Browsing by Author "Sisay, Dawit"

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    Flood Risk Analysis in Illu Floodplain, Upper Awash River Basin, Ethiopia
    (Addis Ababa University, 2015-12) Sisay, Dawit; Nigussie, Agizew(PhD)
    A flood has negative effect to human beings and properties even if it has positive effect. Because less attention is paid for risk, it should be analyzed and quantified properly. The Upper Awash River and flooding remain inseparable for long time in cultivated area. The objective of this study is to quantify and estimate the risk of flooding on crop production in the study area. The basic assumptions in statistical flood frequency analysis are the independence and stationarity of the data series and that the data come from the same distribution. Homogeneity and stationarity tests at different significance levels were made using Wald-Wolfowitz and Mann-Whitney tests. Using the method of moments of parameter estimation technique, the time series of the flow data was fitted to extreme value type one (EV I). The flood hazard mapping was done through HEC-GEORAS and HEC-RAS software’s. Finally, by comparing the amount of crop yield produced previously from a hectare of land and the expected crop yield from the inundated area the flood damage could be estimated. Thus indicates that, improved Awash Bello stream flow gauge station which measures flow data appropriately for the entire period i.e. it properly records the flow data without any disturbance from 1960 to 2010. The flow data of Awash Bello s station was found to be independent, homogenous, stationary and no outlier at 5% significance level. The quantile estimates of the 2, 5, 50, 100, and 500 year return periods for the site were also found to be 39.30, 50.38, 73.86, 80.69 and 96.46 m3/s, respectively. These floods inundated croplands having sizes of 1,959.50, 2,107.38, 2,299.16, 2,318.84, 2,354.06 hectares, respectively. These corresponded to losses of 44,088.66, 47,415.96, 51,731.03, 52,173.84, 52,966.25 quintals of crop, respectively. This study has shown that the upper most part of the cultivated is more inundated than the middle and lower parts. The areas affected by the flooding are found closer to the Awash River. Therefore, the affected areas is to be free of any agricultural activities, infrastructure development, investment and residence of people in order to avoid the risk of flooding in the area especially closer to the Awash River Keywords: Hec-Ras, Hec-GeoRAS, Flood hazard map and Crop production.
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    HIV seroconversion and associated factors among booked seronegative pregnant women in Kobo town and Raya Kobo woreds, North wollo,Ethiopia: institution based cross- sectional study.
    (Addis Abeba University, 2020-12) Sisay, Dawit; Gebremariam, Mulugeta Betre(AssocProf.-Dr.); Firdawek, Ewunetu (PhD)
    Background: Under the current practice, pregnant women who were Human Immunodeficiency Virus (HIV) negative on the first test are considered to be HIV negative throughout. A repeat HIV test three months later would identify HIV seroconversion and ensure early intervention to prevent mother to child transmission of the virus. The objective of this study is therefore to measure the magnitude of HIV seroconversion and to identify factors associated with HIV seroconversion among booked first-time test seronegative pregnant women. Methods: An institution-based cross-sectional study was conducted among HIV negative pregnant women in Kobo Town and Raya Kobo Woreda, North Wollo, Ethiopia from June to July 2020. Data were collected using a questionnaire through face-to-face interviews along with a client card review. HIV re-testing was performed to know the current HIV status of pregnant women. The collected data were entered into Epi data version 4.4.1 and were exported and analyzed by SPSS version 25. A p-value < 0.25 in the bivariate analysis were entered in the multivariable logistic regression analysis and a p-value of < 0.05 was taken as statistically significant. Result: From a total of 494 pregnant women who were screened and reported negative for HIV at first ANC, six (1.2%) were HIV seropositive during retesting. Upon multivariable logistic regression, pregnant women who have had a reported history of sexually transmitted infections [AOR=7.98; 95% CI (1.206, 52.818)], participants’ partners reported travel history for work frequently [AOR=6.00; 95% CI (1.093, 32.993)], and sexually abused pregnant women [AOR=7.82; 95% CI (1.194, 51.243)] were significantly associated with HIV seroconversion. Conclusion: The notable seroconversion rate found in this study implies that it is not enough to test pregnant mothers once during the first antenatal care clinic. Rescreening of pregnant women after the booking is a beneficial strategy to allow the timely provision of ART prophylaxis to HIV seroconverting women and their exposed babies for the elimination of mother to child transmission of HIV. Further expanded and large scale study should be conducted to understand the magnitude and the factors of HIV seroconversion during pregnancy at various levels.