Air quality concerns continue to pose a challenge to the transportation industry. This project investigated the extent to which traffic flow impacted particulate emissions from roadways in Birmingham, Alabama. Through repeated measurements at five locations, it was determined that truck flow is a controlling influence on roadway particulate emissions. In particular, queuing of trucks greatly increases emissions. Therefore, emissions and planning models and activities must include a description of truck operational mode to accurately describe roadway contributions. If roadway particulate emissions are to be minimized, optimizing traffic flow on high truck (not necessarily high average daily traffic) routes needs to be considered.
Information concerning source area runoff characteristics during wet weather events can be very important when developing stormwater management plans that incorporate source area controls, or changes in development patterns.This information is also important when calibrating or testing many stormwater models.Unfortunately, this information is not readily available and can be expensive and tedious to collect.However, a substantial amount of these data have been collected over the past several decades, but are not well known.This chapter, and the next, present summaries of these data, specifically source area sheetflow and particulate quality for a variety of areas.Information is presented for many source areas, including urban wet and dry atmospheric deposition, roofs, urban soils, streets and other pavements.Information showing concentrations of conventional pollutants, heavy metals, and selected organic compounds is summarized for major land use categories.The following chapter summarizes additional source area sheetflow information obtained during detailed projects in Alabama and Wisconsin during the 1990s, and summarizes newer data collected elsewhere.Much of the information was collected in the 1970s and 1980s as part of stormwater research projects for the EPA.This chapter summarizes source area sheetflow quality data obtained from a number of studies conducted in California, Washington, Nevada, Illinois, Ontario, Colorado, New Hampshire, and New York during 1970s and 1980s.Most of the early data obtained were for street dirt chemical quality as part of street cleaning research projects, but a relatively large amount of parking area runoff and roof runoff quality data
: Abstract Evaluating the stability of undercut cliff profiles and assessing longevity of significant overhangs within precipitous coastal cliffs in an active marine environment is a challenge. This was accomplished through innovative use of high resolution digital imagery captured by low level high precision drone flights with photogrammetric processing of the imagery. With detailed GIS software manipulation of the generated point cloud data, complete three-dimensional (3D) wireframe DTM and DEM models were developed of key cliff conditions, allowing thorough stability assessment. The availability of full 3D geometries of entire, often inaccessible, cliff areas allowed detailed analysis of stress states existing around major overhangs and sea caves to be accomplished using FLAC3D. The 3D DTM and DEM models also allowed detailed review of the cliff geometries and profiles could be cut in any direction so that undercut and notched cliffs could also be analyzed in greater detail in two-dimensions (2D). The 2D analysis was carried out using discrete element modelling with application of Voronoi Tessellation approaches in UDEC in order to replicate the complex tensional cracking, overturning and block toppling mechanisms observed on many of the cliffs.
AVAILABILITY OF ATMOSPHERICALLY DEPOSITED MERCURY TO RUNOFF AND RECEIVING WATERSCurrent practice in estimating mercury runoff from the watershed in TMDL analysis assumes much of the atmospherically deposited mercury is available for transport to receiving waters; such estimates are overly conservative, and do not reflect the complex nature of mercury surface reactions. The time-dependence of mercury washoff is critical in assessing the variable availability of mercury to the...Author(s)Mark C. GabrielDerek G. WilliamsonRobert PittSourceProceedings of the Water Environment FederationSubjectSession 15 Estimating and Measuring Wet Weather LoadsDocument typeConference PaperPublisherWater Environment FederationPrint publication date Jan, 2002ISSN1938-6478SICI1938-6478(20020101)2002:8L.1377;1-DOI10.2175/193864702785071994Volume / Issue2002 / 8Content sourceTMDLS ConferenceFirst / last page(s)1377 - 1392Copyright2002Word count467
