Rwanda Journal of Engineering, Science, Technology and Environment最新文献

{"title":"Estimating Soil Erosion to Highlight Potential Areas for Conservation Priority in Rukarara Catchment, South-western Rwanda","authors":"Fabien Rizinjirabake, A. Nyiramana, Théoneste Kamizikunze, J. Mukamugema","doi":"10.4314/rjeste.v5i1.1","DOIUrl":"https://doi.org/10.4314/rjeste.v5i1.1","url":null,"abstract":"Soil erosion is one of the major environmental problems in tropical ecosystems; however, the lack of information on the amount of eroded soils in  Rwandan mountainous watersheds hinders effective decision-making toward sustainable soil management. This study aimed at predicting soil erosion in  the Rukarara River watershed, one of the mountainous watersheds in Rwanda, and identifying potential areas of high erosion risk using the revised  universal soil loss equation (RUSLE) implemented in a GIS environment. The annual soil loss was estimated by computing and performing a spatial  overlay analysis of relevant layers including rainfall erosivity (R), soil erodability (K), slope length and steepness (LS), cover management (C), and  conservation practice (P) factors. The results indicate that the annual soil erosion varies from 54 to 134 t ha−1 year−1 (95% confidence interval) with a  mean of 39.96 t ha−1 year−1. The study area is generally characterized by very low and low soil erosion classes and the mean erosion correlated with literature results in the tropics. Agricultural lands are the hotspots of soil erosion with a mean of soil loss of 61.29 t ha−1 year−1. The produced maps and  soil loss estimates can facilitate informed decision-making toward sustainable soil management in mountainous areas of Rwanda, especially in the  Rukarara River watershed. ","PeriodicalId":418591,"journal":{"name":"Rwanda Journal of Engineering, Science, Technology and Environment","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127564889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geospatial Assessment of Urban Flood Susceptibility Using AHP-Based Multi-Criteria Technique: Case Study of Musanze, Rwanda","authors":"Hubert Hirwa, H. Ngwijabagabo, M. Minani, Simon Pierre Cardinard Tuyishime, Innocent Habimana","doi":"10.4314/rjeste.v5i1.6","DOIUrl":"https://doi.org/10.4314/rjeste.v5i1.6","url":null,"abstract":"Over the last decade, flood events in the northern and western urban areas of Rwanda have increased due to anthropogenic activities and the effects of  climate change. This study aims to use the Analytic Hierarchy Process (AHP) geospatial multi-criteria technique to identify flood susceptibility areas and  exposed assets in Musanze City. Seven factors were considered such as Topographic Wetness Index (TWI), Rainfall, Land Use Land Cover (LULC), Slope,  Soil Texture, River, and Digital Elevation Model (DEM) to create a flood susceptibility map with 5 classes (from very low to very high). To validate the final  map, 26 GPS points were collected from areas with a history of flooding, and the susceptibility classes were compared. Results showed that 33% of the  area (~2367 ha) was classified as high to very high risk, 23% (~1645 ha) was classified as moderate, and 44% (~3113 ha) was classified as low and very low susceptibility. The study also identified physical infrastructure and land use exposed in high and very high flooding areas, including 24 schools, 2  markets, and 1 health facility, 18668 km of roads, and 3400 buildings that are highly exposed to flooding. The applied methods in this study are useful for  urban planners and government officials in developing flood mitigation policies, strategies, and plans. ","PeriodicalId":418591,"journal":{"name":"Rwanda Journal of Engineering, Science, Technology and Environment","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122547327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial Assessment of Urban Growth on Green Spaces in Rwanda: An insight from Rebero Mountain Landscape in Kicukiro District, City of Kigali","authors":"Alphonse Rodrigue Nshimiyimana, Eric Niyigena, E. Nyandwi, H. Ngwijabagabo, Gilbert Rugengamanzi","doi":"10.4314/rjeste.v5i1.5","DOIUrl":"https://doi.org/10.4314/rjeste.v5i1.5","url":null,"abstract":"Green space is a crucial component of sustainable urban development that provides urban dwellers with several environmental and social benefits. This  study investigates the impact of urban growth on green space management on hilly landscape using a case study of Rebero Mountain in Kicukiro District,  Kigali City. The study used medium resolution satellite imagery (Landsat for 2000, 2010, and 2021) and high-resolution imagery (Quick Bird 2010  and Worldview 2 images of 2015) to assess Land Uses Land Covers (LULC) dynamics. To investigate the local community's perception on the effects of  urban growth on green space, interviews were conducted. The LULC changes detection revealed a significant decrease in green space with an increase in  the built-up areas. The urbanized area has been increasing from 7,422.10 Ha up to 14,730.94 Ha during the last two decades. The increasing built-up area  was in parallel with reduction of green space, specifically 44 Ha (-6.7%) of urban forest and 255 Ha (- 26.2%) of agricultural land, for the period  between 2000 and 2021. The reduction of green cover had a negative impact on the environment, such as soil erosion and biodiversity loss. In order to support decision-makers in fostering the development of sustainable and green smart cities, a spatially explicit assessment of the availability,  management, and accessibility of urban green areas is also important. Based on this research findings, the restoration of green spaces, including the  need for land-use and land-cover change monitoring, practical government physical planning interventions, and an inclusive strategy for managing the  city's green spaces that involves NGOs and citizens, and advocates for green city development are strongly recommended. ","PeriodicalId":418591,"journal":{"name":"Rwanda Journal of Engineering, Science, Technology and Environment","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115476764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Leveraging the Potential of Convolutional Neural Network and Satellite Images to Map Informal Settlements in Urban Settings of the City of Kigali, Rwanda","authors":"Esaie Dufitimana, Théophile Niyonzima","doi":"10.4314/rjeste.v5i1.2","DOIUrl":"https://doi.org/10.4314/rjeste.v5i1.2","url":null,"abstract":"The urban population is rapidly increasing and more than half of the world's population is currently living in cities. About 1 billion of city dwellers are  living in slums and informal settlements. Addressing the issue of slums and informal settlements require information on these areas. This study explored  the potential of Convolutional Neural Network (CNN) and Very-High Resolution satellite image to map the informal settlements in urban areas of the city  of Kigali, Rwanda. The study applied modified U-Net model with MobileNetV2 model as the base model to discriminate areas with informal settlements  from other areas. The model was obtained by modifying the original U-Net architecture to incorporate dilated convolutional operations at the beginning  of the network. The findings demonstrate that based on the spatial characteristics of informal settlements, the model was able to detect informal  settlements in urban areas with a recall of 0.862, a precision of 0.810 and an F1-Score of 0.809. Based on these results, the study can be a basis for finding  relevant information about informal settlements that are of concern in the implementation of SDGs, especially goal 11 addressing the issues of  safe and inclusive cities and human settlements.","PeriodicalId":418591,"journal":{"name":"Rwanda Journal of Engineering, Science, Technology and Environment","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114117135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Groundwater Potential Mapping using Geospatial and AHP Techniques in Eastern Province of Rwanda","authors":"H. Ngwijabagabo, A. Tsinda, Angelique Dusengimana, M. Minani, Cardinard Simon Pierre Tuyishime, Hubert Hirwa, Innocent Habimana","doi":"10.4314/rjeste.v5i1.4","DOIUrl":"https://doi.org/10.4314/rjeste.v5i1.4","url":null,"abstract":"The article presents an analysis of the potential groundwater recharge zones in the Eastern Province of Rwanda using Geographic Information System  (GIS) technology. The groundwater potential zones (GWPZs) in the area are influenced by several factors. To conduct the spatial analysis, seven theme  layers were created and integrated, including geology, drainage density, rainfall, slope, soil, land use and land cover (LULC), and normalized difference  vegetation index (NDVI). The Analytical Hierarchy Process (AHP), based on multiple criteria, was utilized to assign weights to each layer. By overlaying the  theme layers with the prescribed weights, a map of potential groundwater recharge zones was generated. These zones were classified into five  categories: poor, fair, medium, good, and excellent, representing 173 km2 (1.9 %), 1002 km2 (11.3%), 5976 km2 (67.2%), 1732 km2 (19.5%), and 12 km2  (0.1%), respectively. The findings revealed that a significant portion of the study area exhibited good to moderate potential zones for groundwater. Among the seven districts in the Eastern Province, Rwamagana district had the highest coverage of good and excellent groundwater potential zones,  accounting for 59% and 1% of the area, respectively. The accuracy of the GWPZ map was assessed by comparing it with borehole yield data, demonstrating the reliability of the chosen methodology. These validated results provide valuable support for the sustainable management and strategic  utilization of groundwater resources in the study area. The study outcomes can guide decision-makers in making informed choices regarding  the conservation of groundwater resources in the research area. ","PeriodicalId":418591,"journal":{"name":"Rwanda Journal of Engineering, Science, Technology and Environment","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133988204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measuring disparities in access to district and referral hospitals in the city of Kigali, Rwanda","authors":"G. Nduwayezu, E. Ingabire, J. Bizimana","doi":"10.4314/rjeste.v5i1.3","DOIUrl":"https://doi.org/10.4314/rjeste.v5i1.3","url":null,"abstract":"The study focused on the identification of theoretical and methodological constructs that can be used to analyse and improve the spatial performance of  public health service delivery systems and the development of a corresponding spatial-analysis and GIS-based planning approach using the city of Kigali  as a case study. Access to health care as a multi-tiered system was measured by using five dimensions of access, namely geographic accessibility,  availability, affordability, acceptability and accommodation. Geo-statistical analysis was performed to measure and evaluate access to the district and  referral health care. For geographic access, the travel time for every trip is approximated for the two main modes of transport (walking and public  transport). To realistically represent the friction of distance, the street network was categorised into several road classes for which different travel speeds  are estimated for each transport mode on the basis of local knowledge. A factor analysis model was used for availability, affordability, acceptability, and  accommodation dimensions. Different indicators were evaluated in various units and scales and standardized to see how satisfaction levels varied with  each dimension. Based on the type of indicator, for the cost or benefit, the score was zero (0) or one (1). One (1) was considered a positive impact, while  zero (0) was considered a negative impact. Summary scores were developed for all indicators by combining more than one indicator into a single value.  The created summary score also ranges from 0 to 1, and the higher the score, the better the access attainment. To find areas that need intervention, the  comparison of all five indicators and the scores of access for each indicator was made. The dimensions of geographic accessibility and availability  appeared to be the most problematic. The district health care dimensions have revealed a low performance level in geographic accessibility (0.64) and a  high-performance level in affordability (0.94). The referral health care dimensions have revealed a low performance level of geographic accessibility (0.17)  and a high-performance level of acceptability (0.92). Health planners and policy makers will commonly require such a planning method,  particularly in the developing world where spatial contexts are highly dynamic as a result of rapid urbanisation. ","PeriodicalId":418591,"journal":{"name":"Rwanda Journal of Engineering, Science, Technology and Environment","volume":"287 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130797276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Docking Studies between the Predicted Model of Mouse Zinc Finger MYND Domain-Containing Protein 19 and Cofactor Product Adohcy; towards Drugs Development against Cancer, Obesity and Cardiovascular Diseases","authors":"Bertin Mugabo, Rene Iradukunda, Jeanne Marie Gatanganwa, J. C. Ufitinema, D. Mutangana","doi":"10.4314/RJESTE.V4I1.3","DOIUrl":"https://doi.org/10.4314/RJESTE.V4I1.3","url":null,"abstract":"Mouse Zinc finger domain-containing protein19 (ZMYND19) is a zinc-finger protein questioned after recently published data reported its C-terminal domain of 49 residues to be associated with cancer, obesity and cardiovascular diseases. The potent drugs are suggested to come from its interactions with ligands understanding. However, the diseases are becoming worse because the three-dimensional structure of Mouse ZMYND19 is not yet reported. Thus, this study analyzed structural interactions between the predicted 3D structure and cofactor products S-Adenosyl homocysteine (AdoHcy) using the computational approaches. Pairwise sequence alignment was performed in the iterated mode of protein blast against protein data bank (PDB) and CLUSTAL omega server was used to perform multiple sequence alignment. Phylogenetic analysis was performed using the PHYLIP package. Structure prediction was successfully completed with the use of SWISS model by exploring homology modeling. The predicted Model structure was evaluated using both ERRAT and PROCHECK servers. Docking studies were performed with the HEX8 package. The evaluation results of the predicted 3D structure suggest that the model is of good quality. Docking studies revealed a high affinity (– 214.24 KjMol-1) between the predicted 3D model and AdoHcy ligand. The interaction between the bound molecules suggests both compounds to be good candidates for cancer, obesity, cardiovascular diseases, thus these two compounds could be considered at the frontline for a potent drug development.","PeriodicalId":418591,"journal":{"name":"Rwanda Journal of Engineering, Science, Technology and Environment","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125818297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solving an optimal control problem of hepatitis B virus dynamics: Efficacy of fuzzy logic strategy","authors":"Marcel Gahamanyi, Wellars Banzi, J. Ntaganda","doi":"10.4314/RJESTE.V4I1.1","DOIUrl":"https://doi.org/10.4314/RJESTE.V4I1.1","url":null,"abstract":"This work aims at using fuzzy logic strategy to solve a hepatitis B virus (HBV) optimal control problem. To test the efficacy of this numerical method, we compare numerical results with those obtained using direct method. We consider a patient under treatment during 12 months where the two drugs are taken as controls. The results are rather satisfactory. In particular, the reaction of HBV to drugs can be modeled and a feedback can be approximated by the solution of a linear quadratic problem. The drugs reduce the risk of HBV. Furthermore, results of both numerical methods are in good agreement with experimental data and this justifies the efficacy of fuzzy logic strategy in solving optimal control problems.","PeriodicalId":418591,"journal":{"name":"Rwanda Journal of Engineering, Science, Technology and Environment","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133257541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Organic Geochemistry of Peat Deposits in southwest Rwanda","authors":"T. Mugerwa, F. Hategekimana, O. Ehinola, I. Oladosu, D. Rwabuhungu, T. Bimenyimana, Fils V. Byiringiro, Cedrick Nsengiyumva","doi":"10.4314/RJESTE.V4I1.15","DOIUrl":"https://doi.org/10.4314/RJESTE.V4I1.15","url":null,"abstract":"Rwanda hosts million tons of peat deposits and that of western province is of great importance as it close to Kivu Lake. The discovery of methane gas in Kivu Lake has attracted investors in methane gas utilization as source of power supply and Compressed Natural Gas (CNG). Researchers identified Kivu Lake and adjacent area as an area of interest for hydrocarbon exploration. However, organic geochemical prospecting for hydrocarbon and energy content assessment is inadequate for the identified areas. The study aimed at determining the organic geochemistry of peat deposits in southwest, Rwanda. Forty (40) subsurface peat samples (1 to 10 m depth) were collected, air-dried and pulverized and screened. Five (5) samples with high organic matter content were subjected to biomarkers analysis using GC-GCMS. The n-alkanes distribution comprised mainly n-C11 to n-C 37. The Pr/Ph ratios (3.3-10.4, the waxiness index (0.09-0.87), CPI (3.6-7.8), OEP (3.5-6.0), C29 steranes (63.0–100.0%), C28 (0.0–28.0%), C27 (0.0–18.0%) and C27/ C29 sterane ratios (0.0-0.28). The ββ/ (ββ + αα) and 20S/ (20S + 20R) are 0.5 and 0.46 respectively. The C30 -moretane/ C30 -hopane ratios ranged from 1.56 to 2.42, while the oleanane index ranged from 0.07 to 0.26. The Ts/ (Ts + Tm) ratios ranged from 0.13 to 1.05. The dominance of C-29 sterols and C29/C27 sterane ratio which ranged from 3.5 to 100 indicating derivation from terrigenous higher plant material. The Pr/Ph ratio (>3) reflect the oxic to sub-oxic environmental condition during peat deposition. The peat deposits in Western Province, Rwanda are very rich in organic matter of mainly terrestrial precursor deposited in dry and cold climate.","PeriodicalId":418591,"journal":{"name":"Rwanda Journal of Engineering, Science, Technology and Environment","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133636293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Use of Geogrids in Mitigating Pavement Defects on Roads Built over Expansive Soils","authors":"Richard Shumbusho, G. Ghataora, Michael Burrow, Digne R. Rwabuhungu","doi":"10.4314/RJESTE.V4I1.4","DOIUrl":"https://doi.org/10.4314/RJESTE.V4I1.4","url":null,"abstract":"This study was conducted to investigate the potential benefits of using geogrids in mitigating pavement defects notably roughness and longitudinal cracking on pavements built over expansive soils. The seasonal changes of expansive soils (periodic wetting and drying) cause detrimental effects on the overlying road pavements. Such detrimental behavior of expansive soils was simulated in a controlled laboratory environment through allowing cyclic wetting and drying of an expansive soil underlying a pavement section. The shrink/swell effects of the expansive soil subgrade were examined through monitoring its change in moisture, and measuring deformation of overlying pavement section. The experimental study suggested that a geogrid layer in a reinforced pavement section can reduce surface differential shrinking and swelling deformation resulting from underlying expansive soils by a factor of 2 and 3 respectively in comparison to unreinforced section. Given that an oedometer test which is typically used to predict swelling potential of expansive soils is known to overpredict in-situ soil swell, experimental program also investigated quantitatively the extent to which the oedometer can overestimate swelling behaviour of the real-field scenarios. It was found that oedometer percent swell can overpredict in-situ swelling behaviour of the expansive soil by a factor ranging between 2 and 10 depending upon the period over which the in-situ expansive soil has been in contact with water.","PeriodicalId":418591,"journal":{"name":"Rwanda Journal of Engineering, Science, Technology and Environment","volume":"302 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116471536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}