Environmental Engineering Reference
In-Depth Information
2.4 Real-Time Air Quality Assessment and
Management: Cascading Models in a Web Based
Implementation
K. Fedra
1
, Y. Rashidi
2
, and T. Kim
3
1
Environmental Software and Services GmbH, Austria
2
Air Quality Control Company, Tehran, Iran
3
BioTel, Seoul, South Korea
Abstract
For the assessment of regional to local air quality in urban and industrial
areas, a system of coupled models (AirWare) that cover several levels of nesting
from regional (several hundred kilometers) to city level and street canyons has
been developed in EUREKA E!3266 WEBAIR. The main objectives are to sup-
port regulatory tasks, compliance monitoring, and public information, and to provide
a reliable basis for the multi-criteria optimization of emission control strategies to
effectively and efficiently meet a range of environmental standards. Examples
from Tehran, Iran, and Seoul/Gyeonggi-do, South Korea are used to demonstrate
the system operation and performance. We compare two very large cities with
different physiographical and socio-economic structures, management objectives,
and policy options, yet a common problem. A web based implementation where
all functions are accessed by a standard web browser provides ease of use for all
major actors and stakeholders including public information functions. The system
includes daily forecasts (meteorology and air quality) for 3-7 days, and hourly
now-casts with data assimilation. In parallel to forecast and now-cast runs, the
system supports interactive scenario analysis for EIA and emission control optimi-
zation tasks. The simulation tools include MM5 and WRF for meteorological
forecasts based on downscaling global (GFS) weather forecasts, and dynamic
emission modeling. The models are linked to several data bases (monitoring data
and emission inventory) and an embedded GIS. CAMx is used for photochemistry
and particulates, AERMOD for conservative substances. A high-resolution con-
volution model with a near-field mixing zone is based on AERMOD as a com-
putational kernel for city-wide line sources and local concentration gradients with
allows for near real-time simulation of thousands of road segments. Additional
models include a 3D FD code for street canyons with explicit building obstacles
for selected hot-spots, and a stochastic implementation of CAMx for probabilistic
ozone forecasts.
