| dc.description.abstract | Physical Development Plans (PDPs), particularly at localized scales in Uganda, are designed minus considerations for flash flood hazard mitigation, leading to the allocation of many land uses in inappropriate zones. This is largely attributed to the limited up-to-date flood data, posing a significant challenge to the planning authorities. This study aimed at exploring how geospatial technology can be leveraged to bridge this flood data gap to determine considerations for flash flood hazard mitigation during the design and implementation of urban physical development plans, in Mbale City.
The study utilized a mixed research design approach, employing Key Informant Interviews (KII) to inform the Analytical Hierarchy Process (AHP) in assessing the flash flood hazard influencing factors in Mbale City. The Flash Flood Hazard Index (FFHI) was employed to determine flash flood hazard susceptibilities within the city. GIS map overlays were used to assess the interplay between flash flood hazard susceptibility. Lastly, the Hazard Informed Land Use Matrix, corroborative evidence, case studies and relevant literature were used to determine non-structural mitigation approaches for flash flood hazards in the City of Mbale.
The 5 major flash flood influencing factors for Mbale City and their respective levels of influence were Land use/Land cover (47.3%), drainage density (18.4%), rainfall (16%), slope (9.9%) and soil (8.4%). Zones highly susceptible to flash flooding constituted 28.19% of Mbale City, while 59.35% were moderately susceptible and 12.37% were low susceptible zones. The flash flood hazard susceptibility map was validated using ground data and yielded an Area Under Curve (AUC) of 0.92, indicating a high level of map reliability. The assessment of the flash flood hazard susceptibility and land use interplay revealed that the presence of major wetlands, residential densities and ward coverage areas significantly influence flash flood occurrences. Key flash flood hazard mitigation considerations highlighted were nature-based solutions, ecosystem-based livelihoods, promotion of green infrastructure, flood insurance, development control and strict adherence to policies and guidelines.
Geospatial technology proved effective in informing flash flood hazard mitigation approaches during the design and implementation of PDPs. The study highlighted Land use as the most significant flash flood conditioning factor, emphasizing the need for a timely and informed land use allocation approach. It also recommends adopting flash flood hazard modelling and a comprehensive mitigation approach for addressing flash flood hazards in PDP design and implementation. | en_US |
