The Truro area consists of a low lying urban development located along the floodplain of the Salmon River estuary in Nova Scotia (Figure 1). Together these models were used to quantify the flood extents of the Salmon River estuary and its tributaries and to evaluate the impacts of over 40 potential flood mitigation solutions. An integrated 1D–2D PCSWMM model was used to simulate the hydrology and the dynamic interaction between river and tidal flows, dyke breaching and urban floodplain hydraulics MIKE21 and MIKE3 models were used to simulate the tidal ingress and amplification between the Bay of Fundy and Salmon River estuary as well as sedimentation rates in the estuary and a HEC–RAS model was used to simulate ice jamming. This paper presents the details of the extensive hydrodynamic modeling that was carried out for the Salmon River estuary and its tributaries as part of a comprehensive flood risk study using the latest in 1D, 2D and 3D modeling software. These high water levels are a result of the complex interactions between large river flows, the highest tides in the world, mudflat sedimentation and ice jamming. Extreme water levels in the Salmon River estuary and its tributaries overtop the dyke system that protects the area from high tides, resulting in widespread flooding of roads, residences, schools, senior homes, offices, commercial areas, industrial facilities and agricultural land.
RAINGUAGE PCSWMM PDF
Comparisons of the design storm using an ensemble of temporal patterns did not significantly improve predictions using a single rain gauge.Ĭlick here to download a static PDF version of the presentation.Ĭlick here to watch recorded presentation on YouTube.The urban development in Truro, Nova Scotia is situated on the floodplain of the Salmon River near its outlet to the Cobequid Bay. The results indicate that the use of spatial rain data (weather radar acquired rainfall data) did not result in improvements to the single rain gauge approach. Three historical floods, in excess of 1 in 50 year events were therefore assessed and simulation results using a single rain gauge measured, 1987 Australian Rainfall and Runoff which is a single design storm approach, 2016 Australian Rainfall and Runoff which is an ensemble design storm approach and weather radar predicted rainfall, were compared against observations. The study compared rainfall collected from point measurements to spatial patterns of rainfall distribution to differential spatial patterns and point measured rainfall against an ensemble approach to study dependence on temporal behaviour.
RAINGUAGE PCSWMM PROFESSIONAL
The professional version of PCSWMM (Stormwater Management Model), developed by Computational Hydraulics International, which incorporates a combination 1-D modelling for storm sewers with 2-D surface flooding was used to investigate historical floods in Geelong, Australia. This study was carried out with the aim of assessing prediction accuracy using rainfall data that spanned across a range of spatial and temporal scales. The impacts of increased flood peaks and flow volume due to urbanization and population growth are expected to exacerbate the risk of floods in major cities in the future.įlood prediction in dense urban environments is a difficult task for engineers due to the complex interactions between flow with land form and structures. This puts a heavy stress on storm drainage systems which may not be designed to cope with such extreme events. Climate change can therefore results in sea level rising, as well as increased intensity of storms. According to the Intergovernmental Panel on Climate Change, “A changing climate leads to changes in the frequency, intensity, spatial extent, duration, and timing of extreme weather and climate events, and can result in unprecedented extreme weather and climate events”. Recent trends in the earth’s weather have seen an increase in the occurrence and severity of floods.