Browsing by Author "Barasa, Bernard"

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Contribution of rainfall on rooftop rainwater harvesting and saving on the slopes of Mt. Elgon, East Africa
(Hindawi: The Scientific World Journal, 2020-07-18) Barasa, Bernard; Asaba, Joyfred
Despite the achievements reported from using rainwater harvesting systems, the contribution and drawbacks that affect their usage in mountainous landscapes have received little attention. The uptake and usage of domestic rooftop rainwater harvesting systems (RRWHS) in developing countries is on the increase due to increasing water scarcities. We explored the effect of rainfall variability on water supply and the downsides of using the systems by rural households in Uganda. The objectives were to assess the variability of rainfall (1985–2018), categorise RRWHS used, and examine the influence of slope ranges on the placement of systems and also to quantify the harvested and saved rainwater and establish the factors that affected system usage. Rainfall variability was assessed using a Mann–Kendall test, while system contributions and drawbacks were examined using socioeconomic data. A representative of 444 households were selected using a multicluster sampling procedure and interviewed using semistructured questionnaires. Findings revealed that the months of March, April, September, August, and October experienced an upward trend of rainfall with a monthly coefficient of variation between 41 and 126%. With this, households responded by employing fixed (reinforced concrete tanks, corrugated iron tanks, and plastic tanks) and mobile RRWHS (saucepans, metallic drums/plastic drums, jerrycans, and clay pots). At the high altitude, households deployed mostly plastic jerrycans and industrial plastic/metallic drums to harvest and save water. Overall, the mean annual volume of rainwater harvested on the slopes of Mt. Elgon was 163,063 m3/yr, while the potential to save water ranged from 4% to 7% of the annual household water demand. The factors that hindered the deployment of RRWHS to harvest and save water were high operational costs, price fluctuations, unreliable rainfall pattern, inadequate funds, and limited accessibility. The rainfall received if well-harvested and saved can redeem households of water insecurity, though there is an urgent need of subsidies from the government to increase accessibility of the systems.
The energy potential of harvested wood fuel by refugees in Northern Uganda
(The Scientific World Journal : Hindawi, 2022-02-22) Barasa, Bernard; Turyabanawe, Loy; Akello, Gertrude; Gudoyi, Paul Makoba; Nabatta, Claire; Mulabbi, Andrew
For the last three decades, Uganda has lost considerable natural vegetation cover in the refugee settlements and buffer zones due to the high demand for wood fuel and timber. It is worthy to note that the supplies of wood fuel are more likely to dwindle in the near future. This study explored the determinants of harvested wood-fuel choices and their energy potential. It also examined the implemented energy conservation measures and constraints faced by the refugees both in Palorinya and Imvepi refugee settlements in Northern Uganda. The data were collected by conducting household interviews and collection of wood species samples for energy potential laboratory analysis. Findings indicate that the major sources of wood fuel were firewood, charcoal, briquettes, and biomass fuels. The major refugee choices that determined wood-fuel collection included the family size of the house hold, culture, method of cooking, type of food cooked, high poverty levels, and availability of family labour (). The sampled wood tree species had the highest energy potential were Celtis durandii (5,837 kcal/kg), Parkinsonia aculeata (5,771 kcal/kg), Delonix regia (5,153 kcal/kg), and Bligihia unijugata (5,034 kcal/kg). Access to wood fuel by the households was mainly constrained by limited household income levels, long distances trekked, and inadequate awareness about wood fuel sources and availability. To conserve wood fuel, the refugees deploy several measures including the use of mobile solar gadgets for cooking and lighting, taking up agroforestry, use of briquettes, adoption of energy-saving cooking stoves, and establishment of new woodlots. Therefore, to reverse this trend, the Ugandan government and development partners should prioritise energy investments by supporting cheaper energy alternatives such as mobile solar gadgets and energy-saving cooking technologies, and establishment of woodlots.
Freshwater lake inundation monitoring using Sentinel-1 SAR imagery in Eastern Uganda
(Taylor&Francis Online: Annals of GIS, 2020-03-18) Barasa, Bernard; Wanyama, Joshua
In flood hazard assessment, little attention has been given to the seasonal observation of freshwater inundation using Sentinel-1 Synthetic-Aperture Radar (SAR) images in the tropics. To assess these spatial variations, this study examined the inundation magnitudes and reflectance of riparian flora in the raining seasons (February-April and September-November) and dry-periods (May-August and December-January). The inundation areas were determined using an object-oriented classification algorithm, whilst the merits concerning the lake, riparian vegetation and shoreline were well-defined using backscatter-coefficient values. Findings indicated that the SAR images are practical to monitor inundation coverages and discern lake basin specific features such as highland areas, shoreline, water and riparian-vegetation. Seasonally, inundated sizes were comparatively higher in February (902 sq. km) and October (700 sq.km). Backscatter values of inundated parts varied from −16 dB to −19 dB, whereas those of riparian vegetation were higher in the months of May and August. This study hence displays a clear-cut correlation between riparian-vegetation, hydrology and climate variables.
Hydrologic response to land use/cover changes and Pteronia incana shrub invasion in Keiskamma catchment, Eastern Cape Province, South Africa
(Geocarto International, 2022-02-07) Mlamla, Sive; Kakembo, Vincent; Barasa, Bernard
The Keiskamma catchment has undergone significant land use/cover changes (LUCC) and invasion by Pteronia incana (P. incana) shrub, and the hydrological implications of the phenomena are not fully understood. This study assessed the hydrological response of the catchment using remote sensing per-pixel classification, the SWAT model between 1994 and 2016, and field experiments. Results revealed a significant increase in woody vegetation encroachment and a decrease in mean annual streamflow, runoff, soil water content, evapotranspiration and groundwater. However, high surface runoff, and sediment loss were evident under P. incana invader shrub at hillslope scale. The study concludes that the hydrological response of the catchment was influenced significantly by LUCC in the form of extensive invader shrub encroachment, expansion of exotic forest tree species, impoundments and infestation of riparian zones by invasive vegetation. Control of alien invasive plants and utilization of indigenous forest species are recommended for catchment management.
The impact of refugee settlements on land use changes and vegetation degradation in West Nile sub-region, Uganda
(Taylor&Francis Online: Geocarto International, 2020-07-31) Barasa, Bernard; Mwiru, Aron; Turyabanawe, Loy; Muhamud, Nabalegwa W.; Ssentongo, Benard
Uganda continues to experience high-refugee population influx that is beyond the established settlement capacities. Little information is available on the present and future impacts of settling refugees and host-communities on landuse changes and vegetation degradation. This study used Sentinel-2 images (20m) of 2016-2019 and Dinamica Ego-software to determine the current and future spatial areal-extent of changes in 2022. Findings revealed a rarefied increase in areas under subsistence-farming, builtups and refugee-settlements while the losses were seen in savannah-grasslands, wetlands and woodlands. In 2021, the most significant increases in the land will be experienced in builtup-areas, settlements and commercial farming. The most degraded vegetation types were savannah-grassland, woodlands and tree-plantations. These were primarily attributed to unending activities of deforestation, bush-burning, high-refugee population, land-conflicts with host-communities and wetland reclamation. Thus, unless sustainable farming and energy-saving practices are promoted and adopted, the landscape is likely to remain not even with remnants of green-cover.
Past, present and future climate trends under varied representative concentration pathways for a sub-humid region in Uganda
(MDPI: Climate, 2019-02-26) Egeru, Anthony; Barasa, Bernard; Nampijja, Josephine; Siya, Aggrey; Makooma, Moses Tenywa; Majaliwa, Mwanjalolo G. J.
Long-term trend analysis at local scale for rainfall and temperature is critical for detecting climate change patterns. This study analysed historical (1980–2009), near future (2010–2039), mid- (1940–2069) and end-century (2070–2099) rainfall and temperature over Karamoja sub-region. The Modern Era-Retrospective Analysis for Research and Applications (MERRA) daily climate data provided by the Agricultural Model Inter-comparison and Improvement Project (AgMIP) was used. The AgMIP delta method analysis protocol was used for an ensemble of 20 models under two representative concentration pathways (RCPs 4.5 and 8.5). Historical mean rainfall was 920.1 ± 118.9 mm and minimum, maximum and mean temperature were 16.8 ± 0.5 °C, 30.6 ± 0.4 °C and 32.0 ± 0.7 °C, respectively. Minimum temperature over the historical period significantly rose between 2000 and 2008. Near future rainfall varied by scenario with 1012.9 ± 146.3 mm and 997.5 ± 144.7 mm for RCP4.5 and RCP8.5 respectively; with a sharp rise predicted in 2017. In the mid-century, mean annual rainfall will be 1084.7 ± 137.4 mm and 1205.5 ± 164.9 mm under RCP4.5 and RCP8.5 respectively. The districts of Kaabong and Kotido are projected to experience low rainfall total under RCP4.5 (mid-century) and RCP8.5 (end-century). The minimum temperature is projected to increase by 1.8 °C (RCP4.5) and 2.1 °C (RCP8.5) in mid-century, and by 2.2 °C (RCP4.5) and 4.0 °C (RCP8.5) in end-century.
A pattern driven approach to knowledge representation in the disaster domain
(Springer Link: SN Computer Science volume., 2020-10-22) Mazimwe, Allan; Hammouda, Imed; Gidudu, Anthony; Barasa, Bernard
Access to integrated disaster-related data through querying is still a problem due to associated semantic barriers. The disaster domain largely relies on the top–down approach of ontology development. This limits reuse due to associated commitments and complex alignments within ontologies. Therefore, there is a need to utilize a bottom-up approach that reuses patterns for representing disaster knowledge. To bridge the availability gap of patterns for representing disaster knowledge, this study identifies existing and emerging patterns for reuse while organizing disaster data from multiple sector stakeholders. Based on the eXtreme Design (XD) methodology and key informant interviews, competency questions (CQs) were elicited from domain stakeholders. The CQs are matched with existing patterns from other contexts. Emerging patterns (e.g the Event Classification and Quality Dependence Description for Objects) are also developed for CQs not captured and subsequently tested using SPARQL queries characterising the CQs. It is in this context that this paper presents a characterisation of disaster risk knowledge using CQs and corresponding patterns (reusable and emerging) covering the knowledge. Accordingly, we illustrate a pattern-driven use case to organise drought hazard data for early warning purposes. This provides a powerful use case for adopting a pattern-based approach to knowledge representation in the disaster domain.
The role of indigenous knowledge (IK) in adaptation to drought by agropastoral smallholder farmers in Uganda
(Indian Journal of Traditional Knowledge (IJTK)., 2020-01) Mfitumukiza, David; Barasa, Bernard; Egeru, Anthony; Mbogga S, Michael; Wokadala, James; Ahabwe, Andrew; Kasajja, Stephen; Namususwa, Zakia; Nabatta, Claire
Majority of agro pastoral smallholder farmers in developing countries are characterised by low pay status, high illiteracy levels and are tied to cultural beliefs and spirits. These drawbacks have led them into using more indigenous knowledge as a way of adapting to droughts. This study explored the contribution of IK in enhancing farmer’s resilience to drought in crop and livestock production systems in semi-arid areas. The objectives were: (i) to examine the agro pastoral farmer’s perceptions of drought indicators and associated impacts and (ii) determinants for the adoption of indigenous knowledge drought adaptation responses. Socio-economic data was collected using oral interviews. The farmers (240) were selected using random sampling procedures and subjected to structured questionnaires and key informant guides. This study highlights that the droughts experienced were perceived to be more severe, recurrent and pervasive but also erratic. The IK drought signs were: flowering of wild plants, blowing of strong winds and appearance of flying and crawling insects. In crop-based systems, droughts reduced yields, caused plant stunted growth, increased incidences of diseases and invasive weed species. In livestock, droughts reduced surface water levels, lowered milk and beef yields, and increased diseases. The farmers reacted to droughts by practicing indigenous agro forestry, mulching, changing planting time, crop rotation and hoeing of trenches to control fires and pests/diseases. They also took their animals to wetlands for foraging and drew water for animals to drink. The uptake of IK drought adaptation practices was related to: household size, personal farming life experience, gender and age of the agro pastoral farmers. Therefore, employing IK drought adaptation responses is an important step towards increasing the resilience of agro pastoral smallholder farmers but also the conservation of IK for forthcoming generations.