30 research outputs found
Deep Neural Networks with 3D Point Clouds for Empirical Friction Measurements in Hydrodynamic Flood Models
Friction is one of the cruxes of hydrodynamic modeling; flood conditions are
highly sensitive to the Friction Factors (FFs) used to calculate momentum
losses. However, empirical FFs are challenging to measure because they require
laboratory experiments. Flood models often rely on surrogate observations (such
as land use) to estimate FFs, introducing uncertainty. This research presents a
laboratory-trained Deep Neural Network (DNN), trained using flume experiments
with data augmentation techniques, to measure Manning's n based on Point Cloud
data. The DNN was deployed on real-world lidar Point Clouds to directly measure
Manning's n under regulatory and extreme storm events, showing improved
prediction capabilities in both 1D and 2D hydrodynamic models. For 1D models,
the lidar values decreased differences with regulatory models for in-channel
water depth when compared to land cover values. For 1D/2D coupled models, the
lidar values produced better agreement with flood extents measured from
airborne imagery, while better matching flood insurance claim data for
Hurricane Harvey. In both 1D and 1D/2D coupled models, lidar resulted in better
agreement with validation gauges. For these reasons, the lidar measurements of
Manning's n were found to improve both regulatory models and forecasts for
extreme storm events, while simultaneously providing a pathway to standardize
the measurement of FFs. Changing FFs significantly affected fluvial and pluvial
flood models, while surge flooding was generally unaffected. Downstream flow
conditions were found to change the importance of FFs to fluvial models,
advancing the literature of friction in flood models. This research introduces
a reliable, repeatable, and readily-accessible avenue to measure
high-resolution FFs based on 3D point clouds, improving flood prediction, and
removing uncertainty from hydrodynamic modeling.Comment: 25 pages, 15 figures, 2 tables. Implementation code available at
https://github.com/f-haces/LidarMannin
Deep Learning Hydrodynamic Forecasting for Flooded Region Assessment in Near-Real-Time (DL Hydro-FRAN)
Hydrodynamic flood modeling improves hydrologic and hydraulic prediction of
storm events. However, the computationally intensive numerical solutions
required for high-resolution hydrodynamics have historically prevented their
implementation in near-real-time flood forecasting. This study examines whether
several Deep Neural Network (DNN) architectures are suitable for optimizing
hydrodynamic flood models. Several pluvial flooding events were simulated in a
low-relief high-resolution urban environment using a 2D HEC-RAS hydrodynamic
model. These simulations were assembled into a training set for the DNNs, which
were then used to forecast flooding depths and velocities. The DNNs' forecasts
were compared to the hydrodynamic flood models, and showed good agreement, with
a median RMSE of around 2 mm for cell flooding depths in the study area. The
DNNs also improved forecast computation time significantly, with the DNNs
providing forecasts between 34.2 and 72.4 times faster than conventional
hydrodynamic models. The study area showed little change between HEC-RAS' Full
Momentum Equations and Diffusion Equations, however, important numerical
stability considerations were discovered that impact equation selection and DNN
architecture configuration. Overall, the results from this study show that DNNs
can greatly optimize hydrodynamic flood modeling, and enable near-real-time
hydrodynamic flood forecasting.Comment: 21 pages, 8 figure
Bacteria Total Maximum Daily Load Task Force Final Report
In September 2006, the Texas Commission on Environmental Quality (TCEQ) and Texas State Soil and Water Conservation Board (TSSWCB) charged a seven-person Bacteria Total Maximum Daily Load (TMDL) Task Force with:
* examining approaches that other states use to develop and implement bacteria TMDLs,
* recommending cost-effective and time-efficient methods for developing TMDLs,
* recommending effective approaches for developing TMDL Implementation Plans (I-Plans),
* evaluating a variety of models and bacteria source tracking (BST) methods available for developing TMDLs and I-Plans, and recommending under what conditions certain methods are more appropriate, and
* developing a roadmap for further scientific research needed to reduce uncertainty about how bacteria behave under different water conditions in Texas.
The Task Force, assisted by an Expert Advisory Group of approximately 50 stakeholders and agency staff, held two two-hour meetings/teleconferences and developed two drafts of the report. These drafts were shared by e-mail and on a Web site and feedback received from the Expert Advisory Group was also made available on the Web site.
The Task Force report describes the characteristics, as well as some of the strengths and weaknesses of several models that have been used and/or are under development to assist bacteria TMDL and I-Plan analysis. These include:
* load duration curves (LDC),
* spatially explicit statistical models, including Arc Hydro, SPARROW and SELECT,
* the mass balance models BLEST and BIT, and
* the mechanistic hydrologic/water quality models HSPF, SWAT, SWMM and WASP.
The Task Force report also describes and makes recommendations for effective use of BST methods that have been used in Texas and elsewhere for TMDL development. These include ERIC-PCR, Ribotyping, PFGE, KB-ARA, CSU and Bacteroidales PCR. Based on recent experience in Texas and elsewhere, the Task Force recommends using library-independent methods like Bacteriodales PCR for preliminary qualitative analyses and more expensive and time-consuming library-dependent methods if more quantitative data are required for TMDL or I-Plan development.
Based on the discussions of bacteria models and source tracking, as well as extensive input from the Expert Advisory Group, the Task Force recommends a three-tier approach to implementing bacteria TMDLs and I-Plans.
Tier 1 is a one-year process that includes the formation of a representative stakeholder group, development of a comprehensive geographic information system (GIS) of the watershed, a survey of potential bacterial sources, calculation of load duration curves from existing monitoring data and analysis by agency personnel and stakeholders of data collected for Tier 1. After reviewing information from Tier 1, the group may choose to complete and submit a draft TMDL for agency approval, request an evaluation of the designated use of the water body (an use attainability analysis) or proceed to Tier 2.
Tier 2 is a one-to-two-year effort designed to collect targeted monitoring data to fill gaps in previously collected data, conduct qualitative library-independent BST data to determine whether humans and/or a few major classes of animals are sources and develop simple spatially explicit or mass balance models of bacteria in the watershed. After analysis of Tier 1 and Tier 2 data, the group may chose to complete and submit the draft TMDL (or I-Plan if a TMDL was developed after Tier 1), request an evaluation of the designated use (an use attainability analysis), or initiate a “phased TMDL” and proceed with Tier 3 analysis.
Tier 3 is a two-to-three-year process designed to continue strong stakeholder involvement, implement more extensive targeted monitoring, conduct quantitative library-dependent BST analysis and develop a detailed hydrologic/water quality model for the watershed. Tier 3 should be implemented only when this level of detailed analysis is needed for I-Plan development or for TMDL development for particularly complex watersheds for which consensus cannot be reached after Tier 2.
The Task Force emphasizes that the agencies and stakeholders may choose to deviate from these recommendations if they reach consensus that a more time- and cost-effective approach is feasible.
The Task Force concludes its report by summarizing a number of research activities needed to strengthen the scientific tools available for TMDL and I-Plan development. The needed research falls into the following categories: characterization of sources, characterization of kinetic rates and transport mechanisms, enhancements to bacteria fate and transport models and bacteria source tracking, determination of effectiveness of control mechanisms and quantification of uncertainty and risk
The global burden of cancer attributable to risk factors, 2010-19 : a systematic analysis for the Global Burden of Disease Study 2019
Background Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. Methods The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk-outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. Findings Globally, in 2019, the risk factors included in this analysis accounted for 4.45 million (95% uncertainty interval 4.01-4.94) deaths and 105 million (95.0-116) DALYs for both sexes combined, representing 44.4% (41.3-48.4) of all cancer deaths and 42.0% (39.1-45.6) of all DALYs. There were 2.88 million (2.60-3.18) risk-attributable cancer deaths in males (50.6% [47.8-54.1] of all male cancer deaths) and 1.58 million (1.36-1.84) risk-attributable cancer deaths in females (36.3% [32.5-41.3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20.4% (12.6-28.4) and DALYs by 16.8% (8.8-25.0), with the greatest percentage increase in metabolic risks (34.7% [27.9-42.8] and 33.3% [25.8-42.0]). Interpretation The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe
Numerical techniques for modeling in situ biorestoration and biodegradation of organic contaminants in groundwater
Biodegradation, the transformation of organic matter using microorganisms, is a promising technology for ground water cleanup. The research presented in this dissertation is aimed at developing numerical techniques for simulating biodegradation coupled with physical transport processes in ground water. The focus is mainly on aerobic biodegradation. A two-dimensional biodegradation model, BIOPLUME II, was developed that incorporates two different conceptual approaches for simulating aerobic biodegradation. The first approach assumes that the transport of oxygen into a contaminant plume is limiting and that biodegradation could be approximated with an instantaneous reaction between the contaminants and oxygen. The second approach argues that the biodegradation of organic contaminants is kinetically limited by microbial utilization rates and that the process could be represented with a dual Monod kinetic relationship between oxygen and the contaminants. Comparisons between the instantaneous model and the kinetic model suggest that oxygen transport is limiting in aquifers with seepage velocities less than 0.03 ft/d. The rate of oxygen utilization takes on more importance in aquifers with high velocities and for organic contaminants which are slowly degrading.
The instantaneous reaction model is applied to a pilot scale bioremediation demonstration project at the Traverse City field site. A nutrient mix containing phosphate, ammonia and an oxygen source is injected into a portion of the contaminated aquifer. The BIOPLUME II model was used to select the design parameters for the test, mainly: the injection flow rate, the number of injection wells and the time required for renovation. Dissolved oxygen and contamination data from the monitoring wells in the demonstration area for the last ten months of operation were analyzed to assess the degree of cleanup. The field data indicate that benzene, toluene, ethyl benzene, and xylenes have been selectively removed from the soils and water in the demonstration area. The field data were compared to the predictions from the BIOPLUME II model. The model results imply that modeling is a useful tool for predicting the biodegradation of organic contaminants in ground water
Development and Assessment of a Web-Based National Spatial Data Infrastructure for Nature-Based Solutions and Their Social, Hydrological, Ecological, and Environmental Co-Benefits
Comprehensive datasets for nature-based solutions (NBS), and their diverse relationships have not yet been accumulated into a deployable format. This research describes the development of a novel National Spatial Data Infrastructure (NSDI) system for NBS co-benefits throughout the contiguous United States. Here, we gather and integrate robust geospatial datasets from the social, ecological, environmental, and hydrologic domains using seamless, cloud-based data services to facilitate the trans-disciplinary assessment of NBSs as a function of society and Earth. This research enhances practical decision making and research by assimilating web-based datasets and describing the missing links between national policy and robust adoption of NBSs as a sustainability solution. This NSDI serves to foster participatory planning capabilities and integrate local sustainability goals into decision–support frameworks. Such a platform strengthens the knowledge base necessary for addressing multiple, co-evolving issues of societal relevance, an essential component of fully espousing NBSs within the realm of socio-technological systems and improving policies and implementation regarding sustainable solutions. The efficacy of the proposed platform to serve as a holistic data information system is assessed by exploring important characteristics associated with geospatial NSDI tools, namely, openness, spatial functionality, scalability, and standardization. By placing GIS strengths and weaknesses in the context of transdisciplinary NBSs, we reveal strategic directions toward further co-production of such NSDIs. We conclude with recommendations for facilitating a shared vision of transdisciplinary technologies to strengthen the amalgamation of broad co-benefits and multi-disciplinary influences in sustainability planning
Assessing COVID-19 risk, vulnerability and infection prevalence in communities.
BackgroundThe spread of coronavirus in the United States with nearly five and half million confirmed cases and over 170,000 deaths has strained public health and health care systems. While many have focused on clinical outcomes, less attention has been paid to vulnerability and risk of infection. In this study, we developed a planning tool that examines factors that affect vulnerability to COVID-19.MethodsAcross 46 variables, we defined five broad categories: 1) access to medical services, 2) underlying health conditions, 3) environmental exposures, 4) vulnerability to natural disasters, and 5) sociodemographic, behavioral, and lifestyle factors. The developed tool was validated by comparing the estimated overall vulnerability with the real-time reported normalized confirmed cases of COVID-19.AnalysisA principal component analysis was undertaken to reduce the dimensions. In order to identify vulnerable census tracts, we conducted rank-based exceedance and K-means cluster analyses.ResultsAll of the 5 vulnerability categories, as well as the overall vulnerability, showed significant (P-values ConclusionPolicymakers can use this planning tool to identify neighborhoods at high risk for becoming hot spots; efficiently match community resources with needs, and ensure that the most vulnerable have access to equipment, personnel, and medical interventions
IMPACT OF NON-AQUEOUS PHASE LIQUIDS (NAPLS) ON GROUNDWATER REMEDIATION
Nonaqueous Phase Liquids (NAPLs) are immiscible (undissolved) hydrocarbons in the subsurface that exhibit different behavior and properties than dissolved contaminant plumes. NAPLs have a tremendous impact on the remediation of contaminated aquifers, as it is very difficult or impossible to remove all of the NAPL from a hazardous waste site once released to the subsurface. Although many NAPL removal technologies are currently being tested, to date there have been few field demonstrations where sufficient NAPL has been successfully removed from the subsurface to restore an aquifer to drinking water quality (EPA, 1992a). The residual NAPL that remains trapped in the soil/aquifer matrix acts as a continuing source of dissolved contaminants to ground water, and effectively prevents the restoration of NAPL-affected aquifers for tens or hundreds of years. This is particularly true for groundwater pump-and-treat systems, the most common remediation technology for addressing contaminated aquifers. This technology pumps groundwater out of contaminated zones to remove dissolved contaminants and, if present, to slowly dissolve any trapped NAPLs. The pumped water is then treated on the surface to remove or destroy the dissolved contaminants. To help designers of pump-and-treat systems evaluate the impact of NAPLs on groundwater remediation, a simple design model has been developed that provides the user with the number of recovery/injection wells and time required to reach cleanup standards. The method uses 1) dissolution data from a simplified dissolution model based on the work o