1. |
- Juma, Benard, et al.
(författare)
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Flooding in the urban fringes : Analysis of flood inundation and hazard levels within the informal settlement of Kibera in Nairobi, Kenya
- 2023
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Ingår i: Physics and Chemistry of the Earth. - : Elsevier BV. - 1474-7065 .- 1873-5193. ; 132, s. 103499-
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Tidskriftsartikel (refereegranskat)abstract
- Overlapping conditions of rapid urbanisation and climate change across developing countries are threatening the capacity of cities to manage climate risks, especially in the flood-exposed low-income peripheral areas. Limited studies have applied hydrodynamic flood models in ascertaining flooding conditions, supportive of risk-informed decisions in such urban fringes. Against this backdrop, we assessed plausible flooding and hazard conditions in the low-lying villages of Lindi and Silanga in Kibera informal settlement. The coupled one-dimensional and two-dimensional hydrodynamic model, customised from the Hydrological Engineering Centre's River Analysis System (HEC-RAS) was parameterised for flood simulation under different hydrological regimes and scenarios associated with flooding in Kibera. Volumetric flow estimates and a computed energy slope were used to define the upstream and downstream modelling boundary conditions respectively. Trial-and-error adjustment of the flow resistance coefficients from land-use features was applied in model calibration, and the results compared to the surveyed flood of 23rd April 2019. Results show that proximal areas to the Ngong River and Nairobi dam face high flood risks. A flood volume of 11.7×105m3 from a 2.5h, 50 mm rainfall could potentially inundate about 2.0% and 8.3% of areas in Lindi and Silanga respectively, while a volume of 48.9×105m3 from a 100-year storm of 172 mm could inundate about 10.6% of Lindi and 29.1% of Silanga. Upstream steeply sloping topographies of the villages increase flood velocities and risk of drowning, while the lower reaches at relatively flatter topographies, experience attenuated flow and rapid accumulation of flood waters, hence, higher flood depths. These results can support policy interventions for integrated flood risk management in Kibera, as a way of mainstreaming the underserved urban communities in climate risk management.
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2. |
- Juma, Benard, et al.
(författare)
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Simulation of flood peak discharges and volumes for flood risk management in the ungauged urban informal settlement of Kibera, Kenya
- 2022
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Ingår i: Physics and Chemistry of the Earth. - : Elsevier BV. - 1474-7065 .- 1873-5193. ; 128
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Tidskriftsartikel (refereegranskat)abstract
- In spite of the increasing extremity and adverse consequences of urban floods under climate change, flood characteristics in most developing countries are still largely unknown due to lack of continuous monitoring. This portentous uncertainty stances high flood risk, especially to a majority low-income urban population inhabiting the flood-prone informal settlements. Physically-based hydrologic models, whose parameters are derivable from catchment features, are often used for hydrological analysis in the ungauged regions. In this study, the Hydro-logic Engineering Centre's-Hydrologic Modelling System (HEC-HMS) was used for rainfall-runoff simulation in the upper Ngong River Basin of Kenya, draining into the Kibera informal settlement, for purposes of estimating flood peak discharges (FPDs) and direct runoff volumes (DRVs), often required for flood risk management. The Soil Conservation Service-Curve Number (SCS-CN), SCS-Unit Hydrograph (SCS-UH) and Muskingum models were used for hydrological simulation from four (4) observed and fifty-four (54) hypothetical extreme rainfalls. The results obtained indicated that a 50 mm rainfall event with a duration of 2.5 h has the potential of producing FPD and DRV of about 90m3s-1 and 1.17 x 106m3 respectively at the Ngong River confluence at Sokomoko in Kibera. On the other hand, the non-intermittent 100-year storm event of about 172 mm in depth, occurring over a period of about 4 h, potentially generated FPD of about 460m3s-1 and DRV of about 4.89 x 106m3, portending calamitous impacts in the basin. These results can offer preliminary information on potential flood character-istics, that can be used as a baseline to support local-level flood risk mitigation measures in the ungauged Ngong River Basin.
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3. |
- Mulligan, Joe, et al.
(författare)
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Participatory flood modelling for negotiation and planning in urban informal settlements
- 2019
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Ingår i: Proceedings of the Institution of Civil Engineers. - : ICE PUBLISHING. - 1478-4629 .- 1751-7680. ; 172:7, s. 354-371
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Tidskriftsartikel (refereegranskat)abstract
- Participatory modelling in water resource management - involving diverse actors in what is traditionally a purely analytical process - is thought to broaden stakeholder engagement and improve outcomes. Further research and case studies are required to explore the practicalities of integrating meaningful participation within modelling processes in the water sector. Participatory modelling may be of particular interest within the context of urban informal areas, where the confluence of climate change, urbanisation and contested land requires new methods for engagement and planning. This paper develops new case-based knowledge to inform the application of participatory modelling and planning for informal urban areas. A flood-modelling project in the large informal neighbourhood of Kibera in central Nairobi, Kenya, is analysed using a newly established framework for the classification of participatory modelling approaches developed by Basco-Carrera et al. in 2017. Conclusions suggest that the further upstream more diverse stakeholders can be involved, the better the chance of co-producing new knowledge and of creating implementable plans and policies. At the same time, delivering 'co-design' of modelling processes in areas of limited co-operation requires a strong vision for participation, a tolerance for contention, a willingness to learn between actors and a budget to support additional time inputs.
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4. |
- Scaini, Anna, et al.
(författare)
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Pathways from research to sustainable development: Insights from ten research projects in sustainability and resilience
- 2024
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Ingår i: AMBIO. - : SPRINGER. - 0044-7447 .- 1654-7209. ; 53
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Tidskriftsartikel (refereegranskat)abstract
- Drawing on collective experience from ten collaborative research projects focused on the Global South, we identify three major challenges that impede the translation of research on sustainability and resilience into better-informed choices by individuals and policy-makers that in turn can support transformation to a sustainable future. The three challenges comprise: (i) converting knowledge produced during research projects into successful knowledge application; (ii) scaling up knowledge in time when research projects are short-term and potential impacts are long-term; and (iii) scaling up knowledge across space, from local research sites to larger-scale or even global impact. Some potential pathways for funding agencies to overcome these challenges include providing targeted prolonged funding for dissemination and outreach, and facilitating collaboration and coordination across different sites, research teams, and partner organizations. By systematically documenting these challenges, we hope to pave the way for further innovations in the research cycle.
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