Environmental Impact Assessment: on-line eConsulting

The Environmental Impact Assessment functionality in AirWare is also supported by on-line tools for remote use with various levels of support.

Within any well-defined region (currenly supported: Malta, Cyprus, UAE, The EU EMEP region) we offer on-line EIA on a "subscription" or pay-as-you-go model use and expert support basis.

Problem definition:   This involves the following problem definition steps by the (remote) user:

• Definition ( on-line, directly and interactive within the AirWare system and web-based interface, also suppored by a simple, on-line questionnaire, alternatively as a set of (free format) specification provided by eMail o of a domain, in terms of its center (on the map or in terms of lat/long coordinates) and extent in km for the main model grid. For the regions supported, we have a 30 m DEM and basic satellite background map (LANSDAT, 15 m resolution) prepared. Once the specific location has been defined, optional high-resolution satellite imagery can be integrated with the embedded GIS.

  Within this domain (typically in the order of 10 to 50 km in width) nested sub-domains can be defined for the high-resolution simulation of any sub-area.
  Around this domain, alarger domain (up to continental scales) can be constrcuted to provide dynamic boundary conditions from a larger surrounding area but at comparatively lower resolution, were apporpriate. Typical example are dust or ozone.

• Definition of the "project", which primarily the emissions from point, area, line and volume sources whose impact should be assessed.
  Other project specific information includes:
  • Other local sources to assess cumulative effects;
  • Monitoring data for the inital calibration and validation of the models;
  • Target areas or receptor points, including population distribution or sensitive areas.

• Scenarios; temporal coverage: for the supported regions, at least three years of hourly 3D meteorology is available at a 3 km (original MM5 output) and 1 km (interpolated for CAMx) resolution; Other scenario parameters include the required spatial (regular grid of receptor points or Eulerian model grid), the substances of concern, and, where applicable design objectives and constraints:
  • Basic compliance or violations of standards as defined by applicable air quality regulations such as the target and limite values from 2008/50/EC, including hourly, daily, or annnual averages and maxima;
  • Least cost compliance, given a set of applicable Emission Control Technologies or strategies with their associated costs and efficiencies;
  • Maximum environmental improvement from a given investment budget (a classical multiple-criteria problem).

Screening:   this is based on the basic USEPA Gaussian regulatory model AERMOD run with AERMET meteorology generated for the model domain from the MM5 re-analysis runs; scenarios are run for at least three years, and all substances of concern including NO2, using the simplified OLM method with a constant ozone boundary condition.

The basic screening model results (set 30-120 Maxima, violations (maxima, average, number), violations at user defined receptor points are recorded and displayed.

Sensitivity Analysis: The violations of the air quality standards (if any) are related to the basic assumptions and input conditions of the model: grid resolution, meteorological conditionsd (wind speed and direction, mixing height (PBL), turbulence (Monin-Obukov length); source geometry and emission height for line and area sources, ozone boundary conditions for the OLM.

Multi-model scenarios:   episodes(dates, hours) that indicate violations of air quality standards are then re-run with alternative models that share the same model domain and resolution, emisison data, and meteorological inputs as far as possible:


• AERMOD (24 hour of hourly results), alternative process formulation for particulate matter;
• CAMx, an 3D Eulerian photochemical nested grid model for episodes of violations, including a two day start-up period to generate reliable initial conditions;
• DUST: a dynamic wind erosion model that provides emission input to CAMx, based on short-term wind speed (Weibull distribution around MM5 generated mean values) and soil erodibility; complements the traditional particulate emission estimates from combustion sources.
• TRAFFIC, a kernel based convolution model for line sources with a mixing zone concept implemented as a low-pass filter;
• PUFF, a Lagrangian multipuff model for highly transient meteorological or emisiosn conditions that clealyt violate the AERMOD steady state assumption, also used for mobile sources.
• TIMES: for complex terrain, near-filed scenarios, a 3D CFD model can be used, that treats (building) obstacles explicityly.
• ODOUR: as an extensions to the basic models this is used to generated probabilistic forecasts of short-term concentration distribution and maxima, relevant for olfactory perception.

Emission control, optimization:   these models at various resolutions are then used to generate alternative solutions that each apply combinations of emission control techchnologies; we use an iterative combination of "satisficing" (finding solutions that meet all constraints such as compliance with air quality standards and economic constraints) and a "reference point apporach" to find compromise solutions (trade-off) between multiple objectives. This may be as simple as determining a minimum stack height or maximum allowable emission rate for a single point source, to a complex mix of technologies and strategies for a larger area with multiple sources.

The Product:   visit the EIA Image Gallery

All the input data (primarily the emission inventories), meteorology, boundary conditions, and the model results and their analysis themselves are summarized in a variety of tabular, graphical, and animation formats (under interactive control) ready to be included in an EIS.