Steven J. Burian

Detection of Urban-Induced Rainfall Anomalies in a Major Coastal City

There is increasing evidence that large coastal cities, like Houston, Texas, can influence weather through complex urban land use- weather-climate feedbacks. Recent work in the literature establishes the ex- istence of enhanced lightning activity over and downwind of Houston. Since lightning is a signature of convection in the atmosphere, it would seem rea- sonable that urbanized Houston would also impact the distribution of rainfall. This paper presents results using data from the worlds first satellite-based precipitation radar (PR) aboard the Tropical Rainfall Measuring Mission (TRMM) and ground-based rain gauges to quantify rainfall anomalies that we hypothesize to be linked to extensive urbanization in the Houston area. It is one of the first rigorous efforts to quantify an urban-induced rainfall anomaly near a major U.S. coastal city and one of the first applications of space-borne radar data to the problem. Quantitative results reveal the presence of annual and warm season rainfall anomalies over and downwind of Houston. Several hypotheses have surfaced to explain how the sea breeze, coastline curvature,

Urban Wastewater Management in the United States: Past, Present, and Future

as either centralized, where all the wastewater is collected and conveyed to a central location for treatment or disposal, or decentralized, where the wastewater is primarily treated or disposed of on-site or near the source. Historically, municipalities, consulting engineers, and individuals have had the option of centralized or decentralized wastewater management and could have chosen from a variety of collection and disposal technologies to implement the management strategy. Although these options were available, the majority of engineers, public health officials, policy makers, and members of the public typically preferred one management strategy and one technology to the others. The reasons for a particular preference were based on a combination of cost, urban development patterns, accepted scientific theories, tradition, religious attitudes, prevailing public opinion on sanitation, the contemporary political environment, and many other factors. The development of urban wastewater management strategies and technologies from the early nineteenth century to the present

National Urban Database and Access Portal Tool

Based on the need for advanced treatments of high-resolution urban morphological features (e.g., buildings and trees) in meteorological, dispersion, air quality, and human-exposure modeling systems for future urban applications, a new project was launched called the National Urban Database and Access Portal Tool (NUDAPT). NUDAPT is sponsored by the U.S. Environmental Protection Agency (U.S. EPA) and involves collaborations and contributions from many groups, including federal and state agencies, and from private and academic institutions here and in other countries. It is designed to produce and provide gridded fields of urban canopy parameters for various new and advanced descriptions of model physics to improve urban simulations, given the availability of new high-resolution data of buildings, vegetation, and land use. Additional information, including gridded anthropogenic heating (AH) and population data, is incorporated to further improve urban simulations and to encourage and facilitate decision sup...

Assessment of GPU computational enhancement to a 2D flood model

This paper presents a study of the computational enhancement of a Graphics Processing Unit (GPU) enabled 2D flood model. The objectives are to demonstrate the significant speedup of a new GPU-enabled full dynamic wave flood model and to present the effect of model spatial resolution on its speedup. A 2D dynamic flood model based on the shallow water equations is parallelized using the GPU approach developed in NVIDIAs Compute Unified Development Architecture (CUDA). The model is validated using observations of the Taum Sauk pump storage hydroelectric power plant dam break flood event. For the Taum Sauk flood simulation, the GPU model speedup compared to an identical CPU model implementation is 80x-88x for computational domains ranging from 65.5 k to 1.05 M cells. Thirty minutes of event time were simulated by the GPU model in 2 min, 15 times faster than real time. An important finding of the analysis of model domain size is the GPU model is not constrained by model domain extent as is the CPU model. Finally, the GPU implementation is shown to be scalable compared with the CPU version, an important characteristic for large domain flood modeling studies.

Low-Impact Development Practices to Mitigate Climate Change Effects on Urban Stormwater Runoff: Case Study of New York City

AbstractUrban stormwater runoff management systems are usually designed to meet performance standards based on historical climate data, which are assumed to be stationary. Based on the evidence from climate change impact studies, in the near future, stormwater management systems, within the built environment, may need to meet performance expectations under climatic conditions different from historical climate. Considering the impacts of climate change on rainfall intensities and stormwater runoff peak flow and volumes, and in turn the effectiveness of mitigation, practices for urban stormwater management are desirable. This paper presents the results of a climate change impact study on urban stormwater runoff in the Bronx River watershed, New York City. Considering the impacts of climate change on watershed runoff, the potential for low-impact development (LID) controls to mitigate the impacts was investigated. Stormwater runoff and LID controls were modeled using the U.S. EPA Storm Water Management Model...

Urban wet-weather flows.

This literature review summarizes significant technical literature published in 2009 regarding the field of urban wet-weather flows. The review addresses characterization, pollution sources, monitoring and sampling, surface and groundwater impacts, decision support systems, regulatory policies, and control and treatment technologies.

Analysis of the Effects of Climate Change on Urban Storm Water Runoff Using Statistically Downscaled Precipitation Data and a Change Factor Approach

AbstractIn urban areas, there is concern that storm water runoff and flooding may be intensified because of the effect of climate change on precipitation amounts, intensities, and frequencies. Studies are needed to help storm water managers to plan and design effective adaptation and mitigation measures. This paper presents a study of the effects of climate change on urban storm water runoff in the Bronx River watershed in New York City. To show the effects of climate change on future precipitation, projections by 134 general circulation models (GCMs) from the fifth phase of the coupled model intercomparison project (CMIP5) are used. A new change factor method is proposed to select minimum, maximum, and mean daily precipitation scenarios for a future time period of 2030–2059. Because of the importance of short duration for extreme storm events, the daily precipitation is disaggregated to hourly increments. The U.S. Environmental Protection Agency storm water management model (SWMM) is used to model the hy...

Modeling the atmospheric deposition and stormwater washoff of nitrogen compounds

Abstract We investigated the suitability of integrating deterministic models to estimate the relative contributions of atmospheric dry and wet deposition onto an urban surface and the subsequent amounts removed by stormwater runoff. The CIT airshed model and the United States Environmental Protection Agency Storm Water Management Model (SWMM) were linked in order to simulate the fate and transport of nitrogen species through the atmosphere and storm drainage system in Los Angeles, California, USA. Coupling CIT and SWMM involved defining and resolving five critical issues: (1) reconciling the different modeling domain sizes, (2) accounting for dry deposition due to plant uptake, (3) estimating the fraction of deposited contaminant available for washoff, (4) defining wet deposition inputs to SWMM, and (5) parameterizing the SWMM washoff algorithm. The CIT–SWMM interface was demonstrated by simulating dry deposition, wet deposition, and stormwater runoff events to represent the time period from November 18, 1987 to December 4, 1987 for a heavily urbanized Los Angeles watershed discharging to Santa Monica Bay. From November 18th to December 3rd the simulated average dry deposition flux of nitrogen was 0.195 kg N/ha-day to the watershed and 0.016 kg N/ha-day to Santa Monica Bay. The simulated rainfall concentrations during the December 4th rainfall event ranged from 3.76 to 8.23 mg/l for nitrate and from 0.067 to 0.220 mg/l for ammonium. The simulated stormwater runoff event mean concentrations from the watershed were 4.86 mg/l and 0.12 mg/l for nitrate and ammonium, respectively. Considering the meteorology during the simulation period, the CIT and SWMM predictions compare well with observations in the Los Angeles area and in other urban areas in the United States.

Incorporating Potential Severity into Vulnerability Assessment of Water Supply Systems under Climate Change Conditions

AbstractIn response to climate change, vulnerability assessment of water resources systems is typically performed based on quantifying the severity of the failure. This paper introduces an approach to assess vulnerability that incorporates a set of new factors. The method is demonstrated with a case study of a reservoir system in Salt Lake City using an integrated modeling framework composed of a hydrologic model and a systems model driven by temperature and precipitation data for a 30-year historical (1981–2010) period. The climate of the selected future (2036–2065) simulation periods were represented by five combinations of warm or hot, wet or dry, and central tendency projections derived from the World Climate Research Programme’s (WCRP’s) Coupled Model Intercomparison Project Phase 5. The results of the analysis illustrate that basing vulnerability on severity alone may lead to an incorrect quantification of the system vulnerability. In this study, a typical vulnerability metric (severity) incorrectly...

Historical perspectives of urban drainage

Historically, urban drainage systems have been viewed with various perspectives. During different time periods and in different locations, urban drainage has been considered a vital natural resource, a convenient cleansing mechanism, an efficient waste transport medium, a flooding concern, a nuisance wastewater, and a transmitter of disease. In general, climate, topography, geology, scientific knowledge, engineering and construction capabilities, societal values, religious beliefs, and other factors have influenced the local perspective of urban drainage. For as long as humans have been constructing cities these factors have guided and constrained the development of urban drainage solutions. Historical accounts provide glimpses of many interesting and unique urban drainage techniques. This paper will highlight several of these techniques dating from as early as 3000 BC to as recently as the twentieth century. For each example discussed, the overriding perspective of urban drainage for that particular time and place is identified. The presentation will follow a chronological path with the examples categorized into the following four time periods: (1) ancient civilizations, (2) Roman Empire, (3) Post-Roman era to the nineteenth century, and (4) modern day. The paper culminates with a brief summary of the present day perspective of urban drainage.