Browsing by Author "Bamutaze, Yazidhi"

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    Analysis of topographic parameters underpinning landslide occurrence in Kigezi highlands of southwestern Uganda
    (Natural Hazards, 2019) Nseka, Denis; Kakembo, Vincent; Bamutaze, Yazidhi; Mugagga, Frank
    An assessment of the influence of topography on landslide occurrence in the Kigezi highlands of southwestern Uganda was conducted. Whereas the frequency and magnitude of landslides in these highlands are on the increase, the topographic attributes underpinning landslide occurrence are not well understood. Sixty-five landslide scars were surveyed and mapped to produce landslide distribution maps. Specific topographic parameters, namely slope gradient, profile curvature, topographic wetness index (TWI), stream power index (SPI), and topographic position index (TPI), were assessed on landslide slope sites. The attributes were parameterized in the field and GIS environment using a 10-m DEM. Landslides were noted to concentrate along narrow topographic hollows, as opposed to broad concave slopes in the landscape. The occurrence is dominant in slope zones where slope gradient, profile curvature, TWI, TPI, and SPI are 25°–35°, 0.1–5, 8–18, − 1–1, and > 10, respectively. It was established that profile curvature and slope gradient are the most and least significant topographic parameters in landslide occurrence (R2 = 0.802, p value = 0.088 and R2 = 0.5665, p value = 0.057), respectively. An understanding of these topographic underpinnings would serve to identify and predict potential landslide zones within the landscape and enhance landslide hazard mitigation.
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    Assessing soil erosion risk in a peri‑urban catchment of the Lake Victoria basin
    (Modeling Earth Systems and Environment, 2022) Ssewankambo, Gyaviira; Kabenge, Isa; Nakawuka, Prossie; Wanyama, Joshua; Zziwa, Ahamada; Bamutaze, Yazidhi; Gwapedza, David; Tally Palmer, Carolyn; Tanner, Jane; Mantel, Sukhmani; Tessema, Bezaye
    Soil erosion and sedimentation contribute to deteriorating water quality, adverse alterations in basin hydrology and overall ecosystem biogeochemistry. Thus, understanding soil erosion patterns in catchments is critical for conservation planning. This study was conducted in a peri-urban Inner Murchison Bay (IMB) catchment on the northern shores of Lake Victoria since most soil erosion studies in Sub-Saharan Africa have been focused on rural landscapes. The study sought to identify sediment sources by mapping erosion hotspots using the revised universal soil loss equation (RUSLE) model in appendage with field walks. RUSLE model was built in ArcGIS 10.5 software with factors including: rainfall erosivity, soil erodibility, slope length and steepness, land cover and support practices. The model was run, producing an erosion risk map and field assessments conducted to ground-truth findings and identify other hotspots. The percentage areas for RUSLE modelled erosion rates were: 66.8% for 0–2 t ha− 1 year− 1; 10.8% for 2–5 t ha− 1 year− 1; 10.1% for 5–10 t ha− 1 year− 1; 9% for 10–50 t ha− 1 year− 1 and 3.3% for 50–100 t ha− 1 year− 1. Average erosion risk was 7 t ha− 1 year− 1 and the total watershed erosion risk was 197,400 t year− 1, with croplands and steep areas (slope factor > 20) as the major hotspots (> 5 t ha− 1 year− 1). Field walks revealed exposed soils, marrum (gravel) roads and unlined drainage channels as other sediment sources. This study provided the first assessment of erosion risk in this peri-urban catchment, to serve as a basis for identifying mitigation priorities. It is recommended that tailored soil and water conservation measures be integrated into physical planning, focusing on identified non-conventional hotspots to ameliorate sediment pollution in Lake Victoria.
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    Differentiated Spatial-Temporal Flood Vulnerability and Risk Assessment in Lowland Plains in Eastern Uganda
    (Hydrology, 2022) Erima, Godwin; Kabenge, Isa; Gidudu, Antony; Bamutaze, Yazidhi; Egeru, Anthony
    This study was conducted to map flood inundation areas along the Manafwa River, Eastern Uganda using HECRAS integrated with the SWAT model. The study mainly sought to evaluate the predictive capacity of SWAT by comparisons with stream flow observations and to derive, using HECRAS, the flood inundation maps. Changes in Land-use/cover showed by decrease in forest areas and wetlands, and conversions into farmlands and built-up areas from 1995 to 2017 have resulted in increased annual surface runoff, sediment yield, and water yield. Flood frequency analysis for 100-, 50-, 10-, and 5-year return periods estimated peak flows of 794, 738, 638, and 510 m3/s, respectively, and total inundated areas of 129, 111, 101, and 94 km2, respectively. Hazard classification of flood extent indicated that built-up areas and commercial farmlands are highly vulnerable, subsistence farmlands are moderately to highly vulnerable, and bushland, grassland, tropical high forest, woodland, and wetland areas are very low to moderately vulnerable to flooding. Results demonstrated the usefulness of combined modeling systems in predicting the extent of flood inundation, and the developed flood risk maps will enable the policy makers to mainstream flood hazard assessment in the planning and development process for mitigating flood hazards.
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    Drivers of forage availability: An integration of remote sensing and traditional ecological knowledge in Karamoja sub-region, Uganda
    (Pastoralism, 2015) Egeru, Anthony; Wasonga, Oliver; Mburu, John; Yazan, Elhadi; Majaliwa, Mwanjalolo G. J.; MacOpiyo, Laban; Bamutaze, Yazidhi
    Low-input pastoral production systems provide up to 90 % of livestock and livestock products consumed in Uganda. However, pastoral communities are increasingly faced with the challenge of meeting their livestock needs in terms of forage, a situation exacerbated by climatic variability. The study identified the patterns of forage availability and quality, compared perceived patterns of forage availability with normalized difference vegetation index (NDVI) and determined drivers of forage availability in Karamoja sub-region. Over a 12-month period, 75.3 % of the respondents perceived forage to be sufficiently available with differentiated availability in the livelihood zones and between livestock species (goats, sheep, cattle, donkeys and camels). A similar pattern was observed with regard to perceived forage quality. A significant relationship between perceived forage availability and long-term mean monthly NDVI dynamics was observed. A lag time of 2.9 months existed between rainfall and vegetation response peak periods. Mean monthly rainfall pattern was found to be correlated with perceived forage availability. The length of residence by a livestock keeper, frequency of grazing, number of kraals, presence of governing rules, and presence of conflicts and knowledge of pasture locations, restricted movement and ease of access to grazing areas significantly (P ≤ 0.05) were the major perceived drivers of forage availability. Therefore, we find that pastoral communities in Karamoja have detailed traditional ecological knowledge of forage status and their perceived determinants. There is a need to conduct nutritional analysis of key forage species available in the different livelihood zones. Finally, there is a need to constantly monitor socio-political conditions that have potential of creating ‘artificial’ forage shortage in the sub-region.
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    The Fragility of Agricultural Landscapes and Resilience of Communities to Landslide Occurrence in the Tropical Humid Environments of Kigezi Highlands in South Western Uganda
    (Springer, Cham., 2019) Nseka, Denis; Bamutaze, Yazidhi; Mugagga, Frank; Nakileza, Bob
    This chapter examines the influence of agricultural land uses on the occurrence of landslides in the humid tropical environments of Kigezi highlands in South Western Uganda. Analysis of the agricultural land use practices is a prerequisite to understanding landscape fragility and community resilience to landslide hazards. An analysis of agricultural land use patterns was undertaken through interpretation of Sentinel 2A images for 2016. The imagery data was acquired from the European Space Agency (ESA) Sentinels Scientific Data Hub. Field surveys and investigations were also carried out to establish and map the spatial distribution of landslide hazards. Six agricultural land use categories were identified, namely, annuals, perennials, grazing, fallow, wood lots and agroforestry. Considering the agricultural land use patterns, annual crops are the dominant agricultural land use type spanning 69% of the total area followed; by perennials (13%). Grazing land and fallows covered 11% and 5%, respectively. The study revealed that annual crop land is the most affected agricultural land use category. Out of the 65 landslide scars mapped, 31% occurred on annual crop areas. Wood lot areas experienced the least landslide occurrence (4%). A close spatial distribution of agricultural land use practices and landslide occurrence is discernible. It is recommended that a comprehensive tree planting campaign be carried out in areas prone to landslides since it was inferred that wood lots suffered least from landslides. It is also recommended that farmers be encouraged to restore and manage terrace bunds which could help to check on water velocity and consequently increase on slope stability.
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    Institutional Determinants to Climate Variability Adaptation by Smallholder Irish Potato Farmers in Rubanda District, South Western Uganda
    (American Journal of Climate Change, 2019) Mugagga, Frank; Elepu, Julius; Nimusiima, Alex; Bamutaze, Yazidhi
    Climate variability and change pose greater challenge not only to human life but to the environment at large. This study sought to evaluate the significance of institutional factors in climate variability adaptation of smallholder Irish potato farmers in Rubanda District, South Western Uganda with the objective of assessing the adaptation measures adopted by smallholder Irish potato farmers, determining the institutional factors that influence adoption of climate variability adaptation measures; and evaluating the institutional challenges that affect the adapting Irish potato farmers. A cross-sectional survey was undertaken to collect data from 197 systematically sampled smallholder farmers from two purposively selected sub counties (Muko and Bubaare) in Rubanda District, using structured questionnaires; whilst key informant interviews were used to elicit data from purposively selected personnel from the local government as well as private and civil society organizations. Multiple linear regression was used to determine the relative influence of selected variables on adaptation measures against climate variability. Results indicate that smallholder Irish potato farmers are adapting to climate variability through agronomic measures such as terracing, mulching, contour ploughing, changing planting dates, early planting, crop-rotation, and technology related measures such as rain water harvesting technologies, adaptive varieties and fertilizers among others. Results from multiple linear regression analysis show that several institutional factors are influencing adoption of climate variability adaptive measures with the most significant ones being access to agricultural extension services, cultivated area and size of land owned. Despite the interventions undertaken, adaptation to climate variability is constrained by the limited access to financial/credit resources and in- adequate technical capacity as well as limited access to information and irregularity of extension services. The study recommends that public and private institutions and personnel, both technical and political, at the various levels of local government, work together to improve extension services, communication as well as enhancing access to credit facilities among smallholder farmers, who will also need to further strengthen existing social groups to enhance their bargaining power.
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    Introduction to the AARSE2016 Special Issue of the South African Journal of Geomatics
    (South African Journal of Geomatics, 2018) Gidudu, Anthony; Bamutaze, Yazidhi
    The papers in this special issue of SAJG are derived from the 11th International Conference of the African Association of Remote Sensing of the Environment hosted in Uganda by Makerere University. The conference was held from the 24th to 28th October 2016 under the theme ‘Our Earth, Our Heritage: Harnessing Geospatial Technologies for Sustainable Development in Africa’, with a view of recognizing not only the past efforts related to resource management challenges, but also positioning to take care of the expected changes, owing to the post 2015 Global Development agenda. The conference attracted scholarship under the following sub themes: Space and earth observation technology for sustainable development goals (SDG’s), Disaster risk management and resilience, From climate change to climate risk management, Human capital development in geospatial science, Big Data and spatial data infrastructure utility and management, Africa space policy and strategy: Cost benefit of space technology, Geospatial science and technology for water and watershed management, Conflict management, human security and peace, Cities and demographic transitions, Geospatial technologies for Energy Management. From these presentations, selected high-quality papers were invited to develop and submit full papers to the SAJG for consideration in a special issue. These papers were subjected to the journal’s review process which involved a double blind peer-review and accepted papers are included in this special issue on successful address of raised concerns.
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    Variabilities and Trends of Rainfall, Temperature, and River Flow in Sipi Sub-Catchment on the Slopes ofMt. Elgon, Uganda
    (Water, 2021) Kilama Luwa, Justine; Mwanjalolo Majaliwa, Jackson-Gilbert; Bamutaze, Yazidhi; Kabenge, Isa; Pilesjo, Petter; Oriangi, George; Bagula Mukengere, Espoir
    The variabilities in rainfall and temperature in a catchment affect water availability and sustainability. This study assessed the variabilities in rainfall and temperature (1981–2015) and river flow (1998–2015) in the Sipi sub-catchment on annual and seasonal scales. Observed daily rainfall and temperature data for Buginyanya and Kapchorwa weather stations were obtained from the Uganda National Meteorological Authority (UNMA), while the daily river-flow data for Sipi were obtained from the Ministry of Water and Environment (MWE). The study used descriptive statistics, the Standardized Precipitation Index (SPI), Mann–Kendall trend analysis, and Sen’s slope estimator. Results indicate a high coefficient of variation (CV) (CV > 30) for August, September, October, and November (ASON) seasonal rainfall, while annual rainfall had a moderate coefficient of variation (20 < CV < 30). The trend analysis shows that ASON minimum and mean temperatures increased at = 0.001 and = 0.05 levels of significance respectively in both stations and over the entire catchment. Furthermore, annual and March, April, and May (MAM) river flows increased at an = 0.05 level of significance. A total of 14 extremely wet and dry events occurred in the sub-catchment during the post-2000 period, as compared to five in the pre-2000. The significant increased trend of river flow could be attributed to the impacts of climate and land-use changes. Therefore, future studies may need to quantify the impacts of future climate and land-use changes on water resources in the sub-catchment.