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• 1. [Article] A Validated Tropical-Extratropical Flood Hazard Assessment for New York Harbor

  Recent studies of flood risk at New York Harbor (NYH) have shown disparate results for the 100 year storm tide, providing an uncertain foundation for the flood mitigation response after Hurricane Sandy. ...

  Citation × Citation Citation Abstract Copy Title: A Validated Tropical-Extratropical Flood Hazard Assessment for New York Harbor Author: Orton, Philip M., Hall, T. M., Talke, Stefan A., Blumberg, Alan F., Georgas, Nickitas, Vinogradov, S. Year: 2016 Recent studies of flood risk at New York Harbor (NYH) have shown disparate results for the 100 year storm tide, providing an uncertain foundation for the flood mitigation response after Hurricane Sandy. Here we present a flood hazard assessment that improves confidence in our understanding of the region's present-day potential for flooding, by separately including the contribution of tropical cyclones (TCs) and extratropical cyclones (ETCs), and validating our modeling study at multiple stages against historical observations. The TC assessment is based on a climatology of 606 synthetic storms developed from a statistical-stochastic model of North Atlantic TCs. The ETC assessment is based on simulations of historical storms with many random tide scenarios. Synthetic TC landfall rates and the final TC and ETC flood exceedance curves are all shown to be consistent with curves computed using historical data, within 95% confidence ranges. Combining the ETC and TC results together, the 100 year return period storm tide at NYH is 2.70 m (2.51–2.92 at 95% confidence), and Hurricane Sandy's storm tide of 3.38 m was a 260 year (170–420) storm tide. Deeper analyses of historical flood reports from estimated Category-3 hurricanes in 1788 and 1821 lead to new estimates and reduced uncertainties for their floods and show that Sandy's storm tide was the largest at NYH back to at least 1700. The flood exceedance curves for ETCs and TCs have sharply different slopes due to their differing meteorology and frequency, warranting separate treatment in hazard assessments. Title: A Validated Tropical-Extratropical Flood Hazard Assessment for New York Harbor Author: Orton, Philip M., Hall, T. M., Talke, Stefan A., Blumberg, Alan F., Georgas, Nickitas, Vinogradov, S. Year: 2016 Recent studies of flood risk at New York Harbor (NYH) have shown disparate results for the 100 year storm tide, providing an uncertain foundation for the flood mitigation response after Hurricane Sandy. Here we present a flood hazard assessment that improves confidence in our understanding of the region's present-day potential for flooding, by separately including the contribution of tropical cyclones (TCs) and extratropical cyclones (ETCs), and validating our modeling study at multiple stages against historical observations. The TC assessment is based on a climatology of 606 synthetic storms developed from a statistical-stochastic model of North Atlantic TCs. The ETC assessment is based on simulations of historical storms with many random tide scenarios. Synthetic TC landfall rates and the final TC and ETC flood exceedance curves are all shown to be consistent with curves computed using historical data, within 95% confidence ranges. Combining the ETC and TC results together, the 100 year return period storm tide at NYH is 2.70 m (2.51–2.92 at 95% confidence), and Hurricane Sandy's storm tide of 3.38 m was a 260 year (170–420) storm tide. Deeper analyses of historical flood reports from estimated Category-3 hurricanes in 1788 and 1821 lead to new estimates and reduced uncertainties for their floods and show that Sandy's storm tide was the largest at NYH back to at least 1700. The flood exceedance curves for ETCs and TCs have sharply different slopes due to their differing meteorology and frequency, warranting separate treatment in hazard assessments. Close

• 2. [Article] A Regional Bayesian Hierarchical Model for Flood Frequency Analysis

  In this study, we propose a regional Bayesian hierarchical model for flood frequency analysis. The Bayesian method is an alternative to the traditional regional flood frequency analysis. Instead of relying ...

  Citation × Citation Citation Abstract Copy Title: A Regional Bayesian Hierarchical Model for Flood Frequency Analysis Author: Yan, Hongxiang, Moradkhani, Hamid Year: 2015 In this study, we propose a regional Bayesian hierarchical model for flood frequency analysis. The Bayesian method is an alternative to the traditional regional flood frequency analysis. Instead of relying on the delineation of implicit homogeneous regions, the Bayesian hierarchical method describes the spatial dependence in its inner structure. Similar to the classical Bayesian hierarchical model, the process layer of our model presents the spatial variability of the parameters by considering different covariates (e.g., drainage area, elevation, precipitation). Beyond the three classical layers (data, process, and prior) of the Bayesian hierarchical model, we add a new layer referred to as the “L-moments layer”. The L-moments layer uses L-moments theory to select the best-fit probability distribution based on the available data. This new layer can overcome the subjective selection of the distribution based on extreme value theory and determine the distribution from the data instead. By adding this layer, we can combine the merits of regional flood frequency and Bayesian methods. A standard process of covariates selection is also proposed in the Bayesian hierarchical model. The performance of the Bayesian model is assessed by a case study over the Willamette River Basin in the Pacific Northwest, U.S. The uncertainty of different flood percentiles can be quantified from the posterior distributions using the Markov Chain Monte Carlo method. Temporal changes for the 100-year flood percentiles are also examined using a 20- and 30-year moving window method. The calculated shifts in flood risk can aid future water resources planning and management. Title: A Regional Bayesian Hierarchical Model for Flood Frequency Analysis Author: Yan, Hongxiang, Moradkhani, Hamid Year: 2015 In this study, we propose a regional Bayesian hierarchical model for flood frequency analysis. The Bayesian method is an alternative to the traditional regional flood frequency analysis. Instead of relying on the delineation of implicit homogeneous regions, the Bayesian hierarchical method describes the spatial dependence in its inner structure. Similar to the classical Bayesian hierarchical model, the process layer of our model presents the spatial variability of the parameters by considering different covariates (e.g., drainage area, elevation, precipitation). Beyond the three classical layers (data, process, and prior) of the Bayesian hierarchical model, we add a new layer referred to as the “L-moments layer”. The L-moments layer uses L-moments theory to select the best-fit probability distribution based on the available data. This new layer can overcome the subjective selection of the distribution based on extreme value theory and determine the distribution from the data instead. By adding this layer, we can combine the merits of regional flood frequency and Bayesian methods. A standard process of covariates selection is also proposed in the Bayesian hierarchical model. The performance of the Bayesian model is assessed by a case study over the Willamette River Basin in the Pacific Northwest, U.S. The uncertainty of different flood percentiles can be quantified from the posterior distributions using the Markov Chain Monte Carlo method. Temporal changes for the 100-year flood percentiles are also examined using a 20- and 30-year moving window method. The calculated shifts in flood risk can aid future water resources planning and management. Close

• 3. [Article] Cleaner Drain

  Water in streets causes several issues, both to our infrastructure and our emotions. The water can harm property by rotting wooden structures. If the water is high enough, it can even stall cars and flood ...

  Citation × Citation Citation Abstract Copy Title: Cleaner Drain Author: Paivarinta, Jonah, Ortiz‐Rojo, Daniel, Klepp, Masson, Likestoskat, Rebekah, Chadney, Macy, Ferrando, Jeremy Year: 2015 Water in streets causes several issues, both to our infrastructure and our emotions. The water can harm property by rotting wooden structures. If the water is high enough, it can even stall cars and flood into buildings. Being forced to walk through or around a puddle can hurt someone's emotional state, which reduces productivity and this affect people around them. It costs about 30 dollars to clean a drain, and there are about 15 thousand drains, which totals to to around$450,000 and if you add in other costs such as employees and street sweeping for a cleaning company it costs around 3.8 million a year. Title: Cleaner Drain Author: Paivarinta, Jonah, Ortiz‐Rojo, Daniel, Klepp, Masson, Likestoskat, Rebekah, Chadney, Macy, Ferrando, Jeremy Year: 2015 Water in streets causes several issues, both to our infrastructure and our emotions. The water can harm property by rotting wooden structures. If the water is high enough, it can even stall cars and flood into buildings. Being forced to walk through or around a puddle can hurt someone's emotional state, which reduces productivity and this affect people around them. It costs about 30 dollars to clean a drain, and there are about 15 thousand drains, which totals to to around$450,000 and if you add in other costs such as employees and street sweeping for a cleaning company it costs around 3.8 million a year. Close