Urban flood risk management of Østerå in Aalborg

Kassam, Saad Allah Ghassan

4. term

Water and Environmental Engineering , Master

2020

2020-06-10

97

Specialet undersøger, hvordan åbningen af en ny kanalstrækning for Østerå i Aalborg påvirker risikoen for byoversvømmelser. En oversvømmelsesrisikovurdering er gennemført ved at indarbejde den nye kanal i MIKE URBAN 2017, et computerbaseret værktøj til afløb og hydraulik. Observerede data fra Østerå og Limfjorden samt historiske regnserier bruges til at opsætte modellen og gøre simuleringerne mere realistiske. Resultaterne viser, at den nye kanal sænker de forventede oversvømmelsesomkostninger og markant reducerer det oversvømmede areal i projektområdet, især i boligområdet Karolinelund. På baggrund af disse resultater undersøges det, om en mere bæredygtig håndtering er mulig ved at indføre styringstiltag, der begrænser afstrømning fra nærliggende boligområder. To strategier testes i modellen: passiv styring (faste indstillinger, der ikke ændres under en hændelse) og aktiv, lokal styring (tiltag, der kan justeres undervejs). Begge scenarier reducerer oversvømmelser og mindsker de samlede omkostninger. Til sidst afprøves løsningerne under fremtidige forhold for at belyse virkningerne af klimaforandringer. Resultaterne peger på, at styring af afstrømningen med enten passiv eller aktiv tilgang kan holde oversvømmelserne i projektområdet under kontrol både nu og i fremtiden.

This thesis examines how opening a new channel for Østerå in Aalborg affects urban flood risk. A flood risk assessment was carried out by representing the new channel in MIKE URBAN 2017, a computer model for urban drainage and hydraulics. Observed data from Østerå and the Limfjord and historical rainfall series were used to set up the model and make the simulations more realistic. The results show that the new channel lowers expected flood costs and significantly reduces the flooded area in the project area, especially in the residential district of Karolinelund. Based on these findings, the study explored a sustainable approach by adding control measures to limit runoff from nearby residential areas. Two strategies were tested in the model: passive control (fixed settings that do not change during a storm) and active, local control (measures that can be adjusted during events). Both scenarios reduced flooding and decreased total costs. Finally, the solutions were tested under future conditions to reflect the effects of climate change. The results indicate that controlling runoff with either passive or active strategies can keep flooding in the project area manageable both now and in the future.

[This abstract was generated with the help of AI]

Urban Flood ; Østerå ; Flood Management

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