Ethiopian Journal of Engineering and Technology

Assessment of the Preparedness Level of the Community towards Earthquake Disaster in Hawassa City, Ethiopia

2024-11-13T14:01:41+03:00

The assessment of earthquake preparedness in Hawassa City, Ethiopia, focuses on evaluating the community's capacity to respond to seismic disasters, given its location within the East African Rift System. This region is characterized by significant geological activity, which contributes to the risk of earthquakes and necessitates robust preparedness strategies. The vulnerability of Hawassa to seismic events, along with its historical exposure to damaging earthquakes, underscores the importance of community readiness in mitigating potential impacts and enhancing resilience(Alaneme & Okotete, 2018; Ayele et al., 2021; Ruch et al., 2021). This study endeavors to assess the community's readiness for earthquake disasters through a qualitative research approach. Employing a community-based cluster sampling method, 200 questionnaires were disseminated within Hawassa city, yielding 179 completed responses. Analysis of the data unveiled noteworthy insights: 72.10% of respondents were male, with 38.5% holding a bachelor's degree or higher and 49.7% having resided in Hawassa for over a decade. Impressively, majority of respondents did not receive information or training on earthquake preparedness, even though most of respondents are aware of the potential risks and hazards associated with earthquakes. Alarmingly, all respondents reported knowing where to seek medical assistance in the event of injuries during an earthquake, a staggering 97.2 % lacked essential first aid supplies. These findings underscore a critical lack of preparedness within the community. In conclusion, while some households have encountered earthquakes, the majority remain ill-prepared. Urgent measures are warranted for the implementation of pre- and post-earthquake disaster management systems within government organizations responsible for disaster response. Additionally, comprehensive training programs for community organizations are imperative to bolstering disaster preparedness initiatives within the city.

Evaluation and Validation of the Causes for Cobblestone Road Failures in Hawassa City

2024-04-30T11:21:11+03:00

Cobblestone road failures are a process of decreasing the serviceability of the cobblestone road by causing potholes, poor bonding, and poor drainage conditions. The present cobblestone road condition of Hawassa city shows high failures. The severity of the cobblestone road is even more critical in the study area because of the significant problems of the construction process, clogged ditches, and poor crossectional slope. Similarly, the effect of failures in this area that is shown on the vehicles that use the road is also the main effect that affects the life span of the road since there is no legal load limit and freight vehicles use this road. This research mainly focuses on the assessment of cobblestone road condition by studying the causes of cobblestone road failure in relation to the sub-grade strength, traffic volume currently handled by the cobblestone road in Hawassa city with relation to standards, studying the drainage condition of the study area based on the availability and functionality of ditches and putting the remedial measures that should have to take through having a primary and secondary data collection method. For this study, different analysis methods are used such as descriptive, laboratory, and exploratory using the purposive sampling method. From this, the analysis of cobblestone road condition assessment is done by taking the weighted average of high failure of the study area based on various measurement and visual methods such as capturing the picture of road condition and measuring the deteriorated route length and width. In another way, cobblestone road failures concerning subgrade soil strength and the analyses were carried out using laboratory tests by taking representative samples from study area route segments. The test integrates density, maximum dry density, and CBR (California bearing ratio) determination. Based on the study the condition of the study area road segments taken as moderate and poor condition, handle higher traffic volume than the recommended standard for route that connects the main road to the public area, have poor crossectional slope compared to the standard manuals and taking visual inspection onsite but the soil strength of study area route segment attain the recommended standard so the cause of the failures are due to unavailability of the ditch and poor functionality, lack of timely maintenance, lack of legal load limit for low volume roads especially for those routes that connect main road with public areas and poor construction experience and the city municipality have to do scheduled survey condition, maintenance, construct ditches and put legal load limit to control the city low volume road to not deteriorate without attaining the service life year

Keywords: Cobblestone road failures, survey condition, Subgrade strength, California Bearing Ratio (CBR), Traffic volume

Impacts of Land Use Land Cover Change in Gidabo Sub-Basin: A Literature Review of the Case of Ethiopia Rift Valley Lake Basin

2022-03-02T04:23:49+03:00

In the past 50 years, there have been tremendous changes in land use pattern which exerted significant influence on land resource of the Ethiopia. This paper comprehensively analysed the primary scientific issues about the impacts of land use and land cover change on the water resource and sedimentation of Gidabo River Basin (Ethiopia. So far LULC change was studied for full basin and, upper parts of the basin from the years 1985 to 2018 by using Landsat TM and Landsat ETM+ and Landsat OLI/TIRS images. As the result, agricultural land and urban settlement is increasing and forest and grassland is decreasing in the basin. The impact of land dynamics on the hydrological response of the basin is studied up the year 2006 and reported as the surface runoff and evapotranspiration increasing staring from the year 1986 to 2006. Sediment yield and hotspot erosion area is identified based on detected land use and available measured sediment data of the basin. In this review, it is analysed that, the detected soil loss rate of the basin is significantly different form study to study and no assessment is done for the last 15 years since the measured stream and sediment flow data is limited at the year 2006. The shortage of such data and empirical estimation of sediment and flow for huge ungauged part of the basin (lower parts) have led for variation of results via analyses. Although a wide watershed interventions activity was held for the last 15 years in the watershed, no study analysed its effect so far. Hence, we would like to recommend undertaking a new study that can alleviate the variation of the previous studies upon land used land cover change, stream and sediment flow, and erosion hot spot area. Since the availability of measured sediment yield of the basin is too low, it is good to develop an empirical model that can substitute the measured sediment by using other watershed parameters.

Strategies to Mitigate the Occurrence of Errors in Construction Contract Documents

2024-03-22T15:17:53+03:00

The purpose of this study is identifying the causes of errors and prioritizing the strategies to mitigate the factors resulting in the occurrence of errors in contract documents considering the context of Ethiopian construction industry. Structured hierarchical matrix was developed based on pre-identified causes of errors, and initially evaluated by experienced professionals as part of content validation of the survey. Professionals working in various construction projects in Ethiopia were invited to participate in the survey. A framework based on Fuzzy AHP-TOPSIS was used to prioritize strategies to mitigate errors in contract documents. Kendall’s coefficient of concordance was conducted to examine and compare experts’ responses. In addition, sensitivity analysis was conducted to evaluate robustness of the prioritized strategies. The findings indicated that the major sources of errors based on their ranking are designer-related factors, client-related factors, management-related factors, and project character-related factors respectively. The prioritized strategies to be adopted to mitigate errors in contract documents are (i) adequate and efficient design team, (ii) design review management, (iii) partnering, (iv) provision of adequate time and money for contract document preparation and (v) realistic client requirements.

Time and Method Study Analysis to Improve Productivity of Shirt Manufacturing for Case of JP Garment

2024-11-10T16:16:02+03:00

Abstract: Productivity is crucial for global market competitiveness, requiring higher labor and machine efficiency. In the case company, the line efficiency of the shirt sewing line is below the target, and this was due to the unbalanced workload distribution and inappropriate working methods. This paper focused on integrating line balancing techniques and method study to improve the efficiency of shirt sewing lines. Method analysis was applied to bottleneck operations to minimize non-value-adding activities performed by operators. Cycle time for all operations was computed after performing adequacy and uniformity tests for time study data. Next, the researcher performed method analysis on four operations, which have a bottlenecking behavior using video analysis. A flow process chart and precedence diagram were developed. A flow process chart was used to analyze which event is value-adding, or non-value-adding. The stopwatch time for sleeve attaching operation shows 62 seconds but the Garment Sewing Data is 46 seconds and the delay time is 16 seconds. This can be improved by revising the working method and this study achieved savings of 13 seconds by eliminating non-value-adding activities. The second sewing operation analyzed was an armhole outline, and savings of 14 seconds were gained. The third operation that was analyzed was cuff attach and a saving of 14 seconds was gained and the last was bottom hem outline to gain a saving of 12 seconds.

Assessing the Impact of Climate Change on Drought Characteristics in the Central Rift Valley of Ethiopia

2024-03-14T14:50:55+03:00

The understanding of past and future droughts is vital for the development and management of water resources at certain area. Thus, this study assessed climate change's impact on meteorological drought based on the Standardized Precipitation Index (SPI) in the Central Rift Valley of Ethiopia. Rainfall data of nine stations for the period of 1985-2019 (historical) were obtained from the Ethiopian National Meteorological Agency. Projected rainfall data of Representative Concentration Pathway (RCP) scenarios under HadGEM2-ES were obtained from the CORDEX-Africa database selected for the years 2020-2049 (near), 2050-20779 (mid), and 2080-2100 (far future). The computed SPI values were, then subjected to frequency, intensity and Mann-Kendall (MK) and Sen’s slope-based trend analyses. Accordingly, based on SPI-3 values, 325 moderate, 141 severe, and 87 extreme drought events were identified in the historical period. Similarly, for the near future, 392 moderate, 171 severe and 95 extreme drought events were identified under RCP4.5, and 456 moderate, 184 severe, and 98 extreme drought events were identified under RCP8.5 scenarios for the far future. MK trend test showed about, 69% no trend and a 19% decreasing trend at 95% confidence level in the historical period. RCP 8.5 showed a significantly decreasing trend with the S-test of -158 and Z = -1.98 in near future and (S-test= -122, Z=-2.3) in the far future. But, RCP4.5 showed decreasing trend in the mid-future (S-test=-178, Z= -2.1). In general, the results showed that drought increased in intensity, severity and duration in the historical and future periods under RCP4.5 and RCP8.5 scenarios.

Quantitative 3D Landslide Susceptibility Assessment Using Finite Difference Method in Hawassa City, Southern Ethiopia

2024-04-30T10:47:17+03:00

Rapid urbanization is forcing settlement expansion to previously uninhabited areas which are potentially susceptible to geo-hazards such as landslides. Residents have moved to the foothills of Alamura Mountain in the last few decades. As a result, it is pertinent to evaluate the potential vulnerability of these settlements to landslide hazard. A three-dimensional finite difference model was developed to compute the factor of safety against rainfall triggered landslide using FLAC3D’s strength reduction algorithm. The models consisted of the rock mass layer and soil layer which were generated using SRTM 30 m DEM and AI generated spatially distributed depth to bed rock (DTB) data sets. Input parameters were estimated from field and laboratory testing and correlation equations for a mohr-coulomb constitutive model. The results show the factor of safety reduces from 1.84 in dry condition to 1.0 for saturated condition with water at the surface level. The model is limited to pore pressure at grid points and no seepage pressure is used due to unfavorable zone conditions. The results show significant reduction in factor of safety and implies these settlements are susceptible for landslides. A contour map of factor of safety were generated to depict the special variation of the landslide hazard.