25438135

  15. Sulfur, heat, and magma budget of Erta ‘Ale lava lake, Ethiopia

    NASA Astrophysics Data System (ADS)

    Oppenheimer, C.; McGonigle, A. J. S.; Allard, P.; Wooster, M. J.; Tsanev, V.

    2004-06-01

    We report here the first measurements of the SO2 flux from Erta ‘Ale volcano (Ethiopia); the measurements were obtained in March 2003 with a portable ultraviolet spectrometer. Emission rates averaged 0.7 kg·s-1 from the active lava lake and 1.3 kg·s-1 from the whole volcano (including fumarolic emissions in the north part of the caldera). This modest output combined with an estimate of the melt sulfur content indicates a magma-supply rate of 350 650 kg·s-1 (˜0.13 0.25 m3·s-1). Radiant heat power from the lava lake, measured by infrared thermography, was found to vary between ˜5 and 30 MW according to activity of the lake surface and time elapsed since resurfacing events. We show that 8% 14% crystallization and/or 30 60 °C cooling of the upwelling magma reaching the lake, as well as degassing, are sufficient to increase magma density in the upper conduit and drive convection between the surface and a feeding reservoir. Fluctuations in the system, such as degree of vesiculation and magma supply rate, can be buffered by ascent or descent of the magma level within a flared vent region whose geometry directly controls lake surface area and hence heat loss.

  16. The ecohydrological biotechnology (SBFS) for reduction of dioxin-induced toxicity in Asella lake, Ethiopia

    NASA Astrophysics Data System (ADS)

    Urbaniak, M.; Zerihun Negussie, Y.; Zalewski, M.

    2012-04-01

    The transfer of dioxins along river continuum is a well know process which indicated permanent increase of their content in the river sediments. Despite this, there is still lack of empirical data highlighting the role of lakes and reservoirs in dioxins transfer along river continuum. Using the ecohydrology as a framework for water problem solving, the reduction of dioxins bioaccumulation in aquatic food chain should be based on two steps: 1) a reduction of dioxins emission to the water ecosystems and 2) an understanding of the role that the factors determining dioxins accumulation, transportation and transformation in the river and lake/reservoir system play for implementation of ecohydrological biotechnologies and system solutions. From limnological perspective lakes and reservoirs are considered as traps for organic and mineral sediments and bounded with them nutrients and other polluting substances. As effect of long term ecological succession the amount of sedimented matter, nutrients and loads and concentrations of pollutants usually increases. Such situation was observed in Asella lake, located in the Arsi zone of the Oromia region about 175 kilometers from Addis Ababa, Ethiopia. As the results of above processes the high concentration of dioxin concentrations in the sediments was observed, inducing decline in the water resources use. During this study the spatial pattern of dioxins concentration and toxicity (measured as WHO TEQ concentration) in the sediments of Asella river and lake taken before (in 2009) and after (in 2010) construction of Sequentional BioFiltering System (SBFS) were compared. The determination of dioxin concentrations were followed according to US EPA 1613 and 1668 Methods. Among the samples collected in the 2009 year, the contamination of lake sediments amounted for 127.65 ng kg-1 dry weight (d.w.), whereas concentration of dioxins in samples taken at the lake outflow decreased to the value of 26.65 ng kg-1 d.w. The WHO

  17. Late Cenozoic fluvial dynamics of the River Tana, Kenya, an uplift dominated record

    NASA Astrophysics Data System (ADS)

    Veldkamp, A.; Buis, E.; Wijbrans, J. R.; Olago, D. O.; Boshoven, E. H.; Marée, M.; van den Berg van Saparoea, R. M.

    2007-11-01

    The Late Cenozoic development of the River Tana in Kenya has been reconstructed for its central reach near its confluence with the River Mutonga, which drains the Mount Kenya region. Age control for this system has been provided by K-Ar and Ar-Ar dating. Between 3.21 and 2.65 Ma a major updoming occurred, in relation to the formation of the Kenyan rift valley. The tilting related to this doming has been reconstructed from lava flows that preserve former river gradients. Linear projection of these trends to the current rift valley rim suggests a net updoming of the eastern Gregory Rift valley by at least ∼1 km during 3.21-2.65 Ma. In contrast, since 2.65 Ma the Tana system has been mainly subject to relatively minor epeirogenic uplift. Changing climatic conditions combined with continuing uplift yielded a typical staircase of strath terraces with at least 10 distinct levels. A more detailed reconstruction of the incision rates since 215 ka has been made, by correlating mineralogically fingerprinted volcaniclastic Tana deposits with dated tephras in a lake record. These volcaniclastic sediments were deposited during glacial periods, contemporaneous with lahars. The reconstructed incision rates for the three youngest terraces are ∼0.1-0.2 mm a-1, thus considerably faster than the overall average rate of valley incision since the Mid-Pliocene, of 0.06 mm a-1. A plausible uplift history has been reconstructed using the estimated ages of the Tana terraces and marine terraces on the Indian Ocean coastline. The result suggests an increase in the rate of incision by the River Tana at ∼0.9 Ma, an observation typical in most European river terrace staircases. The reconstructed Late Quaternary development of Tana valley indicates that a similar Quaternary uplift mechanism has operated in both Europe and East Kenya, suggesting a globally applicable process.

  18. Seismic characteristics of variable convection at Erta ´Ale lava lake, Ethiopia

    NASA Astrophysics Data System (ADS)

    Jones, Joshua; Carniel, Roberto; Harris, Andrew J. L.; Malone, Steve

    2006-05-01

    The active summit lava lake of Erta ´Ale volcano, Ethiopia, offers a unique opportunity to study magma convection. In February 2002, we collected a multiparametric set of seismic, thermal and video data. These data indicate that the lake cycled between periods characterized by low (0.01-0.08 m s - 1 ) and high (0.1-0.4 m s - 1 ) convection rates, typically lasting tens to hundreds of minutes. Three seismometers placed around the active crater recorded continuous tremor with a dominant frequency of 2 Hz, and energy at frequencies from 0.8 to 12 Hz. Here, we characterize the seismic signature of each regime by its spectral content, wavefield polarization, and tremor source location. For both regimes, the wavefield is mostly rectilinear. Azimuths and incidence angles are consistent with P waves originating in one of two locations: the north edge of the active lava lake, or a region 100-150 m ENE of the lava lake. Because both regimes are dominated by a low frequency, rectilinearly polarized wavefield, we investigate the source location using a method that solves for location and isotropic source power by a weighted least-squares amplitude-based inversion of seismic data. We find that tremor source regions are unique to each convective regime, although some location overlap exists when tremor is located in short time windows. Wavefield composition suggests that the convective phases may share a common source process, but their differing locations indicate that either the source region is non-stationary, or a second source skews the location during the high convective phase. Tremor polarization and location suggests that the low-frequency tremor is caused by bubble coalescence and bursting in a conduit whose surface is the lava lake. The higher frequency signal associated with the high convective regime is associated with a scattered, more complex wavefield superimposed on the low-frequency background tremor, caused by bubble bursting and cracking of cooled crust at

  19. The geographic distribution of fluoride in surface and groundwater in Ethiopia with an emphasis on the Rift Valley.

    PubMed

    Tekle-Haimanot, Redda; Melaku, Zenebe; Kloos, Helmut; Reimann, Clemens; Fantaye, Wondwossen; Zerihun, Legesse; Bjorvatn, Kjell

    2006-08-15

    This paper analyzes the most extensive database on fluoride distribution in Ethiopia. Of the total 1438 water samples tested, 24.2% had fluoride concentrations above the 1.5 mg/l recommended optimum concentration recommended by WHO. Regionally, by far the highest fluoride levels were recorded in the Rift Valley, where 41.2% of all samples exceeded the 1.5 mg/l level. Only 1.0% of the samples from the central and northwestern highlands and 10.0% in the southeastern highlands exceeded 1.5 mg/l. Larger proportions of deep wells (50.0%) and hot springs (90.0%) than shallow wells (27.2%) and cold springs (12.6%) exceeded the 1.5 mg/l level. The highest fluoride concentrations were recorded for Rift Valley lakes Shala (264.0 mg/l) and Abijata (202.4 mg/l) and the lowest in Lake Tana, and rivers, wells and springs in the highlands. The fluoride concentrations of the Awash River, which originates in the highlands and flows through the Rift Valley, increase downstream, giving concern over the current diversion of high-fluoride water from Lake Beseka. Of the various flourosis prevention methods tried in Ethiopia, the treatment of surface water has been shown to be the most feasible and effective for towns and large commercial farms in the Rift Valley, although defluoridation methods should be considered for smaller rural communities. PMID:16360195

  20. Teaching the right hydrology with minimum resources in Ethiopia

    NASA Astrophysics Data System (ADS)

    Steenhuis, Tammo; Collick, Amy; Wondie, Ayalew; Jemberu, Tsehai

    2010-05-01

    This presentation will highlight our experience in teaching 19 Master's students from diverse backgrounds hydrology and watershed management in Ethiopia. Although the program was based at Bahir Dar University on the shores of Lake Tana in Ethiopia, the students received an US degree. The goal was to train professionals who can help to institute more effective and sustainable watershed management practices in Ethiopia. Teaching hydrology was a challenge. From the literature and personal observation, it was obvious that the traditional techniques of predicting runoff based on infiltration excess runoff and SCS curve number method were not satisfactory. Saturation excess runoff was more likely. However there was no research to prove that it actually was the case. In class we taught both runoff principles but stressed the saturation excess runoff. It was impossible to convince the students that the techniques that came from the western world be incorrect. For their Masters thesis, eight students did field research on runoff and erosion processes in watershed (some of which has a long record of discharge and sediment data). The students recorded water table heights, measured infiltration rates and determined where most erosion took place in the landscape. Based on this data they modeled the previously observed discharge successful using a saturation excess type model. From these studies we could establish that saturation in the landscape had a great effect on both runoff and sediment losses. As result of the field work, students had changed their mind about the appropriateness of using for example the SCS curve number method in Ethiopian highlands Perhaps the lesson to be learned is that we do not need a lot of funds to teach students the right hydrology. However, there is no substitute for going out in the field and experiencing what the right hydrology is by studying the processes in the landscape itself. By simply teaching in class, students will and cannot accept

  1. The role of large bubbles detected from acoustic measurements on the dynamics of Erta 'Ale lava lake (Ethiopia)

    NASA Astrophysics Data System (ADS)

    Bouche, E.; Vergniolle, S.; Staudacher, T.; Nercessian, A.; Delmont, J.-C.; Frogneux, M.; Cartault, F.; Le Pichon, A.

    2010-06-01

    The activity at the surface of the lava lake on Erta 'Ale volcano (Ethiopia) shows that large bubbles are regularly breaking at a fixed position on the lava lake. This is also where the small lava fountains are sometimes produced. Since this location is likely to be directly above the volcanic conduit feeding the lava lake, we have done continuous measurements between March 22 and 26, 2003 to understand the degassing of a volcano in permanent activity. The bubble size has been first estimated from videos, which once combined with the acoustic pressure, can constrain the source of the sound. The gas volume and overpressure stayed roughly constant, between 36-700 m3 and 4 × 103-1.8 × 104 Pa, respectively. Simultaneous thermal measurements showed regular peaks, which occurred when the crust was broken by a large bubble, hence gave a direct indication on the typical return time between the bubbles (1 h). These spherical cap bubbles had a high Reynolds number, 4600-20000, therefore a wake, periodically unstable, formed and detached from the bubble bottom. The bubbly wake, if the detachment occurs close to the surface, can explain the duration of lava fountains, measured on the videos. The periodic arrival of bubbly wakes, which mostly detach from the driving spherical cap within the lava lake, could explain the absence of cooling at Erta 'Ale, Erebus (Antartica), Villarica (Chile) and Nyiragongo (Democratic Republic of Congo) without invoking a convective downflow of magma in the conduit, as previously done.

  2. Environmental Impact of Controlled-Source Explosions in Ethiopia (Project EAGLE): Geochemical Effects on Lakes and Streams

    NASA Astrophysics Data System (ADS)

    Cash, M.; Klemperer, S. L.; Mengistou, S.

    2003-12-01

    Controlled-source seismologists seek to detonate charges in lakes or rivers because source coupling is an order of magnitude larger in water than in drill holes. Previous studies have documented the biological impact of dynamite explosions on small fish populations; however, little attention has been paid to the potential chemical changes associated with the dispersal of a dynamite charge in a body of water. At the request of the Ethiopian Environmental Protection Authority, we sought to examine the effects on water chemistry resulting from the detonation of one tonne dynamite charges used during the Ethiopia-Afar Geoscientific Lithospheric Experiment (EAGLE), an active source seismic survey of the Main Ethiopian Rift. Water samples from two Ethiopian lakes and six Ethiopian streams were collected in January 2003. Samples were collected immediately preceding and following the detonation of the 2 lake shots and those 6 of our 19 borehole shots for which a stream was present in the surrounding area. Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) analysis has provided concentrations of 16 elements, including: As, B, Ba, Be, Ca, Cd, Co, Cu, Mg, Mn, Mo, Na, Ni, Sr, V, Zn. Additional elements were also examined, however elements such as Cr, Fe, and Pb, had concentrations residing close to the detection limits of the ICP-OES, and the certainty of these numbers is not reliable. We plan to make measurements of Cl and S using the Ion Chromatograph (IC) method. The sites from which the water samples were collected include: (1) Lake Shala, a 12 by 15 km lake, 266 meters deep, (2) Lake Arenguade, an approximately 800m diameter crater lake, 32 m deep, and (3) six streams, each located within close proximity to one of the 19 borehole shots. All samples were filtered using a 2 micron nalgene filter to remove any biotic material. Prior to each shot, water samples were collect. To the extent possible, lake samples were taken 1 hour before the shot, 10 minutes

  3. Understanding Natural and Human-induced Impacts on the Hydrology of Central Rift Valley Lakes in Ethiopia Using Hydrologic Modeling and Remote Sensing

    NASA Astrophysics Data System (ADS)

    Seyoum, W. M.; Milewski, A.

    2013-12-01

    In the past decades lake level fluctuations have been observed in the Central Rift Valley (CRV) lakes of Ethiopia, specifically Lake Abiyata, which is receding at an alarming rate. The cause is largely unknown and thus this research identifies and quantifies the causes and effects of climate variability and human-induced factors on the CRV lakes in Ethiopia using ground data, remote sensing, and hydrologic modeling. The CRV is a closed basin with an area of 10,185 sq. km. and contains three major surficially interconnected lakes: Lake Abiyata, Lake Langano and Lake Ziway. Remote sensing data (e.g. LANDSAT and TRMM) and ground data (e.g. river discharge, lake levels) was analyzed to understand the impact of climate variability on the lakes. Image processing such as radiometric correction and Normalized Difference Water Index (NDWI) was performed to calculate the surface area of the lakes and understand the temporal variation. The semi-distributed physically based hydrologic model, Soil Water Assessment Tool (SWAT), was employed to estimate the total surface runoff to the lakes. SWAT was simulated from 1980 to 2010 and monthly preliminary calibration was performed from 1985 to 2000 using two river gauging stations. The preliminary R2 and Nash-Sutcliffe simulation efficiency values are 0.65 and 0.60, and 0.61 and 0.60. The output from SWAT, total runoff, along with precipitation and evaporation is used to calculate the water budget of each lake. Changes in the total volume of lake water were converted to changes in water heights using the geometry data of lakes (e.g. bathymetry data). The modeled lake level time series, which does not take into account the abstraction rates, are compared with the remote sensing and ground observed data. Surface area mapping from satellite imagery shows that the surface Area of L. Ziway and L. Langano remained unchanged throughout the period 1985 - 2010, whereas the surface area of L. Abiyata is decreasing from approximately 180 sq. km

  4. Understanding Natural and Human-induced Impacts on the Hydrology of Central Rift Valley Lakes in Ethiopia Using Hydrologic Modeling and Remote Sensing

    NASA Astrophysics Data System (ADS)

    Seyoum, W. M.; Milewski, A.

    2011-12-01

    In the past decades lake level fluctuations have been observed in the Central Rift Valley (CRV) lakes of Ethiopia, specifically Lake Abiyata, which is receding at an alarming rate. The cause is largely unknown and thus this research identifies and quantifies the causes and effects of climate variability and human-induced factors on the CRV lakes in Ethiopia using ground data, remote sensing, and hydrologic modeling. The CRV is a closed basin with an area of 10,185 sq. km. and contains three major surficially interconnected lakes: Lake Abiyata, Lake Langano and Lake Ziway. Remote sensing data (e.g. LANDSAT and TRMM) and ground data (e.g. river discharge, lake levels) was analyzed to understand the impact of climate variability on the lakes. Image processing such as radiometric correction and Normalized Difference Water Index (NDWI) was performed to calculate the surface area of the lakes and understand the temporal variation. The semi-distributed physically based hydrologic model, Soil Water Assessment Tool (SWAT), was employed to estimate the total surface runoff to the lakes. SWAT was simulated from 1980 to 2010 and monthly preliminary calibration was performed from 1985 to 2000 using two river gauging stations. The preliminary R2 and Nash-Sutcliffe simulation efficiency values are 0.65 and 0.60, and 0.61 and 0.60. The output from SWAT, total runoff, along with precipitation and evaporation is used to calculate the water budget of each lake. Changes in the total volume of lake water were converted to changes in water heights using the geometry data of lakes (e.g. bathymetry data). The modeled lake level time series, which does not take into account the abstraction rates, are compared with the remote sensing and ground observed data. Surface area mapping from satellite imagery shows that the surface Area of L. Ziway and L. Langano remained unchanged throughout the period 1985 - 2010, whereas the surface area of L. Abiyata is decreasing from approximately 180 sq. km

  5. From the Sound of Erta Ale Lava Lake (Ethiopia) to Eruption Dynamics Into a Magma Reservoir

    NASA Astrophysics Data System (ADS)

    Bouche, E.; Vergniolle, S.

    2007-12-01

    The basaltic volcano of Erta Ale, located on the East African Rift, has a permanent lava lake whose behaviour presents similarity with a shallow magma reservoir. In March 2003, continuous measurements of acoustic pressure, images from video, temperature, seismicity and wind velocity were perfomed to quantify degassing of the lava lake in order to understand the eruptive behaviour of this volcano. The videos show that two types of gas bubbles break at the lava lake surface. Modelling acoustic pressure gives bubble overpressure and size. Bubbles are either large (radius 2 m) and overpressurised (4.104 Pa) or of intermediate size (radius 1 m) and weakly overpressurised (450 Pa). The large bubbles come from the conduit at the base of the lava lake whereas bubbles of intermediate size are produced by the destabilisation of a foam accumulated below the crust overlying the lava lake. Hence, their overpressure is related to capillary pressure of the rising small bubbles, suggesting that their diameter is 3.6 mm. The formation of bubbles of intermediate size is related to the local foam coalescence because of foam sluggish drainage. However, overpressure of intermediate size bubbles shows sudden peaks every eighteen hours, up to 6000 Pa. Each peak is related to a massive coalescence of a foam having reached its critical thickness. This involves a much larger number of bubbles than foam drainage, hence a much larger overpressure and energy. The rapid and massive coalescence leads to a sudden withdrawal of the foam. The disappearence of the foam suppress the buoyancy that sustained the cold and dense crust at the top of the lava lake, forcing the crust to sink. The average gas flux (6.10-3 m3s-1) is estimated over an eighteen-hour cycle from modelling the frequency of sound waves. Furthermore the diameter of the small bubbles deduced from the overpressure on synthetic waveforms can be combined with gas volume fraction observed on videos to estimate the gas flux between 3

  6. Investigation of volcanic gas analyses and magma outgassing from Erta' Ale lava lake, Afar, Ethiopia

    NASA Astrophysics Data System (ADS)

    Gerlach, T. M.

    1980-05-01

    The analyses of 18 volcanic gas samples collected over a two-hour period at 1075°C from Erta' Ale lava lake in December 1971 and of 18 samples taken over a half-hour period at 1125-1135°C in 1974 display moderately to intensely variable compositions. These variations result from imposed modifications caused by (1) atmospheric contamination and oxidation, (2) condensation and re-evaporation of water during collection, (3) analytical errors, and (4) chemical reactions between the erupted gases and a steel lead-in tube. Detailed examinations of the analyses indicate the erupted gases were at chemical equilibrium before collection. This condition was partially destroyed by the imposed modifications. High-temperature reaction equilibria were more completely preserved in the 1974 samples. Numerical procedures based on thermodynamic calculations have been used to restore each analysis to a composition representative of the erupted gases. These procedures have also been used to restore the anhydrous mean compositions reported for two series of collections taken at the lava lake in January 1973. The corrected analyses for 1971 and 1973 have similar compositions (69.6-71.3% H 2O, 1.6-2.4% H 2, 17.8-19.4% CO 2, 0.8-1.6% CO, 4.9-8.8% SO 2, 0.2-0.5% S 2, and 0.4-1.0% H 2S); those for 1974 were somewhat different (77.1% H 2O, 1.6% H 2, 11.7% CO 2, 0.5% CO, 7.4% SO 2, 0.3% S 2, 0.9% H 2S and 0.4% HCl). The O 2 and S 2 fugacities of all restored analyses are similar when compared at the same temperatures. O 2 fugacities are close to those of the quartz-magnetite-fayalite buffer. The restored analyses show no evidence of significant short-term (minutes, hours) variations in the compositions of the gases released from the lava lake, and evidence of long-term variations is limited. The restored analyses indicate the O 2 and S 2 potentials of the lava lake remained nearly constant from 1971 to 1974. However, there is a relative decrease in CO 2 between the 1973 and 1974 corrected

  7. Estimating eruption temperature from thermal emission spectra of lava fountain activity in the Erta'Ale (Ethiopia) volcano lava lake: Implications for observing Io's volcanoes

    USGS Publications Warehouse

    Davies, Ashley G.; Keszthelyi, Laszlo P.; McEwen, Alfred S.

    2011-01-01

    We have analysed high-spatial-resolution and high-temporal-resolution temperature measurements of the active lava lake at Erta'Ale volcano, Ethiopia, to derive requirements for measuring eruption temperatures at Io's volcanoes. Lava lakes are particularly attractive targets because they are persistent in activity and large, often with ongoing lava fountain activity that exposes lava at near-eruption temperature. Using infrared thermography, we find that extracting useful temperature estimates from remote-sensing data requires (a) high spatial resolution to isolate lava fountains from adjacent cooler lava and (b) rapid acquisition of multi-color data. Because existing spacecraft data of Io's volcanoes do not meet these criteria, it is particularly important to design future instruments so that they will be able to collect such data. Near-simultaneous data at more than two relatively short wavelengths (shorter than 1 μm) are needed to constrain eruption temperatures. Resolving parts of the lava lake or fountains that are near the eruption temperature is also essential, and we provide a rough estimate of the required image scale.

  8. Estimating eruption temperature from thermal emission spectra of lava fountain activity in the Erta'Ale (Ethiopia) volcano lava lake: Implications for observing Io's volcanoes

    USGS Publications Warehouse

    Davies, A.G.; Keszthelyi, L.; McEwen, A.S.

    2011-01-01

    We have analysed high-spatial-resolution and high-temporal-resolution temperature measurements of the active lava lake at Erta'Ale volcano, Ethiopia, to derive requirements for measuring eruption temperatures at Io's volcanoes. Lava lakes are particularly attractive targets because they are persistent in activity and large, often with ongoing lava fountain activity that exposes lava at near-eruption temperature. Using infrared thermography, we find that extracting useful temperature estimates from remote-sensing data requires (a) high spatial resolution to isolate lava fountains from adjacent cooler lava and (b) rapid acquisition of multi-color data. Because existing spacecraft data of Io's volcanoes do not meet these criteria, it is particularly important to design future instruments so that they will be able to collect such data. Near-simultaneous data at more than two relatively short wavelengths (shorter than 1 ??m) are needed to constrain eruption temperatures. Resolving parts of the lava lake or fountains that are near the eruption temperature is also essential, and we provide a rough estimate of the required image scale. ?? 2011 by the American Geophysical Union.

  9. Estimating eruption temperature from thermal emission spectra of lava fountain activity in the Erta'Ale (Ethiopia) volcano lava lake: Implications for observing Io's volcanoes

    NASA Astrophysics Data System (ADS)

    Davies, Ashley Gerard; Keszthelyi, Laszlo; McEwen, Alfred S.

    2011-11-01

    We have analysed high-spatial-resolution and high-temporal-resolution temperature measurements of the active lava lake at Erta'Ale volcano, Ethiopia, to derive requirements for measuring eruption temperatures at Io's volcanoes. Lava lakes are particularly attractive targets because they are persistent in activity and large, often with ongoing lava fountain activity that exposes lava at near-eruption temperature. Using infrared thermography, we find that extracting useful temperature estimates from remote-sensing data requires (a) high spatial resolution to isolate lava fountains from adjacent cooler lava and (b) rapid acquisition of multi-color data. Because existing spacecraft data of Io's volcanoes do not meet these criteria, it is particularly important to design future instruments so that they will be able to collect such data. Near-simultaneous data at more than two relatively short wavelengths (shorter than 1 μm) are needed to constrain eruption temperatures. Resolving parts of the lava lake or fountains that are near the eruption temperature is also essential, and we provide a rough estimate of the required image scale.

  10. Ecological correlates of abundance in the Tana mangabey (Cercocebus galeritus).

    PubMed

    Wieczkowski, Julie

    2004-07-01

    I investigated the ecological correlates of abundance in the Tana mangabey (Cercocebus galeritus), one of the world's most endangered primates, with the goal of recommending management strategies. I systematically selected 31 forest fragments throughout the mangabey's 60-km distribution along the lower Tana River in southeastern Kenya. Within the 31 fragments, I measured vegetation structure, food abundance, and human forest product use in 107 belt transects, and conducted 370 mangabey surveys. I used a weighted multiple regression analysis to determine whether there was a dependence between the selected forest attributes and the mean number of mangabey groups per fragment. Fragment area and density of trees > or =10 cm diameter at breast height (DBH) were the only variables that significantly correlated with the variation in mangabey abundance. No additional variables were significant when the analysis was limited to forest fragments inside the Tana River Primate National Reserve (TRPNR) or to fragments outside the TRPNR. When I estimated the resources available before recent human forest product use by adding nonharvested and harvested variables, the total basal area of the top 15 food species became significant. This was only within the TRPNR, however. Management, therefore, should focus on increasing forest area, density of trees > or =10 cm DBH, and coverage of food trees throughout the mangabey's distribution. Solutions must be found for the problem of forest clearing, and forest product use must be better managed to protect the habitat of this critically endangered primate. The significance of food abundance only within the TRPNR suggests a need to collect dietary data from mangabey groups in fragments toward the southern limit of the mangabey's distribution, where plant species composition differs from that in fragments in which dietary data have been previously collected. PMID:15258957

  11. An integrated approach for spatio-temporal variability analysis of wetlands: a case study of Abaya and Chamo lakes, Ethiopia.

    PubMed

    Tibebu Kassawmar, N; Ram Mohan Rao, K; Lemlem Abraha, G

    2011-09-01

    Starting with the intensification of irrigation activities in the beginning of 1980s in Abaya and Chamo lakes area, the decreasing water inflow to the lakes caused denudation of the wetlands. The ecological situation in the lake region changed significantly during last four decades. The lakes and associated wetlands change have been studied using Landsat MSS (1973), Landsat TM (1986), and Ladsat ETM (2000) satellite imagery. Along with satellite imagery, other hydro-meteorological data were collected and hydro-meteorological data analyses were done to assess the variability of wetlands. From these data, lakes morphometric property estimation at different time series and water balance analysis for both lakes were done. Wetlands are mapped from the TCT image and these maps are subject to change detection to see the temporal and spatial variability of the wetlands. Moreover, the lake-morphometric area and volume variation have been studied. The result showed that between 1986 and 2000, a significant reduction has been observed but lesser than the previous decades (6.4 km(2)). The identified reason behind this change is that the free settlement and shoreline cultivation of the wetlands causing the soil erosion and eventually adds the sediment to the wetlands. PMID:21108000

  12. Plan form changes of Gumara River channel over 50 years (Upper Blue Nile basin, Ethiopia)

    NASA Astrophysics Data System (ADS)

    Abate, Mengiste; Nyssen, Jan; Mehari, Michael

    2014-05-01

    Channel plan form changes were investigated along the 65 km long Gumara River in Lake Tana basin (Ethiopia) by overlaying information from aerial photographs and SPOT imagery. Two sets of aerial photographs (1957 and 1980) were scanned, and then orthorectified in ENVI 4.2 environment. Recent channel plan form information was extracted from SPOT images of 2006. ERDAS 2010 and ArcGIS 10.1 tools were used for the data preparation and analysis. The information on river plan form changes spans from 1957 to 2006 (49 years), during which time the Gumara catchment has been subjected to changes in land use/cover and increasing water abstraction, which may have affected its hydrogeomorphology. The results indicated that the lower reach of Gumara at its mouth has undergone major plan form changes. A delta of 1.12 km² was created between 1957 and 1980 and additional 1.00 km² land has been created between 1980 and 2006. The sinuosity of the plan form changed only slightly through the study period: 1.78 in 1957, 1.76 in 1980, and 1.81 in 2006. Comparison of cross sections at the hydrological gauging station showed that the river bed aggraded in the order of 1.5 m to 2.5 m for the period 1963-2009. The trend analysis of stream flow of Gumara River versus rainfall in the catchment also indicated that the bed level of the Gumara river at its gauging station has risen. From field observations, the impact of direct human interventions was identified. The building of artificial levees along the river banks has contributed to huge deposition in the river bed. At locations where intensive irrigation takes place in the floodplain, seepage water through the banks created river bank failure and modifications in plan form. The unstable segments of the river reach were identified and will be further analysed.

  13. Assessing Impact of Climate Change on the Runoffs of Gilgel Abbay Watershed, the upper Blue Nile Basin, Ethiopia

    NASA Astrophysics Data System (ADS)

    Ayele, H. S.; Li, M. H.; Tung, C. P.; Liu, T. M.

    2015-12-01

    Water is the most climate sensitive sector in changing climate. Hydrological vulnerability assessment is critical to the implementation of adaption measures. In this study, projections of 7 GCMs in association with high (RCP8.5) and medium low (RCP4.5) representative concentration path way from the CMPI5 (fifth phase of the Coupled Model Intercomparison Project) for the period 2021-2040 and 2081-2100 were adopted to assess the impacts of climate change on the runoffs of Gilgel Abbay watershed, the upper Blue Nile basin, in Ethiopia. The GCMs selected were first screened in harmony with baseline climate statistics of study areas. Based on climate projections and statistical characteristics of historical weather data, a weather generator was employed to generate daily temperature and precipitation as inputs for the GWLF hydrological model to simulate runoffs. Changes of projected temperature and precipitation were analyzed to explain variations of evapotranspiration and influences on future runoffs. We found that, despite the fact that the projected magnitude varies among different GCMs, increasing in the wet and a decreasing in dry seasons runoffs were observed in both time windows, which mainly attributes to the increase of precipitations projected by most of GCMs. In contrast to great increases in runoffs, the increase of evapotranspiration by elevating temperature is less significant. The increasing runoffs in both time windows will provide more water inflow to the Lake Tana. On the other hand, the increase of precipitation in wet season makes the wet season wetter and implies higher possibility of flash floods. This will have deleterious consequences in the local community. Therefore, concerned water organizations in local, state, and federal levels shall be prepared to harness the opportunities with more water resources for utilization and management, as well as flood preventive measures.

  14. Organic and inorganic carbon fluxes in a tropical river system (Tana River, Kenya) during contrasting wet seasons

    NASA Astrophysics Data System (ADS)

    Geeraert, Naomi; Omengo, Fred O.; Bouillon, Steven; Borges, Alberto V.; Govers, Gerard

    2015-04-01

    overall C flux: while POC dominated during wet seasons without flooding (60-70%), DIC was the dominant transported C pool (55-67%) when flooding took place. This is not only due to the loss of POC associated with overbank sediment deposition but also to the downstream increase of the DIC flux during flooding, which we attribute to the in-stream decomposition of organic carbon as well as to the decomposition of organic matter in flooded environments (oxbow lakes, backswamps, ...). Similarly, the downstream increase of the DOC flux during flooding is likely to be caused by the release of DOC from flooded soils. We conclude that flooding events significantly altered both the magnitude and speciation of C fluxes in the lower Tana River, as they were found to lead to a general reduction of the POC flux, and simultaneously resulted in substantial lateral inputs of both DIC and DOC. The effect of flooding on carbon retention by rivers can only correctly be assessed if all three carbon fractions are accounted for.

  15. Lake

    ERIC Educational Resources Information Center

    Wien, Carol Anne

    2008-01-01

    The lake is blue black and deep. It is a glaciated finger lake, clawed out of rock when ice retracted across Nova Scotia in a northerly direction during the last ice age. The lake is narrow, a little over a mile long, and deep, 90 to 190 feet in places according to local lore, off the charts in others. The author loves to swim there, with a sense…

  16. Assessment of heavy metals in water samples and tissues of edible fish species from Awassa and Koka Rift Valley Lakes, Ethiopia.

    PubMed

    Dsikowitzky, Larissa; Mengesha, Mesfin; Dadebo, Elias; de Carvalho, Carlos Eduardo Veiga; Sindern, Sven

    2013-04-01

    The Ethiopian Rift Valley Lakes host populations of edible fish species including Oreochromis niloticus, Labeobarbus intermedius and Clarias gariepinus, which are harvested also in other tropical countries. We investigated the occurrence of six heavy metals in tissues of these fish species as well as in the waters of Lake Koka and Lake Awassa. Both lakes are affected by industrial effluents in their catchments, making them ideal study sites. Mercury concentrations were very low in the water samples, but concentrations in the fish samples were relatively high, suggesting a particularly high bioaccumulation tendency as compared with the other investigated metals. Mercury was preferentially accumulated in the fish liver or muscle. It was the only metal with species-specific accumulation with highest levels found in the predatory species L. intermedius. Lower mercury concentrations in O. niloticus could be attributed to the lower trophic level, whereas mercury values in the predatory C. gariepinus were unexpectedly low. This probably relates to the high growth rate of this species resulting in biodilution of mercury. Accumulation of lead, selenium, chromium, arsenic and cadmium did not differ between species, indicating that these elements are not biomagnified in the food chain. Values of cadmium, selenium and arsenic were highest in fish livers, while lead and chromium levels were highest in the gills, which could be related to the uptake pathway. A significant impact of the industrial discharges on the occurrence of metals in the lakes could not be detected, and the respective concentrations in fish do not pose a public health hazard. PMID:22821322

  17. Impact of vetch cover crop on runoff, soil loss, soil chemical properties and yield of chickpea in North Gondar, Ethiopia

    NASA Astrophysics Data System (ADS)

    Demelash, Nigus; Klik, Andreas; Holzmann, Hubert; Ziadat, Feras; Strohmeier, Stefan; Bayu, Wondimu; Zucca, Claudio; Abera, Atikilt

    2016-04-01

    Cover crops improve the sustainability and quality of both natural system and agro ecosystem. In Gumara-Maksegnit watershed which is located in Lake Tana basin, farmers usually use fallow during the rainy season for the preceding chickpea production system. The fallowing period can lead to soil erosion and nutrient losses. A field experiment was conducted during growing seasons 2014 and 2015 to evaluate the effect of cover crops on runoff, soil loss, soil chemical properties and yield of chickpea in North Gondar, Ethiopia. The plot experiment contained four treatments arranged in Randomized Complete Block Design with three replications: 1) Control plot (Farmers' practice: fallowing- without cover crop), 2) Chickpea planted with Di-ammonium phosphate (DAP) fertilizer with 46 k ha-1 P2O5 and 23 k ha-1 nitrogen after harvesting vetch cover crop, 3) Chick pea planted with vetch cover crop incorporated with the soil as green manure without fertilizer, 4) Chick pea planted with vetch cover crop and incorporated with the soil as green manure and with 23 k ha-1 P2O5 and 12.5 k ha-1 nitrogen. Each plot with an area of 36 m² was equipped with a runoff monitoring system. Vetch (Vicia sativa L.) was planted as cover crop at the onset of the rain in June and used as green manure. The results of the experiment showed statistically significant (P < 0.05) differences on the number of pods per plant, above ground biomass and grain yield of chick pea. However, there was no statistically significant difference (P > 0.05) on average plant height, average number of branches and hundred seed weight. Similarly, the results indicated that cover crop has a clear impact on runoff volume and sediment loss. Plots with vetch cover crop reduce the average runoff by 65% and the average soil loss decreased from 15.7 in the bare land plot to 8.6 t ha-1 with plots covered by vetch. In general, this result reveales that the cover crops, especially vetch, can be used to improve chickpea grain yield

  18. Tuberculosis lymphadenitis in Ethiopia.

    PubMed

    Biadglegne, Fantahun; Tesfaye, Weghata; Anagaw, Belay; Tessema, Belay; Debebe, Tewodrose; Anagaw, Berhanu; Mulu, Andargachew; Sack, Ulrich; Rodloff, Arne C

    2013-01-01

    Tuberculosis (TB) is one of the most serious public health challenges in Ethiopia. Indeed, Ethiopia ranks 7th among 22 countries with a high burden of TB worldwide. Both pulmonary TB and extrapulmonary TB (EPTB) are issues of concern. Ethiopia ranks 3rd in terms of the number of EPTB patients worldwide, with TB lymphadenitis (TBL) being the most common. According to the World Health Organization's Global TB Report 2009, the estimated number of TB patients in Ethiopia was 314,267 in 2007, with an estimated incidence rate of 378 patients per 100,000 population. Furthermore, 36% patients suffered from EPTB, with TBL accounting for 80% of these patients. In Ethiopia, pathological services, culture, and drug susceptibility testing for mycobacterium species are not available as routine tests, not even for cases with suspected infection by drug-resistant strains. Therefore, the management of multidrug-resistant (MDR) TB in Ethiopia is currently unsatisfactory. Against this background, a high index of clinical doubt and timely use of diagnostic methods, prompt confirmation of diagnosis, and early initiation of specific anti-TB treatment are the key factors for the successful management of MDR-TB and TBL in Ethiopia. PMID:23883834

  19. Hydrologic interconnection between the volcanic aquifer and springs, Lake Tana basin on the Upper Blue Nile

    NASA Astrophysics Data System (ADS)

    Nigate, Fenta; Van Camp, Marc; Kebede, Seifu; Walraevens, Kristine

    2016-09-01

    Hydrochemical and stable isotope (δ18O, δ2H) data were used to identify the recharge sources of major springs and the hydraulic interconnection between the volcanic aquifer and springs in the Gilgel Abay catchment and adjacent areas. The hydrochemical data analysis showed that all water samples of springs and shallow wells have freshwater chemistry, Casbnd HCO3 to Casbnd Mgsbnd HCO3 types. This is mainly controlled by dissolution/hydrolysis of silicate minerals. The analyzed stable isotope data indicate that springs water, except Dengel Mesk, Kurt Bahir and Bility springs, and well waters, except Dangila well, fall close to the LMWL. This clearly shows that the infiltrated rainwater did not undergo much evaporation and δ18O values for spring water and groundwater are nearly equal to the value of Ethiopian summer rainfall, which is -2.5‰. Therefore, generally both stable isotope and hydrochemical data show the recharge source to springs and shallow groundwater is primarily from precipitation. Furthermore, data suggest that rock-water interaction has remained relatively limited, pointing to relatively short residence times, and local recharge rather than regional recharge.

  20. Characterisation of stable isotopes to identify residence times and runoff components in two meso-scale catchments in the Abay/Upper Blue Nile basin, Ethiopia

    NASA Astrophysics Data System (ADS)

    Tekleab, S.; Wenninger, J.; Uhlenbrook, S.

    2014-06-01

    Measurements of the stable isotopes oxygen-18 (18O) and deuterium (2H) were carried out in two meso-scale catchments, Chemoga (358 km2) and Jedeb (296 km2) south of Lake Tana, Abay/Upper Blue Nile basin, Ethiopia. The region is of paramount importance for the water resources in the Nile basin, as more than 70% of total Nile water flow originates from the Ethiopian highlands. Stable isotope compositions in precipitation, spring water and streamflow were analysed (i) to characterise the spatial and temporal variations of water fluxes; (ii) to estimate the mean residence time of water using a sine wave regression approach; and (iii) to identify runoff components using classical two-component hydrograph separations on a seasonal timescale. The results show that the isotopic composition of precipitation exhibits marked seasonal variations, which suggests different sources of moisture generation for the rainfall in the study area. The Atlantic-Indian Ocean, Congo basin, Upper White Nile and the Sudd swamps are the potential moisture source areas during the main rainy (summer) season, while the Indian-Arabian and Mediterranean Sea moisture source areas during little rain (spring) and dry (winter) seasons. The spatial variation in the isotopic composition is influenced by the amount effect as depicted by moderate coefficients of determination on a monthly timescale (R2 varies from 0.38 to 0.68) and weak regression coefficients (R2 varies from 0.18 to 0.58) for the altitude and temperature effects. A mean altitude effect accounting for -0.12‰/100 m for 18O and -0.58‰/100 m for 2H was discernible in precipitation isotope composition. Results from the hydrograph separation on a seasonal timescale indicate the dominance of event water, with an average of 71 and 64% of the total runoff during the wet season in the Chemoga and Jedeb catchments, respectively. Moreover, the stable isotope compositions of streamflow samples were damped compared to the input function of

  1. Identifying residence times and streamflow generation processes using δ18O and δ2H in meso-scale catchments in the Abay/Upper Blue Nile, Ethiopia

    NASA Astrophysics Data System (ADS)

    Tekleab, S.; Wenninger, J.; Uhlenbrook, S.

    2013-08-01

    Measurements of the stable isotopes oxygen-18 (18O) and deuterium (2H) were carried out in two meso-scale catchments, Chemoga (358 km2) and Jedeb (296 km2) south of Lake Tana, Abay/Upper Blue Nile basin, Ethiopia. The region is of paramount importance for the water resources in the Nile basin. Stable isotope composition in precipitation, spring water and streamflow were analyzed (i) to characterize the spatial and temporal variations of water fluxes; (ii) to estimate the mean residence time of water using a sine wave regression approach; and (iii) to identify runoff components using classical two component hydrograph separations at a seasonal time scale. The results show that the isotopic composition of precipitation exhibit marked seasonal variations, which suggests different sources of moisture generation for the rainfall in the study area. The Atlantic-Indian ocean, Congo basin, and the Sud swamps are the likely the potential moisture source areas during the main rainy (summer) season. While, the Indian-Arabian, and Mediterranean Sea moisture source areas during little rain (spring), and dry (winter) seasons. The spatial variation of the isotopic composition is affected by the amount effect and to less extent by altitude and temperature effects. A mean altitude effect of -0.12‰ (100 m)-1 for 18O and -0.58‰ (100 m)-1 for 2H were discernable in precipitation isotope composition. The seasonal variations of the isotopic signature of the spring water exhibit a damped response as compared to the river waters, which shows that the spring water has longer residence times than the river water. Results from the hydrograph separation at a seasonal time scale indicate the dominance of event water with an average of 71% and 64% of the total runoff during the wet season in the Chemoga and Jedeb catchment, respectively. The stable isotope compositions of streamflow samples were damped compared to the input function of precipitation for both catchments and this damping was

  2. Ethiopia's Grand Renaissance Dam: Implications for Downstream Riparian Countries

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Block, P. J.; Hammond, M.; King, A.

    2013-12-01

    Ethiopia has begun seriously developing their significant hydropower potential by launching construction of the Grand Ethiopian Renaissance Dam (GERD) on the Blue Nile River to facilitate local and regional growth. Although this has required substantial planning on Ethiopia's part, no policy dictating the reservoir filling rate strategy has been publicly issued. This filling stage will have clear implications on downstream flows in Sudan and Egypt, complicated by evaporative losses, climate variability, and climate change. In this study, various filling policies and future climate states are simultaneously explored to infer potential streamflow reductions at Lake Nasser, providing regional decision-makers with a set of plausible, justifiable, and comparable outcomes. Schematic of the model framework Box plots of 2017-2032 percent change in annual average streamflow at Lake Nasser for each filling policy constructed from the 100 time-series and weighted precipitation changes. All values are relative to the no dam policy and no changes to future precipitation.

  3. Journey of Ethiopia Astronomy

    NASA Astrophysics Data System (ADS)

    Belay Tessema, Solomon

    2015-08-01

    Ancient astronomy had contributed away for the modern development of astronomy. The history of astronomy development in Ethiopian was liked with different beliefs and culture of the society. The Ethiopians were the first who invented the science of stars, and gave names to the planets, not at random and without meaning, but descriptive of the qualities which they conceived them to possess; and it was from them that this art passed, still in an imperfect state, to the Egyptians. Even though, Ethiopian’s contributions for astronomy in the world were immense but the journey of modern astronomy is still in the infant stage. The modern astronomy and space program in Ethiopia was started in 2004 in well organized form from three individuals to the public. In the past eleven years of journey of astronomy development in Ethiopia was the most challenging from national to international level. After strong struggle of a few committed individuals for the past eleven years the development of astronomy is completely changed from dark age to bright age. This paper will try to address the details of journey of astronomy in Ethiopia.

  4. Deposition and fate of organic carbon in floodplains along a tropical semiarid lowland river (Tana River, Kenya)

    NASA Astrophysics Data System (ADS)

    Omengo, Fred O.; Geeraert, Naomi; Bouillon, Steven; Govers, Gerard

    2016-04-01

    Inland waters organic carbon (OC) burial by sedimentation has recently been shown to be an important component in river catchment carbon (C) budgets. However, data on OC burial by sedimentation are hitherto largely limited to temperate zones. We investigated the deposition and fate of sediment-associated OC in the floodplains of the tropical lowland Tana River (Kenya), between two main gaging stations (Garissa and Garsen). Freshly deposited surface sediments and sediment cores were sampled and analyzed for OC, total nitrogen content, stable isotope signatures (δ13C) of OC, and grain size distribution. In addition, we incubated sediment cores to quantify CO2 production as a proxy for OC mineralization. While the floodplain receives sediment with a relatively low OC content (1.56 ± 0.42%), sediments are enriched with OC inputs from floodplain vegetation to levels above 3%. Sediment cores show a sharp decrease of OC with depth, from 3 to 12% OC in the (sub) surface to less than 1% OC below approximately 60 cm depth. Relatively elevated OC mineralization rates (0.14 ± 0.07 mol. CO2 kgC-1 d-1) were recorded. We used these data to make a first assessment of the C burial efficiency of the Tana River floodplain. In contrast to what is observed in temperate environments, over 50% of C present in the top layers is lost in less than a century. While significant amounts of OC are buried in the Tana River floodplain, the high rates of postdepositional loss limit the development of a long-term C sink within this tropical floodplain.

  5. Deposition and fate of organic carbon in floodplains along a tropical semi-arid lowland river (Tana River, Kenya)

    NASA Astrophysics Data System (ADS)

    Omengo, Fred; Geeraert, Naomi; Boullion, Steven; Govers, Gerard

    2016-04-01

    Inland organic carbon (OC) burial by sedimentation has recently been shown to be an important component in river catchment carbon(C) budget. However, data on OC burial by sedimentation are hitherto largely limited to temperate zones. We investigated the deposition and fate of sediment-associated OC in the floodplains of a tropical lowland Tana river (Kenya), between two main gauging stations (Garissa and Garsen). Freshly deposited surface sediments and sediment cores were sampled and analysed for OC and total nitrogen content, stable isotope signatures (δ13C) of OC, and grain size distribution. In addition, we incubated sediment cores to quantify CO2 production as a proxy of OC mineralization. The floodplain receives sediment with a relatively low OC content (1.56±0.42%), sediments are enriched with OC inputs from floodplain vegetation to levels above 3%. Sediment cores show a sharp decrease of OC with depth, from 3 - 12%C in the (sub) surface to less than 1%OC below ~60cm depth. Relatively high and deep OC mineralization rates (0.14±0.07mol CO2 kg-1C d-1) were recorded. We used our data to make a first assessment of the carbon burial efficiency of the Tana river floodplain: in contrast to what is observed in temperate environments, over 50% of carbon present in the top layers is lost in less than a century. While significant amounts of OC are deposited in the Tana river floodplain, the high post-depositional loss limits the long-term C sink.

  6. Magmatic degassing at Erta 'Ale volcano, Ethiopia

    NASA Astrophysics Data System (ADS)

    Sawyer, G. M.; Oppenheimer, C.; Tsanev, V. I.; Yirgu, G.

    2008-12-01

    Here we report measurements of the chemical composition and flux of gas emitted from the central lava lake at Erta 'Ale volcano (Ethiopia) made on 15 October 2005. We determined an average SO 2 flux of ˜ 0.69 ± 0.17 kg s - 1 using zenith sky ultraviolet spectroscopy of the plume, and molar proportions of magmatic H 2O, CO 2, SO 2, CO, HCl and HF gases to be 93.58, 3.66, 2.47, 0.06, 0.19 and 0.04%, respectively, by open-path Fourier transform infrared (FTIR) spectrometry. Together, these data imply fluxes of 7.3, 0.7, 0.008, 0.03 and 0.004 kg s - 1 for H 2O, CO 2, CO, HCl and HF, respectively. These are the first FTIR spectroscopic observations at Erta 'Ale, and are also some of the very few gas measurements made at the volcano since the early 1970s (Gerlach, T.M., 1980b. Investigation of volcanic gas analyses and magma outgassing from Erta 'Ale lava lake, Afar, Ethiopia. Journal of Volcanology and Geothermal Research, 7(3-4): 415-441). We identify significant increases in the proportion of H 2O in the plume with respect to both CO 2 and SO 2 across this 30-year interval, which we attribute to the depletion of volatiles in magma that sourced effusive eruptions during the early 1970s and/or to fractional magma degassing between the two active pit craters located in the summit caldera.

  7. Characterizing floods in the poorly gauged wetlands of the Tana River Delta, Kenya, using a water balance model and satellite data

    NASA Astrophysics Data System (ADS)

    Leauthaud, C.; Belaud, G.; Duvail, S.; Moussa, R.; Grünberger, O.; Albergel, J.

    2013-08-01

    Wetlands, such as those of the Tana River Delta in Kenya, are vital but threatened ecosystems. The flooding characteristics of wetlands largely determine their physical, chemical and biological properties, so their quantification is crucial for wetland management. This quantification can be achieved through hydrological modelling. In addition, the analysis of satellite imagery provides essential hydrological data to monitor floods in poorly gauged zones. The objective of this study was to quantify the main water fluxes and flooding characteristics (extent, duration and number of floods) in the poorly gauged Tana River Delta in East Africa during 2002-2011. To do so, we constructed a lumped hydrological model (the Tana Inundation Model, TIM) that was calibrated and validated with MODIS data. Further analysis of the MYD09A1 500 m composite product provided a map of the empirical probability of flooded state. In non-extreme years and for the current topology of the delta, the flood extent exceeded 300 km2. Floods over 200 km2 occurred on average once a year, with a mean duration of 18 days. River discharge from the upper basin counted for over 95% of the total water inflow. The results are discussed in the light of possible improvements of the models and wetland management issues. This study provides the first known quantification of spatial and temporal flooding characteristics in the Tana River Delta. As such, it is essential for the water and natural resource management of the Tana River basin. The water balance approach was pertinent to the study of this system, for which information on its internal properties and processes is limited. The methodology, a combination of hydrological modelling and flood mapping using MODIS products, should be applicable to other areas, including those for which data are scarce and cloud cover may be high, and where a medium spatial resolution is required.

  8. Hydrological research in Ethiopia

    NASA Astrophysics Data System (ADS)

    Gebremichael, M.

    2012-12-01

    Almost all major development problems in Ethiopia are water-related: food insecurity, low economic development, recurrent droughts, disastrous floods, poor health conditions, and low energy condition. In order to develop and manage existing water resources in a sustainable manner, knowledge is required about water availability, water quality, water demand in various sectors, and the impacts of water resource projects on health and the environment. The lack of ground-based data has been a major challenge for generating this knowledge. Current advances in remote sensing and computer simulation technology could provide alternative source of datasets. In this talk, I will present the challenges and opportunities in using remote sensing datasets and hydrological models in regions such as Africa where ground-based datasets are scarce.

  9. Water and Productivity of Floodplain Grasslands: Exploring Linkages through Experimentations and Models in the Tana River Delta, Kenya

    NASA Astrophysics Data System (ADS)

    Leauthaud, C.; Musila, W.; Kergoat, L.; Hiernaux, P.; Manuela, G.; Duvail, S.

    2014-12-01

    Floodplain grasslands have one of the highest productivities of non-cultivated ecosystems on Earth. They procure a wide variety of benefits to human beings. In Eastern Africa, grasslands of Echinochloa stagnina are primordial for pastoralists as highly productive dry-season grazing zones. Regular flooding is a critical property in maintaining their productivity and resulting services. Yet, construction of hydrologic infrastructure modifies the flooding regime of rivers and the consequences on downstream floodplain grasslands need to be assessed. This presentation focuses on quantifying the productivity of the floodplain grasslands in the Tana River Delta, Kenya, in order to assess potential changes under varying flooding regimes. The interactions between growth and floods are explored firstly at an experimental site, then through the construction of a process-based plant growth model adapted to floodplain grasslands. The 15-month experiment consisted in quantifying daily growth rates under various rainfall, irrigation, cutting and flooding regimes . Floods increased growth rates three-folds, and high productivities were maintained after the floods. The cutting regime and contribution of non-flood water also influenced productivity. Modelling allowed exploring the underlying processes explaining such behaviour. In an exploratory endeavour, the productivity of the grassland at the ecosystem scale was assessed with the model for a variety of flood and non-flooded scenarios. Decreasing floods led to a drop in annual productivity that could have serious consequences for the livestock keeping activities of the zone. This research highlights the importance of floods in the maintenance of high productivities for a floodplain grassland typical of East Africa, and maybe of the Sahelian band. The model, once further validated, could be used on other floodplain grasslands, such as those of the Niger delta. Results for the Tana River Delta would need to be discussed with the

  10. Floods and wetlands: combining a water-balance model and remote-sensing techniques to characterize hydrological processes of ecological importance in the Tana River Delta (Kenya)

    NASA Astrophysics Data System (ADS)

    Leauthaud, C.; Duvail, S.; Belaud, G.; Moussa, R.; Grünberger, O.; Albergel, J.

    2012-10-01

    The Tana River Delta (TRD) provides a multitude of ecosystem services for the local communities including fishing, farming and livestock keeping. The hydrological regime of its river determines for a large part the environmental health of the delta. The development of upstream irrigation schemes and hydroelectric infrastructure can seriously impact the ecological status of the TRD. The Tana Inundation Model (TIM) presented here is the first known hydrological model of the TRD. Using it, we quantify essential hydrological variables of ecological importance for 2002-2011 such as flood extent and duration, flood timing and frequency, flood peaks and water height. TIM also provides an annual water balance. The model simulates river inflows and outflows, precipitation, overland flow, evapotranspiration and infiltration. The TRD is characterized by scarce hydrological data and a high cloud cover limiting the use of many remote sensing techniques. The methodology therefore combined a conventional water-balance analysis with the extraction of inundation extents from MODIS satellite imagery at a medium spatial and temporal resolution. In non extreme years and for the actual configuration of the Tana River, the flooded area exceeds 560 km2. Floods over 200 km2 occur approximately every two years, with a mean duration of less than 25 days. River discharge from the upper catchment counts for over 96% of the total water inflow. This study provides the first known estimates of these variables for the Tana River Delta and is therefore primordial for the management of the water and other natural resources of the zone. The hydrological model based on the Generalized Likelihood Uncertainty Estimation (GLUE) is generic enough to be applied to other catchments with scarce hydrological data.

  11. Adapting Active Learning in Ethiopia

    ERIC Educational Resources Information Center

    Casale, Carolyn Frances

    2010-01-01

    Ethiopia is a developing country that has invested extensively in expanding its educational opportunities. In this expansion, there has been a drastic restructuring of its system of preparing teachers and teacher educators. Often, improving teacher quality is dependent on professional development that diversifies pedagogy (active learning). This…

  12. Morphological changes of Gumara River channel over 50 years, upper Blue Nile basin, Ethiopia

    NASA Astrophysics Data System (ADS)

    Abate, Mengiste; Nyssen, Jan; Steenhuis, Tammo S.; Moges, Michael M.; Tilahun, Seifu A.; Enku, Temesgen; Adgo, Enyew

    2015-06-01

    In response to anthropogenic disturbances, alluvial rivers adjust their geometry. The alluvial river channels in the upper Blue Nile basin have been disturbed by human-induced factors since a longtime. This paper examines channel adjustment along a 38-km stretch of the Gumara River which drains towards Lake Tana and then to the Blue Nile. Over a 50 years period, agriculture developed rapidly in the catchment and flooding of the alluvial plain has become more frequent in recent times. The objectives of this study were to document the changes in channel planform and cross-section of the Gumara River and to investigate whether the changes could have contributed to the frequent flooding or vice versa. Two sets of aerial photographs (1957 and 1980) were scanned, and then orthorectified. Recent channel planform information was extracted from SPOT images of 2006 and Google Earth. Channel planform and bed morphology (vertical changes) were determined for these nearly 50 years period. The vertical changes were determined based on aggradation along a permanent structure, historic information on river cross-sections at a hydrological gauging station, and field observations. The results indicate that the lower reach of Gumara near its mouth has undergone major planform changes. A delta with approx. 1.12 km2 of emerged land was created between 1957 and 1980 and an additional 1 km2 of land has been added between 1980 and 2006. The sinuosity of the river changed only slightly: negatively (-1.1% i.e. meandering decreased) for the period from 1957 to 1980 and positively (+3.0%) for the period 1980-2006. Comparison of cross-sections at the hydrological gauging station showed that the deepest point in the river bed aggraded by 2.91 m for the period 1963-2009. The importance of sediment deposition in the stream and on its banks is related to land degradation in the upper catchment, and to artificial rising of Lake Tana level that creates a backwater effect and sediment deposition in

  13. Rights of the Child in Ethiopia.

    ERIC Educational Resources Information Center

    Schonveld, Ben; Mejia, Fernando

    This report to the United Nations Committee on the Rights of the Child contains observations of the World Organisation Against Torture (OMCT) concerning the application of the U.N. Convention on the Rights of the Child by the nation of Ethiopia. The report's introduction asserts that despite the considerable lip service being paid by Ethiopia's…

  14. Flow regime change in an Endorheic basin in Southern Ethiopia

    NASA Astrophysics Data System (ADS)

    Worku, F. F.; Werner, M.; Wright, N.; van der Zaag, P.; Demissie, S.

    2014-01-01

    Endorheic basins, often found in semi-arid and arid climates, are particularly sensitive to changes in climatological fluxes such as precipitation, evaporation and runoff, resulting in variability of river flows as well as of water levels in end-point lakes that are often present. In this paper we apply the Indicators of Hydrological Alteration (IHA) to characterise change to the natural flow regime of the Omo-Ghibe basin in Southern Ethiopia. This endorheic basin is considered relatively pristine, with the basin being the main source of flow to Lake Turkana, the end-point lake in the East-African rift valley. The water level in Lake Turkana shows significant fluctuation, but an increasing trend can be observed over the past 20 yr. The reasons are currently not well understood. Of the five groups of metrics in the IHA, only those related to magnitude were found to show significant trends, with the main trend being the increase of flow during the dry season. This trend was not reflected in climatological drivers such as rainfall, evaporation, and temperature (which shows an increasing trend), but rather is attributed to the substantial changes in Land Use and Land Cover (LULC) in the basin. The impact on the basin hydrology is apparent mainly in the more humid part of the basin. The significant shift from forest and woodland to grassland and cropland results in a decrease of actual evaporation and subsequent increase in (dry season) runoff. The long term trend of the increasing levels in lake Turkana are related to these trends in dry season flows, while shorter term fluctuations of the lake levels are attributed primarily to anomalies in consecutive wet and dry season rainfall.

  15. Meat Consumption Culture in Ethiopia

    PubMed Central

    Jo, Cheorun

    2014-01-01

    The consumption of animal flesh food in Ethiopia has associated with cultural practices. Meat plays pivotal and vital parts in special occasions and its cultural symbolic weight is markedly greater than that accorded to most other food. Processing and cooking of poultry is a gender based duty and has socio-cultural roles. Ethiopians are dependent on limited types of animals for meats due to the taboo associated culturally. Moreover, the consumption of meat and meat products has a very tidy association with religious beliefs, and are influenced by religions. The main religions of Ethiopia have their own peculiar doctrines of setting the feeding habits and customs of their followers. They influence meat products consumption through dictating the source animals that should be used or not be used for food, and scheduling the days of the years in periodical permeation and restriction of consumptions which in turn influences the pattern of meat consumption in the country. In Ethiopia, a cow or an ox is commonly butchered for the sole purpose of selling within the community. In special occasions, people have a cultural ceremony of slaughtering cow or ox and sharing among the group, called Kircha, which is a very common option of the people in rural area where access of meat is challenging frequently. PMID:26760739

  16. The Stability of Lava Lakes

    NASA Astrophysics Data System (ADS)

    Witham, F.; Llewellin, E. W.; Woods, A. W.; Gladstone, C.

    2007-12-01

    Lava lakes may exhibit complex cycles of filling and draining on time-scales of hours to weeks. Such activity is recorded at Pu`u `O`o, Hawai`i. Other examples, e.g. Erta Ale in Ethiopia, do not display these draining episodes; instead an 'equilibrium' system is observed in which the lake may persist for years. We present the results of a theoretical and experimental investigation of lava lakes and identify behavioural regimes distinguished by system geometry and gas content. Laboratory analogue modelling shows that even a simple conduit-lake system, driven by a constant gas flux, can display steady-state equilibrium or cyclic behaviour, depending on the rate of gas flux. A theoretical approach to the same system captures this range of behaviour. By testing the stability of an 'equilibrium' lake to small perturbations, we show that the degree of stability is controlled by the ratio of conduit to lake areas, and the gas volume fraction at the top of the conduit. Despite the simplicity of the modelled system, a rich spectrum of behaviour is found. The model predicts that a stable system must drain over time. This implies that lakes which exhibit ongoing degassing for years or decades (e.g. Erta Ale) either must have an exogenous supply of gas bubbles from depth, or an effective conduit convection mechanism must exist.

  17. Flow regime change in an endorheic basin in southern Ethiopia

    NASA Astrophysics Data System (ADS)

    Worku, F. F.; Werner, M.; Wright, N.; van der Zaag, P.; Demissie, S. S.

    2014-09-01

    Endorheic basins, often found in semi-arid and arid climates, are particularly sensitive to variation in fluxes such as precipitation, evaporation and runoff, resulting in variability of river flows as well as of water levels in end-point lakes that are often present. In this paper we apply the indicators of hydrological alteration (IHA) to characterise change to the natural flow regime of the Omo-Ghibe Basin in southern Ethiopia. Little water resource infrastructure has been developed in the basin to date, and it is considered pristine. The basin is endorheic and is the main source of flow to Lake Turkana in the East African Rift Valley. The water level in Lake Turkana shows significant fluctuation, but increase of its level can be observed over the past 20 years. The reasons are currently not well understood. Of the five groups of hydrological characteristics in the IHA (magnitude, timing, duration, frequency and variability), only those related to magnitude were found to show significant trends, with the main trend being the increase of flow during the dry season. This trend was not reflected in climatological drivers such as rainfall, evaporation and temperature (which shows a positive trend), but rather is attributed to the substantial changes in land use and land cover in the basin. The change in the basin hydrology is apparent mainly in the more humid part of the basin. The significant shift from forest and woodland to grassland and cropland results in a decrease of actual evaporation and subsequent increase in (dry season) runoff. The long-term trend of the increasing levels in Lake Turkana are related to these trends in dry season flows, while shorter-term fluctuations of the lake levels are attributed primarily to anomalies in consecutive wet and dry season rainfall.

  18. The seismicity of Ethiopia; active plate tectonics

    USGS Publications Warehouse

    Mohr, P.

    1981-01-01

    Ethiopia, descended from the semimythical Kingdom of Punt, lies at the strategic intersection of Schmidt's jigsaw puzzle where the Red Sea, Gulf of Aden, and the African Rift System meet. Because of geologically recent uplift combined with rapid downcutting erosion by rivers, notably the Blue Nile (Abbay), Ethiopia is the most mountainous country in Africa. It is also the most volcanically active, while its historical seismicity matches that of the midocean ridges. And, in a sense, Ethiopia is host to an evoloving ocean ridge system. 

  19. Tropical pyomyositis in Gondar, Ethiopia.

    PubMed

    Selassie, F G

    1995-01-01

    Seventy-two cases of pyomyositis are reported from the north-western highlands of Ethiopia. The majority (76.4%) came from highland areas over 1,800 meters above sea level. The clinical picture of the disease was similar to that seen in other East African countries. Staphylococcus aureus was recovered from 69 of 72 pus cultures. Spontaneous rupture of abscesses was seen in two cases. Four of the five deaths were assumed to be due to complications of the pyomyositis. Further search into non-altitudinal factors is implicated to get a better insight into the nature of the disorder. PMID:8553441

  20. Lake Life.

    ERIC Educational Resources Information Center

    Ohrn, Deborah Gore, Ed.

    1993-01-01

    This quarterly publication of the State Historical Society of Iowa features articles and activities for elementary school students. This summer issue focuses on the topic of lake life. The issue includes the following features: (1) "Where the Lakes Are Map"; (2) "Letter from the Lake"; (3) "Lake People"; (4) "Spirit Lake"; (5) "Lake Manawa"; (6)…

  1. Visceral leishmaniasis in Ethiopia: an evolving disease.

    PubMed

    Leta, Samson; Dao, Thi Ha Thanh; Mesele, Frehiwot; Alemayehu, Gezahegn

    2014-09-01

    Visceral leishmaniasis (also known as kala-azar) is classified as one of the most neglected tropical diseases. It is becoming a growing health problem in Ethiopia, with endemic areas that are continually spreading. The annual burden of visceral leishmaniasis (VL) in Ethiopia is estimated to be between 4,500 and 5,000 cases, and the population at risk is more than 3.2 million. There has been a change in the epidemiology of VL in Ethiopia. Over the last decades, almost all cases and outbreaks of VL were reported from arid and semi-arid parts of the country; however, recent reports indicated the introduction of this disease into the highlands. Migration of labourers to and from endemic areas, climatic and environmental changes, and impaired immunity due to HIV/AIDS and malnutrition resulted in the change of VL epidemiology. HIV spurs the spread of VL by increasing the risk of progression from asymptomatic infection towards full VL. Conversely, VL accelerates the onset of AIDS. In Ethiopia, VL epidemiology remains complex because of the diversity of risk factors involved, and its control is becoming an increasing challenge. This paper reviews the changes in epidemiology of VL in Ethiopia and discusses some of the possible explanations for these changes. The prospects for novel approaches to VL control are discussed, as are the current and future challenges facing Ethiopia's public health development program. PMID:25188253

  2. Child Mortality Rate in Ethiopia

    PubMed Central

    Susuman, A Sathiya

    2012-01-01

    Ethiopia’s childhood mortality has continued to decline although at a swift pace. The drop in urban childhood mortality decline, duration of breastfeeding is the principle reason for the overall decline in mortality trends in Ethiopia. Data from the Ethiopian Demographic and Health Surveys 2000 and 2005 were used. Indirect estimation of Brass and Trussell’s methods were adopted. Selected demographic and socio-economic variables were included in the analysis with statistically significant effects. Findings clearly show neonatal and post neonatal mortality decline gradually. Even though, Ethiopia’s childhood mortality rates are still high. The result shows less than 2 years birth interval have higher infant mortality rates than higher birth interval (113 deaths per 1000). The proper spacing of births allows more time for childcare to make more maternal resources available for the care of the child and mother. Therefore, further research is urgent for regional level and national level investigation. PMID:23113145

  3. A climate trend analysis of Ethiopia

    USGS Publications Warehouse

    Funk, Christopher C.; Rowland, Jim; Eilerts, Gary; Kebebe, Emebet; Biru, Nigist; White, Libby; Galu, Gideon

    2012-01-01

    This brief report, drawing from a multi-year effort by the U.S. Agency for International Development (USAID) Famine Early Warning Systems Network (FEWS NET), examines recent trends in March-June, June-September, and March-September rainfall and temperature, identifying significant reductions in rainfall and increases in temperature over time in many areas of Ethiopia. Conclusions: * Spring and summer rains in parts of Ethiopia have declined by 15-20 percent since the mid-1970s. * Substantial warming across the entire country has exacerbated the dryness.* An important pattern of observed existing rainfall declines coincides with heavily populated areas of the Rift Valley in south-central Ethiopia, and is likely already adversely affecting crop yields and pasture conditions. * Rapid population growth and the expansion of farming and pastoralism under a drier, warmer climate regime could dramatically increase the number of at-risk people in Ethiopia during the next 20 years.* Many areas of Ethiopia will maintain moist climate conditions, and agricultural development in these areas could help offset rainfall declines and reduced production in other areas.

  4. Valuing investments in sustainable land management using an integrated modelling framework to support a watershed conservation scheme in the Upper Tana River, Kenya

    NASA Astrophysics Data System (ADS)

    Hunink, Johannes E.; Bryant, Benjamin P.; Vogl, Adrian; Droogers, Peter

    2015-04-01

    We analyse the multiple impacts of investments in sustainable land use practices on ecosystem services in the Upper Tana basin (Kenya) to support a watershed conservation scheme (a "water fund"). We apply an integrated modelling framework, building on previous field-based and modelling studies in the basin, and link biophysical outputs to economic benefits for the main actors in the basin. The first step in the modelling workflow is the use of a high-resolution spatial prioritization tool (Resource Investment Optimization System -- RIOS) to allocate the type and location of conservation investments in the different subbasins, subject to budget constraints and stakeholder concerns. We then run the Soil and Water Assessment Tool (SWAT) using the RIOS-identified investment scenarios to produce spatially explicit scenarios that simulate changes in water yield and suspended sediment. Finally, in close collaboration with downstream water users (urban water supply and hydropower) we link those biophysical outputs to monetary metrics, including: reduced water treatment costs, increased hydropower production, and crop yield benefits for upstream farmers in the conservation area. We explore how different budgets and different spatial targeting scenarios influence the return of the investments and the effectiveness of the water fund scheme. This study is novel in that it presents an integrated analysis targeting interventions in a decision context that takes into account local environmental and socio-economic conditions, and then relies on detailed, process-based, biophysical models to demonstrate the economic return on those investments. We conclude that the approach allows for an analysis on different spatial and temporal scales, providing conclusive evidence to stakeholders and decision makers on the contribution and benefits of the land-based investments in this basin. This is serving as foundational work to support the implementation of the Upper Tana-Nairobi Water Fund

  5. Energy and the agroeconomic complexity of Ethiopia

    NASA Astrophysics Data System (ADS)

    Karakatsanis, Georgios

    2016-04-01

    Since the Industrial Revolution, modern agriculture has transformed from a net energy supplier to a net energy user, via the extensive use fossil fuels -that substituted solar energy inputs- and petroleum derivative products (fertilizers) (Pimentel and Pimentel 2008; Woods et al. 2010). This condenses a significant overview of agricultural energetics, especially for economies set on their first stage of development, growth and economic diversification, such as Ethiopia. Ethiopia is the Blue Nile's most upstream country, constituting a very sensitive hydroclimatic area. Since 2008, Ethiopian agriculture experiences a boost in energy use and agricultural value-added per worker, due to the rapid introduction of oil-fueled agricultural machinery that increased productivity and allowed crop diversification. Agriculture in Ethiopia accounts for ~82% of its total exports, ~45% of its Gross Domestic Product (GDP) and ~75% of its total labor force. In addition, Ethiopia's agricultural sector is equipped with a set of new financial tools to deal with hydroclimatic extremes, like the 1983-85 droughts that deteriorated its crop output, causing a devastating famine. In fact, Ethiopia's resilience from the (most) recent drought (2015-16) has been remarkable. These facts signify that Ethiopia satisfies the necessary conditions to become a regional agritrade gravity center in the Blue Nile, granted that the dispersion of agricultural trade comprises a primary tool for securing food supply. As gravity equations have been used to model global trade webs (Tinbergen 1962), similar principles may apply to agritrade as well, for identifying emergent topological structures and supply chains. By examining the relation between energy inputs in agriculture with crop diversification and value-added chains of Ethiopia's agritrade, we could extract accurate information on the importance of energy for the country's agroeconomic complexity and regionalization trend across its first stages of

  6. Communities and community genetics in Ethiopia

    PubMed Central

    Tadesse, Luche; Tafesse, Fikru; Hamamy, Hanan

    2014-01-01

    The rates of congenital and genetic disorders in low and middle income countries are similar or might be higher than in high income countries due to a multitude of risk factors and the dearth of community genetic services. To direct effective preventive, diagnostic and counseling services, collecting data on the incidence and prevalence of various congenital and genetic disorders and their risk factors is a pre-requisite for establishing genetic services at the community level and mainly at the primary health care setting. This brief review is meant to assess the available epidemiological data in Ethiopia pertaining to congenital and genetic disorders on which the future community genetic services could be built. Existing epidemiological data on congenital and genetic disorders in Ethiopia is limited, and the few studies conducted revealed that folate and iodine deficiencies are prevalent among women in the reproductive age. Pregnant women's infection with syphilis and rubella is prevailing. Based on available data, cleft lip and palate, congenital heart diseases, club-foot, and gastro-intestinalmalformations are the most common birth defects in Ethiopia. Community based studies to accurately demonstrate the incidence and prevalence levels of these disorders are almost unavailable. To plan for organization and implementation of community genetic services at the primary health care level in Ethiopia, conducting standardized epidemiological studies is currently highly recommended. PMID:25404975

  7. Early Childhood in Ethiopia: Initiatives in Education

    ERIC Educational Resources Information Center

    Szente, Judit; Hoot, James; Tadesse, Selamawit

    2007-01-01

    This article informs readers about early childhood in one of the poorest nations in the world--Ethiopia. Within the context of ecological systems theory, it emphasizes the characteristics of early education programs such as pre-school and basic (primary) education, and creates connections with families' views about education. The article concludes…

  8. Borrelia recurrentis in Head Lice, Ethiopia

    PubMed Central

    Boutellis, Amina; Mediannikov, Oleg; Bilcha, Kassahun Desalegn; Ali, Jemal; Campelo, Dayana; Barker, Stephen C.

    2013-01-01

    Since the 1800s, the only known vector of Borrelia recurrentis has been the body louse. In 2011, we found B. recurrentis DNA in 23% of head lice from patients with louse-borne relapsing fever in Ethiopia. Whether head lice can transmit these bacteria from one person to another remains to be determined. PMID:23648147

  9. Developing a Near-Continuous Estimation of Volumetric Fluctuations in Tropical Lakes and Reservoirs Using Satellite Remote Sensing

    NASA Astrophysics Data System (ADS)

    Keys, T.; Scott, D.

    2015-12-01

    Lakes and reservoirs play an integral role in water resources management by storing large quantities of water commonly used for irrigation, hydroelectric power, water supply, and flood mitigation. Knowing the exact quantity of stored water and necessary water for each of these usages is a critical component of sustainable water resources management. However, limited amounts of hydrologic data in developing nations, most of which are located in the tropics, hinders the accurate monitoring of water storage and allocation. Recent improvements in remote sensing have greatly enhanced the ability to calculate volumetric fluctuations of lakes and reservoirs at given points through time but are limited by temporal resolution as well as the computational time required for image processing. This study utilizes the newly developed MODISTools package for the programming language R in conjunction with satellite altimetry from three different altimetry databases to estimate lake and reservoir volumes at eight day intervals over a 15 year period. The study specifically examines three large lakes and reservoirs: Balbina Reservoir in the Amazon River Basin, Lake Tana in the Nile River Basin, and Tonle Sap Lake in the Mekong River Basin. Altimetry-based water level estimations are validated by in situ water level data from monitoring stations while surface area estimations are validated by Sound Navigation and Ranging (SONAR) generated bathymetric maps with corresponding stage-area relationships. Preliminary results indicate that both remotely sensed water levels and surface areas agree well with in situ measurements, supporting the appropriateness of this methodology.

  10. A comparative Study of Circulation Patterns at Active Lava Lakes

    NASA Astrophysics Data System (ADS)

    Lev, Einat; Oppenheimer, Clive; Spampinato, Letizia; Hernandez, Pedro; Unglert, Kathi

    2016-04-01

    Lava lakes present a rare opportunity to study magma dynamics in a large scaled-up "crucible" and provide a unique natural laboratory to ground-truth dynamic models of magma circulation. The persistence of lava lakes allows for long-term observations of flow dynamics and of lava properties, especially compared to surface lava flows. There are currently five persistent lava lakes in the world: Halemaumau in Kilauea (Hawaii, USA), Erta Ale (Ethiopia), Nyiragongo (Congo), Erebus (Antarctica), and Villarica (Chile). Marum and Benbow craters of Ambrym volcano (Vanuatu) and Masaya (Nicaragua) have often hosted lava lakes as well. We use visible-light and thermal infrared time-lapse and video footage collected at all above lakes (except Villarica, where the lake is difficult to observe), and compare the circulation patterns recorded. We calculate lake surface motion from the footage using the optical flow method (Lev et al., 2012) to produce 2D velocity fields. We mined both the surface temperature field and the surface velocity field for patterns using machine learning techniques such as "self-organizing maps (SOMs)" and "principle component analysis (PCA)". We use automatic detection technique to study the configuration of crustal plates at the lakes' surface. We find striking differences among the lakes, in flow direction, flow speed, frequency of changes in flow direction and speed, location and consistency of upwelling and downwelling, and crustal plate configuration. We relate the differences to lake size, shallow conduit geometry, lava viscosity, crystal and gas content, and crust integrity.

  11. Regional and local tectonics at Erta Ale caldera, Afar (Ethiopia)

    NASA Astrophysics Data System (ADS)

    Acocella, Valerio

    2006-10-01

    Erta Ale volcano lies along the on-shore Red Sea Rift (northern Afar, Ethiopia), separating the Nubia and Danakil plates. Erta Ale has a NNW-SSE elongated caldera, with a subvertical rim scarp, hosting a lava lake. Structural field work was aimed at defining the deformation pattern around the caldera. The caldera consists of along-rim and across-rim structures, resulting from local and regional (maximum extension ˜NE-SW) stress fields, respectively. These structures cross-cut each other at high angles, suggesting that the two stress fields remain distinct, each prevailing during rifting or caldera collapse. The local along-rim extensional fractures are gravity-driven structures that formed due to the retreat of the caldera wall after collapse, and are confined to the region of caldera subsidence. The across-rim structures are mainly located to the N and S of the caldera, where they form rift zones each accommodating a similar amount of extension (˜6.3 m), but displaying different trends and extension directions. Analogue models of interacting fractures are consistent with the Southern Rift being representative of the regional fault kinematics, while the Northern Rift is a local perturbation, resulting from the interaction between two right-stepping rift segments along the Erta Ale Range.

  12. Quaternary fossil fish from the Kibish Formation, Omo Valley, Ethiopia.

    PubMed

    Trapani, Josh

    2008-09-01

    The late Quaternary Kibish Formation of the Omo Valley, southwestern Ethiopia, preserves environments reflecting a history of fluctuations in the level of nearby Lake Turkana over the past 200,000 years. The Kibish Formation has yielded a diverse mammalian fauna (as well as birds and crocodiles), stone tools, and the oldest anatomically modern Homo sapiens. Fish, the most common vertebrate fossils in this unit, are reported in this study. Catfish (especially clariids and Synodontis) and Nile perch (Lates niloticus) predominate, but the gymnarchid Gymnarchus, a cyprinid (Barbus), tigerfish (Hydrocynus), pufferfish (Tetraodon), and other catfish are also present. In total, nine teleost genera are found in the Kibish Formation, representing a subset of the 37 genera that constitute the modern Omo-Turkana ichthyofauna. Several taxa present in the modern fauna, including Polypterus and members of the family Cichlidae, are not found in the Kibish deposits. Most specimens are preserved as disarticulated or broken skeletal elements, but some preservation of articulated elements (e.g., sets of vertebrae, crania with lower jaws or cleithra) also occurs. Many of the catfish and Nile perch specimens are larger than the largest reported from the modern river or lake. Faunas of Kibish Members I and III closely resemble one another; the fauna from Member IV contains only the three most common taxa (Clarias, Synodontis, Lates), though this may result from insufficient sampling. Barbed bone points have been collected from the upper part of the formation, indicating a long association between the human inhabitants and the fish fauna of the Omo Valley. PMID:18691738

  13. CONNECTICUT LAKES

    EPA Science Inventory

    This is a 1:24,000-scale datalayer of named lakes in Connecticut. It is a polygon Shapefile that includes all lakes that are named on the U.S. Geologicial Survey (USGS) 7½ minute topographic quadrangle maps that cover the State of Connecticut, plus other officially named lakes i...

  14. Lake Powell

    Atmospheric Science Data Center

    2014-05-15

    article title:  Lake Powell     View Larger Image ... (14.42 mb)   This true-color image over Lake Powell was acquired by Multi-angle Imaging SpectroRadiometer (MISR) in late March 2000. Lake Powell was formed with the construction of the Glen Canyon Dam in 1963, on the ...

  15. Lake Eyre

    Atmospheric Science Data Center

    2013-04-16

    ...   View Larger Image Lake Eyre is a large salt lake situated between two deserts in one of Australia's driest regions. ... the effect of sunglint at the nadir camera view angle. Dry, salt encrusted parts of the lake appear bright white or gray. Purple areas have ...

  16. Targeting and valuing conservation investments in support of a water fund: linking upstream land management with downstream services in the Upper Tana catchment, Kenya

    NASA Astrophysics Data System (ADS)

    Bryant, B. P.; Droogers, P.; Hunink, J.; Vogl, A.; Wolny, S.

    2014-12-01

    We apply an integrated modeling framework to both target and value watershed management interventions in the Upper Tana watershed, which provides municipal water, irrigation water, and hydropower services to Nairobi and surrounding areas. The analysis begins by applying an index model approach that incorporates existing land use and land surface characteristics to prioritize the type and location of conservation investments in different subbasins, subject to budget constraints and stakeholder concerns (Resource Investment Optimization System -- RIOS). We then run the Soil and Water Assessment Tool (SWAT) using the RIOS-identified investment scenarios to produce spatially explicit scenarios that simulate changes in water yield and suspended sediment. Finally, we link those biophysical outputs to monetary and non-monetary human well-being metrics for multiple benefit streams, including: Reduced water treatment costs, increased hydropower production, and crop yield benefits for upstream farmers in the conservation area. The viability of a payment for watershed services scheme is discussed, with attention to the various components of value assessed and to dependencies on water management approaches. While other studies have examined links between land use and the provision of hydrologic services, this study is novel in that it presents an integrated analysis that targets interventions in a decision context and then relies on calibrated, process-based, biophysical models to demonstrate the return on those investments considering multiple (and sometimes competing) hydrological services, doing so at a sub-annual time-scale.

  17. The Practices of Student Network as Cooperative Learning in Ethiopia

    ERIC Educational Resources Information Center

    Reda, Weldemariam Nigusse; Hagos, Girmay Tsegay

    2015-01-01

    Student network is a teaching strategy introduced as cooperative learning to all educational levels above the upper primary schools (grade 5 and above) in Ethiopia. The study was, therefore, aimed at investigating to what extent the student network in Ethiopia is actually practiced in line with the principles of cooperative learning. Consequently,…

  18. Extension Agents' Awareness of Climate Change in Ethiopia

    ERIC Educational Resources Information Center

    Abegaz, Dagmawi M.; Wims, Padraig

    2015-01-01

    Purpose: The fact that highly vulnerable countries like Ethiopia face far greater challenges from climate change makes agricultural adaptation a top priority. Even though the public agriculture extension system in Ethiopia plays a central role in facilitating and supporting adaptation, very limited information is available on how aware the actual…

  19. Lake Naivasha, Kenya

    NASA Technical Reports Server (NTRS)

    2008-01-01

    If you live in Europe and buy roses, there is a good chance that they were grown in Kenya specifically, in one of the colossal greenhouses that blot out the once wild shores of Lake Naivasha, 90km north-west of Nairobi. Some 25% of Europe's cut flowers come from Kenya. After a tentative start in the 1980s the industry is now the country's third-largest foreign-currency earner, bringing in $120m a year. But the recent violence in Kenya is having a major impact on the flower growers. A local trade union says 3,000 of the 30,000 workers employed in Naivasha's flower farms have abandoned their jobs. Kenya emerged as a flower power when Israel scaled down its own industry. It has since lost business to neighboring Ethiopia, which offers tax breaks and better security, but Naivasha's perfect intensity of sunlight and days of near-constant length should keep it on top.

    The ASTER image was acquired February 2, 2008, covers an area of 25 x 26.6 km, and is located near 0.8 degrees south latitude, 36.4 degrees east longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  20. Evaluation of stream water quality data generated from MODIS images in modeling total suspended solid emission to a freshwater lake.

    PubMed

    Ayana, Essayas K; Worqlul, Abeyou W; Steenhuis, Tammo S

    2015-08-01

    Modeling of suspended sediment emission into freshwater lakes is challenging due to data gaps in developing countries. Existing models simulate sediment concentration at a gauging station upstream and none of these studies had modeled total suspended solids (TSS) emissions by inflowing rivers to freshwater lakes as there are no TSS measurements at the river mouth in the upper Blue Nile basin. In this study a 10year TSS time series data generated from remotely sensed MODIS/Terra images using established empirical relationship is applied to calibrate and validate a hydrology model for Lake Tana in Upper Blue Nile Basin. The result showed that at a monthly time scale TSS at the river mouth can be replicated with Nash-Sutcliffe efficiency (NS) of 0.34 for calibration and 0.21 for validation periods. Percent bias (PBIAS) and ratio of the root-mean-square error to the standard deviation of measured data (RSR) are all within range. Given the inaccessibility and costliness to measure TSS at river mouths to a lake the results found here are considered useful for suspended sediment budget studies in water bodies of the basin. PMID:25863508

  1. Health and medical care in Ethiopia.

    PubMed

    Hodes, R M; Kloos, H

    1988-10-01

    Ethiopia is a country of 45 million people in northeast Africa. With a stagnant, agriculture-based economy and a per capita gross national product of $110 in 1984, it is one of the world's poorest nations. 70% of the children are mildly to severely malnourished, and 25.7% of children born alive die before the age of 5. Life expectancy is 41 years. The population is growing at the rate of 2.9%/year, but only 2% of the people use birth control. After the 1974 revolution, the socialist government nationalized land and created 20,000 peasant associations and kebeles (urban dwellers' associations), which are the units of local government. The government has set ambitious goals for development in all sectors, including health, but famine, near famine, forced resettlement programs, and civil war have prevented any real progress from being made. The government's approach to health care is based on an emphasis on primary health care and expansion of rural health services, but the Ministry of Health is allocated only 3.5% of the national budget. Ethiopia has 3 medical schools -- at Addis Ababa, Gondar, and the Jimma Institute of Health Sciences. Physicians are government employees but also engage in private practice. A major problem is that a large proportion of medical graduates emigrate. Ethiopia has 87 hospitals with 11,296 beds, which comes to 1 bed per 3734 people. There are 1949 health stations and 141 health centers, but many have no physician, and attrition among health workers is high due to lack of ministerial support. Health care is often dispensed legally or illegally by pharmacists. Overall, there is 1 physician for 57,876 people, but in the southwest and west central Ethiopia 1 physician serves between 200,000 and 300,000 people. In rural areas, where 90% of the population lives, 85% live at least 3 days by foot from a rural health unit. Immunization of 1-year olds against tuberculosis, diphtheria-pertussis-tetanus, poliomyelitis, and measles is 11, 6, 6, and

  2. Balancing ecosystem services with energy and food security - assessing trade-offs for reservoir operation and irrigation investment in Kenya's Tana basin

    NASA Astrophysics Data System (ADS)

    Hurford, A. P.; Harou, J. J.

    2014-01-01

    Competition for water between key economic sectors and the environment means agreeing on allocation is challenging. Managing releases from the three major dams in Kenya's Tana River basin with its 4.4 million inhabitants, 567 MW of installed hydropower capacity, 33 000 ha of irrigation and ecologically important wetlands and forests is a pertinent example. This research seeks to identify and help decision-makers visualise reservoir management strategies which result in the best possible (Pareto-optimal) allocation of benefits between sectors. Secondly we seek to show how trade-offs between achievable benefits shift with the implementation of new proposed rice, cotton and biofuel irrigation projects. To identify the Pareto-optimal trade-offs we link a water resources management model to a multi-criteria search algorithm. The decisions or "levers" of the management problem are volume dependent release rules for the three major dams and extent of investment in new irrigation schemes. These decisions are optimised for objectives covering provision of water supply and irrigation, energy generation and maintenance of ecosystem services which underpin tourism and local livelihoods. Visual analytic plots allow decision makers to assess multi-reservoir rule-sets by understanding their impacts on different beneficiaries. Results quantify how economic gains from proposed irrigation schemes trade-off against disturbance of the flow regime which supports ecosystem services. Full implementation of the proposed schemes is shown to be Pareto-optimal, but at high environmental and social cost. The clarity and comprehensiveness of "best-case" trade-off analysis is a useful vantage point from which to tackle the interdependence and complexity of water-energy-food "nexus" challenges.

  3. Balancing ecosystem services with energy and food security - Assessing trade-offs from reservoir operation and irrigation investments in Kenya's Tana Basin

    NASA Astrophysics Data System (ADS)

    Hurford, A. P.; Harou, J. J.

    2014-08-01

    Competition for water between key economic sectors and the environment means agreeing allocations is challenging. Managing releases from the three major dams in Kenya's Tana River basin with its 4.4 million inhabitants, 567 MW of installed hydropower capacity, 33 000 ha of irrigation and ecologically important wetlands and forests is a pertinent example. This research seeks firstly to identify and help decision-makers visualise reservoir management strategies which result in the best possible (Pareto-optimal) allocation of benefits between sectors. Secondly, it seeks to show how trade-offs between achievable benefits shift with the implementation of proposed new rice, cotton and biofuel irrigation projects. To approximate the Pareto-optimal trade-offs we link a water resources management simulation model to a multi-criteria search algorithm. The decisions or "levers" of the management problem are volume-dependent release rules for the three major dams and extent of investment in new irrigation schemes. These decisions are optimised for eight objectives covering the provision of water supply and irrigation, energy generation and maintenance of ecosystem services. Trade-off plots allow decision-makers to assess multi-reservoir rule-sets and irrigation investment options by visualising their impacts on different beneficiaries. Results quantify how economic gains from proposed irrigation schemes trade-off against the disturbance of ecosystems and local livelihoods that depend on them. Full implementation of the proposed schemes is shown to come at a high environmental and social cost. The clarity and comprehensiveness of "best-case" trade-off analysis is a useful vantage point from which to tackle the interdependence and complexity of "water-energy-food nexus" resource security issues.

  4. LAKE FORK

    EPA Science Inventory

    The Lake Fork of the Arkansas River Watershed has been adversely affected through mining, water diversion and storage projects, grazing, logging, and other human influences over the past 120 years. It is the goals of the LFWWG to improve the health of Lake fork by addressing th...

  5. Lake Constance

    Atmospheric Science Data Center

    2013-04-17

    ... Swiss shores of Lake Constance at the town of Rorschach. Eutrophication, or the process of nutrient enrichment, is rapidly accelerated ... of the value of Lake Constance, efforts to mitigate eutrophication were initiated in the 1970's. MISR was built and is managed ...

  6. An NGO at work: CARE-Ethiopia.

    PubMed

    1999-01-01

    Cooperation for American Relief to Everywhere (CARE) was established in response to the needs of the people after World War II through the distribution of food and clothes. CARE/Ethiopia, which signed its first Basic Agreement with the Relief and Rehabilitation Commission, was provided with assistance during the 1994 drought that affected Ethiopia. The primary objective of CARE was to alleviate the suffering brought about by severe food shortages and to expand the program to mitigation and development. This approach was based on the premise of a community-based development philosophy and as an implementation strategy for reaching the rural poor. The five programmatic areas highlighted by the CARE projects were the rural and urban infrastructure; water and sanitation; small-scale irrigation; reproductive health and HIV/AIDS; and microcredit. On the other hand, the family planning and HIV/AIDS project aimed to improve the knowledge, attitude and practice of rural communities towards family planning and reproductive health through community-based family planning services. Results of the project evaluation emphasize the significance of community-based programs in the improvement of health status. Two critical program constraints identified in this paper are lack of access to referral-level services and lack of systemic provision of contraceptive commodities. Several suggestions for future programs include the assurance that the volunteers would be provided with aid in work, childcare and free health services for their families. PMID:12349450

  7. Global mental health: perspectives from Ethiopia

    PubMed Central

    Fekadu, Abebaw; Thornicroft, Graham

    2014-01-01

    Background Global mental health (GMH) advocates for access to and the equitable provision of mental health care. Although the treatment gap is a useful construct to measure access and equitability of care, it fails to communicate the real-life consequences of the treatment gap and the urgent need to address care disparities. Objective The aim of this article is to present a perspective on the practical application of the principles of GMH to understand the real-life impact of the treatment gap and the approaches taken to improve treatment coverage in Ethiopia. Design A case study method is used. Results Multiple international collaborations undertaken in Ethiopia and facilitated by GMH to improve care, capacity, and the evidence base for increased treatment coverage are described briefly. A series of steps taken at the local and national levels to address the treatment gap are highlighted. The stories of two patients are also presented to illustrate the real-life consequences of the treatment gap and the potential transformational impact of addressing the treatment gap on patients, families, and communities. Conclusions GMH has a key role to play in addressing the treatment gap, which improves the life of people with mental disorders, their families, and their communities. However, national-level policy support and coordination are essential for any realistic improvement in treatment coverage. The reflections offered through the case examples may have utility in similar low-income settings. PMID:25280740

  8. Current views on liver diseases in Ethiopia.

    PubMed

    Tsega, E

    1977-04-01

    The chief causes of liver disease in Ethiopia are reviewed, considering hospital data on admissions for hepatitis, cirrhosis, ascites and hepatoma. Liver diseases account for 11.4% of all medical admissions in 3 medical wards in Addis Ababa. The causes are viral hepatitis, post- hepatic and post necrotic and mixed cirrhosis and hepatocellular carcinoma. Alcoholic cirrhosis is rare. Viral hepatitis with shivering, rigor and fever and elevated direct bilirubin levels are common in Ethiopians, especially in child-bearing women. The hepatitis B surface antigen (HBsAg) is often associated with hepatitis. The disease may be transmitted by several species of mosquitoes, placental transmission, or feces, urine, saliva or semen. Blood products are not screened for hepatitis B. Cirrhosis is common, and causes significant mortality, usually from esophageal varices and hepatic coma. Chronic active hepatitis patients may live for a time, especially if they are near a hospital and are treated with steroids. In Ethiopia presenting symptoms for hepatoma are anorexia, weight loss, persistent, burning, right upper quadrant pain, and a hard, nodular, tender RUQ mass. Over 5% of malignancies seen are primary hepatocellular carcinomas. 50% have HBsAG, compared to 3.8% of controls. 65% have alpha-fetoglobulins. It is suggested that some viral hepatitis cases progress to cirrhosis, of which some go on to hepatocellular carcinoma. Herbal medicines, aflatoxins and other toxins may also contribute to liver disease. PMID:201462

  9. A Secret Decoder Ring for Volcanic Tremor: Method and Application to Erta 'Ale, Ethiopia

    NASA Astrophysics Data System (ADS)

    Jones, J. P.; Carniel, R.; Malone, S. D.

    2009-12-01

    A new method of analyzing volcanic tremor is presented, which uses properties of undecimated wavelet packet transforms to filter, decompose, and recover signals from continuous multichannel data. The method preserves many standard properties that are used to characterize tremor, such as wavefield polarization and seismic energy. In this way, we can better understand the (potentially many) seismic sources that combine to form continuous volcanic tremor, and we can specifically address the problem of what causes changing tremor spectral content. Using example data from two experiments at Erta 'Ale, Ethiopia, this method suggests that continuous volcanic tremor generally has multiple, simultaneously active seismic sources, not all of which are persistent. Our analysis suggests that continuous tremor was simultaneously generated at Erta 'Ale by magma flow in a conduit, degassing at a system of fumaroles, gas bubbles coalescing in the shallow, active lava lake, and degassing in a crater that formerly held a lava lake. Evidence for these diverse seismic sources can be seen in both the 2002 and 2003 data. Energy-based location of recovered signals from 2003 strongly supports this interpretation. The spectral transitions seen at Erta 'Ale in 2002 are resolved using this method, and result from secondary signals introduced during rapid convection. The signal which we interpret as being generated by magma flow in a conduit did not change between the two convective regimes. Thus, the recovered signals from the 2002 data argue strongly that changes in the rate of lava lake convection (and corresponding spectral changes) were driven entirely by shallow processes in the lava lake, rather than changing properties of the magma supply. This example demonstrates that using wavelet-based methods to understand the sources of continuous volcanic tremor can prove useful in understanding volcanic behavior, as well as detecting signals that relate to unrest.

  10. Diagenetic contrast of sandstones in hydrocarbon prospective Mesozoic rift basins (Ethiopia, UK, USA)

    NASA Astrophysics Data System (ADS)

    Wolela, A.

    2014-11-01

    Diagenetic studied in hydrocarbon-prospective Mesozoic rift basins were carried out in the Blue Nile Basin (Ethiopia), Ulster Basin (United Kingdom) and Hartford Basin (United States of America). Alluvial fan, single and amalgamated multistorey meandering and braided river, deep and shallow perennial lake, shallow ephemeral lake, aeolian and playa mud-flat are the prominent depositional environments. The studied sandstones exhibit red bed diagenesis. Source area geology, depositional environments, pore-water chemistry and circulation, tectonic setting and burial history controlled the diagenetic evolution. The diagenetic minerals include: facies-related minerals (calcrete and dolocrete), grain-coating clay minerals and/or hematite, quartz and feldspar overgrowths, carbonate cements, hematite, kaolinite, illite-smectite, smectite, illite, chlorite, actinolite, laumontite, pyrite and apatite. Diversity of diagenetic minerals and sequence of diagenetic alteration can be directly related to depositional environment and burial history of the basins. Variation in infiltrated clays, carbonate cements and clay minerals observed in the studied sandstones. The alluvial fan and fluviatile sandstones are dominated by kaolinite, illite calcite and ferroan calcite, whereas the playa and lacustrine sandstones are dominated by illite-smectite, smectite-chlorite, smectite, chlorite, dolomite ferroan dolomite and ankerite. Albite, pyrite and apatite are predominantly precipitated in lacustrine sandstones. Basaltic eruption in the basins modified mechanically infiltrated clays to authigenic clays. In all the studied sandstones, secondary porosity predominates over primary porosity. The oil emplacement inhabited clay authigenesis and generation of secondary porosity, whereas authigenesis of quartz, pyrite and apatite continued after oil emplacement.

  11. Rainfall and runoff variability in Ethiopia

    NASA Astrophysics Data System (ADS)

    Billi, Paolo; Fazzini, Massimiliano; Tadesse Alemu, Yonas; Ciampalini, Rossano

    2014-05-01

    Rainfall and river flow variability have been deeply investigated and and the impact of climate change on both is rather well known in Europe (EEA, 2012) or in other industrialized countries. Reports of international organizations (IPCC, 2012) and the scientific literature provide results and outlooks that were found contrasting and spatially incoherent (Manton et al., 2001; Peterson et al., 2002; Griffiths et al., 2003; Herath and Ratnayake, 2004) or weakened by limitation of data quality and quantity. According to IPCC (2012), in East Africa precipitation there are contrasting regional and seasonal variations and trends, though Easterling et al. (2000) and Seleshi and Camberlin (2006) report decreasing trends in heavy precipitation over parts of Ethiopia during the period 1965-2002. Literature on the impact of climate change on river flow is scarce in Africa and IPCC Technical Paper VI (IPCC, 2008) concluded that no evidence, based on instrumental records, has been found for a climate-driven globally widespread change in the magnitude/frequency of floods during the last decades (Rosenzweig et al., 2007), though increases in runoff and increased risk of flood events in East Africa are expected. Some papers have faced issues regarding rainfall and river flow variability in Ethiopia (e.g. Seleshi and Demaree, 1995; Osman and Sauerborn, 2002; Seleshi and Zanke, 2004; Meze-Hausken, 2004; Korecha and Barnston, 2006; Cheung et al., 2008) but their investigations are commonly geographically limited or used a small number of rain and flow gauges with the most recent data bound to the beginning of the last decade. In this study an attempt to depict rainfall and river flow variability, considering the longer as possible time series for the largest as possible number of meteo-stations and flow gauge evenly distributed across Ethiopia, is presented. 25 meteo-stations and 21 flow gauges with as much as possible continuous data records were selected. The length of the time

  12. 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

  13. The characteristics and chronology of the earliest Acheulean at Konso, Ethiopia.

    PubMed

    Beyene, Yonas; Katoh, Shigehiro; Woldegabriel, Giday; Hart, William K; Uto, Kozo; Sudo, Masafumi; Kondo, Megumi; Hyodo, Masayuki; Renne, Paul R; Suwa, Gen; Asfaw, Berhane

    2013-01-29

    The Acheulean technological tradition, characterized by a large (>10 cm) flake-based component, represents a significant technological advance over the Oldowan. Although stone tool assemblages attributed to the Acheulean have been reported from as early as circa 1.6-1.75 Ma, the characteristics of these earliest occurrences and comparisons with later assemblages have not been reported in detail. Here, we provide a newly established chronometric calibration for the Acheulean assemblages of the Konso Formation, southern Ethiopia, which span the time period ∼1.75 to <1.0 Ma. The earliest Konso Acheulean is chronologically indistinguishable from the assemblage recently published as the world's earliest with an age of ∼1.75 Ma at Kokiselei, west of Lake Turkana, Kenya. This Konso assemblage is characterized by a combination of large picks and crude bifaces/unifaces made predominantly on large flake blanks. An increase in the number of flake scars was observed within the Konso Formation handaxe assemblages through time, but this was less so with picks. The Konso evidence suggests that both picks and handaxes were essential components of the Acheulean from its initial stages and that the two probably differed in function. The temporal refinement seen, especially in the handaxe forms at Konso, implies enhanced function through time, perhaps in processing carcasses with long and stable cutting edges. The documentation of the earliest Acheulean at ∼1.75 Ma in both northern Kenya and southern Ethiopia suggests that behavioral novelties were being established in a regional scale at that time, paralleling the emergence of Homo erectus-like hominid morphology. PMID:23359714

  14. The characteristics and chronology of the earliest Acheulean at Konso, Ethiopia

    PubMed Central

    Beyene, Yonas; Katoh, Shigehiro; WoldeGabriel, Giday; Hart, William K.; Uto, Kozo; Sudo, Masafumi; Kondo, Megumi; Hyodo, Masayuki; Renne, Paul R.; Suwa, Gen; Asfaw, Berhane

    2013-01-01

    The Acheulean technological tradition, characterized by a large (>10 cm) flake-based component, represents a significant technological advance over the Oldowan. Although stone tool assemblages attributed to the Acheulean have been reported from as early as circa 1.6–1.75 Ma, the characteristics of these earliest occurrences and comparisons with later assemblages have not been reported in detail. Here, we provide a newly established chronometric calibration for the Acheulean assemblages of the Konso Formation, southern Ethiopia, which span the time period ∼1.75 to <1.0 Ma. The earliest Konso Acheulean is chronologically indistinguishable from the assemblage recently published as the world’s earliest with an age of ∼1.75 Ma at Kokiselei, west of Lake Turkana, Kenya. This Konso assemblage is characterized by a combination of large picks and crude bifaces/unifaces made predominantly on large flake blanks. An increase in the number of flake scars was observed within the Konso Formation handaxe assemblages through time, but this was less so with picks. The Konso evidence suggests that both picks and handaxes were essential components of the Acheulean from its initial stages and that the two probably differed in function. The temporal refinement seen, especially in the handaxe forms at Konso, implies enhanced function through time, perhaps in processing carcasses with long and stable cutting edges. The documentation of the earliest Acheulean at ∼1.75 Ma in both northern Kenya and southern Ethiopia suggests that behavioral novelties were being established in a regional scale at that time, paralleling the emergence of Homo erectus-like hominid morphology. PMID:23359714

  15. Depositional environments during the Late Palaeozoic ice age (LPIA) in northern Ethiopia, NE Africa

    NASA Astrophysics Data System (ADS)

    Bussert, Robert

    2014-11-01

    polythermal glaciers covered the whole basin, many sections document at least a second major phase of ice advance and retreat, and some sections additional minor advance-retreat cycles. Whether most of the LPIA sediments in northern Ethiopia were deposited in lakes or in fjords is not yet clear. Although univocal evidence of marine conditions is missing, the presence of carbonate-rich beds and the trace fossil assemblage are compatible with a restricted marine environment such as broad palaeofjords affected by strong freshwater discharge during deglaciation. A restricted marine environment for most of the sediments in northern Ethiopia could challenge models of the LPIA sediments in Arabia as primarily glaciolacustrine and glaciofluviatile deposits.

  16. Lake Powell

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The white ring around Lake Powell tells the story. The surface is down 98 feet. This is critical, because Powell, Lake Mead, and other lakes along the Colorado River provide water for millions of people in five states. We are in the eighth year of a drought on the Colorado River. This year was the driest year ever reported in Southern California, and there is a severe drought in Northern California, down to less than 30-percent of snow pack. This ASTER image of part of Lake Powell was acquired in 2001. The gray area depicts the shrunken, reduced 2007 lake extent compared to the extended, larger black area in 2001.

    The image covers an area of 24 x 30 km, and is centered near 37.1 degrees north latitude, 111.3 degrees west longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  17. Geochronology of the Turkana depression of northern Kenya and southern Ethiopia.

    PubMed

    Brown, Francis H; McDougall, Ian

    2011-01-01

    Mesozoic and Cenozoic sedimentary rocks in the Turkana Depression of northern Kenya and southern Ethiopia rest on basement rocks that yield K/Ar cooling ages between 433 and 522 Ma. Proven Cretaceous strata are exposed in Lokitaung Gorge in northwest Kenya. Eocene basalts and rhyolites in Lokitaung Gorge, the Nabwal Hills, and at Kangamajoj, date between 34 and 36 Ma, recording the earliest volcanism in the region. Oligocene volcanic rocks, with associated fossiliferous sedimentary strata at Eragaleit, Nakwai, and Lokone, all west of Lake Turkana, are 23 to 28 Ma old, as is the Langaria Formation east of Lake Turkana. Lower and Middle Miocene volcanic and sedimentary sequences are present both east and west of Lake Turkana, where ages from 17.9 to 9.1 Ma have been measured at many levels. Upper Miocene strata are presently known only at Lothagam, with ages ranging from 7.4 to 6.5 Ma. Deposition of Pliocene strata of the Omo Group begins in the Omo-Turkana, Kerio, and South Turkana basins -4.3 Ma ago and continues in parts of those basins until nearly the present time, but with some gaps. These strata are linked through volcanic ash correlations at many levels, as are Pleistocene strata of the Omo Group (principally the Shungura, Koobi Fora, and Nachukui formations). (40) Ar/(39) Ar dates on many volcanic ash layers within the Omo Group, supplemented by K/Ar ages on intercalated basalts and paleomagnetic polarity stratigraphy, provide excellent age control from 4.2 to 0.75 Ma, although there is a gap in the record between -1 Ma and 0.8 Ma. Members I to III of the Kibish Formation in the lower Omo Valley record deposition between 0.2 and 0.1 Ma ago; Member IV, correlative with the Galana Boi Formation, was deposited principally between 12 and 7 ka BP. PMID:22170691

  18. Establishing space research capability in Ethiopia

    NASA Astrophysics Data System (ADS)

    Bosinger, T.; Damtie, B.; Usoskin, I. G.

    It is often considered by various sources and institutions around the world that promotion of space physics activities in a developing country like Ethiopia is a waste of time and resources. It has, of course, some sense: developing countries should put all their efforts in improving the standard of life, infrastructure and basic education. However, it is straightforward to realize that nowadays improvement in any of the basic needs of developing countries is related to high technology (e.g. mobile phones, GPS, remote sensing). This means that a developing country has to take care of recruiting specialists among their own people who can take part in the decision making processes which are increasingly of global nature. Moreover, many citizens of developing countries are studying and working abroad attaining high expertise. As a matter of fact, there are more Ethiopians with PhD in physics working abroad than in the country. These people are lost for the benefit of their own country if there is no need for their profession in their home country. There is no doubt that the main task of improving the standard of living cannot be achieved without development and social transformation of the society, which can take place efficiently in a self-adopting and dynamic process. In line with the above argument, we have initiated the establishment of the Washera Space Physics Laboratory (WASPL) at Addis Ababa University in Ethiopia. It is a collaboration project between Oulu University and Addis Ababa University. The laboratory is expected to start operation of a pulsation magnetometer and photometer in September 2004. Other types of standard geophysical instruments are to be installed in subsequent missions. The project is of mutual interest of both parties. The equatorial ionosphere is still a poorly investigated region of our near Earth's space. In a first pilot investigation the existence and properties of the ionospheric Alfvén resonator (IAR) in the equatorial ionosphere

  19. Discovering the African freshwater "torpedo": legendary Ethiopia, religious controversies, and a catfish capable of reanimating dead fish.

    PubMed

    Piccolino, Marco; Finger, Stanley; Barbara, Jean-Gaël

    2011-07-01

    The electric catfishes of African rivers and lakes, once depicted on Egyptian tomb art, have been largely overlooked in histories and reviews of electric fish biology and animal electricity. This article examines how Westerners, especially Dominican and Jesuit missionaries, discovered them in Ethiopia and other parts of Africa at the beginning of the seventeenth century. What transpired took place against the backdrop of tales involving the Bible, Prester John's mythical empire, and imaginary animals with fabulous powers. In effect, how they were found is related to attempts to convert Ethiopian Christians to true Catholicism, hopes of discovering great riches, and opportunities to trade, and not with the efforts of skilled natural philosophers to document and conduct experiments on the wildlife of this continent. Nevertheless, the early descriptions by Europeans circulated, and during the next century these catfishes began to be used in experiments that helped to make animal electricity a reality. PMID:21736441

  20. Solar UV-treatment of water samples for stripping-voltammetric determination of trace heavy metals in Awash river, Ethiopia.

    PubMed

    Woldemichael, Gelaneh; Tulu, Taffa; Flechsig, Gerd-Uwe

    2016-03-01

    We report about testing a new mobile and sustainable water sample digestion method in a preliminary field trial in Ethiopia. In order to determine heavy metals at the ultra-trace level by stripping voltammetric techniques in water samples from Awash River, we applied our new method of solar UV-assisted sample pretreatment to destroy the relevant interfering dissolved organic matter. The field tests revealed that 24 h of solar UV irradiation were sufficient to achieve the same sample pretreatment results as with classic digestion method based on intense and hard UV. Analytical results of this study suggest that both a hydroelectric power station and agrichemical applications at Koka Lake have increased the levels of the investigated metals zinc, cadmium, lead, copper, cobalt, nickel, and uranium. PMID:27441266

  1. Ethiopia's health extension program: improving health through community involvement.

    PubMed

    Banteyerga, Hailom

    2011-07-01

    The Health Extension Program is one of the most innovative community-based health programs in Ethiopia. It is based on the assumption that access to and quality of primary health care in rural communities can be improved through transfer of health knowledge and skills to households. Since it became operational in 2004-2005, the Program has had a tangible effect on the thinking and practices of rural people regarding disease prevention, family health, hygiene and environmental sanitation. It has enabled Ethiopia to increase primary health care coverage from 76.9% in 2005 to 90% in 2010. PMID:21778960

  2. Pliocene volcano-tectonics and paleogeography of the Turkana Basin, Kenya and Ethiopia

    NASA Astrophysics Data System (ADS)

    Bruhn, Ronald L.; Brown, Francis H.; Gathogo, Patrick N.; Haileab, Bereket

    2011-02-01

    The distribution of hominin fossil sites in the Turkana Basin, Kenya is intimately linked to the history of the Omo River, which affected the paleogeography and ecology of the basin since the dawn of the Pliocene. We report new geological data concerning the outlet channel of the Omo River between earliest Pliocene and final closure of the Turkana Basin drainage system in the latest Pliocene to earliest Quaternary. Throughout most of the Pliocene the Omo River entered the Turkana Basin from its source in the highlands of Ethiopia and exited the eastern margin of the basin to discharge into the Lamu embayment along the coast of the Indian Ocean. During the earliest Pliocene the river's outlet was located in the northern part of the basin, where a remnant outlet channel is preserved in basalts that pre-date eruption of the Gombe flood basalt between 4.05 and 3.95 Ma. The outlet channel was faulted down to the west prior to 4.05 Ma, forming a natural dam behind which Lake Lonyumun developed. Lake Lonyumun was drained between 3.95 and 3.9 Ma when a new outlet channel formed north of Loiyangalani in the southeastern margin of the Turkana Basin. That outlet was blocked by Lenderit Basalt lava flows between 2.2 and 2.0 Ma. Faulting that initiated either during or shortly after eruption of the Lenderit Basalt closed the depression that is occupied by modern Lake Turkana to sediment and water. Several large shield volcanoes formed east of the Turkana Basin beginning by 2.5-3.0 Ma, volcanism overlapping in time, but probably migrating eastward from Mount Kulal on the eastern edge of the basin to Mount Marsabit located at the eastern edge of the Chalbi Desert. The mass of the volcanic rocks loaded and depressed the lithosphere, enhancing subsidence in a shallow southeast trending depression that overlay the Cretaceous and Paleogene (?) Anza Rift. Subsidence in this flexural depression guided the course of the Omo River towards the Indian Ocean, and also localized

  3. Partners against tuberculosis: Ethiopia's "TB clubs".

    PubMed

    Getahun, H

    1998-11-01

    TB (tuberculosis) clubs were first introduced in the Estie district of South Gonder administrative zone, Amhara region of northwestern Ethiopia in January 1997, in an attempt to improve TB control in rural areas. Before the clubs were introduced, patients who were family members or close neighbors were given different treatment follow-up dates. Walking long distances alone to secure treatment, patients often grew discouraged from continuing treatment once their health began to improve. However, upon the introduction of the TB clubs, neighboring patients, or those in the same family, had their follow-up appointment dates rearranged in the same clinics. Local neighborhoods were also used to group nearby patients in the same follow-up clinic. The patients then formed their own groups (TB clubs) and elected leaders. 3-10 members usually comprise each club, with the club leaders monitoring drug intake and new developments, such as drug side effects and toxic skin reactions. The social ostracism and stigma otherwise experienced by patients have been largely overcome as a result of the TB information disseminated within the communities by the clubs, while patient attendance for treatment has increased from 68% to 98%, according to one study's findings. This intervention has taken place using the long-course treatment protocol (2STH/EH and 10TH/EH). TB clubs are improving patient adherence to treatment, passive case detection, defaulter tracing, TB reporting and recording, and community involvement in health care. PMID:12294916

  4. Gastrointestinal parasites of working donkeys of Ethiopia.

    PubMed

    Getachew, M; Trawford, A; Feseha, G; Reid, S W J

    2010-01-01

    The general prevalence and population composition of gastrointestinal and pulmonary helminths of working donkeys were studied. For the purpose 2935 working donkeys were coprologically examined for nematode and cestode, and 215 donkeys for trematode infections. Seven donkeys that died due to various health problems or were euthanased on a welfare ground were necropsied and the parasites were recovered and identified to the species level. The study was conducted during the periods 1996-1999.Coprological examination revealed 99% strongyle, 80% Fasciola, 51% Parascaris, 30% Gastrodiscus, 11% Strongyloides westeri, 8% cestodes and 2% Oxyuris equi infection prevalence. Over 55% of donkeys had more than 1000 eggs per gram of faeces (epg). Forty two different species of parasites consisting of 33 nematodes, 3 trematodes, 3 cestodes and 3 arthropod larvae were identified from postmortem examined donkeys. Among the nematodes 17 species of Cyathostominae and 7 species of Strongylinae were identified. Other parasites identified include, Habronema muscae, Draschia megastoma, Trichostrongylus axei, Strongyloides westeri, Anoplocephala perfoliata, Anoplocephala magna, Anoplocephaloides (Paranoplocephala) mamillana, Parascaris equorum, Fasciola hepatica, Fasciola gigantica, Gastrodiscus aegyptiacus, Dictyocaulus arnfieldi, Oxyuris equi, Probstmayria vivipara, Gasterophilus intestinalis, Gasterophilus nasalis, Rhinoestrus uzbekistanicus and Setaria equina. This study revealed that working donkeys in Ethiopia are infected with a range of helminths and arthropod larvae, which are representatives of the important pathogenic parasites found in equids worldwide. PMID:19548106

  5. Household Constraints on Schooling by Gender: Empirical Evidence from Ethiopia.

    ERIC Educational Resources Information Center

    Rose, Pauline; Al-Samarrai, Samer

    2001-01-01

    Examines individual and household characteristics that affect the probability of a boy or girl attending and completing primary school in two regions of Ethiopia. Finds that school attendance was related to household wealth, parents' education, and child's nutritional status, while completion was affected more by economic constraints and, for…

  6. Higher Education in Ethiopia: Expansion, Quality Assurance and Institutional Autonomy

    ERIC Educational Resources Information Center

    Akalu, Girmaw Abebe

    2014-01-01

    This article chronicles the key challenges facing Ethiopia as it embarks on an ambitious, ideologically-driven and aggressive expansion of its higher education system in an effort to address its national goals of economic growth and poverty reduction. It is argued that the urge for higher education expansion has placed undue pressures particularly…

  7. Molecular characterization of Theileria orientalis from cattle in Ethiopia.

    PubMed

    Gebrekidan, Hagos; Gasser, Robin B; Baneth, Gad; Yasur-Landau, Daniel; Nachum-Biala, Yaarit; Hailu, Asrat; Jabbar, Abdul

    2016-07-01

    This study reports the first molecular characterization of Theileria orientalis in local breeds of cattle in Ethiopia. A conventional PCR utilizing major piroplasm surface protein (MPSP) gene and an established multiplexed tandem PCR (MT-PCR) were used to characterize T. orientalis and to assess the infection intensity, respectively. Of 232 blood samples tested, T. orientalis DNA was detected in only 2.2% of samples using conventional PCR; two genotypes buffeli (1.3%; 3/232) and type 5 (0.9%; 2/232) of T. orientalis were detected. Phylogenetic analysis revealed that the buffeli MPSP sequences from Ethiopia were closely related to those reported from Kenya, Sri Lanka and Myanmar, and type 5 sequences from Ethiopia grouped with those from Korea, Japan, Vietnam and Thailand. A higher number of samples (3.9%; 9/232) were test-positive by MT-PCR and four genotypes (buffeli, chitose, ikeda and type 5) of T. orientalis were detected. The average intensity of infections with genotypes buffeli (DNA copy numbers 11,056) and type 5 (7508) were significantly higher (P<0.0001) than the pathogenic genotype ikeda (61 DNA copies). This first insight into T. orientalis from cattle in Ethiopia using MPSP gene provides a basis for future studies of T. orientalis in various agroclimatic zones and of the impact of oriental theilerosis on cattle in this and other countries of Africa. PMID:27034193

  8. Adult Basic Literacy "Initiatives" in Ethiopia: Change and Continuity

    ERIC Educational Resources Information Center

    Kenea, Ambissa

    2014-01-01

    The major purpose of the study was to look into change and continuity in the policy and practices of adult basic literacy initiatives in Ethiopia and to deduce lessons that can be drawn from the experiences for the future of adult basic literacy program in the country and elsewhere. Data was obtained through critical review of documents on the…

  9. Household Demand for Primary Schooling in Ethiopia: Preliminary Findings.

    ERIC Educational Resources Information Center

    Honig, Benson

    This paper presents findings of a study that examined the role of economic, social, and logistical factors on Ethiopian parents' decisions whether or not to enroll their children in public primary school. Data were obtained from a survey of four rural regions in Ethiopia--130 households per region. Findings indicate that parents made enrollment…

  10. Determinants of Children's Schooling: The Case of Tigray Region, Ethiopia

    ERIC Educational Resources Information Center

    Abafita, Jemal; Kim, Chang-Soo

    2015-01-01

    We analyze the determinants of educational outcomes of primary school children in Tigray region of Ethiopia using a survey data gathered from four villages in 2013. Four different measures of schooling were used to examine the impact of household and child-specific factors. First, we examine the determinants of school attendance (ever-attendance,…

  11. Growth and Visual Information Processing in Infants in Southern Ethiopia

    ERIC Educational Resources Information Center

    Kennedy, Tay; Thomas, David G.; Woltamo, Tesfaye; Abebe, Yewelsew; Hubbs-Tait, Laura; Sykova, Vladimira; Stoecker, Barbara J.; Hambidge, K. Michael

    2008-01-01

    Speed of information processing and recognition memory can be assessed in infants using a visual information processing (VIP) paradigm. In a sample of 100 infants 6-8 months of age from Southern Ethiopia, we assessed relations between growth and VIP. The 69 infants who completed the VIP protocol had a mean weight z score of -1.12 plus or minus…

  12. Quality Education Reform and Aid Effectiveness: Reflections from Ethiopia

    ERIC Educational Resources Information Center

    Berry, Chris; Bogale, Solomon Shiferaw

    2011-01-01

    Ethiopia is a large country in the Horn of Africa. It has a diverse population of eighty million people who speak over thirty distinct languages. Approximately 80% of the population live in rural areas and rely on subsistence agriculture. Despite economic growth and an abundance of natural resources, it is a country with a per-capita income of…

  13. Hemoglobin, Growth, and Attention of Infants in Southern Ethiopia

    ERIC Educational Resources Information Center

    Aubuchon-Endsley, Nicki L.; Grant, Stephanie L.; Berhanu, Getenesh; Thomas, David G.; Schrader, Sarah E.; Eldridge, Devon; Kennedy, Tay; Hambidge, Michael

    2011-01-01

    Male and female infants from rural Ethiopia were tested to investigate relations among hemoglobin (Hb), anthropometry, and attention. A longitudinal design was used to examine differences in attention performance from 6 (M = 24.9 weeks, n = 89) to 9 months of age (M = 40.6 weeks, n = 85), differences hypothesized to be related to changes in iron…

  14. Teacher Preparation in Ethiopia: A Critical Analysis of Reforms

    ERIC Educational Resources Information Center

    Semela, Tesfaye

    2014-01-01

    The purpose of this article is to provide a more comprehensive picture of teacher preparation in Ethiopia on top of a closer scrutiny of current teacher education reforms. In particular, it presents teacher education within the context of policy implementation over the last six decades by highlighting key reforms and how these reforms impacted the…

  15. Examining Some Aspects of Alternative Basic Education Programmes in Ethiopia

    ERIC Educational Resources Information Center

    Onwu, Gilbert O. M.; Agu, Augustine

    2010-01-01

    This study examines some aspects of the quality of Alternative Basic Education (ABE) provision in Ethiopia. Educational indicators of quality were formulated under two general topic areas of ABE programme process and content, and pupil learning outcomes. A qualitative-interpretative research approach and survey design was used to collect data from…

  16. Outcomes of Orphanhood in Ethiopia: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Camfield, Laura

    2011-01-01

    The paper addresses the question of whether parental death always has a strongly negative effect on children's outcomes using quantitative and qualitative data from Young Lives, a longitudinal study of childhood poverty in Ethiopia. It investigates the validity of potential mediating factors identified by other studies in Sub-Saharan Africa using…

  17. What Community Participation in Schooling Means: Insights from Southern Ethiopia

    ERIC Educational Resources Information Center

    Swift-Morgan, Jennifer

    2006-01-01

    Community participation is a term frequently used and often cited in international educational development. In this article, Jennifer Swift-Morgan investigates the definition and impact of community participation in schooling in rural Ethiopia. Although national governments, development agencies, and nongovernmental organizations across the…

  18. Fossil fuel energy resources of Ethiopia: Oil shale deposits

    NASA Astrophysics Data System (ADS)

    Wolela, Ahmed

    2006-10-01

    The energy crisis affects all countries in the world. Considering the price scenarios, many countries in Africa have begun to explore various energy resources. Ethiopia is one of the countries that depend upon imported petroleum products. To overcome this problem, geological studies suggest a significant occurrence of oil shale deposits in Ethiopia. The Inter-Trappean oil shale-bearing sediments are widely distributed on the South-Western Plateau of Ethiopia in the Delbi-Moye, Lalo-Sapo, Sola, Gojeb-Chida and Yayu Basins. The oil shale-bearing sediments were deposited in fluviatile and lacustrine environments. The oil shales contain mixtures of algal, herbaceous and higher plant taxa. They are dominated by algal-derived liptinite with minor amounts of vitrinite and inertinite. The algal remains belong to Botryococcus and Pediastrum. Laboratory results confirm that the Ethiopian oil shales are dominated by long-chain aliphatic hydrocarbons and have a low sulphur content. Type-II and Type-I kerogen dominated the studied oil shales. Type-II and Type-I are good source rocks for oil and gas generation. Hydrogen index versus Tmax value plots indicated that most of the oil shale samples fall within the immature-early mature stage for hydrocarbon generation, consistent with the Ro values that range from 0.3% to 0.64%. Pyrolysis data of the oil shales sensu stricto indicate excellent source rocks with up to 61.2% TOC values. Calorific value ranges from 400 to 6165 cal/g. Palynological studies confirmed that the oil shale-bearing sediments of Ethiopia range from Eocene to Miocene in age. A total of about 253,000,000 ton of oil shale is registered in the country. Oil shale deposits in Ethiopia can be used for production of oil and gas.

  19. Gully Development in North Ethiopia's Mountains

    NASA Astrophysics Data System (ADS)

    Frankl, Amaury; Nyssen, Jan; Poesen, Jean; de Mûelenaere, Stephanie; Meire, Ellen; de Dapper, Morgan; Deckers, Jozef; Haile, Mitiku

    2010-05-01

    Understanding trends in gully erosion, and the relation with changes in its triggers, is important to make sustainable development possible in semi-arid regions suffering from low food security and threatened by climatic deterioration. The reconstruction of long-term (1868-2009) patterns in gully erosion in North Ethiopia and environmental control, i.e. LUC changes and rainfall pattern changes, requires an extensive database of ground-based photographs (1868-1975), aerial photographs (1964-1992), satellite images (1972-2009), meteorological station data (1950s-2009) and field measurements. Quantifying gully erosion networks and volumes is done from an integrated analysis of historical ground-based photographs, aerial photographs and IKONOS imagery. Therefore, new methodologies are being developed based on fieldwork, digital photogrammetry and Geographic Information Science techniques. LUC mapping and change analysis for periods prior to satellite imagery and aerial photography is done by developing a new methodology that georeferences LUC boundaries identified on historical photographs to the horizontal plane of the map. For the LANDSAT LUC analysis (1972-2000), images dated 1974-5 were calibrated using photographs of the same period. Therefore, a methodology was developed that involves the development of spectral signatures based on LUC observed on the photographs, and the recording of the location of those LUC units by GPS. Rainfall pattern changes will be analyzed from Rainfall Estimates(2001-2009) and meteorological station data. Early results show that gully erosion was already extensive in the late 19th century, caused by a largely degraded environment and that critical gully expansion occurred after the mid 20th century. Little care was given to land management in 1868 resulting in very low vegetation cover which depleted to a minimum in dry spells like in the 1980s. In recent decades land management practices result in an environmental recovery and

  20. Identification of variable convective regimes at Erta Ale Lava Lake

    NASA Astrophysics Data System (ADS)

    Harris, Andrew J. L.; Carniel, Roberto; Jones, Josh

    2005-04-01

    During February 17-19, 2002, we collected a combined thermal and seismic data set for persistent lava lake activity at Erta Ale volcano, Ethiopia. These data indicate that the lake cycled between periods characterized by low (0.01-0.08 m s -1) and high (0.1-0.4 m s -1) surface velocities, typically lasting tens to hundreds of minutes. These periods of high and low velocity motion define periods of vigorous and sluggish convection, respectively. Spectral analysis revealed that vigorous convection periods were characterized by high frequencies and energies in the thermal data and an increased presence of high-frequency energy in the seismic data. The data show that vigorous periods were characterized by formation of hot, short-lived, plastic crusts, and sluggish periods by cooler, longer lived, brittle crusts. Here, the higher transit velocity across the lake surface from upwelling zones of crust formation to downwelling zones of crust destruction during the vigorous periods decreases the crust lifetime. This in turn decreases the total cooling and thickening experienced by a plate of crust moving across the lake surface. Two scenarios can be envisaged to explain such convection cycles. The first relates variable convection rates to changes in the volume flux and rheology of magma entering the lake. In the second, cyclic convection is set up by the generation of convective instabilities within the lake. In this case, cooling of a surface layer generates a slow moving, viscous, increasingly dense convection layer at the lake surface which is consumed and replaced during overturn.

  1. Tephrochronology of the Western Margin, Gona, Ethiopia

    NASA Astrophysics Data System (ADS)

    Kleinsasser, L. L.; Quade, J.; Levin, N.; McIntosh, W.; Simpson, S. W.; Semaw, S.

    2006-12-01

    The Gona Paleoanthropological Research Project (GPRP) area includes many rich fossil localities that are of great consequence to the study of human evolution. Genetic estimates of the divergence between human and chimpanzee lineages indicate that this split happened between 5 and 7 Mya. The sedimentary deposits at Gona range in age from .15 Ma to 4.5 Ma at the base of the Sagantole Formation, with additional minor sedimentary deposits in the underlying Adu-Asa Formation. These older sedimentary deposits occur as small, disconnected packages interlayered with lava flows and are repeated due to NS-trending, west-dipping normal faults that accommodated extension in the Afar rift. New 40Ar-39Ar dates on tuffs from the Adu-Asa Formation indicate that the oldest hominid fossils thus found at Gona are around 5.5 Ma, and that all of the fossil sites in the Adu-Asa Formation identified thus far are approximately the same age. One tuff, named the Belewa, is dated at 5.51+/- .03 Ma, while the Kobo'o tuff, which outcrops to the west and thus is lower in the section, is dated at 5.42 +/-.07 Ma. Both dates are from sanidine and errors are at the 2 sigma level. In addition to these 40Ar-39Ar dates for the Adu-Asa Formation, the relative ages of many deposits have been clarified through studies of the major element geochemistry of glass shards from ashfall tuffs, which occur as beds within the sedimentary deposits. These geochemical comparisons, along with detailed stratigraphic sections through many sedimentary packages, have allowed the identification and correlation of four major tuffs, including the Belewa and Kobo'o tuffs, throughout the pre-4.5 Ma deposits of the Gona project area. Such studies may also lead to larger-scale correlations between the Gona project and other paleoanthropological projects in Ethiopia. Additional work on the tephrochronology and stratigraphy in the younger Sagantole, Hadar, and Busidima Formations has furthered our understanding of those deposits

  2. The ICDP-Hominin Sites and Paleolakes Drilling Project (HSPDP): new data from the Chew Bahir site in Ethiopia

    NASA Astrophysics Data System (ADS)

    Leng, Melanie; Dean, Jonathan; Asrat, Asfawossen; Cohen, Andrew; Foerster, Verena; Just, Janna; Klasen, Nicole; Lamb, Henry; Schäbitz, Frank; Trauth, Martin; Viehberg, Finn; Wagner, Bernd

    2016-04-01

    There are currently few long, continuous, Pleistocene records from East Africa, meaning it has been difficult to establish the relative influence of low- versus high-latitude forcing on East African climate and climatic conditions at the time of anatomically modern human origin and subsequent dispersal. We have been attempting to address these gaps in our knowledge by analysing lake sediments taken from Chew Bahir, an area of playa mudflats in southern Ethiopia close to the site of the oldest-known anatomically modern human fossils at Omo-Kibish. In March 2014, Chew Bahir was cored to a depth of ~40 metres, and the resulting sediment sequence is estimated to cover the last ~115ka. In December 2014, a nearby site was drilled to a depth of ~280 metres as part of the International Continental scientific Drilling Programme - Hominin Sites and Paleolakes Drilling Project (HSPDP). The oxygen and carbon isotope composition of endogenic calcite and other data from these cores will be presented. The data show some significant changes in water balance variability, the period prior to 70ka appears very unstable with some significant periods of drought and flood. Between 70-20ka the lake was stable and evaporative. The last 20ka years was wetter.

  3. Sheep production and marketing system in southern Ethiopia: the case of Awassazuria district.

    PubMed

    Tadesse, Estefanos; Negesse, Tegene; Abebe, Girma

    2015-10-01

    A survey was conducted in Awassazuria district of southern Ethiopia to characterize sheep production system. A structured questionnaire was used to collect data. Using purposive sampling, a total of 120 households from the district were included in the survey. Collected data were analyzed using descriptive statistics. Result indicated that Kajima neighbourhood has more (p<0.05) grazing land than the others. Communal grazing, roadside grazing, enset (false banana, Ensete ventricosum), banana leaf and private grazing land were major feed resources for sheep. Lake Awassa and tap water were permanent water sources. Watering frequency of sheep varies from once a day to once in 4 days. Sheep are primarily kept to generate income and equilibrate benefit and risk and for home consumption. The criteria used by the households for purchase and sale of sheep are physical characteristics (coat colour, horn and tail) (46.7 %), body conformation (35 %), age (10.8 %) and known local ecotype (7.5 %). The reasons of slaughter of sheep include festival (55 %), childbirth (18.3 %), wedding (12.5 %), mutton for home (9 %), circumcision (5 %) and for guest (1.7 %). Farmers fatten sheep for New Year (60 %), Easter (30.8 %), Christmas and Arefa (Eid al-Adha celebration (Feast of the Sacrifice); <10 %). The reasons for expansion of sheep flock in the future were market price, high market demand, immediate return, ease of management, equilibrium between benefits and risks and suitability for home consumption, ranked in decreasing order of importance. The sheep production in southern Ethiopia is constrained by shortage of grazing land (23.3 %), recurrent drought (17.5 %), disease and parasite (15 %), marketing (10.8 %), water shortage (9 %) and other constraints including predators and lack of input, capital and lack of extension service. The presence of diversified and environmentally adaptable sheep breeds, high demand of mutton in the Awassa town and presence of nutritious and unutilized

  4. Blood meal origins and insecticide susceptibility of Anopheles arabiensis from Chano in South-West Ethiopia

    PubMed Central

    2013-01-01

    Background Anopheles arabiensis, the main malaria vector in Ethiopia, shows both anthropophilic and zoophilic behaviours. Insecticide resistance is increasing, and alternative methods of vector control are needed. The objectives of this study were to determine the blood meal origins and the susceptibility to insecticides of An. arabiensis from Chano village near Arba Minch in South-West Ethiopia. Methods Blood meal sources of anopheline mosquitoes collected using Centers for Disease Control and Prevention (CDC) light traps and pyrethrum spray catches (PSC) from human dwellings, and hand-held mouth aspirators from outdoor pit shelters were analysed using a direct enzyme-linked-immunosorbent assay (ELISA). The susceptibility of An. arabiensis to pyrethroid insecticides (alphacypermethrin, lambdacyhalothrin, deltamethrin, and cyfluthrin) and DDT was assessed using females reared from larval and pupal collections from natural breeding sites. Results The blood meal origins of 2967 freshly fed Anopheles mosquitoes were determined. An. arabiensis was the predominant species (75%), and it fed mainly on cattle. The densities of both freshly fed An. arabiensis and those fed on human blood followed similar seasonal patterns. The overall human blood index (HBI) of An. arabiensis, including mixed blood meals, was 44% and the bovine blood index (BBI) was 69%. The HBI of An. arabiensis from CDC light trap collections was 75% and this was higher than those for PSC (38%) and outdoor pit shelter collections (13%), while the BBI was 65% for PSC, 68% for outdoor pit shelters and 72% for CDC light traps. More freshly fed and human blood-fed An. arabiensis were sampled from houses close to the shore of Lake Abaya (the major breeding site). A high proportion of An. arabiensis was resistant to the pyrethroid insecticides, with a mortality rate of 56% for lambdacyhalothrin, 50% for cyfluthrin and alphacypermethrin, 47% for deltamethrin, and 10% for DDT. Conclusion Anopheles arabiensis is

  5. Longevity of Lake Superior lake trout

    USGS Publications Warehouse

    Schram, Stephen T.; Fabrizio, Mary C.

    1998-01-01

    The age structure of mature lake trout Salvelinus namaycush from the Wisconsin waters of Lake Superior increased following a population recovery that has taken place since the 1960s. As the population aged, it became apparent that scales were unreliable aging structures. Beginning in 1986, we examined both scale and sagittal otolith ages from tagged fish with a known period at liberty. We found large discrepancies in scale and sagittal otolith ages of mature fish, such that scale ages were biased low. We estimated lake trout living up to 42 years, which is greater than previously reported from Lake Superior. Investigators studying lake trout population dynamics in the Great Lakes should be aware that lake trout can live longer than previously thought.

  6. Lake Volta, Ghana

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This true-color image of Lake Volta in Ghana was acquired March 31, 2002 by the Moderate Resolution Imaging Spectroradiometer (MODIS). Lake Volta is one of the world's largest artificially created lakes. Lake Volta is actually a reservoir formed from the damming of the Volta River, and extends 250 miles north of the Akosombo Dam. The lake covers an area of 8,482 square km. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  7. Inclusion of Students with Disabilities in Formal Vocational Education Programs in Ethiopia

    ERIC Educational Resources Information Center

    Malle, Abebe Yehualawork; Pirttimaa, Raija; Saloviita, Timo

    2015-01-01

    In Ethiopia, individuals with disabilities have limited access to educational and vocational training opportunities. This study investigates prevailing challenges and opportunities for the participation of students with disabilities in vocational education programs in Ethiopia. Data for the study were gathered from the five biggest regions out of…

  8. 78 FR 16029 - Waiver of Restriction on Assistance to the Central Government of Ethiopia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-13

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE Waiver of Restriction on Assistance to the Central Government of Ethiopia Pursuant to Section 7031(b)(3) of... Section 7031(b)(1) of the Act with respect to Ethiopia and I hereby waive this restriction....

  9. Instructional Language Policy in Ethiopia: Motivated by Politics or the Educational Needs of Children?

    ERIC Educational Resources Information Center

    Alemu, Daniel S.; Tekleselassie, Abebayehu A.

    2006-01-01

    The purpose of this study is to explain the formulation, implementation, and outcome of Ethiopia's instructional language policy in light of the PRINCE system of power analysis as adapted by Fowler (2004), along with several literature references pertinent to the issue. After providing a brief background on Ethiopia and its education and language…

  10. Expansion vs. Quality: Emerging Issues of For-Profit Private Higher Education Institutions in Ethiopia

    ERIC Educational Resources Information Center

    Alemu, Daniel S.

    2010-01-01

    Private for-profit higher education has been rapidly expanding in developing countries worldwide since the early 1990s. This global trend has been particularly evident in Ethiopia, where only three public universities existed until 1996. By 2005, about 60 private for-profit higher education institutions had been founded in Ethiopia. This has led…

  11. 76 FR 61134 - Waiver of Restriction on Assistance to the Central Government of Ethiopia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-03

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF STATE Waiver of Restriction on Assistance to the Central Government of Ethiopia Pursuant to Section 7086(c)(2) of... Section 7086(c)(1) of the Act with respect to Ethiopia and I hereby waive such restriction....

  12. Hydroclimate Forecasts in Ethiopia: Benefits, Impediments, and Ways Forward

    NASA Astrophysics Data System (ADS)

    Block, P. J.

    2014-12-01

    Numerous hydroclimate forecast models, tools, and guidance exist for application across Ethiopia and East Africa in the agricultural, water, energy, disasters, and economic sectors. This has resulted from concerted local and international interdisciplinary efforts, yet little evidence exists of rapid forecast uptake and use. We will review projected benefits and gains of seasonal forecast application, impediments, and options for the way forward. Specific case studies regarding floods, agricultural-economic links, and hydropower will be reviewed.

  13. Pacific SST influence on spring precipitation in Addis Ababa, Ethiopia

    NASA Astrophysics Data System (ADS)

    Eden, J. M.; Widmann, M.; Wild, S.; Evans, G. R.; Hughes, J. G.

    2012-04-01

    In Ethiopia and other parts of East Africa, interannual variability of seasonal precipitation is dependent on variations in sea surface temperature (SST) and atmospheric circulation on both regional and global scales. The majority of research into large-scale atmospheric controls and predictability has focused on the heavier summer rains and the establishment of links to large-scale modes of climate variability such as ENSO. By contrast, relatively little work has focused on the potential for predictability of rainfall during the spring months, which is of great importance to much of southern Ethiopia. Additionally, failure of the spring rains may have important agricultural implications, particularly for crops requiring the full extent of the spring-summer growing season. Here, we analyse the links between Pacific SST and precipitation in Addis Ababa, Ethiopia for a century-long period (1900-2004). A tripole correlation pattern between spring precipitation and SST is found in the Pacific basin. We develop regression-based models to estimate spring precipitation from Pacific SST with a lead time of 2-3 months. When subject to a rigorous cross-validation, models based on principal component multiple linear regression (PC-MLR) calibrated on Pacific SST during December show good skill in reproducing observed temporal variability in Addis Ababa precipitation during February (r = 0.48) and March (r = 0.40), and the period spanning February to April (r = 0.44). Reconstructed precipitation is correlated with temperature and specific humidity in the surrounding region; estimates of heavy spring precipitation are associated with anomalously warm, moist conditions across the western Indian Ocean. Our findings suggest that inclusion of Pacific SST in predictive models may benefit drought forecasting across Ethiopia. The relationships identified provide a potential basis for forecasting models for spring rainfall and further analysis may focus on drought forecasting using ROC

  14. Indoor air pollution in slum neighbourhoods of Addis Ababa, Ethiopia

    NASA Astrophysics Data System (ADS)

    Sanbata, Habtamu; Asfaw, Araya; Kumie, Abera

    2014-06-01

    An estimated 95% of the population of Ethiopia uses traditional biomass fuels, such as wood, dung, charcoal, or crop residues, to meet household energy needs. As a result of the harmful smoke emitted from the combustion of biomass fuels, indoor air pollution is responsible for more than 50,000 deaths annually and causes nearly 5% of the burden of disease in Ethiopia. Very limited research on indoor air pollution and its health impacts exists in Ethiopia. This study was, therefore, undertaken to assess the magnitude of indoor air pollution from household fuel use in Addis Ababa, the capital city of Ethiopia. During January and February, 2012, the concentration of fine particulate matter (PM2.5) in 59 households was measured using the University of California at Berkeley Particle Monitor (UCB PM). The raw data was analysed using Statistical Package of Social Science (SPSS version 20.0) software to determine variance between groups and descriptive statistics. The geometric mean of 24-h indoor PM2.5 concentration is approximately 818 μg m-3 (Standard deviation (SD = 3.61)). The highest 24-h geometric mean of PM2.5 concentration observed were 1134 μg m-3 (SD = 3.36), 637 μg m-3 (SD = 4.44), and 335 μg m-3 (SD = 2.51), respectively, in households using predominantly solid fuel, kerosene, and clean fuel. Although 24-h mean PM2.5 concentration between fuel types differed statistically (P < 0.05), post hoc pairwise comparison indicated no significant difference in mean concentration of PM2.5 between improved biomass stoves and traditional stoves (P > 0.05). The study revealed indoor air pollution is a major environmental and health hazard from home using biomass fuel in Addis Ababa. The use of clean fuels and efficient cooking stoves is recommended.

  15. Flow, melt and fossil seismic anisotropy beneath Ethiopia

    NASA Astrophysics Data System (ADS)

    Hammond, James; Kendall, J.-Michael; Wookey, James; Stuart, Graham; Keir, Derek; Ayele, Atalay

    2014-05-01

    Ethiopia is a region where continental rifting gives way to oceanic spreading. Yet the role that pre-existing lithospheric structure, melt, mantle flow or active upwellings may play in this process is debated. Measurements of seismic anisotropy are often used to attempt to understand the contribution that these mechanisms may play. In this study we use new data in Afar, Ethiopia along with legacy data across Ethiopia, Djibouti and Yemen to obtain estimates of mantle anisotropy using SKS-wave splitting. We show that two layers of anisotropy exist, and use shear-wave splitting tomography to invert for these. We show that fossil anisotropy with fast directions oriented northeast-southwest may be preserved in the lithosphere away from the rift. Beneath the Main Ethiopian Rift and parts of Afar, anisotropy due aligned melt due to sharp changes in lithospheric thickness dominate the shear-wave splitting signal in the mantle. Beneath Afar, away from lithospheric topography, melt pockets associated with the crustal magma storage dominate the signal and little anisotropy is seen in the uppermost mantle suggesting melt retains no preferential alignment, possibly due to a lack of mantle lithosphere. These results show the important role melt plays in weakening the lithosphere and imply that as rifting evolves passive upwelling sustains extension. A dominant northeast-southwest anisotropic fast direction is observed in a deeper layer across all of Ethiopia. This suggests that a conduit like plume is absent beneath Afar today, rather a broad flow from the southwest dominates in the upper mantle.

  16. Linking long-term gully and river channel dynamics to environmental change using repeat photography (Northern Ethiopia)

    NASA Astrophysics Data System (ADS)

    Frankl, Amaury; Nyssen, Jan; De Dapper, Morgan; Haile, Mitiku; Billi, Paolo; Munro, R. Neil; Deckers, Jozef; Poesen, Jean

    2011-06-01

    In the Highlands of Northern Ethiopia gully occurrence is linked to poverty-driven unsustainable use of the land in a vulnerable semi-arid and mountainous environment, where intensive rainfall challenges the physical integrity of the landscape. Trends in gully and river channel erosion, and their relation to triggering environmental changes can proffer valuable insights into sustainable development in Northern Ethiopia. In order to assess the region-wide change in gully and river channel morphology over 140 years, a set of 57 historical photographs taken in Tigray, and, clearly displaying gully cross-sections, were precisely repeated from 2006 till 2009. Ninety-two percent of the gully and river sections (n = 38) increased in cross-sectional area during the studied period, especially after 1975. Two repeatedly photographed catchments of Lake Ashenge and Atsela allowed a detailed study of gully development from 1936 until 2009. A conceptual hydrogeomorphic model was devised for these catchments and validated for the Northern Ethiopian Highlands. Three major phases can be distinguished in the hydrological regime of the catchments. In the first phase, between 1868 (or earlier) and ca. 1965, the relatively stable channels showed an oversized morphology inherited from a previous period when external forcing in environmental conditions had caused the channels to shape. In the second phase (ca. 1965 - ca. 2000), increased aridity and continued vegetation clearance accelerated the channel dynamics of the gully and river system. The third phase (ca. 2000 - present) started after the large-scale implementation of soil and water conservation measures. In 2009, 23% of the gully and river sections were stabilizing. This paper validates previous research indicating severe land degradation in the second half of the 20th century. Additionally, it demonstrates that the recent erosive cycle started around 1965 and, that at the present time, improved land management stabilizes

  17. Assessment of Late Quaternary strain partitioning in the Afar Triple Junction: Dobe and Hanle grabens, Ethiopia and Djibouti

    NASA Astrophysics Data System (ADS)

    Polun, S. G.; Stockman, M. B.; Hickcox, K.; Horrell, D.; Tesfaye, S.; Gomez, F. G.

    2015-12-01

    As the only subaerial exposure of a ridge - ridge - ridge triple junction, the Afar region of Ethiopia and Djibouti offers a rare opportunity to assess strain partitioning within this type of triple junction. Here, the plate boundaries do not link discretely, but rather the East African rift meets the Red Sea and Gulf of Aden rifts in a zone of diffuse normal faulting characterized by a lack of magmatic activity, referred to as the central Afar. An initial assessment of Late Quaternary strain partitioning is based on faulted landforms in the Dobe - Hanle graben system in Ethiopia and Djibouti. These two extensional basins are connected by an imbricated accommodation zone. Several fault scarps occur within terraces formed during the last highstand of Lake Dobe, around 5 ka - they provide a means of calibrating a numerical model of fault scarp degradation. Additional timing constraints will be provided by pending exposure ages. The spreading rates of both grabens are equivalent, however in Dobe graben, extension is partitioned 2:1 between northern, south dipping faults and the southern, north dipping fault. Extension in Hanle graben is primarily focused on the north dipping Hanle fault. On the north margin of Dobe graben, the boundary fault bifurcates, where the basin-bordering fault displays a significantly higher modeled uplift rate than the more distal fault, suggesting a basinward propagation of faulting. On the southern Dobe fault, surveyed fault scarps have ages ranging from 30 - 5 ka with uplift rates of 0.71, 0.47, and 0.68 mm/yr, suggesting no secular variation in slip rates from the late Plestocene through the Holocene. These rates are converted into horizontal stretching estimates, which are compared with regional strain estimated from velocities of relatively sparse GPS data.

  18. Natural resources and their prospects in the closed basins of rift valley marginal grabens in northern Ethiopia

    NASA Astrophysics Data System (ADS)

    Meaza, Hailemariam; Frankl, Amaury; Poesen, Jean; Zenebe, Amanuel; Deckers, Jozef; Vaneetvelde, Veerle; Lanckriet, Sil; Nyssen, Jan

    2016-04-01

    With increasing population, producing more food and fibers has led to an expansion of the area under cultivation. For this, much attention is given to low-lying flat areas in search of suitable agricultural lands. The objectives of this paper are therefore: (1) to review the opportunities and challenges of natural resources in the marginal grabens for rural development; (2) to highlight the knowledge gaps and priorities in research and development in the marginal grabens, and (3) to supplement the literature review through repeat transect walks, focus group discussions and interviews across the western rift valley of northern Ethiopia. The paper shows that marginal grabens along the rift valleys are rich both in blue and green water resources due to their topographical and geological characteristics. Spate irrigation has been a growing water management practice to respond to soil moisture deficit. Besides, marginal grabens are fertile plains as a result of alluvial deposition that could be suitable for agricultural development. However, rainfall variability and groundwater withdrawal lead to graben basin closure and salinization. Notably, riverbed incisions and sediment deposition affects drainage systems and water supply in the marginal grabens. As a result, socioeconomic and natural capital of the marginal graben farmers are continuously threatened. Thus, the benefits of natural resources for rural development in the marginal grabens along the rift valley can be optimized if the current bottlenecks are converted into opportunities. A better understanding of the complex marginal graben system via a robust land evaluation framework will improve livelihoods of the communities that live in the (closed) marginal grabens. Keywords: population pressure, marginal grabens, endorheic lakes, salinization, Ethiopia

  19. Seasonal Water Balance Forecasts for Drought Early Warning in Ethiopia

    NASA Astrophysics Data System (ADS)

    Spirig, Christoph; Bhend, Jonas; Liniger, Mark

    2016-04-01

    Droughts severely impact Ethiopian agricultural production. Successful early warning for drought conditions in the upcoming harvest season therefore contributes to better managing food shortages arising from adverse climatic conditions. So far, however, meteorological seasonal forecasts have not been used in Ethiopia's national food security early warning system (i.e. the LEAP platform). Here we analyse the forecast quality of seasonal forecasts of total rainfall and of the meteorological water balance as a proxy for plant available water. We analyse forecast skill of June to September rainfall and water balance from dynamical seasonal forecast systems, the ECMWF System4 and EC-EARTH global forecasting systems. Rainfall forecasts outperform forecasts assuming a stationary climate mainly in north-eastern Ethiopia - an area that is particularly vulnerable to droughts. Forecasts of the water balance index seem to be even more skilful and thus more useful than pure rainfall forecasts. The results vary though for different lead times and skill measures employed. We further explore the potential added value of dynamically downscaling the forecasts through several dynamical regional climate models made available through the EU FP7 project EUPORIAS. Preliminary results suggest that dynamically downscaled seasonal forecasts are not significantly better compared with seasonal forecasts from the global models. We conclude that seasonal forecasts of a simple climate index such as the water balance have the potential to benefit drought early warning in Ethiopia, both due to its positive predictive skill and higher usefulness than seasonal mean quantities.

  20. Divorce in Ethiopia: the impact of early marriage and childlessness.

    PubMed

    Tilson, D; Larsen, U

    2000-07-01

    Forty-five per cent of first marriages in Ethiopia end in divorce within 30 years, and two-thirds of women who divorce do so within the first 5 years of marriage. This paper looks at two factors that may have an impact on the risk of divorce in Ethiopia: early age of first marriage, and childlessness within the first marriage. Data used were from the 1990 National Family and Fertility Survey conducted by the Government of Ethiopia. A total of 8757 women of reproductive age (15-49) were analysed. Life table analysis was used to determine the median age at first marriage, first birth and the median duration of marriage. Cox models were analysed to determine the differentials of divorce. The results of this analysis showed that both early age at marriage and childlessness have a significant impact on the risk of divorce. An inverse relationship was found between age at marriage and risk of divorce. Having a child within the first marriage also significantly reduced the risk of divorce. In addition, several cultural and socioeconomic variables were significant predictors of divorce. PMID:10979229

  1. Barriers to Cataract Surgical Uptake in Central Ethiopia

    PubMed Central

    Mehari, Zelalem Addisu; Zewedu, Redda Tekle Haimanot; Gulilat, Fitsum Bekele

    2013-01-01

    Purpose: The aim of this study was to assess the factors that delay surgical intervention in patients suffering from age related mature cataract in Ethiopia. Materials and Methods: A short term descriptive study was performed that evaluated patients with mature cataract presenting to outreach eye care clinics in rural central Ethiopia. Patients were interviewed to determine the reasons for delay in their cataract surgeries. Result: A total of 146 subjects (57 male and 89 females) with operable age related cataract were evaluated at 31 outreach clinics. Over 86% of the respondents were above 55 years of age, (range, 45–78 years). The male to female ratio was 1:1.5 and 30.2% of the subjects were blind bilaterally (best corrected visual acuity <3/60). The majority of the respondents were farmers (53.4%) and 86.3% were illiterate. The major factors that delayed cataract surgery included: Cost of surgery (91.8%), insufficient family income (78.1%), good vision in the fellow (unaffected) eye (39.7%), and the distance to hospital from their village (47.9%). Conclusion: Surgical cost, insufficient family income, and the distance to an eye care centre were the major factors delaying cataract surgery in rural Ethiopia. PMID:24014987

  2. Climatic trends over Ethiopia: regional signals and drivers

    USGS Publications Warehouse

    Jury, Mark R.; Funk, Christopher C.

    2013-01-01

    This study analyses observed and projected climatic trends over Ethiopia, through analysis of temperature and rainfall records and related meteorological fields. The observed datasets include gridded station records and reanalysis products; while projected trends are analysed from coupled model simulations drawn from the IPCC 4th Assessment. Upward trends in air temperature of + 0.03 °C year−1 and downward trends in rainfall of − 0.4 mm month−1 year−1 have been observed over Ethiopia's southwestern region in the period 1948-2006. These trends are projected to continue to 2050 according to the Geophysical Fluid Dynamics Lab model using the A1B scenario. Large scale forcing derives from the West Indian Ocean where significant warming and increased rainfall are found. Anticyclonic circulations have strengthened over northern and southern Africa, limiting moisture transport from the Gulf of Guinea and Congo. Changes in the regional Walker and Hadley circulations modulate the observed and projected climatic trends. Comparing past and future patterns, the key features spread westward from Ethiopia across the Sahel and serve as an early warning of potential impacts.

  3. Exploring Agro-Climatic Trends in Ethiopia Using CHIRPS

    NASA Astrophysics Data System (ADS)

    Pedreros, D. H.; Funk, C. C.; Brown, M. E.; Korecha, D.; Seid, Y. M.

    2015-12-01

    The Famine Early Warning Systems Network (FEWS NET) uses the Climate Hazards Group Infrared Precipitation with Stations (CHIRPS) to monitor agricultural food production in different regions of the world. CHIRPS is a 1981-present, 5 day, approximately 5km resolution, rainfall product based on a combination of geostationary satellite observations, a high resolution climatology and in situ station observations. Furthermore, FEWS NET has developed a gridded implementation of the Water Requirement Satisfaction Index (WRSI), a water balance measurement indicator of crop performance. This study takes advantage of the CHIRPS' long term period of record and high spatial and temporal resolution to examine agro-climatic trends in Ethiopia. We use the CHIRPS rainfall dataset to calculate the WRSI for the boreal spring and summer crop seasons, as well as for spring-summer rangelands conditions. We find substantial long term rainfall declines in the spring and summer seasons across southeastern and northeastern Ethiopia. Crop Model results indicate that rainfall declines in the cropped regions have been associated with water deficits during the critical grain filling periods in well populated and/or highly vulnerable parts of eastern Ethiopia. WRSI results in the pastoral areas indicate substantial reductions in rangeland health during the later part of the growing seasons. These health declines correspond to the regions of Somaliland and Afar that have experienced chronic severe food insecurity since 2010. Key words: CHIRPS, satellite estimated rainfall, agricultural production

  4. Afar unrest: the 2008 Alu eruption in the Erta `Ale volcanic system (Ethiopia)

    NASA Astrophysics Data System (ADS)

    Pagli, C.; Wright, T. J.; Ayele, A.; Barnie, T.

    2009-04-01

    The Alu volcano is located within the Erta ‘Ale volcanic system in northern Afar (Ethiopia), about 30 km to the north of the Erta ‘Ale volcano whose summit caldera hosts a lava lake. Aster, Hotspot and S02 emissions images formed on 3rd November, 2008 showed that a fissural eruption was occurring east of the Alu volcano. Here we present an InSAR study of the area, using data from four tracks of the Envisat satellite both in descending ad ascending orbits, also including data in Wide Swath acquisition mode. The interferograms span different time periods allowing us to separate pre-, co- and post-eruptive deformation. In particular, an acquisition made on 3rd November at 19:20 (the day of the eruption) is used to observe deformation over two different co-eruptive periods. The co-eruptive interferograms show two closely-spaced but distinct concentric deformation patterns, both consistent with deflation, on the Alu volcano and on another unnamed volcano 3 km south of Alu. Most deformation in both volcanoes occurred during the first part of 3rd November (until 19:20) but significant deflation, up to ~ 45 cm, is also observed in the following interferogram from 3rd November at 19:20 to 8th December. Interestingly, no significant pre-eruptive deformation was observed in the area, nor any deformation was observed at the Erta ‘Ale lava lake prior to, during or after the Alu eruption. Preliminary modelling results, using two deflating Mogi sources, suggest that the two shallow magma chambers at ~1-1.5 km depth deflated during the eruption, with a volume change of the sources of ~-0.01 km3. Lack of pre-eruptive deformation suggests that the erupted magma was sitting at shallow depth under the Alu volcanoes. The lava lake in the nearby Erta 'Ale volcano also indicates that shallow magma reservoirs are a common feature in the area. We plan to model the observed deformations using different models, i.e. sill, penny shaped crack and ellipsoidal source and to compare our

  5. New Borrelia species detected in ixodid ticks in Oromia, Ethiopia.

    PubMed

    Kumsa, Bersissa; Socolovschi, Cristina; Raoult, Didier; Parola, Philippe

    2015-04-01

    Little is known about Borrelia species transmitted by hard ticks in Ethiopia. The present study was conducted from November 2011 through March 2014 to address the occurrence and molecular identity of these bacteria in ixodid ticks infesting domestic animals in Oromia, Ethiopia. A total of 767 ixodid ticks collected from domestic animals were screened for Borrelia DNA by quantitative (q) real-time PCR followed by standard PCR and sequencing to identify the species. Overall, 3.8% (29/767) of the tested ticks were positive for Borrelia DNA, including 8/119 (6.7%) Amblyomma cohaerens, 1/42 (2.4%) Am. gemma, 3/53 (5.7%) Am. variegatum, 5/22 (22.7%) Amblyomma larvae, 3/60 (5%) Amblyomma nymphs, 2/139 (1.4%) Rhipicephalus (Boophilus) decoloratus, 2/31 (6.4%) Rh. decoloratus nymphs, and 5/118 (4.2%) Rh. pulchellus using 16S genus-specific qPCR. The prevalence of Borrelia DNA was significantly higher in genus Amblyomma (20/298, 6.7%) than in the genus Rhipicephalus (9/417, 2.1%) ticks (P=0.001). Sequencing of PCR products from the flaB and 16S rRNA genes of Borrelia spp. from Amblyomma ticks showed the presence of a new species between the relapsing fever and Lyme disease groups. However, Borrelia sp. detected in Rhipicephalus ticks clustered with B. theileri/B. lonestari. The human pathogenicity of the Borrelia sp. detected in Amblyomma ticks from Ethiopia has not yet been investigated, whereas the Borrelia sp. detected in Rhipicephalus ticks in our study is the causative agent of bovine borreliosis in cattle and may have veterinary importance in different parts of Ethiopia. Furthermore, the detection of previously unrecognized Borrelia species in Amblyomma and Rhipicephalus ticks in Ethiopia generates additional questions concerning the bacterial fauna in hard ticks and will prompt researchers to perform detailed studies for better understanding of ixodid ticks associated bacteria. PMID:25843811

  6. Lake Nasser and Toshka Lakes, Egypt

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Lake Nasser (center) and the Toshka Lakes (center left) glow emerald green and black in this MODIS true-color image acquired March 8, 2002. Located on and near the border of Egypt and Norther Sudan, these lakes are an oasis of water in between the Nubian (lower right) and Libyan Deserts (upper left). Also visible are the Red Sea (in the upper right) and the Nile River (running north from Lake Nasser). Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  7. Utah: Salt Lake Region

    Atmospheric Science Data Center

    2014-05-15

    article title:  Winter and Summer Views of the Salt Lake Region     View Larger Image Magnificent views of the region surrounding Salt Lake City, Utah are captured in these winter and summer images from the ...

  8. Lakes Ecosystem Services Online

    EPA Science Inventory

    Northeastern lakes provide valuable ecosystem services that benefit residents and visitors and are increasingly important for provisioning of recreational opportunities and amenities. Concurrently, however, population growth threatens lakes by, for instance, increasing nutrient ...

  9. Lake trout rehabilitation in Lake Ontario

    USGS Publications Warehouse

    Elrod, Joseph H.; O'Gorman, Robert; Schneider, Clifford P.; Eckert, Thomas H.; Schaner, Ted; Bowlby, James N.; Schleen, Larry P.

    1995-01-01

    Attempts to maintain the native lake trout (Salvelinus namaycush) population in Lake Ontario by stocking fry failed and the species was extirpated by the 1950s. Hatchery fish stocked in the 1960s did not live to maturity because of sea lamprey (Petromyzon marinus) predation and incidental commercial harvest. Suppression of sea lampreys began with larvicide treatments of Lake Ontario tributaries in 1971 and was enhanced when the tributaries of Oneida Lake and Lake Erie were treated in the 1980s. Annual stocking of hatchery fish was resumed with the 1972 year class and peaked at about 1.8 million yearlings and 0.3 million fingerlings from the 1985–1990 year classes. Survival of stocked yearlings declined over 50% in the 1980 s and was negatively correlated with the abundance of lake trout > 550 mm long (r = −0.91, P < 0.01, n = 12). A slot length limit imposed by the State of New York for the 1988 fishing season reduced angler harvest. Angler harvest in Canadian waters was 3 times higher in eastern Lake Ontario than in western Lake Ontario. For the 1977–1984 year classes, mean annual survival rate of lake trout age 6 and older was 0.45 (range: 0.35–0.56). In U.S. waters during 1985–1992, the total number of lake trout harvested by anglers was about 2.4 times greater than that killed by sea lampreys. The number of unmarked lake trout < 250 mm long in trawl catches in 1978–1992 was not different from that expected due to loss of marks and failure to apply marks at the hatchery, and suggested that recruitment of naturally-produced fish was nil. However, many of the obstacles which may have impeded lake trout rehabilitation in Lake Ontario during the 1980s are slowly being removed, and there are signs of a general ecosystem recovery. Significant recruitment of naturally produced lake trout by the year 2000, one interim objective of the rehabilitation plan for the Lake, may be achieved.

  10. Lake Layers: Stratification.

    ERIC Educational Resources Information Center

    Brothers, Chris; And Others

    This teacher guide and student workbook set contains two learning activities, designed for fifth through ninth grade students, that concentrate on lake stratification and water quality. In the activities students model the seasonal temperature changes that occur in temperate lakes and observe the resulting stratification of lake waters. Students…

  11. Great Lakes: Chemical Monitoring

    ERIC Educational Resources Information Center

    Delfino, Joseph J.

    1976-01-01

    The Tenth Great Lakes Regional Meeting of the American Chemical Society met to assess current Chemical Research activity in the Great Lakes Basin, and addressed to the various aspects of the theme, Chemistry of the Great Lakes. Research areas reviewed included watershed studies, atmospheric and aquatic studies, and sediment studies. (BT)

  12. Great Minds? Great Lakes!

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Chicago, IL. Great Lakes National Program Office.

    This book contains lesson plans that provide an integrated approach to incorporating Great Lakes environmental issues into elementary subjects. The book is divided into three subject areas: (1) History, which includes the origins of the Great Lakes, Great Lakes people, and shipwrecks; (2) Social Studies, which covers government, acid rain as a…

  13. A Killer Lake

    ERIC Educational Resources Information Center

    Horvath, Thomas

    2005-01-01

    In 1986, Lake Nyos, a volcanic lake in Cameroon, released a huge amount of carbon dioxide gas, killing over 1,700 people in the surrounding area. This case study, developed for use in a limnology or aquatic biology course, explores that event, introducing students to concepts relating to lake formation, thermal stratification, and dissolved gases.…

  14. Lake Effects: The Lake Superior Curriculum Guide.

    ERIC Educational Resources Information Center

    Beery, Tom; And Others

    This curriculum guide was launched in response to a need for Lake Superior-specific educational materials and contains lessons and activities that can be used to teach about Lake Superior. The lessons in this book are divided into four sections. Each of the first three sections has a background section that provides basic information about Lake…

  15. Discrete Wavelet Packet Transforms and volcanic tremor: method and application to Erta 'Ale, Ethiopia

    NASA Astrophysics Data System (ADS)

    Jones, J. P.; Carniel, R.; Malone, S.

    2005-12-01

    The time-varying properties of volcanic tremor demand advanced techniques capable of analyzing changes in both time and frequency domains. Specifically, rapid data preprocessing techniques with the ability to distinguish signal from noise are especially valuable in analyzing the temporal, spatial, and spectral properties of these signals. To this end, we use the Discrete Wavelet Packet Transform and the Best Shift Basis algorithm to select an orthonormal basis for continuous volcanic tremor data, then apply a simple statistical test to eliminate frequency bands that primarily consist of Gaussian white noise. We then use the Maximal Overlap Discrete Wavelet Packet Transform to compute and analyze features in the detail coefficients of each "signal" band. Because MODWPT detail coefficients are equivalent to a time series convolved with a zero phase filter, we apply standard polarization and amplitude-based location techniques to each frequency band's detail coefficients to analyze possible source locations and mechanisms. To demonstrate the usefulness of these techniques, we present a sample analysis of data from Erta 'Ale volcano, Ethiopia, recorded on a temporary network in November 2003. Data were sampled at 100 Hz and the DWPT was computed with the LA(16) wavelet to a maximum level of j = 7. The optimal basis for this data set consists of 54 frequency bands, but only 9 contain meaningful "signal" energy. We identify two frequency bands whose locations suggest a distributed source; three frequency bands whose signals may come from the lava lake itself; three high-frequency bands of scattered energy; and one very high frequency band of non-Gaussian instrument noise. Finally, we discuss optimization efforts, computational efficiency, and the feasibility of using similar wavelet methods to preprocess data in real time or near real time.

  16. Chloroquine-resistant Plasmodium vivax malaria in Debre Zeit, Ethiopia

    PubMed Central

    Teka, Hiwot; Petros, Beyene; Yamuah, Lawrence; Tesfaye, Gezahegn; Elhassan, Ibrahim; Muchohi, Simon; Kokwaro, Gilbert; Aseffa, Abraham; Engers, Howard

    2008-01-01

    Background Plasmodium vivax accounts for about 40% of all malaria infection in Ethiopia. Chloroquine (CQ) is the first line treatment for confirmed P. vivax malaria in the country. The first report of CQ treatment failure in P. vivax was from Debre Zeit, which suggested the presence of chloroquine resistance. Methods An in vivo drug efficacy study was conducted in Debre Zeit from June to August 2006. Eighty-seven patients with microscopically confirmed P. vivax malaria, aged between 8 months and 52 years, were recruited and treated under supervision with CQ (25 mg/kg over three days). Clinical and parasitological parameters were assessed during the 28 day follow-up period. CQ and desethylchloroquine (DCQ) blood and serum concentrations were determined with high performance liquid chromatography (HPLC) in patients who showed recurrent parasitaemia. Results Of the 87 patients recruited in the study, one was lost to follow-up and three were excluded due to P. falciparum infection during follow-up. A total of 83 (95%) of the study participants completed the follow-up. On enrolment, 39.8% had documented fever and 60.2% had a history of fever. The geometric mean parasite density of the patients was 7045 parasites/μl. Among these, four patients had recurrent parasitaemia on Day 28. The blood CQ plus DCQ concentrations of these four patients were all above the minimal effective concentration (> 100 ng/ml). Conclusion Chloroquine-resistant P. vivax parasites are emerging in Debre Zeit, Ethiopia. A multi-centre national survey is needed to better understand the extent of P. vivax resistance to CQ in Ethiopia. PMID:18959774

  17. Spotted fever group rickettsiae in ixodid ticks in Oromia, Ethiopia.

    PubMed

    Kumsa, Bersissa; Socolovschi, Cristina; Raoult, Didier; Parola, Philippe

    2015-02-01

    In Ethiopia, information on the transmission of human zoonotic pathogens through ixodid ticks remains scarce. To address the occurrence and molecular identity of spotted fever group rickettsiae using molecular tools, a total of 767 ixodid ticks belonging to thirteen different species were collected from domestic animals from September 2011 to March 2014. Rickettsia africae DNA was detected in 30.2% (16/53) Amblyommma variegatum, 28.6% (12/42) Am. gemma, 0.8% (1/119) Am. cohaerens, 18.2% (4/22) Amblyomma larvae, 6.7% (2/60) Amblyomma nymphs, 0.7% (1/139) Rhipicephalus (Boophilus) decoloratus and 25% (1/4) nymphs of Rh. (Bo.) decoloratus. A markedly low prevalence of R. africae was recorded in both Am. cohaerens and Rh. (Bo.) decoloratus (p<0.0001) compared with that in Am. variegatum and Am. gemma. The prevalence of R. africae was markedly low in the western districts (Gachi and Abdela) (p<0.0001); however, the prevalence of R. africae was relatively high in the central (Ada'a, Wolmara and Arsi) and eastern (Arero, Moyale and Yabelo) districts, where Am. variegatum and Am. gemma were predominantly associated with R. africae, respectively. R. aeschlimannii DNA was detected in 45.4% (5/11) Hyalomma marginatum rufipes and 2.2% (1/46) Hy. truncatum. Moreover, the first report of R. massiliae DNA in 1.9% (1/52) Rhipicephalus praetextatus ticks in Ethiopia is presented herein. Altogether, these results suggest that the transmission of spotted fever group rickettsiae through ixodid ticks is a potential risk for human health in different parts of Ethiopia. Clinicians in this country should consider these pathogens as a potential cause of febrile illness in patients. PMID:25262832

  18. Theileria infection in domestic ruminants in northern Ethiopia.

    PubMed

    Gebrekidan, Hagos; Hailu, Asrat; Kassahun, Aysheshm; Rohoušová, Iva; Maia, Carla; Talmi-Frank, Dalit; Warburg, Alon; Baneth, Gad

    2014-02-24

    Piroplasmosis caused by different tick-borne hemoprotozoan parasites of the genera Theileria and Babesia is among the most economically important infections of domestic ruminants in sub-Saharan Africa. A survey for piroplasm infection was conducted in three locations in Northern Ethiopia. Of 525 domestic ruminants surveyed, 80% of the cattle, 94% of the sheep and 2% of the goats were positive for different Theileria spp. based on PCR of blood followed by DNA sequencing. Sheep had a significantly higher rate of infection compared with cattle (P<0.0003) and both sheep and cattle had higher rates of infection compared to goats (P<0.0001). Four species of Theileria were detected in cattle: T. velifera, T. mutans, T. orientalis complex and T. annulata with infection rates of 66, 8, 4, and 2%, respectively. This is the first report of T. annulata, the cause of Tropical Theileriosis in Ethiopia. Of the two Theileria spp. detected in small ruminants, T. ovis was highly prevalent (92%) in sheep and rare in goats (1.5%) whereas T. seperata was infrequent in sheep (2%) and rare in goats (0.4%). None of the animals were positive for Babesia spp.; however, Sarcocystis capracanis and S. tenella were detected in one goat and a sheep, respectively. The widespread distribution of Theileria spp. among cattle in northern Ethiopia including the virulent T. annulata and more mildly pathogenic T. mutans and T. orientalis, and the high infection rate in sheep with the usually sub-clinical T. ovis indicate extensive exposure to ticks and transmission of piroplasms with an important economic impact. PMID:24360645

  19. Differentiating flow, melt, or fossil seismic anisotropy beneath Ethiopia

    NASA Astrophysics Data System (ADS)

    Hammond, J. O. S.; Kendall, J.-M.; Wookey, J.; Stuart, G. W.; Keir, D.; Ayele, A.

    2014-05-01

    is a region where continental rifting gives way to oceanic spreading. Yet the role that pre-existing lithospheric structure, melt, mantle flow, or active upwellings may play in this process is debated. Measurements of seismic anisotropy are often used to attempt to understand the contribution that these mechanisms may play. In this study, we use new data in Afar, Ethiopia along with legacy data across Ethiopia, Djibouti, and Yemen to obtain estimates of mantle anisotropy using SKS-wave splitting. We show that two layers of anisotropy exist, and we directly invert for these. We show that fossil anisotropy with fast directions oriented northeast-southwest may be preserved in the lithosphere away from the rift. Beneath the Main Ethiopian Rift and parts of Afar, anisotropy due to shear segregated melt along sharp changes in lithospheric thickness dominates the shear-wave splitting signal in the mantle. Beneath Afar, away from regions with significant lithospheric topography, melt pockets associated with the crustal and uppermost mantle magma storage dominate the signal in localized regions. In general, little anisotropy is seen in the uppermost mantle beneath Afar suggesting melt retains no preferential alignment. These results show the important role melt plays in weakening the lithosphere and imply that as rifting evolves passive upwelling sustains extension. A dominant northeast-southwest anisotropic fast direction is observed in a deeper layer across all of Ethiopia. This suggests that a conduit like plume is lacking beneath Afar today, rather a broad flow from the southwest dominates flow in the upper mantle.

  20. Surface water risk assessment of pesticides in Ethiopia.

    PubMed

    Teklu, Berhan M; Adriaanse, Paulien I; Ter Horst, Mechteld M S; Deneer, John W; Van den Brink, Paul J

    2015-03-01

    Scenarios for future use in the pesticide registration procedure in Ethiopia were designed for 3 separate Ethiopian locations, which are aimed to be protective for the whole of Ethiopia. The scenarios estimate concentrations in surface water resulting from agricultural use of pesticides for a small stream and for two types of small ponds. Seven selected pesticides were selected since they were estimated to bear the highest risk to humans on the basis of volume of use, application rate and acute and chronic human toxicity, assuming exposure as a result of the consumption of surface water. Potential ecotoxicological risks were not considered as a selection criterion at this stage. Estimates of exposure concentrations in surface water were established using modelling software also applied in the EU registration procedure (PRZM and TOXSWA). Input variables included physico-chemical properties, and data such as crop calendars, irrigation schedules, meteorological information and detailed application data which were specifically tailored to the Ethiopian situation. The results indicate that for all the pesticides investigated the acute human risk resulting from the consumption of surface water is low to negligible, whereas agricultural use of chlorothalonil, deltamethrin, endosulfan and malathion in some crops may result in medium to high risk to aquatic species. The predicted environmental concentration estimates are based on procedures similar to procedures used at the EU level and in the USA. Addition of aquatic macrophytes as an ecotoxicological endpoint may constitute a welcome future addition to the risk assessment procedure. Implementation of the methods used for risk characterization constitutes a good step forward in the pesticide registration procedure in Ethiopia. PMID:25481716

  1. Eco-epidemiology of visceral leishmaniasis in Ethiopia.

    PubMed

    Gadisa, Endalamaw; Tsegaw, Teshome; Abera, Adugna; Elnaiem, Dia-Eldin; den Boer, Margriet; Aseffa, Abraham; Jorge, Alvar

    2015-01-01

    Visceral leishmaniasis (VL, Kala-azar) is one of the growing public health challenges in Ethiopia with over 3.2 million people at risk and estimated up to 4000 new cases per year. Historically, VL was known as the diseases of the lowlanders; in the lower and upper Kola agro-ecological zones of Ethiopia. The 2005-07 out breaks in highlands of Libo Kemkem and Fogera, in the Woina Degas, that affected thousands and claimed the life of hundreds misdiagnosed as drug resistance malaria marked that VL is no more the problem of the lowlanders. The Kola (lower and upper) and the Woina Dega are the most productive agroecological zones, supporting both the ongoing and planned expansions of large or small scale agriculture and/or agriculture based industries. Thus, the (re)emergence of VL is not only a public health and social problem but also have a direct implication on the country's economy and further development. Thus is high time for its control and/or elimination. Yet, the available data seem incomplete to plan for a cost-effective and efficient VL control strategy: there is a need to update data on vector behaviour in specific ecosystems and the roles of domestic animals need to be ascertained. The effectiveness and social acceptability of available vector control tools need be evaluated. There is a need for identifying animal reservoir(s), or establish the absence of zoonosis in Ethiopia. The planning of prevention of (re)emergence and spread of VL to areas adjacent to endemic foci need be supported with information from spatio-temporal mapping. In affected communities, available data showed that their knowledge about VL is generally very low. Thus, well designed studies to identify risk factors, as well as better tools for social mobilization with the understanding of their knowledge, aptitude and practice towards VL are necessary. PMID:26187584

  2. Does Economic Growth Reduce Childhood Undernutrition in Ethiopia?

    PubMed Central

    Biadgilign, Sibhatu; Shumetie, Arega; Yesigat, Habtamu

    2016-01-01

    Background Policy discussions and debates in the last couple of decades emphasized efficiency of development policies for translating economic growth to development. One of the key aspects in this regard in the developing world is achieving improved nutrition through economic development. Nonetheless, there is a dearth of literature that empirically verifies the association between economic growth and reduction of childhood undernutrition in low- and middle-income countries. Thus, the aim of the study is to assess the interplay between economic growth and reduction of childhood undernutrition in Ethiopia. Methods The study used pooled data of three rounds (2000, 2005 and 2010) from the Demographic and Health Surveys (DHS) of Ethiopia. A multilevel mixed logistic regression model with robust standard errors was utilized in order to account for the hierarchical nature of the data. The dependent variables were stunting, underweight, and wasting in children in the household. The main independent variable was real per capita income (PCI) that was adjusted for purchasing power parity. This information was obtained from World Bank. Results A total of 32,610 children were included in the pooled analysis. Overall, 11,296 (46.7%) [46.0%-47.3%], 8,197(33.8%) [33.2%-34.4%] and 3,175(13.1%) [12.7%-13.5%] were stunted, underweight, and wasted, respectively. We found a strong correlation between prevalence of early childhood undernutrition outcomes and real per capita income (PCI). The proportions of stunting (r = -0.1207, p<0.0001), wasting (r = -0.0338, p<0.0001) and underweight (r = -0.1035, p<0.0001) from the total children in the household were negatively correlated with the PCI. In the final model adjustment with all the covariates, economic growth substantially reduced stunting [β = -0.0016, SE = 0.00013, p<0.0001], underweight [β = -0.0014, SE = 0.0002, p<0.0001] and wasting [β = -0.0008, SE = 0.0002, p<0.0001] in Ethiopia over a decade. Conclusion Economic growth

  3. Erosion-driven environmental degradation in Tigray, Ethiopia

    NASA Astrophysics Data System (ADS)

    Strong, N.; Willenbring, J.; Terwilliger, V. J.

    2009-12-01

    The Tigray Plateau of Northern Ethiopia is a key region for the study of relationships between climate, land use and the rise and fall of complex societies. Tigray has been the home to a succession of highly developed and powerful kingdoms and has a long history of agriculture, dating back to ~ 6,000 yrs BP. Unfortunately its mountainous topography makes the region particularly susceptible to accelerated erosion and mass wasting from intense land use practices and its location along the ITCZ and the East African rift system make the area prone to climatic changes. Today, after 6,000 years of agriculture, of which the last ~3,000 years have involved intense land use, the once fertile Tigray region is now highly degraded with frequent famine and some of the highest rates of soil erosion in the world. We find, based on a comparison of background (long-term) and anthropogenic short-term time-averaged erosion rates that deforestation and a transition to cropland farming likely increased rates of localized upstream erosion and downstream deposition by up to an order of magnitude greater than the natural background rates. We define three distinct periods of note in terms of rates and patterns of Holocene erosion and deposition in the east Tigray Plateau of Ethiopia. First, we take note of the depositional record and paleo-flaural reconstructions of a time of regional climate change yet little landuse change in Ethiopia, 7,500 - 6,000 cal yr BP (Late Prehistory and the beginning of the migration of peoples out of the Sahara and into Sudan and the highlands of Ethiopia). Second, we look at the stratigraphic record of the beginning of intense landuse and cultivation in the gently sloping lowland areas, 3200 -2300 Cal yrs BP (Pre-Aksumite period and the establishment of the first large centralized government in the upper Highlands). Third, we identify from the geological record a period of deforestation and farming of higher elevation, steep sloped hillsides and terraces 2300

  4. Food of lake trout in Lake Superior

    USGS Publications Warehouse

    Dryer, William R.; Erkkila, Leo F.; Tetzloff, Clifford L.

    1965-01-01

    Stomachs were examined from 1,492 lake trout and 83 siscowets collected from Lake Superior. Data are given on the food of lake trout of legal size (17 inches or longer) by year, season, and depth of water, and on the relation between food and size among smaller lake trout. Fish contributed 96.7 to 99.9 per cent of the total volume of food in the annual samples. Ciscoes (Coregonus spp.) were most common (52.2 to 87.5 per cent of the volume) in 1950 to 1953 and American smelt ranked first (65.6 per cent of the volume) in 1963. Cottids were in 8.9 to 12.3 per cent of the stomachs in 1950 to 1953 but in only 4.3 per cent in 1963. Insects ranked second to fish in occurrence (9.6 per cent for the combined samples) and crustaceans followed at 3.9 per cent. The greatest seasonal changes in the food of lake trout were among fish caught at 35 fathoms and shallower. The occurrence of Coregonus increased from 34.6 per cent in February-March to 71.1 per cent in October-December. Smelt were in 76.9 per cent of the stomachs in February-March but in only 2.2 per cent in October-December. Cottids, Mysis relicta, and insects were most common in the July-September collections. Lake trout taken at depths greater than 35 fathoms had eaten a higher percentage of Cottidae and Coregonus than had those captured in shallower water. Smelt, ninespine sticklebacks, Mysis, and insects were more frequent in stomachs of lake trout from less than 35 fathoms. Crustaceans comprised more than 70 per cent of the total volume of food for 4.0- to 7.9-inch lake trout but their importance decreased as the lake trout grew larger. Pontoporeia affinis was the most common in the stomachs of 4.0- to 6.9-inch lake trout and Mysis held first rank at 7.0 to 12.9 inches. Ostracods were important only to 4.0- to 4.9-inch lake trout. As the lake trout became larger, the importance of fish grew from 4.4-per cent occurrence at 5.0 to 5.9 inches to 93.9 per cent at 16.0 to 16.9 inches. Smelt were most commonly eaten by

  5. Help-Seeking Behavior for Children with Acute Respiratory Infection in Ethiopia: Results from 2011 Ethiopia Demographic and Health Survey

    PubMed Central

    2015-01-01

    Background Acute respiratory infection is a major contributor to morbidity and mortality among children under five years of age in Ethiopia. While facilities have been implemented to address this problem they are underused due to a lack in help-seeking behavior. This study investigates factors related to the help-seeking behavior of mothers for children with acute respiratory infection using data from the 2011 Ethiopia Demographic and Health Survey. Methods Data on 11,030 children aged 0–59 months obtained through interviewing women aged 15–49 years throughout Ethiopia was available. Descriptive statistics and logistic regression analyses were performed to determine which factors are related to help-seeking behavior for acute respiratory infection. Results In the two weeks prior to the survey, 773(7%) of the children were reported to have symptoms of acute respiratory infection while treatment was sought for only 209 (27.2%). The odds ratio for acute respiratory infection was 1.6 (95% CI: 1.2–2.0) for rural residence with only 25.2% of these mothers seeking help compared to 46.4% for mothers with an urban residence. Smaller family size, younger mothers’ age and having had prenatal care had a statistically significant odds ratio greater than 1 for both urban and rural residences. Highest wealth index had a statistically significant odds ratio greater than 1 for rural residence only, whereas primary education or higher had a statistically significant odds ratio greater than 1 for urban residence. Conclusions Children from rural areas are more at risk for acute respiratory infection while their mothers are less likely to seek help. Nevertheless, there is also underuse of available services in urban areas. Interventions should target mothers with less education and wealth and older mothers. Expanding prenatal care among these groups would encourage a better use of available facilities and subsequently better care for their children. PMID:26560469

  6. Nonlinear vegetation cover changes in the North Ethiopian Highlands: Evidence from the Lake Ashenge closed basin.

    PubMed

    Lanckriet, Sil; Rucina, Stephen; Frankl, Amaury; Ritler, Alfons; Gelorini, Vanessa; Nyssen, Jan

    2015-12-01

    Vegetation cover changes in African drylands are often thought to result from population growth, social factors and aridification. Here we show that long-term vegetation proxy records can help disentangling these main driving factors. Taking the case of North Ethiopia, we performed an integrated investigation of land cover changes over the last four centuries around the endorheic Lake Ashenge, as derived from pollen analysis and repeat photography complemented with information from historical sources. Pollen and sediment analysis of radiocarbon-dated lake deposits shows a phase of environmental destabilization during the 18th century, after a more stable previous period. This is evidenced by decreases of tree pollen (Juniperus, Olea, Celtis, Podocarpus<5%), increases in Poaceae (>40%) and deposition of coarser silt lake sediments (>70%). Quantitative analysis of 30 repeated landscape photographs around the lake indicates a gradual decline of the vegetation cover since a relative maximum during the mid-19th Century. Vegetation cover declined sharply between the 1950s and the 1980s, but has since begun to recover. Overall, the data from around Lake Ashenge reveal a nonlinear pattern of deforestation and forest regrowth with several periods of vegetation cover change over the past four centuries. While there is forcing of regional drought and the regional land tenure system, the cyclic changes do not support a simplified focus on aridification or population growth. PMID:26117500

  7. Water quality of Lake Austin and Town Lake, Austin, Texas

    SciTech Connect

    Andrews, F.L.; Wells, F.C.; Shelby, W.J.; McPherson, E.M.

    1988-01-01

    Lake Austin and Town Lake are impoundments on the Colorado River in Travis County, central Texas, and are a source of water for municipal industrial water supplies, electrical-power generation, and recreation for more than 500,000 people in the Austin metropolitan area. Small vertical temperature variations in both lakes were attributed to shallow depths in the lakes and short retention times of water in the lakes during the summer months. The largest areal variations in dissolved oxygen generally occur in Lake Austin during the summer as a result of releases of water from below the thermocline in Lake Travis. Except for iron, manganese, and mercury, dissolved concentrations of trace elements in water collected from Lake Austin and Town Lake did not exceed the primary or secondary drinking water standards set by the US Environmental Protection Agency. Little or no effect of stormwater runoff on temperature, dissolved oxygen, or minor elements could be detected in either Lake Austin or Town Lake. Little seasonal or areal variation was noted in nitrogen concentrations in Lake Austin or Town lake. Total phosphorus concentrations generally were small in both lakes. Increased concentrations of nitrogen and phosphorus were detected after storm runoff inflow in Town Lake, but not in Lake Austin; densities of fecal-coliform bacteria increased in Lake Austin and Town Lake, but were substantially greater in Town Lake than in Lake Austin. 18 refs., 38 figs., 59 tabs.

  8. Lake trout rehabilitation in Lake Huron

    USGS Publications Warehouse

    Eshenroder, Randy L.; Payne, N. Robert; Johnson, James E.; Bowen, Charles, II; Ebener, Mark P.

    1995-01-01

    Efforts to restore lake trout (Salvelinus namaycush) in Lake Huron after their collapse in the 1940s were underway in the early 1970s with completion of the first round of lampricide applications in tributary streams and the stocking of several genotypes. We assess results of rehabilitation and establish a historical basis for comparison by quantifying the catch of spawning lake trout from Michigan waters in 1929-1932. Sixty-eight percent of this catch occurred in northern waters (MH-1) and most of the rest (15%) was from remote reefs in the middle of the main basin. Sea lampreys (Petromyzon marinus) increased in the early 1980s in the main basin and depressed spawning populations of lake trout. This increase was especially severe in northern waters and appeared to be associated with untreated populations in the St. Marys River. Excessive commercial fishing stemming from unresolved treaty rights also contributed to loss of spawning fish in northern Michigan waters. Seneca-strain lake trout did not appear to be attacked by sea lampreys until they reached a size > 532 mm. At sizes > 632 mm, Seneca trout were 40-fold more abundant than the Marquette strain in matched-planting experiments. Natural reproduction past the fry stage has occurred in Thunder Bay and South Bay, but prospects for self-sustaining populations of lake trout in the main basin are poor because sea lampreys are too abundant, only one side of the basin is stocked, and stocking is deferred to allow commercial gillnetting in areas where most of the spawning occurred historically. Backcross lake trout, a lake trout x splake (s. Fontinalis x s. Namaycush) hybrid, did not reproduce in Georgian Bay, but this genotype is being replaced with pure-strain lake trout, whose early performance appears promising.

  9. Hydrologic modelling for Lake Basaka: development and application of a conceptual water budget model.

    PubMed

    Dinka, Megersa O; Loiskandl, Willibald; Ndambuki, Julius M

    2014-09-01

    Quantification of fluxes of water into and out of terminal lakes like Basaka has fundamental challenges. This is due to the fact that accurate measurement and quantification of most of the parameters of a lake's hydrologic cycle are difficult. Furthermore, quantitative understanding of the hydrologic systems and hence, the data-intensive modelling is difficult in developing countries like Ethiopia due to limitation of sufficient recorded data. Therefore, formulation of a conceptual water balance model is extremely important as it presents a convenient analytical tool with simplified assumptions to simulate the magnitude of unknown fluxes. In the current study, a conceptual lake water balance model was systematically formulated, solved, calibrated, and validated successfully. Then, the surface water and groundwater interaction was quantified, and a mathematical relationship developed. The overall agreement between the observed and simulated lake stage at monthly time step was confirmed based on the standard performance parameters (R(2), MAE, RMSE, E(f)). The result showed that hydrological water balance of the lake is dominated by the groundwater (GW) component. The net GW flux in recent period (post-2000s) accounts about 56% of the total water inflow. Hence, GW plays a leading role in the hydrodynamics and existence of Lake Basaka and is mostly responsible for the expansion of the lake. Thus, identification of the potential sources/causes for the GW flux plays a leading role in order to limit the further expansion of the lake. Measurement of GW movement and exchange in the area is a high priority for future research. PMID:24816590

  10. Maternal risk factors for childhood anaemia in Ethiopia.

    PubMed

    Habte, Dereje; Asrat, Kalid; Magafu, Mgaywa G M D; Ali, Ibrahim M; Benti, Tadele; Abtew, Wubeshet; Tegegne, Girma; Abera, Dereje; Shiferaw, Solomon

    2013-09-01

    A total of 8260 children between the ages of 6-59 months were analyzed to identify the risk factors associated with childhood anaemia in Ethiopia. The overall mean (SD/standard deviation) haemoglobin (Hgb) level among the under-five children was 10.7 (2.2) g/dl and 50.3% were anaemic. Childhood anaemia demonstrated an increasing trend with maternal anaemia levels of mild, moderate and severe anaemia: odds ratio of 1.82, 2.16 and 3.73 respectively (p< 0.01). Children whose mothers had no formal education were 1.38 times more likely to be anaemic (p<0.01). The poorest and poorer wealth index groups had 1.52 and 1.25 increased odds of childhood anaemia respectively (p< 0.01). Childhood anaemia in Ethiopia is a severe public health problem. Maternal anaemia and socio-economic status were found to be associated with anaemia in children. A holistic approach of addressing mothers and children is of paramount importance. PMID:24069773

  11. Stigma against Tuberculosis Patients in Addis Ababa, Ethiopia

    PubMed Central

    Tadesse, Sebsibe

    2016-01-01

    Background Stigma attached to tuberculosis contributes to the limited effectiveness of current TB control approaches. However, there is a dearth of studies that explore the causes of stigma attached to tuberculosis and its effects on patients and tuberculosiscontrol programs in Ethiopia. Methods An institution-based qualitative study was conducted at St. Peter Tuberculosis Specialized Hospital in Addis Ababa, Ethiopia from July to August, 2015. Ten in-depth interviews and 6 key-informant interviews were carried out among tuberculosis patients and healthcare workers, respectively.The Open Code computer software package was used to analyze the data thematically. Results The study revealed that fear of infection and inappropriate health education messages by media were the main causes of tuberculosis stigma. The patients experienced isolation within their family and community, separation, and financial crisis. The stigma attached to tuberculosis may contribute to delayed healthcare seeking, poor treatment adherence, and poor prognosis. Conclusion Interventions thatreduce the stigma attached to tuberculosis should target on areas, such as creating community awareness, patient counseling on problem-solving and emotional skills, preparing culturally sensitive and scientifically sound media messages, providing financial support for the patients, and enhancing the qualities of the healthcare workers, such as empathy, concern, respect for the patient and cultural sensitivity. PMID:27054714

  12. Regionalization and Prediction of Seasonal Precipitation in Ethiopia

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Block, P.

    2014-12-01

    Rainfed agriculture continues to be an important part of Ethiopia's livelihoods and economy. Highly variable inter-annual precipitation, however, presents a serious challenge to sustainable production and subsistence survival. An improved understanding of what drives hydroclimatic extremes and an effective prediction system may help to buffer resulting impacts through improved decision-making. Precipitation data from the National Meteorological Agency at 0.1 x 0.1 grids for 1983 - 2011 during the June-September rainy season over western Ethiopia is evaluated through a cluster analysis to investigate homogeneous regions with similar rainfall patterns for subsequent prediction of seasonal precipitation for each region. A k-means clustering method is applied with the optimal number of clusters (K) selected by the within cluster sum of square errors (WSS) metric. Homogenous regions are defined with relatively clear and smooth boundaries, low inter-cluster correlations, and high intra-cluster correlations. The precipitation prediction models are statistically based, with a seasonal total prediction for each cluster; grid-based predictions are subsequently conditioned on the cluster level prediction through regression. Prospective model predictors include large-scale ocean-land-atmospheric climate variables and local variables and conditions. These predictions will be used in economic and water management models.

  13. Soil erosion assessment and control in Northeast Wollega, Ethiopia

    NASA Astrophysics Data System (ADS)

    Adugna, A.; Abegaz, A.; Cerdà, A.

    2015-12-01

    Soil erosion is the main driver of land degradation in Ethiopia, and in the whole region of East Africa. This study was conducted at the Northeast Wollega in West Ethiopia to estimate the soil losses by means of the Revised Universal Soil Loss Equation (RUSLE). The purpose of this paper is to identify erosion spot areas and target locations for appropriate development of soil and water conservation measures. Fieldwork and household survey were conducted to identify major determinants of soil erosion control. Six principal factors were used to calculate soil loss per year, such as rainfallerosivity, soil erodiblity, slope length, slope steepness, crop management and erosion-control practices. The soil losses have shown spatio-temporal variations that range from 4.5 Mg ha-1 yr-1 in forest to 65.9 Mg ha-1 yr-1 in cropland. Results from the analysis of stepwise multiple linear regression show that sustainable soil erosion control are determined byknowledge of farmers about soil conservation, land tenure security and off-farm income at community level. Thus, policy aim at keeping land productivity will need to focus on terracing, inter-cropping and improved agro-forestry practices.

  14. Natural infection of bats with Leishmania in Ethiopia.

    PubMed

    Kassahun, Aysheshm; Sadlova, Jovana; Benda, Petr; Kostalova, Tatiana; Warburg, Alon; Hailu, Asrat; Baneth, Gad; Volf, Petr; Votypka, Jan

    2015-10-01

    The leishmaniases, a group of diseases with a worldwide-distribution, are caused by different species of Leishmania parasites. Both cutaneous and visceral leishmaniasis remain important public health problems in Ethiopia. Epidemiological cycles of these protozoans involve various sand fly (Diptera: Psychodidae) vectors and mammalian hosts, including humans. In recent years, Leishmania infections in bats have been reported in the New World countries endemic to leishmaniasis. The aim of this study was to survey natural Leishmania infection in bats collected from various regions of Ethiopia. Total DNA was isolated from spleens of 163 bats belonging to 23 species and 18 genera. Leishmania infection was detected by real-time (RT) PCR targeting a kinetoplast (k) DNA and internal transcribed spacer one (ITS1) gene of the parasite. Detection was confirmed by sequencing of the PCR products. Leishmania kDNA was detected in eight (4.9%) bats; four of them had been captured in the Aba-Roba and Awash-Methara regions that are endemic for leishmaniasis, while the other four specimens originated from non-endemic localities of Metu, Bedele and Masha. Leishmania isolates from two bats were confirmed by ITS1 PCR to be Leishmania tropica and Leishmania major, isolated from two individual bats, Cardioderma cor and Nycteris hispida, respectively. These results represent the first confirmed observation of natural infection of bats with the Old World Leishmania. Hence, bats should be considered putative hosts of Leishmania spp. affecting humans with a significant role in the transmission. PMID:26232657

  15. New species from Ethiopia further expands Middle Pliocene hominin diversity.

    PubMed

    Haile-Selassie, Yohannes; Gibert, Luis; Melillo, Stephanie M; Ryan, Timothy M; Alene, Mulugeta; Deino, Alan; Levin, Naomi E; Scott, Gary; Saylor, Beverly Z

    2015-05-28

    Middle Pliocene hominin species diversity has been a subject of debate over the past two decades, particularly after the naming of Australopithecus bahrelghazali and Kenyanthropus platyops in addition to the well-known species Australopithecus afarensis. Further analyses continue to support the proposal that several hominin species co-existed during this time period. Here we recognize a new hominin species (Australopithecus deyiremeda sp. nov.) from 3.3-3.5-million-year-old deposits in the Woranso-Mille study area, central Afar, Ethiopia. The new species from Woranso-Mille shows that there were at least two contemporaneous hominin species living in the Afar region of Ethiopia between 3.3 and 3.5 million years ago, and further confirms early hominin taxonomic diversity in eastern Africa during the Middle Pliocene epoch. The morphology of Au. deyiremeda also reinforces concerns related to dentognathic (that is, jaws and teeth) homoplasy in Plio-Pleistocene hominins, and shows that some dentognathic features traditionally associated with Paranthropus and Homo appeared in the fossil record earlier than previously thought. PMID:26017448

  16. Participatory Forest Management in Ethiopia: Learning from Pilot Projects

    NASA Astrophysics Data System (ADS)

    Ameha, Aklilu; Larsen, H. O.; Lemenih, Mulugeta

    2014-04-01

    Different arrangements of decentralized forest management have been promoted as alternatives to centralized and top down approaches to halt tropical deforestation and forest degradation. Ethiopia is one of the countries piloting one of these approaches. To inform future programs and projects it is essential to learn from existing pilots and experiences. This paper analyses five of the pilot participatory forest management (PFM) programs undertaken in Ethiopia. The study is based on the Forest User Group (FUG) members' analyses of the programs using selected outcome variables: forest income, change in forest conditions, forest ownership feelings and effectiveness of FUGs as forest managing institutions. These variables were assessed at three points in time—before the introduction of PFM, during the project implementation and after the projects ended. Data were collected using group discussions, key informant interviews and transect walks through the PFM forests. The results show that in all of the five cases the state of the forest is perceived to have improved with the introduction of PFM, and in four of the cases the improvement was maintained after projects ended. Regulated access to the forests following introduction of PFM was not perceived to have affected forest income negatively. There are, however, serious concerns about the institutional effectiveness of the FUGs after projects ended, and this may affect the success of the PFM approach in the longer term.

  17. Patterns of caesarean-section delivery in Addis Ababa, Ethiopia

    PubMed Central

    Mashalla, Yohana J.S.; Thupayagale-Tshweneagae, Gloria

    2016-01-01

    Setting The study was conducted in Addis Ababa, the capital city of Ethiopia. Specifically, it was conducted in all healthcare facilities offering maternity and obstetric services. Objective The objective of the study was to explore the patterns of caesarean-section (CS) delivery in Addis Ababa. Methods A cross-sectional survey was carried out between December 2013 and January 2014. The population for the study were women aged between 15 and 19 years of age who had given birth in the last 1–3 years before the date of data collection. The Census and Survey Processing System software was used for data capturing and analysing both descriptive and inferential statistics using Statistical Package for Social Sciences version 20.0. Results Amongst the 835 women who delivered at health facilities, 19.2% had given birth by CS. The prevalence of CS based on medical indication was 91.3%. However, 6.9% of CS performed had no medical indication. Private health facilities performed more CSs than public health facilities, 41.1% and 11.7% respectfully. CS was high amongst women of higher socio-economic standing. Conclusion Overall, CS deliveries rate in Ethiopia is above the rate recommended by the World Health Organisation. Because socio-economic factors influence CS delivery, governments should play a key role in regulating performance of CSs in private institutions. PMID:27542289

  18. Dynamically downscaled multi-model ensemble seasonal forecasts over Ethiopia

    NASA Astrophysics Data System (ADS)

    Asharaf, Shakeel; Fröhlich, Kristina; Fernandez, Jesus; Cardoso, Rita; Nikulin, Grigory; Früh, Barbara

    2016-04-01

    Truthful and reliable seasonal rainfall predictions have an important social and economic value for the east African countries as their economy is highly dependent on rain-fed agriculture and pastoral systems. Only June to September (JJAS) seasonal rainfall accounts to more than 80% crop production in Ethiopia. Hence, seasonal foresting is a crucial concern for the region. The European Provision of Regional Impact Assessment on a seasonal to decadal timescale (EUPORIAS) project offers a common framework to understand hindcast uncertainties through the use of multi-model and multi-member simulations over east Africa. Under this program, the participating regional climate models (RCMs) were driven by the atmospheric-only version of the ECEARTH global climate model, which provides hindcasts of a five-months period (May to September) from 1991-2012. In this study the RCMs downscaled rainfall is evaluated with respect to the observed JJAS rainfall over Ethiopia. Both deterministic and probabilistic based forecast skills are assessed. Our preliminary results show the potential usefulness of multi-model ensemble simulations in forecasting the seasonal rainfall over the region.

  19. The burden of neglected tropical diseases in Ethiopia, and opportunities for integrated control and elimination

    PubMed Central

    2012-01-01

    Background Neglected tropical diseases (NTDs) are a group of chronic parasitic diseases and related conditions that are the most common diseases among the 2·7 billion people globally living on less than US$2 per day. In response to the growing challenge of NTDs, Ethiopia is preparing to launch a NTD Master Plan. The purpose of this review is to underscore the burden of NTDs in Ethiopia, highlight the state of current interventions, and suggest ways forward. Results This review indicates that NTDs are significant public health problems in Ethiopia. From the analysis reported here, Ethiopia stands out for having the largest number of NTD cases following Nigeria and the Democratic Republic of Congo. Ethiopia is estimated to have the highest burden of trachoma, podoconiosis and cutaneous leishmaniasis in sub-Saharan Africa (SSA), the second highest burden in terms of ascariasis, leprosy and visceral leishmaniasis, and the third highest burden of hookworm. Infections such as schistosomiasis, trichuriasis, lymphatic filariasis and rabies are also common. A third of Ethiopians are infected with ascariasis, one quarter is infected with trichuriasis and one in eight Ethiopians lives with hookworm or is infected with trachoma. However, despite these high burdens of infection, the control of most NTDs in Ethiopia is in its infancy. In terms of NTD control achievements, Ethiopia reached the leprosy elimination target of 1 case/10,000 population in 1999. No cases of human African trypanosomiasis have been reported since 1984. Guinea worm eradication is in its final phase. The Onchocerciasis Control Program has been making steady progress since 2001. A national blindness survey was conducted in 2006 and the trachoma program has kicked off in some regions. Lymphatic Filariasis, podoconiosis and rabies mapping are underway. Conclusion Ethiopia bears a significant burden of NTDs compared to other SSA countries. To achieve success in integrated control of NTDs, integrated mapping

  20. View of Lake Sabrina Dam and Lake Sabrina from east ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of Lake Sabrina Dam and Lake Sabrina from east ridge showing spillway at photo center, view southwest - Bishop Creek Hydroelectric System, Plant 2, Lake Sabrina Dam, Bishop Creek, Bishop, Inyo County, CA

  1. Environmental change and human occupation of southern Ethiopia and northern Kenya during the last 20,000 years

    NASA Astrophysics Data System (ADS)

    Foerster, Verena; Vogelsang, Ralf; Junginger, Annett; Asrat, Asfawossen; Lamb, Henry F.; Schaebitz, Frank; Trauth, Martin H.

    2015-12-01

    Our understanding of the impact of climate-driven environmental change on prehistoric human populations is hampered by the scarcity of continuous paleoenvironmental records in the vicinity of archaeological sites. Here we compare a continuous paleoclimatic record of the last 20 ka before present from the Chew Bahir basin, southwest Ethiopia, with the available archaeological record of human presence in the region. The correlation of this record with orbitally-driven insolation variations suggests a complex nonlinear response of the environment to climate forcing, reflected in several long-term and short-term transitions between wet and dry conditions, resulting in abrupt changes between favorable and unfavorable living conditions for humans. Correlating the archaeological record in the surrounding region of the Chew Bahir basin, presumably including montane and lake-marginal refugia for human populations, with our climate record suggests a complex interplay between humans and their environment during the last 20 ka. The result may contribute to our understanding of how a dynamic environment may have impacted the adaptation and dispersal of early humans in eastern Africa.

  2. Evaporation estimation of rift valley lakes: comparison of models.

    PubMed

    Melesse, Assefa M; Abtew, Wossenu; Dessalegne, Tibebe

    2009-01-01

    Evapotranspiration (ET) accounts for a substantial amount of the water flux in the arid and semi-arid regions of the World. Accurate estimation of ET has been a challenge for hydrologists, mainly because of the spatiotemporal variability of the environmental and physical parameters governing the latent heat flux. In addition, most available ET models depend on intensive meteorological information for ET estimation. Such data are not available at the desired spatial and temporal scales in less developed and remote parts of the world. This limitation has necessitated the development of simple models that are less data intensive and provide ET estimates with acceptable level of accuracy. Remote sensing approach can also be applied to large areas where meteorological data are not available and field scale data collection is costly, time consuming and difficult. In areas like the Rift Valley regions of Ethiopia, the applicability of the Simple Method (Abtew Method) of lake evaporation estimation and surface energy balance approach using remote sensing was studied. The Simple Method and a remote sensing-based lake evaporation estimates were compared to the Penman, Energy balance, Pan, Radiation and Complementary Relationship Lake Evaporation (CRLE) methods applied in the region. Results indicate a good correspondence of the models outputs to that of the above methods. Comparison of the 1986 and 2000 monthly lake ET from the Landsat images to the Simple and Penman Methods show that the remote sensing and surface energy balance approach is promising for large scale applications to understand the spatial variation of the latent heat flux. PMID:22303142

  3. International Clinical Trial Day and clinical trials in Ethiopia and Africa.

    PubMed

    Fekadu, Abebaw; Teferra, Solomon; Hailu, Asrat; Gebre-Mariam, Tsige; Addissie, Adamu; Deressa, Wakgari; Yimer, Getnet; Reja, Ahmed

    2014-01-01

    Low income countries like Ethiopia are underrepresented in clinical research. As a major public commitment to clinical research, Ethiopia celebrated the International Clinical Trial Day (ICTD) for the first time on 20 May 2014 under the auspices of Addis Ababa University. The motto for the day was 'Clinical Trials for Excellence in Patient Care'. The celebration offered an opportunity to inform academic staff, researchers, students and the leadership about clinical trials being conducted and to discuss the future of clinical trials in the country. Although clear challenges to the conduct of trials abound, clinical trials registered from Ethiopia in trial registration databases is increasing. Cross-country collaborations, international funding support, motivation of academic staff to conduct clinical trials and the commitment and engagement of the leadership in research are all improving. The overall impact of clinical trials is also encouraging. For example, some of the trials conducted in Ethiopia have informed treatment guidelines. However, administrative capacity, research infrastructure as well as financial support remain weak. There is a need for enhanced university-industry linkage and translation of research findings into locally relevant evidence. Ethiopia, as well as the whole of Africa, has an unparalleled opportunity to lead the way in clinical trials, given its prospect of development and the need to have locally relevant evidence for its growing population. In this commentary we reflect on the celebration of ICTD, the status and opportunities for conducting clinical trials and the way forward for facilitating clinical trials in Ethiopia and Africa. PMID:25526797

  4. Origins of rainbow smelt in Lake Ontario

    USGS Publications Warehouse

    Bergstedt, Roger A.

    1983-01-01

    The first rainbow smelt (Osmerus mordax) to enter Lake Ontario were probably migrants from an anadromous strain introduced into New York's Finger Lakes. Since the upper Great Lakes were originally stocked with a landlocked strain from Green Lake, Maine, subsequent migration to Lake Ontario from Lake Erie makes Lake Ontario unique among the Great Lakes in probably having received introductions from two distinct populations.

  5. David Morrison on Lake Vostok

    NASA Video Gallery

    Dr. David Morrison discusses the implications of research possibilities at Lake Vostok, one of the largest subglacial lakes located over two miles beneath the ice in Antarctica. The lake has been c...

  6. Lake Mead, NV

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Lake Mead, Nevada, (36.0N, 114.5E) where the water from the Colorado River empties after it's 273 mile journey through the Grand Canyon of Arizona is the subject of this photo. Other features of interest are Hoover Dam on the south shore of Lake Mead where cheap hydroelectric power is secondary to the water resources made available in this northern desert region and the resort city of Las Vegas, just to the west of Lake Mead.

  7. Great Lakes Literacy Principles

    NASA Astrophysics Data System (ADS)

    Fortner, Rosanne W.; Manzo, Lyndsey

    2011-03-01

    Lakes Superior, Huron, Michigan, Ontario, and Erie together form North America's Great Lakes, a region that contains 20% of the world's fresh surface water and is home to roughly one quarter of the U.S. population (Figure 1). Supporting a $4 billion sport fishing industry, plus $16 billion annually in boating, 1.5 million U.S. jobs, and $62 billion in annual wages directly, the Great Lakes form the backbone of a regional economy that is vital to the United States as a whole (see http://www.miseagrant.umich.edu/downloads/economy/11-708-Great-Lakes-Jobs.pdf). Yet the grandeur and importance of this freshwater resource are little understood, not only by people in the rest of the country but also by many in the region itself. To help address this lack of knowledge, the Centers for Ocean Sciences Education Excellence (COSEE) Great Lakes, supported by the U.S. National Science Foundation and the National Oceanic and Atmospheric Administration, developed literacy principles for the Great Lakes to serve as a guide for education of students and the public. These “Great Lakes Literacy Principles” represent an understanding of the Great Lakes' influences on society and society's influences on the Great Lakes.

  8. 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

  9. Lakes, Lagerstaetten, and Evolution

    NASA Astrophysics Data System (ADS)

    Kordesch, E. G.; Park, L. E.

    2001-12-01

    The diversity of terrestrial systems is estimated to be greater than in the marine realm. However no hard data yet exists to substantiate this claim. Ancient lacustrine deposits may preserve an exceptionally diverse fossil fauna and aid in determining continental faunal diversities. Fossils preserved in lake deposits, especially those with exceptional preservation (i.e. Konservat Lagerstaetten), may represent a dependable method for determining species diversity changes in the terrestrial environment because of their faunal completeness. Important Konservat Lagerstaetten, such as the Green River Formation (US) and Messel (Germany), both Eocene in age, are found in lake sediments and show a remarkable faunal diversity for both vertebrates and invertebrates. To date information from nearly 25 lake lagerstaetten derived from different types of lake basins from the Carboniferous to the Miocene have been collected and described. Carboniferous sites derive from the cyclothems of Midcontinent of the US while many Cenozoic sites have been described from North and South America as well as Europe and Australia. Asian sites contain fossils from the Mesozoic and Cenozoic. With this data, insight into the evolutionary processes associated with lake systems can be examined. Do lakes act as unique evolutionary crucibles in contrast to marine systems? The speciation of cichlid fishes in present-day African lakes appears to be very high and is attributed to the diversity of environments found in large rift lakes. Is this true of all ancient lakes or just large rift lakes? The longevity of a lake system may be an important factor in allowing speciation and evolutionary processes to occur; marine systems are limited only in the existence of environments as controlled by tectonics and sea level changes, on the order of tens of millions of years. Rift lakes are normally the longest lived in the millions of years. Perhaps there are only certain types of lakes in which speciation of

  10. 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

  11. 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

  12. 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

  13. Phenotypic variation of native chicken populations in northwest Ethiopia.

    PubMed

    Halima, Hassen; Neser, F W C; van Marle-Koster, E; de Kock, A

    2007-10-01

    Seven indigenous chicken populations were identified and characterized from four administrative zones in northwest Ethiopia. A total of three hundred chickens were characterized under field conditions for qualitative and quantitative traits following standard chicken descriptors. Large phenotypic variability among chicken populations was observed for plumage color. About 25.49, 22.3, and 16.4 % of the chickens have white, grayish and red plumage colors, respectively. The rest showed a considerable heterogeneity like black, multicolor, black with white tips, red brownish and white with red striped plumage colors. The following characteristics were also displayed: plain head shape (51.18%), yellow shank color (64.42%) and pea comb (50.72%). About 97.52% of the chickens did not have feathers on their legs. Variations were also observed on quantitative characters such as shank length, egg size and body weight and other reproductive traits characterized on intensive management system. PMID:17969713

  14. Hemoglobin, Growth, and Attention of Infants in Southern Ethiopia

    PubMed Central

    Aubuchon-Endsley, Nicki L.; Grant, Stephanie L.; Berhanu, Getenesh; Thomas, David G.; Schrader, Sarah E.; Eldridge, Devon; Kennedy, Tay; Hambidge, Michael

    2011-01-01

    Researchers tested male and female infants from rural Ethiopia to investigate relations among hemoglobin, anthropometry, and attention. They utilized a longitudinal design to examine differences in attention performance from 6 (M = 24.9 weeks, n = 89) to 9 months of age (M = 40.6 weeks, n = 85), differences hypothesized to be related to changes in iron status and growth delays. Stunting (length-for-age z-scores < −2.0) and attention performance [t(30) = −2.42, p = .022] worsened over time. Growth and hemoglobin predicted attention at 9 months [R2 = .15, p < .05], but not at 6. The use of the attention task at 9 months was supported. The study contributes to the knowledge base of hemoglobin, growth, and attention. PMID:21545582

  15. Lake Effect Clouds

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The lake effect is particularly clear in this Sea-viewing Wide field-of-view Sensor (SeaWiFS) true-color image of the North American Great Lakes region, acquired December 5, 2000. Lakes Nipigon, Superior, and Michigan show striking contrasts between clear and cloudy air as the wind blows from the northwest across the lakes. As it flows across the relatively warm lakes, the cold dry air gathers heat and moisture from the surface. The warm moist air rises into the atmosphere and mixes vigorously with the cold dry air above. The layer of warm moist air deepens as it travels across the lake. Some of the evaporated water from the lake condenses into streamers of fog rising from the surface, while much of the moisture condenses to form a stratocumulus cloud in the upper half of the mixed layer. The cloud-forming water droplets may freeze into ice crystals and, due to accumulated water deposition over time, grow into snowflakes. This process can generate snowstorms that produce significant amounts of snowfall downwind. It is not uncommon for lake effect snowstorms to produce as much as two feet of snow within a 24-hour period in northwestern parts of New York and Pennsylvania. Image provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  16. GREAT LAKES LIMNOLOGY MONITORING

    EPA Science Inventory

    The Great Lakes National Program Office (GLNPO) of the United States Environmental Protection Agency (USEPA) has primary responsibility within the U.S. for conducting surveillance monitoring of the offshore waters of the Great Lakes. This monitoring is intended to fulfill provis...

  17. Lessons from a Lake.

    ERIC Educational Resources Information Center

    Goethals, Susan

    1997-01-01

    Describes a study that included classroom lessons on hydroelectric power, the history and construction of a nearby lake, data recording, the use of field guides, and methods of counting natural populations. The study culminated in a field trip to the lake. (JRH)

  18. Great Lakes: Great Gardening.

    ERIC Educational Resources Information Center

    New York Sea Grant Inst., Albany, NY.

    This folder contains 12 fact sheets designed to improve the quality of gardens near the Great Lakes. The titles are: (1) "Your Garden and the Great Lakes"; (2) "Organic Gardening"; (3) "Fruit and Vegetable Gardening"; (4) "Composting Yard Wastes"; (5) "Herbicides and Water Quality"; (6) "Watering"; (7) "Soil Erosion by Water"; (8) "Soil…

  19. Venezuela: Lake Maracaibo

    Atmospheric Science Data Center

    2013-04-18

    article title:  Oil Slicks on Lake Maracaibo, Venezuela     View Larger Image Several oil slicks occurred on Lake Maracaibo in northwestern Venezuela between ... wave facets divert reflected rays into many directions. An oil film dampens the presence of small wind-driven "capillary" waves, resulting ...

  20. Great Lakes Teacher's Guide.

    ERIC Educational Resources Information Center

    Reid, Ron

    The Great Lakes are one of the world's greatest reservoirs of fresh water, the foundation of Ontario's economic development, a primary force in ecological systems, and a base for pleasure and recreation. They are also a magnificent resource for the teachers of Ontario. Study of the Great Lakes can bring to life the factors that shape the ecology…

  1. The Great Lakes.

    ERIC Educational Resources Information Center

    Seasons, 1987

    1987-01-01

    The Great Lakes are one of the world's greatest reserviors of fresh water, the foundation of Ontario's economic development, a primary force in ecological systems, and a base for pleasure and recreation. These lakes and their relationship with people of Canada and the United States can be useful as a subject for teaching the impact of human…

  2. Lake Wobegon Dice

    ERIC Educational Resources Information Center

    Moraleda, Jorge; Stork, David G.

    2012-01-01

    We introduce Lake Wobegon dice, where each die is "better than the set average." Specifically, these dice have the paradoxical property that on every roll, each die is more likely to roll greater than the set average on the roll, than less than this set average. We also show how to construct minimal optimal Lake Wobegon sets for all "n" [greater…

  3. The lakes of Titan

    USGS Publications Warehouse

    Stofan, E.R.; Elachi, C.; Lunine, J.I.; Lorenz, R.D.; Stiles, B.; Mitchell, K.L.; Ostro, S.; Soderblom, L.; Wood, C.; Zebker, H.; Wall, S.; Janssen, M.; Kirk, R.; Lopes, R.; Paganelli, F.; Radebaugh, J.; Wye, L.; Anderson, Y.; Allison, M.; Boehmer, R.; Callahan, P.; Encrenaz, P.; Flamini, E.; Francescetti, G.; Gim, Y.; Hamilton, G.; Hensley, S.; Johnson, W.T.K.; Kelleher, K.; Muhleman, D.; Paillou, P.; Picardi, G.; Posa, F.; Roth, L.; Seu, R.; Shaffer, S.; Vetrella, S.; West, R.

    2007-01-01

    The surface of Saturn's haze-shrouded moon Titan has long been proposed to have oceans or lakes, on the basis of the stability of liquid methane at the surface. Initial visible and radar imaging failed to find any evidence of an ocean, although abundant evidence was found that flowing liquids have existed on the surface. Here we provide definitive evidence for the presence of lakes on the surface of Titan, obtained during the Cassini Radar flyby of Titan on 22 July 2006 (T16). The radar imaging polewards of 70?? north shows more than 75 circular to irregular radar-dark patches, in a region where liquid methane and ethane are expected to be abundant and stable on the surface. The radar-dark patches are interpreted as lakes on the basis of their very low radar reflectivity and morphological similarities to lakes, including associated channels and location in topographic depressions. Some of the lakes do not completely fill the depressions in which they lie, and apparently dry depressions are present. We interpret this to indicate that lakes are present in a number of states, including partly dry and liquid-filled. These northern-hemisphere lakes constitute the strongest evidence yet that a condensable-liquid hydrological cycle is active in Titan's surface and atmosphere, in which the lakes are filled through rainfall and/or intersection with the subsurface 'liquid methane' table. ??2007 Nature Publishing Group.

  4. Lake trophic applications: Wisconsin

    NASA Technical Reports Server (NTRS)

    Scarpace, F.

    1981-01-01

    Efforts to classify the water quality characteristics of lakes using LANDSAT imagery are reported. Image processing and registration techniques are described. A lake classification scheme which involves the assignment of a trophic class number was used in the data analysis. The resulting values were compared to the corresponding rank assignment derived from field measurements.

  5. Participatory evaluation of chicken health and production constraints in Ethiopia.

    PubMed

    Sambo, Emmanuel; Bettridge, Judy; Dessie, Tadelle; Amare, Alemayehu; Habte, Tadiose; Wigley, Paul; Christley, Robert M

    2015-01-01

    Chicken production has a major role in the economy of developing countries and backyard production is particularly important to women. Several programmes, in Ethiopia and elsewhere, have attempted to improve chicken production as a means to reduce poverty. A key constraint to chicken production identified by farmers is disease. This study used participatory rural appraisal methods to work with chicken-keepers in order to prioritise chicken diseases, place these within the context of other production constraints, and to explore perceptions of disease risk factors and biosecurity measures. The study, focused on Debre Zeit, Ethiopia, included 71 poultry keepers (41 backyard and 30 semi-intensive chicken producers). Although women played an important role in backyard production systems, semi-intensive farms were more likely to be controlled by men. Participants identified 9 constraints to production: 7 of 8 groups of backyard producers and 15/31 semi-intensive producers ranked diseases as the most important constraint to chicken production. In contrast to previous reports, farmers in both groups had considerable knowledge of diseases and of factors affecting disease risk. Both groups, but particularly semi-intensive producers, highlighted access to feed as a constraint. Many of the challenges faced by both groups were associated with difficulty accessing agricultural and veterinary inputs and expertise. Whilst many of the constraints identified by farmers could be viewed as simply technical issues to be overcome, we believe it is important to recognise the social factors underpinning what are, in reality, relatively modest technical challenges. The low involvement of women in semi-intensive production needs to be recognised by poultry development schemes. Provision needs to be made to allow access to inputs for a wide range of business models, particularly for those, such as women, who have limited access to the capital to allow them to make the jump from backyard to

  6. Participatory evaluation of chicken health and production constraints in Ethiopia

    PubMed Central

    Sambo, Emmanuel; Bettridge, Judy; Dessie, Tadelle; Amare, Alemayehu; Habte, Tadiose; Wigley, Paul; Christley, Robert M.

    2015-01-01

    Chicken production has a major role in the economy of developing countries and backyard production is particularly important to women. Several programmes, in Ethiopia and elsewhere, have attempted to improve chicken production as a means to reduce poverty. A key constraint to chicken production identified by farmers is disease. This study used participatory rural appraisal methods to work with chicken-keepers in order to prioritise chicken diseases, place these within the context of other production constraints, and to explore perceptions of disease risk factors and biosecurity measures. The study, focused on Debre Zeit, Ethiopia, included 71 poultry keepers (41 backyard and 30 semi-intensive chicken producers). Although women played an important role in backyard production systems, semi-intensive farms were more likely to be controlled by men. Participants identified 9 constraints to production: 7 of 8 groups of backyard producers and 15/31 semi-intensive producers ranked diseases as the most important constraint to chicken production. In contrast to previous reports, farmers in both groups had considerable knowledge of diseases and of factors affecting disease risk. Both groups, but particularly semi-intensive producers, highlighted access to feed as a constraint. Many of the challenges faced by both groups were associated with difficulty accessing agricultural and veterinary inputs and expertise. Whilst many of the constraints identified by farmers could be viewed as simply technical issues to be overcome, we believe it is important to recognise the social factors underpinning what are, in reality, relatively modest technical challenges. The low involvement of women in semi-intensive production needs to be recognised by poultry development schemes. Provision needs to be made to allow access to inputs for a wide range of business models, particularly for those, such as women, who have limited access to the capital to allow them to make the jump from backyard to

  7. Desertification? Northern Ethiopia re-photographed after 140 years.

    PubMed

    Nyssen, Jan; Haile, Mitiku; Naudts, Jozef; Munro, Neil; Poesen, Jean; Moeyersons, Jan; Frankl, Amaury; Deckers, Jozef; Pankhurst, Richard

    2009-04-01

    A collection of sepia photographs, taken during Great Britain's military expedition to Abyssinia in 1868, are the oldest landscape photographs from northern Ethiopia, and have been used to compare the status of vegetation and land management 140 years ago with that of contemporary times. Thirteen repeat landscape photographs, taken during the dry seasons of 1868 and 2008, were analyzed for various environmental indicators and show a significant improvement of vegetation cover. New eucalypt woodlands, introduced since the 1950s are visible and have provided a valuable alternative for house construction and fuel-wood, but more importantly there has also been locally important natural regeneration of indigenous trees and shrubs. The situation in respect to soil and water conservation measures in farmlands has also improved. According to both historical information and measured climatic data, rainfall conditions around 1868 and in the late 19th century were similar to those of the late 20th/early 21st century. Furthermore, despite a ten-fold increase in population density, land rehabilitation has been accomplished over extensive areas by large-scale implementation of reforestation and terracing activities, especially in the last two decades. In some cases repeat photography shows however that riparian vegetation has been washed away. This is related to river widening in recent degradation periods, particularly in the 1970s-1980s. More recently, riverbeds have become stabilized, and indicate a decreased runoff response. Environmental recovery programmes could not heal all scars, but this study shows that overall there has been a remarkable recovery of vegetation and also improved soil protection over the last 140 years, thereby invalidating hypotheses of the irreversibility of land degradation in semi-arid areas. In a highly degraded environment with high pressure on the land, rural communities were left with no alternative but to improve land husbandry: in northern

  8. Anemia among Primary School Children in Eastern Ethiopia

    PubMed Central

    2015-01-01

    Background Anemia during childhood impairs physical growth, cognitive development and school performance. Identifying the causes of anemia in specific contexts can help efforts to prevent negative consequences of anemia among children. The objective of this study was to assess prevalence and identify correlates of anemia among school children in Eastern Ethiopia. Methods A cross sectional study was conducted from January 2012 to February 2012 in Kersa, Eastern Ethiopia. The study included randomly selected primary school students. Hemoglobin concentration was measured using a Hemocue haemoglobinometer. A child was identified as anemic if the hemoglobin concentration was <11.5 g/dl for children (5–11 yrs) and < 12 g/dl for child older than 12 years age. Poisson regression model with robust variance was used to calculate prevalence ratios. Result The overall prevalence of anemia was 27.1% (95% CI: 24.98, 29.14): 13.8% had mild, 10.8% moderate, and 2.3% severe anemia. Children with in the age group of 5-9 years (APR, 1.083; 95% CI, 1.044- 1.124) were at higher risk for anemia. Paternal education (Illiterate, 1.109; 1.044 - 1.178) was positively associated with anemia. Children who had irregular legume consumption (APR, 1.069; 95% CI, 1.022 -1.118) were at higher risk for anemia. Conclusion About a quarter of school children suffer from anemia and their educational potential is likely to be affected especially for those with moderate and severe anemia. Child age, irregular legume consumption, and low paternal schooling were associated with anemia. Intervention programmes aimed to reduce anemia among school children are crucial to ensure proper growth and development of children. PMID:25902055

  9. The changing face of obstetric fistula surgery in Ethiopia

    PubMed Central

    Wright, Jeremy; Ayenachew, Fekade; Ballard, Karen D

    2016-01-01

    Objective To examine the incidence and type of obstetric fistula presenting to Hamlin Fistula Ethiopia over a 4-year period. Study design This is a 4-year retrospective survey of obstetric fistula treated at three Hamlin Fistula Hospitals in Ethiopia, where approximately half of all women in the country are treated. The operation logbook was reviewed to identify all new cases of obstetric fistula presenting from 2011 to 2015. New cases of urinary fistula were classified by fistula type (high or low), age, and parity of the woman. Results In total, 2,593 new cases of urinary fistulae were identified in the study period. The number of new cases fell by 20% per year over the 4 years (P<0.001). A total of 1,845 cases (71.1%) were low (ischemic) fistulae, and 804 cases (43.6%) of these had an extreme form of low circumferential fistula. A total of 638 (24.6%) women had a high bladder fistula, which predominantly occurs following surgery, specifically cesarean section or emergency hysterectomy, and 110 (4.2%) women had a ureteric fistula. The incidence of high fistulae increased over the study period from 26.9% to 36.2% (P<0.001). A greater proportion of multiparous women had a high bladder fistula (70.3%) compared with primigravid women (29.7%) (P<0.001). Conversely, a greater proportion of primiparous women experienced a low circumferential fistulae (68.6%) compared with multiparous women (31.4%) (P<0.001). Conclusion There appears to be a decline in the number of Ethiopian women being treated for new obstetric urinary fistulae. However, the type of fistula being presented for treatment is changing, with a rise in high fistulae that very likely occurred following cesarean section and a decline in the classic low fistulae that arise following obstructed childbirth. PMID:27445505

  10. Water Allocation Modeling of Awash River Basin, Ethiopia

    NASA Astrophysics Data System (ADS)

    Asfaw, D. H.; Berhe, F.; Melesse, A. M.

    2012-12-01

    Awash River basin is one of the twelve basins of Ethiopia which is highly utilized and the first basin to be introduced to modern agriculture. A study was conducted on water allocation modeling of Awash River basin, Ethiopia using MODSIM, a river basin management decision support system (DSS) designed as a computer-aided tool for developing improved basin wide planning. This study was conducted to analyze the water balance of the Awash basin under different levels of irrigation development and also determine the water allocation in the Upper, Middle and Lower Valleys in the basin. Awash basin includes Koka Dam and two dams under completion: Kessem and Tendaho Reservoirs. Four scenarios were set: Scenario I-present withdrawal rate in the basin; Scenario II-Scenario I plus Downstream Tendaho Dam Operational; Scenario III-Scenario II plus expansion of middle valley farms and Kessem Dam Operational; and Scenario IV-Scenario III plus additional expansion in the middle valley. Analysis of flow records within the basin was done for a period of 1963-2003. Estimation of system losses, runoff from ungauged tributaries, and Gedebessa Swamp model parameters were considered in the flow process study. Simulation was conducted based on four scenarios. Consumptive and non-consumptive uses were considered in allocation modeling. The results of MODSIM model depict that there will be incremental release from Koka Dam from 2.8% to 5.7% in years 2018 and 2038, respectively. Due to increased diversions in Scenario III when compared to scenario I, losses in to Gedebessa Swamp will significantly decrease by an average of 27.6%. In the year 2038, owing to less capacity of upstream reservoirs due to sedimentation, water will be lost in the swamp complex causing slight decrease of inflow to Tendaho Dam. Additional storage at or upstream of Koka Dam will be mandatory in the future. Unaccounted water diversions upstream of Koka and water losses in Gedebessa Swamp should be considered in the

  11. The mineral industry of Ethiopia: present conditions and future prospects

    NASA Astrophysics Data System (ADS)

    Assefa, Getaneh

    Despite a record of mineral activity that dates back to Biblical times and the occurrence of a wide variety of minerals, as well as continuing efforts to discover major ore deposits, Ethiopia's mineral resources ahve remained of minor importance in the world economy. Mineral production in the last 20 years, for example, forms less than 1% of the estimated GDP. Well known minerals andmineral products available in the country in commercial quantities are: gold, platinum, manganese ore, natural agas, clays and clay products, feldspars, gypsum and anhydrite, slat, lime, limestone, cement, sand, structural and crushed stones, marble, mineral water and pumice. There are also vast reserves of water and geothermal power. Recently discovered deposits (over the last 20 years), with major reserves that may attain an important role in mineral production in the future, include potash salts, copper ore and diatomites. Minerals which are known to occur in Ethiopia, but of which supplies are deficient, or which have not yet been proved to exist in economic quantities are: nickel, iron, chromium, mineral fuels (oil, coal and uranium), sulphur, asbesttos, mica, talc, barytes, fluorites, borates, soda-ash, phosphates, wolframite, abrasives (garnet), molybdenite and vanadium. Within the last few years there has been an increasing appreciation of the economic significance of a mineral industry and a definite attempt to foster it. Mineral ownership is vested in the state are cotnrolled by the MInistry of Mines, Energy and Water Resources. The law relating to foreign investment in mines is liberal. The plans for the future have to provide for detailed and intensive exploration of the country's mineral resources, manufacture and fabrication.

  12. Agriculture, population, and economic planning in Ethiopia, 1953-1980.

    PubMed

    Robinson, W C; Yamazaki, F

    1986-04-01

    This paper deals with the economic development of Ethiopia in the 3 decades between 1950 and 1980. In particular, it examines governmental efforts at agricultural planning during this period compared to the actual experience of the country. The dominant forces governing the changes that occurred in this period were accelerated population growth and the declining availability of arable land, which combined to push a fragile, traditional ecosystem to the brink of disaster. Government planning efforts had little impact in the pre-1974 period, since they were too modest and small scale to affect the highly traditional and primitive mode of peasant cultivation. The sweeping structural changes introduced by the new regime since 1974 seem to have mainly adverse effects and to have decreased both productivity and yields. Ethiopia lacks the basic infrastructure and incentive system to create an environment in which technological change is possible. Presumably the declining agricultural growth rate from 1953 to 1974 suggests that the traditional, prerevolution system was failing to create these favorable conditions and hence was losing the race with population growth. The post-1974 revolutionary government's policy has been, in effect, an effort to jump to an advanced phase of agricultural development, and this seems to have been even less successful. These plans have, in all fairness, been hamstrung since 1981 by drought, famine, and civil war, but have probably themselves contributed to the severity of those events. Overall, Ethiopian agricultural planning has not been notably successful. From 1953-1980, total agricultural production is estimated to have grown at a slowly decreasing rate. The collapse of agriculture due to several years of drought obviously cannot be blamed on government planning, but its severity clearly has been at least partly a function of policy failures. PMID:12280692

  13. Factors associated with place of death in Addis Ababa, Ethiopia

    PubMed Central

    2013-01-01

    Background Dying at home is highly prevalent in Africa partly due to lack of accessibility of modern health services. In turn, limited infrastructure and health care deliveries in Africa complicate access to health services. A weak infrastructure and limited health facilities with lower quality in Ethiopia resulted poor health service utilization and coverage, high morbidity and mortality rates. We examined whether people in Addis Ababa died in health facilities and investigated the basic factors associated with place of death. Methods We used verbal autopsy data of 4,776 adults (age>14 years) for the years 2006–2010 from the Addis Ababa Mortality Surveillance Program (AAMSP). The main data source of AAMSP is the burial surveillance from all cemeteries in Addis Ababa. We provide descriptive statistics of place of adult deaths and discussed their covariates using multivariate analyses. Results Only 28.7% died at health facilities, while the remaining died out of health facilities. There was an increase trend in the proportion of health facility deaths from 25.3% in 2006 to 32.5% in 2010. The risk of health facility death versus out of health facility deaths decreased with age. Compared with those who had no education educated people were more likely to die at health facilities. The chance of in health facility death was a little higher for females than males while religion, occupational status and ethnicity of the deceased had no any significance difference in place of death. Conclusion Both demographic and social factors determine where adults will die in Addis Ababa, Ethiopia. The majority of people in Addis Ababa died out of health facilities. The health system should also give special attention to the emerging non communicable diseases like cancer for effective treatment of patients. PMID:23530478

  14. Healthcare situation dismal, says government official. International (Ethiopia).

    PubMed

    1997-05-12

    According to Dr. Kebede Tadesse, Minister of Social and Administrative Affairs, as stated in a speech before the Consultative Group Meeting in Addis Ababa in December 1996, the health status of Ethiopia is one of the worst in the world because of "backward socio-economic development, poor environmental quality, high fertility rate, repeated natural and man-made disasters, and inadequate health services." An article in the April 11, 1997, Addis Tribune supports this claim by describing the horrific conditions found in a public hospital in Addis Ababa. Patients returned home to die because of the shortage of beds. Dr. Kebede gave the following statistics: the average daily per capita food intake is 1750 calories, 80% of that recommended; 5% of children show signs of wasting; 64% of children have stunted growth; 17% of pregnant and lactating women are anemic; the average national fertility rate is 6.1%; the percentage of AIDS cases per 100,000 people is 10.7; 18% of people have access to potable water; 14% of births are attended; 16% of people receive antenatal care; 40% of the population is immunized; 8% of the population receives family planning services; the infant mortality rate is 130/1000 live births; the maternal mortality rate is 500-700/100,000 live births; there is 1 physician per 33,333 Ethiopians; and the life expectancy at birth is 48 years. The article recommended the following "basic principles and guidelines" to improve the situation: 1) the population should be educated about good hygiene; 2) family planning should be popularized by the government; 3) the health budget should be increased to meet overall demand for health services and to target diseases such as malaria and tuberculosis; 4) private investment in health care is needed; 5) a safe drinking water supply must be made available; and 6) domestic conditions should be made favorable so that Ethiopian doctors educated abroad will return to practice in Ethiopia. PMID:12320872

  15. Lakes and reservoirs

    SciTech Connect

    Taub, F.B.

    1984-01-01

    This volume in the Ecosystems of the World series studies lakes and reservoirs. The book opens with a discussion of the ecosystem processes that are common to all lakes and reservoirs and then proceeds to a description of mathematical models of these processes. The chapters concentrate on lakes and reservoirs in different parts of the world, ranging from polar to tropical lakes, and in many of the chapters the effects of human activities such as dam construction, increased nutrient inputs, toxic contaminants and fish introduction, are also considered. The book concludes with a summary of the efforts at lake restoration that are being undertaken in many communities in an attempt to undo the damage that has resulted from some of these activities.

  16. Spatial patterns in PCB concentrations of Lake Michigan lake trout

    USGS Publications Warehouse

    Madenjian, Charles P.; DeSorcie, Timothy J.; Stedman, Ralph M.; Brown, Edward H., Jr.; Eck, Gary W.; Schmidt, Larry J.; Hesselberg, Robert J.; Chernyak, Sergei M.; Passino-Reader, Dora R.

    1999-01-01

    Most of the PCB body burden in lake trout (Salvelinus namaycush) of the Great Lakes is from their food. PCB concentrations were determined in lake trout from three different locations in Lake Michigan during 1994–1995, and lake trout diets were analyzed at all three locations. The PCB concentrations were also determined in alewife (Alosa pseudoharengus), rainbow smelt (Osmerus mordax), bloater (Coregonus hoyi), slimy sculpin (Cottus cognatus), and deepwater sculpin (Myoxocephalus thompsoni), five species of prey fish eaten by lake trout in Lake Michigan, at three nearshore sites in the lake. Despite the lack of significant differences in the PCB concentrations of alewife, rainbow smelt, bloater, slimy sculpin, and deepwater sculpin from the southeastern nearshore site near Saugatuck (Michigan) compared with the corresponding PCB concentrations from the northwestern nearshore site near Sturgeon Bay (Wisconsin), PCB concentrations in lake trout at Saugatuck were significantly higher than those at Sturgeon Bay. The difference in the lake trout PCB concentrations between Saugatuck and Sturgeon Bay could be explained by diet differences. The diet of lake trout at Saugatuck was more concentrated in PCBs than the diet of Sturgeon Bay lake trout, and therefore lake trout at Saugatuck were more contaminated in PCBs than Sturgeon Bay lake trout. These findings were useful in interpreting the long-term monitoring series for contaminants in lake trout at both Saugatuck and the Wisconsin side of the lake.

  17. Lake trout in northern Lake Huron spawn on submerged drumlins

    USGS Publications Warehouse

    Riley, Stephen C.; Binder, Thomas; Wattrus, Nigel J.; Faust, Matthew D.; Janssen, John; Menzies, John; Marsden, J. Ellen; Ebener, Mark P.; Bronte, Charles R.; He, Ji X.; Tucker, Taaja R.; Hansen, Michael J.; Thompson, Henry T.; Muir, Andrew M.; Krueger, Charles C.

    2014-01-01

    Recent observations of spawning lake trout Salvelinus namaycush near Drummond Island in northern Lake Huron indicate that lake trout use drumlins, landforms created in subglacial environments by the action of ice sheets, as a primary spawning habitat. From these observations, we generated a hypothesis that may in part explain locations chosen by lake trout for spawning. Most salmonines spawn in streams where they rely on streamflows to sort and clean sediments to create good spawning habitat. Flows sufficient to sort larger sediment sizes are generally lacking in lakes, but some glacial bedforms contain large pockets of sorted sediments that can provide the interstitial spaces necessary for lake trout egg incubation, particularly if these bedforms are situated such that lake currents can penetrate these sediments. We hypothesize that sediment inclusions from glacial scavenging and sediment sorting that occurred during the creation of bedforms such as drumlins, end moraines, and eskers create suitable conditions for lake trout egg incubation, particularly where these bedforms interact with lake currents to remove fine sediments. Further, these bedforms may provide high-quality lake trout spawning habitat at many locations in the Great Lakes and may be especially important along the southern edge of the range of the species. A better understanding of the role of glacially-derived bedforms in the creation of lake trout spawning habitat may help develop powerful predictors of lake trout spawning locations, provide insight into the evolution of unique spawning behaviors by lake trout, and aid in lake trout restoration in the Great Lakes.

  18. Operationalization of National Objectives of Ethiopia into Educational Objectives. African Studies in Curriculum Development & Evaluation. No. 60.

    ERIC Educational Resources Information Center

    Adaye, Abebe Alaro

    This paper reports on past educational objectives of the old political regime in Ethiopia and new educational objectives of revolutionary Ethiopia. It is reported that these new objectives focus on education for production, scientific research, and socialist consciousness, and that all subjects are based on Marxism-Leninism. Curricular objectives…

  19. Evidence of offshore lake trout reproduction in Lake Huron

    USGS Publications Warehouse

    DeSorcie, Timothy J.; Bowen, Charles A., II

    2003-01-01

    Six Fathom Bank-Yankee Reef, an offshore reef complex, was an historically important spawning area believed to represent some of the best habitat for the rehabilitation of lake trout Salvelinus namaycush in Lake Huron. Since 1986, lake trout have been stocked on these offshore reefs to reestablish self-sustaining populations. We sampled with beam trawls to determine the abundance of naturally reproduced age-0 lake trout on these offshore reefs during May-July in 1994-1998 and 2000-2002. In total, 123 naturally reproduced lake trout fry were caught at Six Fathom Bank, and 2 naturally reproduced lake trout fry were caught at nearby Yankee Reef. Our findings suggest that this region of Lake Huron contains suitable habitat for lake trout spawning and offers hope that lake trout rehabilitation can be achieved in the main basin of Lake Huron.

  20. Lake whitefish and lake herring population structure and niche in ten south-central Ontario lakes

    USGS Publications Warehouse

    Carl, Leon M.; McGuiness, Fiona

    2006-01-01

    This study compares simple fish communities of ten oligotrophic lakes in south-central Ontario. Species densities and population size structure vary significantly among these lake communities depending on fish species present beyond the littoral zone. Lake whitefish are fewer and larger in the presence of lake herring than in their absence. Diet analysis indicates that lake whitefish shift from feeding on both plankton and benthic prey when lake herring are absent to a primarily benthic feeding niche in the presence of lake herring. When benthic round whitefish are present, lake whitefish size and density decline and they move lower in the lake compared to round whitefish. Burbot are also fewer and larger in lakes with lake herring than in lakes without herring. Burbot, in turn, appear to influence the population structure of benthic coregonine species. Lower densities of benthic lake whitefish and round whitefish are found in lakes containing large benthic burbot than in lakes with either small burbot or where burbot are absent. Predation on the pelagic larvae of burbot and lake whitefish by planktivorous lake herring alters the size and age structure of these populations. As life history theory predicts, those species with poor larval survival appear to adopt a bet-hedging life history strategy of long-lived individuals as a reproductive reserve.

  1. Seroepidemiological study of ovine toxoplasmosis in East and West Shewa Zones of Oromia Regional State, Central Ethiopia

    PubMed Central

    2013-01-01

    Background Toxoplasmosis is a globally distributed zoonosis. Consumption of raw or undercooked meat, which is among the main risk factors for acquiring human infection, is a popular tradition in Ethiopia. However, studies on toxoplasmosis in food animals used for human consumption in Ethiopia are very scarce. Thus, the objectives of the present study were to estimate the seroprevalence and the risk factors of T. gondii infection in sheep in Ambo, Ada’a-Liben and Fentale districts of Central Ethiopia. Sera from 1130 sheep were analyzed for Toxoplasma gondii specific IgG antibodies using an indirect enzyme linked immunosorbent assay (ELISA) with the P30 antigen. A questionnaire was administered to assess potential risk factors for T. gondii seropositivity. Association of seroprevalence with potential risk factors related to altitude, host and farm characteristics were analyzed by univariable and multivariable logistic regression. Results Overall flock and animal level seroprevalences were 70.48% (160/227; 95% CI: 64.51, 76.46) and 31.59% (357/1130; 95% CI: 28.88, 34.31), respectively. The multivariable logistic regression model indicated that the probability of acquiring T. gondii was higher in sheep from highland (2300 – 3200 meters above sea level) [Odds ratio (OR) = 4.11, 95% confidence interval (CI): 2.65, 6.36; P < 0.001] and midland (OR = 4.54, 95% CI: 2.76, 7.49; P < 0.001) than from lowland (<1500 meters above sea level), in females than in males (OR = 1.60, 95% CI: 1.04, 2.43, P = 0.033), in adult than in young animals (OR = 2.93, 95% CI: 1.97, 4.35, P < 0.001), in small than in large flocks (OR = 3.34, 95% CI: 1.26, 8.86, P = 0.016), and in sheep that were given tap water (OR = 4.07, 95% CI: 1.07, 15.42, P = 0.039) and river water (OR = 4.18, 95% CI: 1.54, 11.35, P = 0.005) than in those that drunk water from mixed sources (i.e., river, well, lake and pond). Conclusions The high flock and animal

  2. Taphonomy of fossils from the hominin-bearing deposits at Dikika, Ethiopia.

    PubMed

    Thompson, Jessica C; McPherron, Shannon P; Bobe, René; Reed, Denné; Barr, W Andrew; Wynn, Jonathan G; Marean, Curtis W; Geraads, Denis; Alemseged, Zeresenay

    2015-09-01

    Two fossil specimens from the DIK-55 locality in the Hadar Formation at Dikika, Ethiopia, are contemporaneous with the earliest documented stone tools, and they collectively bear twelve marks interpreted to be characteristic of stone tool butchery damage. An alternative interpretation of the marks has been that they were caused by trampling animals and do not provide evidence of stone tool use or large ungulate exploitation by Australopithecus-grade hominins. Thus, resolving which agents created marks on fossils in deposits from Dikika is an essential step in understanding the ecological and taphonomic contexts of the hominin-bearing deposits in this region and establishing their relevance for investigations of the earliest stone tool use. This paper presents results of microscopic scrutiny of all non-hominin fossils collected from the Hadar Formation at Dikika, including additional fossils from DIK-55, and describes in detail seven assemblages from sieved surface sediment samples. The study is the first taphonomic description of Pliocene fossil assemblages from open-air deposits in Africa that were collected without using only methods that emphasize the selective retention of taxonomically-informative specimens. The sieved assemblages show distinctive differences in faunal representation and taphonomic modifications that suggest they sample a range of depositional environments in the Pliocene Hadar Lake Basin, and have implications for how landscape-based taphonomy can be used to infer past microhabitats. The surface modification data show that no marks on any other fossils resemble in size or shape those on the two specimens from DIK-55 that were interpreted to bear stone tool inflicted damage. A large sample of marks from the sieved collections has characteristics that match modern trampling damage, but these marks are significantly smaller than those on the DIK-55 specimens and have different suites of characteristics. Most are not visible without magnification

  3. 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

  4. Legal harvest and illegal trade: Trends, challenges, and options in khat production in Ethiopia.

    PubMed

    Cochrane, Logan; O'Regan, Davin

    2016-04-01

    The production of khat in Ethiopia has boomed over the last two decades, making the country the world's leading source. Khat is now one of Ethiopia's largest crops by area of cultivation, the country's second largest export earner, and an essential source of income for millions of Ethiopian farmers. Consumption has also spread from the traditional khat heartlands in the eastern and southern regions of Ethiopia to most major cities. This steady growth in production and use has unfolded under negligible government support or regulation. Meanwhile, khat, which releases a stimulant when chewed, is considered an illicit drug in an increasing number of countries. Drawing on government data on khat production, trade, and seizures as well as research on the political, socioeconomic, and development effects of plant-based illicit narcotics industries, this commentary identifies possible considerations and scenarios for Ethiopia as the country begins to manage rising khat production, domestic consumption, and criminalization abroad. Deeply embedded in social and cultural practices and a major source of government and agricultural revenue, Ethiopian policymakers have few enviable choices. Criminalization abroad raises a small but not insignificant possibility that previously nonexistent linkages between khat and transnational organized crime and trafficking networks will emerge. Likewise, more stringent regulation of khat in Ethiopia could merge with lingering political cleavages and anti-government sentiments, exacerbating low-level domestic conflicts. PMID:26949190

  5. Lake sturgeon population characteristics in Rainy Lake, Minnesota and Ontario

    USGS Publications Warehouse

    Adams, W.E., Jr.; Kallemeyn, L.W.; Willis, D.W.

    2006-01-01

    Rainy Lake contains a native population of lake sturgeon Acipenser fulvescens that has been largely unstudied. The aims of this study were to document the population characteristics of lake sturgeon in Rainy Lake and to relate environmental factors to year-class strength for this population. Gill-netting efforts throughout the study resulted in the capture of 322 lake sturgeon, including 50 recaptures. Lake sturgeon in Rainy Lake was relatively plump and fast growing compared with a 32-population summary. Population samples were dominated by lake sturgeon between 110 and 150 cm total length. Age–structure analysis of the samples indicated few younger (<10 years) lake sturgeon, but the smallest gill net mesh size used for sampling was 102 mm (bar measure) and would not retain small sturgeon. Few lake sturgeon older than age 50 years were captured, and maximum age of sampled fish was 59 years. Few correlations existed between lake sturgeon year-class indices and both annual and monthly climate variables, except that mean June air temperature was positively correlated with year-class strength. Analysis of Rainy Lake water elevation and resulting lake sturgeon year-class strength indices across years yielded consistent but weak negative correlations between late April and early June, when spawning of lake sturgeon occurs. The baseline data collected in this study should allow Rainy Lake biologists to establish more specific research questions in the future.

  6. Yellowstone Lake Nanoarchaeota

    PubMed Central

    Clingenpeel, Scott; Kan, Jinjun; Macur, Richard E.; Woyke, Tanja; Lovalvo, Dave; Varley, John; Inskeep, William P.; Nealson, Kenneth; McDermott, Timothy R.

    2013-01-01

    Considerable Nanoarchaeota novelty and diversity were encountered in Yellowstone Lake, Yellowstone National Park (YNP), where sampling targeted lake floor hydrothermal vent fluids, streamers and sediments associated with these vents, and in planktonic photic zones in three different regions of the lake. Significant homonucleotide repeats (HR) were observed in pyrosequence reads and in near full-length Sanger sequences, averaging 112 HR per 1349 bp clone and could confound diversity estimates derived from pyrosequencing, resulting in false nucleotide insertions or deletions (indels). However, Sanger sequencing of two different sets of PCR clones (110 bp, 1349 bp) demonstrated that at least some of these indels are real. The majority of the Nanoarchaeota PCR amplicons were vent associated; however, curiously, one relatively small Nanoarchaeota OTU (71 pyrosequencing reads) was only found in photic zone water samples obtained from a region of the lake furthest removed from the hydrothermal regions of the lake. Extensive pyrosequencing failed to demonstrate the presence of an Ignicoccus lineage in this lake, suggesting the Nanoarchaeota in this environment are associated with novel Archaea hosts. Defined phylogroups based on near full-length PCR clones document the significant Nanoarchaeota 16S rRNA gene diversity in this lake and firmly establish a terrestrial clade distinct from the marine Nanoarcheota as well as from other geographical locations. PMID:24062731

  7. Whiting in Lake Michigan

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Satellites provide a view from space of changes on the Earth's surface. This series of images from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) aboard the Orbview-2 satellite shows the dramatic change in the color of Lake Michigan during the summer. The bright color that appears in late summer is probably caused by calcium carbonate-chalk-in the water. Lake Michigan always has a lot of calcium carbonate in it because the floor of the lake is limestone. During most of the year the calcium carbonate remains dissolved in the cold water, but at the end of summer the lake warms up, lowering the solubility of calcium carbonate. As a result, the calcium carbonate precipitates out of the water, forming clouds of very small solid particles that appear as bright swirls from above. The phenomenon is appropriately called a whiting event. A similar event occured in 1999, but appears to have started later and subsided earlier. It is also possible that a bloom of the algae Microcystis is responsible for the color change, but unlikely because of Lake Michigan's depth and size. Microcystis blooms have occured in other lakes in the region, however. On the shore of the lake it is possible to see the cities of Chicago, Illinois, and Milwaukee, Wisconsin. Both appear as clusters of gray-brown pixels. Image courtesy the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  8. LAKE RESTORATION BY DILUTION: MOSES LAKE, WASHINGTON

    EPA Science Inventory

    Dilution water, low in macronutrients, was added to Moses Lake on three occasions in 1977 and once in 1978 during the spring-summer period. The addition resulted in reducing the annual average inflow concentration of phosphorus from about 130-140 micrograms/l to 100 micrograms/l....

  9. Lake Mead, NV

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Lake Mead, Nevada, (36.0N, 114.5E) where the water from the Colorado River empties after it's 273 mile journey through the Grand Canyon of Arizona is the subject of this photo. Other features of interest are Hoover Dam on the south shore of Lake Mead where cheap hydroelectric power is secondary to the water resources made available in this northern desert region and the resort city of Las Vegas, just to the west of Lake Mead. In this harsh desert environment, color infrared photography readily penetrates haze, detects and portrays vegetation as shades of red.

  10. Erta Ale Lava Lake: Identification and Modelling of Variable Convective Regimes

    NASA Astrophysics Data System (ADS)

    Carniel, R.; Harris, A. J.; Jones, J.

    2002-12-01

    After more than twenty years without access to Erta Ale volcano, field campaigns are once again feasible. Between February 15 and February 20, 2002, a combined thermal and seismic data set was recorded at Erta Ale volcano, Ethiopia, to study activity of the persistent lava lake. Analysis of continuous tremor and thermal fluctuations suggests that lava lake activity, as recorded by temperature variations, is related to seismic energy and spectral content. When we compare these parameters at timescales of minutes to hours, we find that correlations range from good to poor. However, these two parameters do not significantly correlate on timescales of a full day. Both thermal and seismic data indicate that the lava lake exhibits cyclical behavior between 20 to 80 minute periods characterized by low (~0.05 ms-1) and high (~0.2 ms-1) rates of convection, respectively. We use our measurements to constrain two models to explain these convection cycles. The first model relates variable convection rates to pulses in the rate at which magma is supplied to the lake. This model requires supply rates to cycle between high convection rate phases fed by a magma volume flux of 0.2 m3s-1 and low convection rate phases fed by a magma volume flux of 0.03 m3s-1. The second model assumes that supply to the lake is steady and that cyclic convection is set up by the generation of convective instabilities within the lake. In this case, cooling of the surface layer generates a slow moving, viscous convection cell at the lake surface overlying a faster moving convection cell of lower viscosity. Recharge of the lower cell increases the buoyancy of the lower layer, and eventually triggers an overturn event. At this point the surface of the low viscosity cell extends to the lake surface and the high viscosity cell sinks to be drained from the lake. We find that the second model, whereby cyclic convection is generated by processes acting within the lake, is more plausible.