Evaluation of flood protection measures under climate change scenarios : master thesis no.: /II. VOI-FRM

Unger, Kristina (author), Bezak, Nejc (mentor), Šraj, Mojca (comentor)

Floods are estimated to be one of the most frequently occurring natural hazards in Europe, which brings significant damages and threats to human life. Different mitigating strategies are being implemented nowadays to cope with different flood events due to the unpredictability of each particular flood disaster. What is more, the frequency and magnitude of this devastating natural phenomenon is expected to increase over time, which makes it necessary to establish effective flood mitigation measures to deal with the severe hazard. This research was conducted in order to define the most effective and suitable flood mitigation facilities for the selected case study, which is the Glinščica River catchment, located within the Ljubljana municipality in Slovenia. In this study to achieve the main research objective the following grey, green and hybrid flood mitigation measures were chosen for further modelling based on the conducted literature review: sidewalks and drywells/cisterns (grey measures), urban trees and rain gardens (green measures), green roofs and stormwater tree trenches (hybrid measures). The hydrological modelling was performed in HEC-HMS software to analyze the performance of the selected flood mitigation measures and define the most feasible ones for the chosen case study. To accomplish this, synthetic rainfall events and climate change scenarios were used as precipitation data. The modelling procedure was based on the SCS Curve Number (CN) method, where the CNs for each subbasin and each particular scenario were chosen according to the SCS soil type and land use type maps. In addition, lag time parameters were also calculated for each case based on the defined CNs and characteristics of each subbasin. In this study rain gardens were found to be the most effective measure with respect to the reduction in peak discharge and outflow volume at the final point of the Glinščica River model. Both green roofs and stormwater cisterns 1 (volume~11.4 m3) also showed relatively good results compared to the remaining measures. Depending on the scenario (1-8), the last place was occupied by permeable sidewalks and stormwater cisterns 2 (volume~5.7 m3). The detailed modelling procedure and final outcomes of the research are presented throughout this study.

• Language: English
• Keywords: civil engineering, master thesis, flood risk management study
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FGG - Faculty of Civil and Geodetic Engineering
• Place of publishing: Ljubljana
• Publisher: K. Unger
• Year: 2023
• Number of pages: X, 46 str., pril.
• PID: 20.500.12556/RUL-148918-60a78602-5930-f050-a246-ce1168e66e77
• UDC: 551.583:556.166(043.3)
• COBISS.SI-ID: 185883651
• Publication date in RUL: 01.09.2023

Secondary language

• Language: Slovenian
• Title: Vrednotenje protipoplavnih ukrepov z upoštevanjem podnebnih sprememb : master's thesis

Abstract

Ocenjuje se, da so poplave ena najpogostejših naravnih nesreč v Evropi, ki povzroča znatno škodo in ogroža človeška življenja. Dandanes se zaradi nepredvidljivosti vsake posamezne poplave izvajajo različne strategije za zmanjšanje tveganja, da bi se spopadli z različnimi poplavnimi dogodki. Poleg tega se pričakuje, da se bosta pogostost in intenzivnost tpoplav povečala, zaradi česar je treba vzpostaviti učinkovite ukrepe za zmanjšanje poplavne škode. Raziskava je bila izvedena z namenom, da bi opredelili najučinkovitejše in najprimernejše ukrepe za ublažitev poplav za izbrano študijo primera, to je povodje reke Glinščice, ki se nahaja v občini Ljubljana v Sloveniji. V tej nalogi smo za dosego glavnega raziskovalnega cilja uporabili modeliranje na podlagi izvedenega pregleda literature izbranih sivih, zelenih in hibridnih ukrepov za ublažitev poplav. Upoštevali smo naslednje ukrepe: porozni pločniki in zadrževalniki vode/cisterne (sivi ukrepi), urbana drevesa in dežni vrtovi (zeleni ukrepi), zelene strehe in jarki za meteorne vode (hibridni ukrepi). Hidrološko modeliranje je bilo izvedeno v programski opremi HEC-HMS, da bi analizirali uspešnost izbranih ukrepov za zmanjšanje poplav in opredelili najbolj učinkovite ukrepe za izbrano študijo primera. Da bi to dosegli, smo kot vhodne podatke o padavinah uporabili sintetične dogodke padavin in scenarije podnebnih sprememb. Postopek modeliranja je temeljil na metodi SCS Curve Number (CN), pri kateri so bili CN parametri za vsak primer in vsak posamezen scenarij izbrani glede na karte vrste tal in vrste rabe zemljišč. Poleg tega so bili za vsak primer izračunani tudi parametri časovnega zamika na podlagi opredeljenega CN parametra in značilnosti vsakega podporečja. V tej študiji je bilo ugotovljeno, da so dežni vrtovi najbolj učinkovit ukrep glede zmanjšanja odtoka (konica in volumen) na sotočju Glinščice in Gradaščice. Tako zelene strehe kot cisterne za meteorne vode (prostornina~11.4 m3) so pokazale tudi razmeroma dobre rezultate v primerjavi s preostalimi ukrepi. Glede na scenarije (1-8) so zadnje mesto zasedli drenažni pločniki in meteorne cisterne (prostornina~5.7 m3). Podroben postopek modeliranja in končni rezultati raziskave so predstavljeni v celotni nalogi.

• Keywords: gradbeništvo, magistrska dela, FRM študij