Masters Degree Dissertations

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Evaluation of the factors influencing performance of building construction projects in Uganda : a case study of Masaka city
(Kyambogo University (Unpublished work), 2024-08) Hakizimana, Venust
In Uganda, over twelve percent (12%) of the gross domestic product (GDP) is contributed by building construction sector and is of great significance in current economy. Despite this contribution to the sector, building construction fail due to performance issues and limited research exists on the major factors contributing to this trend resulting in project delays and potential compromises in project quality. Finding ways to make building construction projects in Ugandan cities more effective was the aim of this study. a case study on the city of Masaka. Using the Krejcie and Morgan table for sample size determination, a sample of 201 respondents were chosen from the population of 420 participants in the study, which used a survey research design. A set of interview guidelines and a questionnaire were used to gather data. Excel and SPSS version 21 were utilized for the data analysis. Cost considerations, health and safety factors, time factors, productivity factors, quality factors, project stakeholders' factors, environmental factors, and resource variables were all identified. The findings of the regression analysis showed that the time factors (RII 0.751), quality factors (RII 0.717), and cost factors (RII 0.706) had a substantial influence on the performance of building construction projects in Masaka city. To enhance the performance of building construction projects, a framework was developed based on time, quality, and cost variables (factors with major influence). These findings highlight the need to prioritize these factors with significant impact when evaluating and managing building construction projects in Masaka City.
Comparative analysis of force account mechanism and contracting in implementation of road projects in central Uganda
(Kyambogo University (Unpublished work), 2024-10) Gamubaka, Fred Cedric
A well-maintained road network is critical to the transformation of a country’s economic development. This study compared the unit costs for implementing road improvements in Uganda using the force account mechanism versus contracting. Both quantitative and qualitative research designs were used in the study. The use of questionnaires with closed-ended questions helped collect quantitative data, and interview guides helped collect qualitative data. Stata (V13) was used to analyze the primary data that were gathered from the field, while Excel spreadsheets were used to analyze the secondary data. The findings on the influences for effective implementation of force account mechanism on implementation of road projects found that the cost per unit of the road was the most important, followed by employee skills, the availability of road equipment, and human resource costs. The study also found that the biggest barriers to the effective implementation of FAM were a lack of equipment, accountability for funds, and insufficient funding for road upgrades. The findings further, on comparison of the Unit cost for FAM and Contracting revealed that the unit cost incurred under contracting was five times higher than that incurred under force account mechanism. While on the strategies, the most significant strategy was adherence to public procurement laws followed by establishment of a supervision committee. In conclusion, FAM has saved the implementation costs of road projects in local governments though it still faces challenges most especially funding and equipment that the government has to solve. The study recommends that the government doubles the funding for implementation, buy enough equipment for districts, outfit the areas without workshops, evaluate the procedures for routine manual maintenance, conduct personnel training, and raise worker pay.
Assessment of moisture related defects in masonry walls
(Kyambogo University (Unpublished work), 2024-04) Elem, Joel
Moisture intrusion into walls continues to be one of the top challenges in the building construction industry in Uganda. The study assessed and investigated moisture related defects in masonry walls, materials and construction methods to mitigate moisture rise and related defects in masonry. This study made an assessment on moisture related defects in masonry walls, together with; carrying out a baseline survey on the building industry practice to find the cement to sand mix commonly used, and to assess prevalence of capillary water rise in buildings, determining the height of water rise by capillarity in masonry walls from damp proof course level, and finding out the materials and construction methods that can be used to mitigate moisture rise and related defects in masonry walls, as the specific objectives. Experimental masonry wall models measuring; 1.6m wide x 1.9m height x 230mm thick for the study. The models were built of ordinary clay bricks, well plastered and built with cement sand mortar / plaster of mix ratios; 1:1, 1:2, 1:3, & 1:4. Selected vertical points on the wall surface were cored and tested for moisture content. It was found that the masonry walls were susceptible to moisture rise, and it was also observed that; the stronger the mortar mix, the less the capillary rise of moisture in the wall. The height of water / dampness is highest at the bottom, just above the damp proof course levels, and moisture rise ranged between 0 – 0.6m above dpc levels. The study further investigated the efficiency of various water proofing materials that can be applied on the external walls to minimise capillary rise. The percentage reduction in moisture content was as follows; overlapping dpc 95, stone slates 94.1, glazed tiles 82.3, cement sand mortar in plaster with 4% clay giving 66.8, bituminous paint 44, facing bricks 43.7, and finally weep holes in plaster 30.5. All the three objectives were observed to be realistic, and true. And the study therefore concluded that water proofing treatment of masonry walls should be done to heights of not less than 0.70m above DPC level to improve durability of masonry walls against related effects. This provides knowledge, and innovation to the construction industry. And this study also recommends; the use of overlapping of damp proof course, together with slates, as some of the best water proofing materials. There is also need for conducting more research on the areas of; variation of strength of building units with moisture content, and failure mechanism of most water proofing materials.
Compression Index for cohesive soils from Quasi-static Cone Tests
(Kyambogo University (Unpublished work), 2024-04) Bivako, Richard
Compression indexiisiani important soili parameter in the design of foundations of structures yeti the Oedometer test used for its determination is time consuming, cumbersome and very costly. This prompted a number of studies to be done toi address the above limitations by relating Atterberg limits to compression index. However, determination of Atterberg limits has limitations which include stress-strain effects during penetration for the fall cone human reliability errors for the Casagrande method of liquid limits determination and Health & safety issues in handling contaminated soili material for Plastic limits. The aim of this research was toi develop ai simple, fast and accurate method of determining the compression index of cohesive soils using the Quasi-static cone test which addresses all the above limitations. 51i soili samples were collected from three districts of Uganda (Area = 1230km2) and tested for the compression index using Oedometer test, liquid limit using fall cone and Plastic limit using thread rolling. The Atterbergi limits were correlated toi compression index using regression analysis. The same soili samples were tested using the quasiistatic method and forces close toi 1020gfi and 60gfi were obtained for plastic and liquid limit respectively at 20mmi penetration depth. The empirical relationships relating the force from the quasiistatic method and compression index was found toi be 98%i accurate compared toi the compression index from Oedometer test.
Undrained shear strength based on piezocone and laboratory tests for tropical soils
(Kyambogo University (Unpublished work), 2024-06) Mubiru, David
This paper presents a study on the geotechnical properties of two residual soil sites (Buloba a less seismic zone and Buliisa an extreme seismic zone in Uganda) to characterize, propose and recommend models for the estimation of Undrained shear strength (Su). The analysis utilized data from 32 (Thirty-Two) piezocone penetration tests, Twenty-Eight (28) Liquid Limit tests, Twenty-Eight (28) Plastic Limit tests, Twenty-Eight (28) Linear Shrinkage tests, Twelve (12) Consolidation tests, 13 (Thirteen) Consolidated Undrained Triaxial tests. The results showed that the fine content, natural moisture content, liquid limit, plasticity index, and linear shrinkage varied within each site. Furthermore, the undrained shear strength, internal friction, and cohesive values also varied between sites. The study proposed appropriate empirical correlations for obtaining the Su of residual soils, and observed that Nkt value of 56 is proposed for slightly consolidated residual soils while Nkt = 288 should be used for heavily consolidated residual soils during the obtaining of the Su. Furthermore, the study concluded that SHANSEP constants of s = 0.07 and m = 0.82 should be appropriate for estimating the undrained shear strength of residual soils. However, caution should be taken as these empirical relationships are site-specific and considerate of uncertainties. Overall, this paper provides valuable insights for geotechnical engineers to consider for residual soil analysis.
The effect of cow dung ash and banana peels ash as a filler on marshall and volumetric properties of hot mix asphalt
(Kyambogo University (Unpublished work), 2024-05) Ntwirenabo, Coleb
Increased cost of construction materials for flexible pavements has urged researchers to opt for alternative filler materials instead of the conventional cement filler towards greener materials. In this work, cow dung ash (CDA) and banana peels ash (BPA) were investigated as potential substitutes at varied percentage filler contents. The first approach involved replacing the 4 % cement filler content with 25 %, 50 %, 75 % and 100 % with either BPA or CDA filler materials in the Hot Mix Asphalt (HMA). Secondly, the cement filler material within the prepared HMA was fully replaced with either BPA or CDA filler materials at varied amounts of 2 %, 4 %, 6 % and 8 % each. Marshal and volumetric properties including voids in the mix, flow, voids in the mineral aggregate, stability, and voids filled with bitumen in both scenarios were evaluated. Indirect tensile strength (ITS) was obtained for the full cement filler material replacement condition. For partially replacing the cement filler material, optimum parameters were revealed at 50 % CDA and 50 % BPA. For 50 % CDA, voids in the mix, voids in the mineral aggregate (VMA), voids filled with bitumen (VFB), stability and flow were 4.4 %, 16.2 %, 72 %, 16.7 kN, and 3.6 mm respectively. Meanwhile, for 50% BPA, voids in the mix, VMA, VFB, stability and flow were 4.4 %, 16.1 %,72.7 %, 10.63 kN and 3.37 mm. On the other hand, optimum parameters for fully replacing the cement filler material were obtained at 4 % CDA and 4 % BPA. For 4 % CDA, voids in the mix, VMA, VFB, stability and flow were 3.89 %, 16.9 %, 77 %, 13.9 kN, and 3.61 mm respectively. Meanwhile, for 4% BPA, voids in the mix, VMA, VFB, stability and flow were 4.06 %, 16.98 %,76.08 %, 10.7 kN and 3.31 mm. An ITS of 93 % and 98 % for 4 % CDA and 4 % BPA were noted respectively. From the test results, the developed CDA and BPA materials met the Uganda MoWT general specifications for roads and bridges for lighter traffic loading less than 1x106 Equivalent standard axle (ESAS). Thus, the green filler materials portrayed a viable potentiality to substitute the cement filler in the HMA which fosters reduction in the overall cost of road construction materials. This will have a positive impact on the Sustainable Development Goals, specifically targeting SDG 9 (pertaining to Industry, Innovation, and Infrastructure), SDG 11 (focusing on Sustainable Cities and Communities), and SDG 13 (centered around Climate Action).
Investigating the performance of precipitation products and outputs of cmip6 gcms in reproducing precipitation extremes observed across Uganda
(Kyambogo University (Unpublished work), 2024-11) Nakabugo, Joanita Irene
Precipitation products are increasingly being utilized as substitutes for observed precipitation data. This study evaluated the performance of five well-known precipitation products including CFSR, CHIRPS, JRA-55, ERA-5, and PGF and outputs from the CMIP6 General Circulation Models (GCMs) in replicating observed precipitation extremes across Uganda. Annual precipitation extreme events observed at 20 meteorological stations were compared with those from the precipitation products and GCMs outputs over the period 1979-2022. Utilized 6 precipitation extreme indices i.e. total precipitation (TPREC1), annual maxima series (AMS), number of dry days (NDD1), maximum dry spell (MWS1), number of wet days (NWD1), and maximum wet spell (MWS1) using a threshold of 1mm/day. To compare observed data with precipitation products, frequency analysis and bias ratios were applied. Correlation analysis and Taylor diagrams were utilized for comparing observed data with GCMs outputs. The quantile mapping bias correction method, implemented using the qmap package in R Studio, was applied to downscale GCM outputs with both observed data and precipitation products. This approach facilitated the determination of future climate change projections for the SSP2- 8.5 and SSP5-8.5 scenarios for the 2050s and 2080s. PGF systematically overestimated observed AMS at all the selected stations. Contrastingly, JRA-55, ERA-5, and CHIRPS datasets consistently underestimated observed AMS quantiles across all stations and return periods. The regression line for AMS when plotted against log-transformed return period exhibited a steeper slope for CFSR than that of the observed data. The null hypothesis (H0) of no correlation between observed and GCMs-based historical AMS, was rejected in varying proportions of the 20 meteorological stations. For instance, the H0 was rejected (p < 0.05) in 10% of the 20 precipitation stations across Uganda when observed AMS was compared with that of NOR_ESM2. For each of the three GCMs including CESSM_WACCM, INM_CM5, MRI_ESM2, the H0 was rejected (p < 0.05) in 5% of the 20 stations considered. The extent to which GCMs capture precipitation extremes varies due to their coarse spatial resolution. Bias correction of GCM outputs using quantile mapping method yielded different climate change signals in the cases when observations and precipitation products were considered. For instance, climate change impact on the total of precipitation above 1 mm/day intensity were over the ranges 40-170%, 20-61%, 15-41%, 5-36%, 8-67%, and 20-55% when bias correction of GCMs outputs were done using CFSR, PGF, CHIRPS, ERA-5, JRA-55, and observed precipitation, respectively. The choice of precipitation product significantly impacts climate projections. Thus, there is a need for careful selection of which precipitation product should be used for bias correction of GCMs’ outputs in absence of observed precipitation when analysis is being done for planning water resource management and climate change impact assessments.
Exploring the implications of community engagements in ensuring access to safe borehole water in rural setting in Uganda
(Kyambogo University (Unpublished work), 2024-09) Edhaya, David
Groundwater is essential for human consumption, agriculture and industry, traditionally deemed safe due to natural filtration. However, increasing pollution and limited community participation in borehole development have raised contamination concerns in Uganda's rural districts like Arua, Nakaseke, Lyantonde and Bugweri, where this study was conducted. This research examined the relationship between community engagement and borehole water quality using a mixed-methods approach, including surveys, water quality testing and geographical mapping. It assesses how community involvement in borehole site selection, construction, monitoring and maintenance influences water source protection and quality. A total of 530 structured questionnaires were analyzed to gauge engagement levels, while direct water quality analysis was conducted in Bugweri, with secondary data from Nakaseke, Lyantonde and Arua. Results show a significant link between community engagement and water quality, with better quality maintained in districts with higher community involvement. Factors like inadequate drainage and cracks around boreholes contributed to water contamination. For instance, Arua district showed a reduction in E. coli contamination with higher community adherence to borehole maintenance instructions. This study highlights the importance of active community participation in borehole development and maintenance for ensuring safe water access and improving public health, particularly during the wet season.
Investigating factors affecting contractors’ response to local government construction bids in Uganda
(Kyambogo University (Unpublished work), 2024-10) Bafaki, Gilvazio
Bidding is critical in identifying the best bidder for construction projects. More than 55% of Uganda’s national budget is spent through public procurement processes although the execution of the construction projects is not appeasing. This study aimed to investigate factors affecting contractors’ response to Local Government bids in selected districts in south western Uganda. It added new insights to the existing body of knowledge about contractors’ response to LG bids in Uganda which was scanty in literature. Descriptive study design was used and data was collected using questionnaire survey and interview method from a sample of 126 respondents who were randomly and purposively selected from a population of 188 comprised of contractors and community members in the selected districts. To analyse data, SPSS version 20 was used. The study revealed that there is a positive strong relationship between characteristics of construction bids and contractor’s response to LG bids (Pearson = 0.784; P-value = 0.00 < 0.05). The study also found out that there is a positive strong relationship between Factors (capacity, time and contract type) and contractor’s response to LG bids (Pearson value of 0.879; P-value 0.000 < 0.05). A proposed decision model for proficient bidding revealed that if the mark up is ≥ 62% then bidding process must be undertaken. The proposed framework developed showed a coordination gap among actors that can be included in the bid evaluation process. Standard construction bids in Uganda are mainly characterised by high bid security thus local governments should from time to time review the impact of bid security measures on contractor participation in local government construction bids.
Performance evaluation of waste stabilization ponds in the removal of pharmaceutically active compounds : a case of Lubigi wastewater treatment plant
(Kyambogo University (Unpublished work), 2024-11) Asiimwe, Brendah Patience
Waste stabilization ponds (WSPs) have been extensively used for the treatment of wastewater due to their simplicity and cost-effectiveness. This study evaluated the performance of WSPs in removing Pharmaceutically Active Compounds (PhACs) at the Lubigi sewage and wastewater treatment plant. Three wastewater streams were sampled; the inlet for the domestic wastewater stream, the point of discharge for cesspool empties containing faecal sludge from septic tanks, and the gulper station receiving faecal sludge from pit latrines. Additionally, samples were collected at different treatment stages i.e. the inlet to the anaerobic pond, the outlet from the anaerobic pond, and the discharge point to the facultative pond. Fresh and dried sludge samples were also collected. Sample analysis was performed using Liquid Chromatography Mass spectrometry (LC-MS-MS). PhACs were present in median concentrations of 19.223 μgL-1 in wastewater from the sewer network, 13.429 μgL-1 in septage and 18.641 μgL-1 in faecal sludge from pit latrines respectively, with average concentrations of in the three source streams of up to 5300 μgL-1. WSPs exhibited the ability to remove a variety of PhACs from wastewater at an overall removal efficiency of 76.15% with the highest removal efficiency of 70-99.99% for chlortetracycline, sulfapyridine, ampicillin, gentamicin, albendazole, ibuprofen, sulfachloropyridazine, sulfaquinoxaline, and penicillin, the moderate removal efficiency was 50-70% for like paracetamol, chloramphenicol and enrofloxacin, and the lowest removal efficiency of 1-40% for sulfadiazine, oxytetracycline, diclofenac, and ciprofloxacin. PhACs like sulfamethoxazole sulfamerazine and amoxicillin were more recalcitrant exhibiting negative removal efficiencies. The study found that faecal sludge (FS) from pit latrines (3.35 ton/year) and conventional sewer network systems (1.63 ton/year), contribute to substantial volumes of wastewater entering the Lubigi sewage treatment plant and therefore consequently reduce the treatment efficiency of WSPs in removing these PhACs as compared to septic tanks (0.74 ton/year). This study recommends the substitution of pit latrines with source-separated technologies, the addition of maturation ponds and other tertiary treatment mechanisms and the use of advanced treatment technologies to effectively remove PhACs, routine monitoring of PhACs, proper disposal and management of pharmaceutical waste, and further research on the behaviour and fate of PhACs particularly regarding their transformation and potential impacts when discharged into wetland environments.
Developing a maintenance management system for public buildings in district local governments of Uganda: a case of amuria district local government
(Kyambogo University [unpublished work], 2020-11) Elolu, Eonya Julius
The practice of building maintenance is globally accepted as the most sustainable way to conserve buildings from deterioration. In most developing countries, costs incurred for assessment, repair and maintenance of buildings are principally met by the local governments other than insurance companies and yet the former have insufficient funds to cater for the challenges of maintenance of buildings. This study sought to develop a maintenance management system for public buildings in District Local Governments of Uganda. Published literature on building maintenance management systems, condition survey index, defects severity and their priorities on the need to rectify was reviewed. The methodology used in this study had mechanisms of collecting both primary and secondary data sources that included key informant interviews, observations, inspections and desk studies. The maintenance management system was used determine the components to be maintained by ranking. This was premised on the severity of defects using a Multi-Criteria Decision Model (MCDM) that was based on the principals of Fuzzy Analytical Hierarchy Process (FAHP). During the study, condition assessment of buildings was conducted using an assessment tool and the staff that were involved in the management of buildings were interviewed. The findings showed that visual observation was the common mechanism used for condition assessment of building components due to the limited allocation maintenance activities in the development budgets. The common defects that affected components of the buildings were mostly cracks, surface deterioration, moisture ingress and debonding which was attributed to the social behavior of users and environmental factors. Most components were in good condition that required regular routine maintenance and a few were dilapidated and required immediate attention. This study recommended that District Local Governments need to establish the Maintenance Management System and regularly conduct condition assessments to inform the planning and budgeting of the built asset portfolio. Key Words: Maintenance, Defects, Components, Assessment, Management System
Assessment of variation in treated water quality and linkage to possible intrusion of contaminants in makindye division, Kampala, Uganda
(Kyambogo University [unpublished work], 2022-10) Twine, Pamela
Good drinking water quality is essential for human well-being. However, water quality in the distribution network tends to be affected at points of leakages through intrusion by pathogens. Maintenance of water tanks also tends to be very irregularly undertaken. The study was carried out through field surveys and data collection. This study aimed at assessing the extent to which the variation in treated water quality could be linked to possible intrusion of contaminants. Makindye Division, Kampala, Uganda was selected as the case study. The study had three specific objectives including: i) assessment of temporal variation in water quality parameters, ii) investigating variation of water quality parameters in space, and iii) determining the possibility of intrusion of contaminants along distribution networks. The research utilised both primary and secondary data for the distribution and storage tanks. With help of the Cochran formula, a sample size was obtained. For primary data, Samples were collected utilizing both Insitu and laboratory measurements for both direct connections and storage tanks. A questionnaire was also used to obtain data from the selected households and direct connections with analysis done in Excel. In objective 1, Turbidity was found to increase with time from 2015 to 2019 at a rate of 0.l45NTU per year. The highest turbidity values were obtained in 2018. Colour increased at a rate of l. l 8PtCo per year. Residual chlorine for the period 2015-2018 had an increasing trend at a rate of 0.0247mg/l/yr and was found highest in 2018. The month of March recorded the highest residual chlorine while the month of May recorded the lowest residual chlorine. pH was found to fall within the standard limits of 6.5 - 8.5. However, over the period 2015 to 2019, pH exhibited a decreasing trend at a rate of -0 .032 per year. In objective 2, the mean values of turbidity in water sampled from direct connections and storage tanks were 0.76±0.38NTU and 5.96±3.8NTU respectively. The average colour of water from the direct connections was 8±4.lPtCo while that of the storage tanks had 57±20.5 PtCo. Colour of water from the direct connections and storage tanks showed significant differences with p = l .74333E-l 0. The mean of residual chlorine in water sampled from direct connections was found to be 0.56±0. l 6mg/I while that from storage tanks was 0.25±0.13mg/1. Using the t-test, these mean values were found to be significantly different (p<0.05). In objective 3, the number of people who do not clean their tanks in the study area was found to be 58% of the study population. Those who clean their water storage tanks after one year or six months was found to constitute 43% of the sampled water users. Water storage tanks which are not cleaned or regularly maintained can be a potential source of contamination of water at consumer points. There was a significant difference (p<0.05) between the water quality in the distribution network and at draw off points for most of the parameters attributed to factors like; approximate of drainage systems (35%), toilets (30%), garbage pits (25%) and main road (48%). The number of leakages in the study area between 2016 and 2019 was found to be 4852 which exhibited a positive trend at a rate of 42 leakages per year. Whereas the significant difference (p<0.05) between water in the storage tanks and direct connection draw offs could have been due to leakages, none routine cleaning of storage tanks and the use storage tanks without covers. Kawuku and Soya villages were the most affected areas in terms of water quality distributed to them and this could be attributed to the connection on the dead end of the pipes. Leakage monitoring and management should be prioritized with constant sensitization of water users on how to clean tanks and maintain good water quality. Key words; Trend, water quality, water pollution, pipe leakages, water contamination.
Critical success factors influencing project performance of local road contractors in Uganda: a case study of selected districts in north eastern Uganda
(Kyambogo University [unpublished work], 2023-10) Awoii, Ahmad Okwir
This research established critical success factors determining project performance of local road contractors in the selected districts in north eastern Uganda. Local road contractors face challenges of time overrun, which leads to cost overrun, poor quality performance, leading to client dissatisfaction. In order to overcome these challenges, this research sought; to establish factors that impact on project execution of local road construction companies, to ascertain the effects of the established factors on road project implementation and to develop a framework to improve road project performance. A descriptive investigative research design was used, with mixed methods. The study population consisted of contractors, supervising engineers, client representatives, District/Town Engineer, local leaders and civil society organizations from which a sample size of 69 respondents was selected using simple random and purposive sampling methods. Questionnaire survey and interviews were the methods for data collection. Data were later analysed using relative importance index (RII) and regression analysis. The study examined a total of four factors and established that funding, ethical practices and technical capacity are the major critical factors that influence the performance of local road projects while managerial efficiency had no critical effect. It was further established that funding, ethical practices and technical capacity have significant (p<0.05) impact on road project performance, from which a framework to improve on performance of local road contractors was developed. The study concluded that critical success factors are; technical capacity, financial capacity and ethical practices. Key words; Success Factors, Projects, Performance, Local Road Contractors, Districts, North Eastern Uganda.
The distribution and bundance of endangered desert date (Balanites aegyptiaca) and its conservation measures in katakwi district
(Kyambogo University [unpublished work], 2022-10) Asiku, Jimmy
The global importance of Indigenous Fruit Trees as natural resource to meet the nutritional, health and socio-economic needs of rural communities cannot be ignored. Balanites aegyptiaca is among the most frequently used IFTs by local communities in Africa for food and medicine. This study was therefore conducted to understand the distribution, abundance, utilization, regeneration and conservation measures of Balanite aegyptiaca in Katakwi district. The objectives were to understand the; (i) distribution; ii) abundance and its associated species; (iii) utilization, methods of harvesting and land use land cover change effect on its generation and (iv) conservation and management practices. Quadrats were established to determine the distribution, abundance, and regeneration while Focus Group Discussion, questionnaires, observations, and photography were used to collect data on utilization, methods of harvesting threats, regeneration, conservation and management practices. GIS/Remote Sensing was used to obtain satellite imageries to depict land use land cover status of study area. Data was analyzed in SPPS and excel. Distribution was analysed from diameter at breast height (dbh) data while abundance was analysed by comparing different species data. Descriptive statistics such as mean was used to analyse utilization and conservation measure. The result showed thatBalanites aegyptiaca with large dbh (33, 29 and 25) were the most distributed and low abundance of Balanites aegyptiaca was recorded compared to the Vitex madiensis L. and Acacia seyal Del. Further, relative dominance was a significant predictor for rate of Balanites aegyptiaca harvested while distribution and abundance were not. There was a 55.5% increase in the mean number of trees harvested for each extra abundant species available. A significant number of respondents (68.6%) agreed that Balanites aegyptiaca is utilized by communities. A strong positive correlation existed between regeneration and, cutting down (r=0.850, p=0.003) and cutting off branches methods (r=0.768, p=0.01) while no correlation existed between picking the leaves directly (r=O, p=0.05) and climbing to pick the leaves (r=O, p=0.05). Balanites aegyptiaca is mainly used for food, medicine, source of income and fuel. The conservation measures included sensitization clan byelaws, cultural norms, controlled grazing and on farm retention. The study concluded that the distribution of Balanites aegyptiaca in study area is dominated by mature/old trees. There is low abundance of Balanites aegyptiaca as compared to Vitex madiensis and Vitex madiensis. The forest cover change over the years has reduced and other land uses are taking over. The local communities significantly utilized Balanite aegyptiaca to improve their socio-economic status. In general, the local community was worried that Balanite aegyptiaca population was reducing and fear it will get extinct if the current trend of harvesting cannot be reversed. Alternative sources of livelihoods need to be sought for the community to give the tree an opportunity to regenerate. The study recommended that the community needs to be supported to promote Balanites aegyptiaca into dry land agroforestry systems, the less harmful methods of harvesting needs to be promoted. Further study needs conducted to understand the Balanites aegyptiaca distribution along moisture gradient of the landscape which may offer an opportunity to restore degraded wetlands and a detailed study to assess its genetic diversity is needed to ascertain which sub species is more threatened to prioritize conservation efforts.
Enhancing phosphorous removal from wastewater using polyphosphate accumulating organisms from different waste streams
(Kyambogo University [unpublished work], 2023-08) Ssempala, Andrew Bbumba
Enhanced Biological Phosphorous Removal process has worldly been accredited for its efficiency m removing phosphorous from different wastewater treatment plants. This study focused on Enhancing Phosphorous Removal from wastewater using Polyphosphate Accumulation Organisms present in the Bugolobi wastewater treatment plant, Kampala city abattoir and Uganda Breweries limited. Wastewater from the Bugolobi wastewater treatment plant, Kampala Abattoir and Uganda Breweries Limited was assessed to establish a suitable source of the Polyphosphate Accumulating Organisms. The effect of inoculation of Polyphosphate Accumulating Organisms rich wastewater on Phosphorous removal in domestic wastewater was evaluated. Microbial tests isolated the bacteria present in the collected wastewater samples and thereafter Desoxyribonucleic Acid extraction from the bacterial broth was done. The extracted Desoxyribonucleic Acid was stored followed by qualitative and quantitative analysis using a nano drop. Microbial tests identified 16 different species of bacteria in the groups: firmicutes; High gram positive, β-proteobacteria α-proteobacteria and y-proteobacteria. Acinetobacter calcoaceticus strain was noted to be the dominate bacteria that accumulated more phosphorous. Different working conditions that enable phosphorus accumulating bacteria to thrive were also determined and amendments of phosphorus accumulating bacteria working condition gave an overall significant difference with acetate as the best carbon source, 25°C as the best optimum temperature and pH 7 for their activity. Of the three wastewater sources, Kampala city abattoir was found to have the most Polyphosphate Accumulating Organisms. Efficient phosphorous removal in the Enhanced Biological Phosphorous Removal system is highly dependent on Polyphosphate Accumulating Organisms suppressing Glycogen Accumulating Organisms. KEYWORDS: Wastewater, Wastewater characteristics, Polyphosphate accumulating organisms
Effect of land use activities on water quality, soil and vegetation cover for the conservation of nsooba lubigi drainage system, Kampala City
(Kyambogo University [unpublished work], 2023-07) Igunga, Kennedy
Human activities such as agriculture, rural-urban development, industrialization as well as excessive deforestation cause land-use changes associated with water pollution and consequently degradation of the natural vegetation and soil resource. This study, thus, sought to assess the impact of such land use activities on water quality, soil and vegetation cover on Nsooba Lubigi drainage system. The study used quantitative research design where the physical-chemical characteristics of soil and water samples along the catchment area were determined by American Public Health Association standard analytical methods. The actual effect of human activities on land use and vegetation coverage was assessed using image acquisition and processing using GIS. A minimum of 48 water samples and 48 soil samples were collected from designated locations within Nsooba Lubigi drainage system and stored in Duran bottles, ready for analysis. Kruskal-Wallis H-test, Fisher's exact test and ANOVA F-test were applied to analyze the obtained data. Results showed that the parameters differed significantly by stream (p < 0.05). The parameter concentrations of land-use types of wetland, built up areas and agriculture were EC (537.5 μs/cm, 472.5 μs/cm and 272.50 μs/cm), TDS(309.00 mg/I, 352.00 mg/I and 155.00 mg/I), TP (0 .84mg/l, 0.82 mg/I and 0.53 mg/I), TN (8.05mg/l, 11.27 mg/I and5.96mg/l), BOD (5.75 mg/I, 14.00 mg/I and 8.75 mg/I), COD (41.00 mg/I, 49.50mg/I and 42.00 mg/I), TSS (25.00 mg/I, 42.00 mg/I and 10.00 mg/I) and TOC (16.70 mg/I, 20.50 mg/I and 5.65 mg/I). E coli and Total Coliforms concentrations for wetland, built up areas and agriculture were 317.50 CFU/ml, 384.00 CFU/ml and 586.50 CFU/ml; and 912.00 CFU/ml, 1481.00 CFU/ml and 1265.00 CFU/ml respectively. Lead and Cadmium values for wetland, built up areas and agriculture for were 0.614 mg/kg, 0.356 mg/kg and 0.495 mg/kg; and 0.002 mg/kg, 0.005 mg/kg and 0.003 mg/kg respectively. Wetland coverage declined by approximately 5 hectares (47.2% to 14.58%) whereas bare land declined from 14.5% in 1998 down to 7% by 2018. Land-use activity had a significant effect on land cover area with built-up area observed to be higher than area under agriculture and bare land. In conclusion, this study identified human activities as the main drivers for decline in water quality, soil quality and vegetation cover change within Nsooba Lubigi drainage system. This calls for urgent attention by responsible authorities such as NEMA, KCCA and sensitization of surrounding communities on the benefits of this catchment area.
Assessment of membranes used in drying faecal sludge to minimise the sand take-away in the sludge drying beds
(Kyambogo University [unpublished work], 2023-08) Ngabirano, Deneth
Sludge drying beds provide sludge dewatering by allowing the liquid to both drain under gravity through a permeable medium on which the sludge sits, and to evaporate under ambient conditions. Lubigi plant with 19 sludge drying beds handles faecal sludge from pit latrines and septic tanks separately for sludge dewatering. Clogging in filter beds and sand membrane material is challenging as it continues to get off with dry sludge cakes. The study's main aim was to assess different membranes used in faecal sludge drying to minimise the sand layer takeaway in the sludge drying beds at Lubigi Faecal Sludge and Wastewater Treatment Plant. This study analysed the chemical and physical characteristics of faecal sludge in the existing and unplanted drying beds at Lubigi. A pilot-scale dewatering facility was designed and constructed with four unplanted sludge drying beds (A, B, C, and D) with a one m2 effective drying area. The cumulative percolate was measured following a non-uniform time interval of 5, 10, 30, 60, 180, 360, 720, and 1440 minutes. This lasted for ten days until the faecal sludge was dewatered entirely. Five raw faecal sludge samples collected from different points of the existing and operating beds were analysed using the Makerere University laboratory. The cake samples had average weights ranging from 0.48 to 46.98% of the respective chemical elements. Carbon and oxygen had the highest weight ratios of 46.96% and 36.73%, whereas sodium had the lowest, with 0.48% in all elements, respectively. Low sodium content implies low alkaline indices in the faecal sludge, which is desirable. Additionally, moisture content (ranging from 73.68% to 75.91 % by mass, mean= 74.81±1.11 %), sand content (between 17.43% (89.62 g) and 19.66% (118.08 g), mean = 18.344±0.86%) and calorific value (between 2846.38 kcal/kg to 3185.46 kcal/kg. Sand (Bed A) exhibited the highest mean dewatering rates with a peak of 502 mm after 4.5 hrs, followed by pavers with 416 mm after 7.5 hrs, nylon with 384 mm in 4.5 hrs and lastly, hessian with 59mm after 20hrs. The efficiency shows that hessian, nylon and pavers were efficient (R2 = 0.632, 0.592, and 0.540), followed by sand (R2 = 0.491). All membranes had a very significant correlation between dewatering time (t min) and percolate (Q ml), p < 0.05 based on a> 95% confidence level. Nevertheless, nylon expedited average filtration rates at all times compared to the rest of the media. This is because its cake yielded moderate moisture, sand, and calorific values compared to the rest of the media hence optimised. Nylon filter media was optimised based on different gauge sizes of 1.0 mm (reference size) (Bed A), 0.5 mm (Bed B), and 2.00 mm (Bed C). The average dewatering times of the filter media in Beds A, B, and C were 5, 60, 180, and 360 minutes, respectively. Bed C (2.0 mm) had the highest flow rate (156.61 ml) but the lowest sand content (82.14%, 85.16%), Bed B (0.5mm) had the lowest flow rate (49.09 ml) and the highest levels of moisture content (86.91 %, 90.92%) and Bed A (1.00mm) had the intermediate flowrate (83.37 ml), moisture (83.28%, 87.28%), sand (13.24%, 14.8%, and calorific value (2745.12 Kcal/kg, 2600.12 Kcal/kg). These were determined based on the size of holes in the filter media, hence recommending the 1.00 mm nylon gauge. Keywords: Calorific value, Dewatering, Faecal Sludge, Lubigi, Moisture Content, Optimisation, Sludge Drying Beds and Sand Content.
The locally designed water treatment technology for a vehicle washing bay’s effluent in Wakiso district, Uganda
(Kyambogo University [unpublished work], 2022-10) Kansiime, Baker
Vehicle washing is a very lucrative industry that is rapidly growing in Uganda due to the increased demand for transport services. In an event of washing vehicles, a lot of water is used that transform into waste water. Therefore, the study focused mainly on quantifying the daily volume of water used, characterizing the pollutants, designing waste water treatment technology and quantifying volume of water recovered. The study used a jerrycan model, Auto card to implement and design the technology, and used Microsoft Excel and R data analysis to organize and analyze data. Daily, 29.3±6 saloon vehicles of weight less than 3.5 tons and 9.4±3.3 heavy truck vehicles of weight at least 3.5 tons and more were washed. However, 4,841±314 litres of water were used daily 97.2±26 litres of water for each saloon vehicle and 212±48 litres for each heavy truck. The designed technology was effective in treatment of the vehicle washing bay waste water for turbidity from (1139±13.4 NTU to 57.5±24.1 NTU), TSS (2878±2.5 mg/l to 46±25.8 mg/l), COD (458±2.5 mg/l to 46±7.3 mg/l), orthophosphates (5±0.5 mg/l to 1.86±0.375±0.5 mg/l) and TDS (107±18.8 mg/l to 96.7±4.33), EC (413±24.3 μS/cm to 372±16) and pH (7 ±0.3 to 7.58±0.21) conforming to the recommended waste water discharge standards at 100% (NEMA, 2014). However, pH, EC and TDS values were within the recommended waste water discharge standards before treatment. In summary, 80% of the waste water was recovered as treated water and 20% of waste water lost by the treatment system. In conclusions, the waste water from Vehicle washing bays is polluted with pollutants levels that do not qualify it to be discharged into the environment without treatment. Therefore, there is a need to adopt a locally designed constructed wetland technology in the treatment and recycling of waste water from the vehicle washing bays, for both environmental protection and reuse.
Assessment of the effect of variation on the performance of paved road projects in Uganda- a case of Uganda national roads maintenance program-Rwenzori region
(Kyambogo University [unpublished work], 2023-10) Lukala, Justine
The Ugandan government has outlined infrastructure development as government priority. However, escalation in cost and time overruns of paved road projects is leading to lower density of roads network. This study was conducted in the Rwenzori region in Uganda considering Kyenjojo – Fort Portal (50km) road, Fort Portal – Hima (55km) road, Hima - Katunguru (58km) road and Katunguru - Ishaka (58km) road rehabilitated under Uganda National Roads Maintenance Program. Both qualitative and quantitative data were collected using survey questionnaires from a sample size of 79 elements and documentary reviews. Data on causes of variation, impacts and mitigation strategy actions were analyzed using IBM SPSS and ranked through mean item scores. The study revealed that delayed issuing of approval documents, changes in scope of works and changes in design were the highly ranked client’s causes of variation. Changes in design, design flaws and delayed decision making were common with consultant whereas poor coordination and project management, delayed acquisition of permits and shortage of skilled manpower were highly ranked contractor’s causes. Delayed project completion, increased project cost and rework and demolitions were the highly ranks impacts of variation. The mitigation strategy actions to control variation and enhance performance were; adequate planning and availability of fund before works start on site, detailed site investigation at pre-construction stage while comprehensive design and financial reviews, client expedite approvals and decision making were recommended at construction stage. In Project performance (PP) model, impacts of variation (Iv) ranked highest with 34.08%, followed by mitigation strategy to control variation (Mv): 33.27%, then causes of variation (Cv): 32.65%. The research recommends a study on developing an appropriate approach of capturing data with regard to variation in paved road rehabilitation projects. Key words: Variation, Paved roads, Project performance, Model, Rwenzori Region
Investigation of the suitability of concrete infilled bamboo for structural performance in compression for low-cost building
(Kyambogo University [unpublished work], 2023-10) Okuda, James Gowon
Various Engineering Scholars and Building construction materials and researchers have been doing experiments on investigating properties of Plain Bamboo, Concrete infilled Bamboo composite, and use of Bamboo to replace reinforcements in Concrete. Little has been disseminated on the Concrete infilled Bamboo with various concrete mix ratios. There are scarce and scanty documented and published information relating to the structural properties of Concrete infilled Bamboo as composite material. It is urgent to venture and understand through experimental investigations the Structural Properties of Concrete infilled bamboo to understand its structural properties to proof reliable usage when designing low-cost buildings, especially when considering axial compressive loading. Bamboo grows fast, and its readily available natural resource, with proven high strength and low weight to height ratio. For decades, Bamboo has been used as a rural building construction, and with recent innovations for domestic furniture. With recent research and innovations to look for alterative building materials to substitute concrete and steel, Bamboo Mechanical and structural properties have proven ideal for construction especially for low-cost houses units. Its major short fall however remains buckling, which is limits their usage in buildings subjected to compressive loads. This thesis outlines an experimental approach to investigate the properties, specifically the compressive strength when bamboo is infilled with concrete to form a composite material. Experimental investigation and results of the compressive strength of concrete infilled composite, with different concrete grades subjected to loads was experimentally investigated to appreciate the compressive strength of Concrete infilled Bamboo at different Bamboo samples lengths. This research mainly was based to assess the compressive strength of plane Bamboo, and concrete infilled Bamboo using varying concrete grades. The positive results from the experiment can outline an avenue and evidence for its suitability in expanding the usage of Bamboo as a construction material for low-cost shelter constructions. In this research paper, the compressive strength of plane Bamboo and concrete infilled Bamboo with concrete grades C12/15, C16/20 and C20/25 was investigated. Overall, there was marked improvement on the compressive strength of Concrete infilled bamboo culms. For Experimental tests done on plain Bamboo, the failure load was found to be decreasing with increasing Bamboo sample lengths. The axial load capacity of plain Bamboo at 0.2m sample length is 26.4% more than that at 1m length. Concrete infilled Bamboo with C15, C20 and C25 led to an increment of 58.7%, 103% and 139.1% of the compressive strength capacity compared to plain bamboo culms sample test length at 1m respectively; and 54.4%, 77.6% and 100.8% at Sample lengths of 0.2m. Concrete infills greatly improves the load capacity of identical bamboo culms. The failure load capacity was increasing when Bamboo sample lengths were infilled with Concrete, and the Load carrying capacity increases when Bamboo was infilled with concrete of higher grades. Bamboo infilled with concrete grade C25 has a large failure load than that infilled with concrete grade C20 and C15, signifying a higher ductility behaviour. From the study therefore, it can be concluded that concrete infill in bamboo can delay the buckling of the culms, and thus significantly improves the compressive strength capacity and ductility. There were observed differences between the experimental and the theoretical results of concrete infilled Bamboo. The difference in results could have come as experimental results were derived from actual laboratory experiments on the plain Bamboo and concrete infilled Bamboo under study. Theoretical “results" was just an application of the latest theories, formulae, and references on confined concrete to try to predict how it works, assuming its relative structural behaviour and performance. Finally, this research can be a resource for reference and formulating further innovations in Structural Engineering design to use Concrete infilled Bamboo composite as a building materials properties understood for effective design, repeatability, adoption for conventional construction and maintenance to meet the current need for innovative and new building materials. Key words: Plain Bamboo, Concrete infilled Bamboo, Compressive strength.

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