DisPolAirby Signum Data · Windows desktop application
Atmospheric Dispersion Modellingv1.0
DisPolAir works out ground-level pollutant concentrations around stacks, roads, storage areas and industrial halls. Draw the sources on a map, give it one weather situation or a full year of AKTerm data, and run one of two dispersion engines built into the program: a fast AERMOD-like Gaussian plume model or an AUSTAL 3.3-like Lagrangian particle model.
Stack · line · area · volume
Annual AKTerm series
23 pollutants
Word report
For a quotation or any question about DisPolAir, write to [email protected]
Key features
From emission sources to a concentration map
Everything happens in one window: the map in the middle, and the whole workflow on the left, one tab per step: location, meteorology, calculation, display, objects and results.
Two dispersion engines
Pick the model per run. Both use the same boundary-layer meteorology, so switching between them changes the method, not the inputs.
Gaussian plume: AERMOD-like similarity dispersion, for fast screening
Lagrangian particle: AUSTAL 3.3-like, VDI 3783 Part 8 boundary layer
Plume rise from AUSTAL’s own PLURIS model, shared by both engines
The particle model runs in parallel on all CPU cores
Sources drawn on the map
Enter the site centre and DisPolAir fetches the base map. Then choose a tool from the toolbar and click the map; objects can be dragged, rotated and switched off without being deleted.
Stacks, with height, diameter, exit velocity and temperature
Line sources for roads, rail and fence lines
Area and volume sources, buildings and receptor points
Emission rates in g/s for every pollutant
OpenStreetMap or Google satellite base maps, fetched for the site; Stereo 70 or Web Mercator coordinates
Meteorology
Run one weather situation, or a full year of data reduced to annual statistics.
Single situation: wind, Pasquill–Gifford class A–F, temperature, mixing height, roughness
Annual series from AKTerm (hourly) or AKS (frequency) files
Klug/Manier classes mapped to Pasquill classes automatically
Annual statistics and limit values
A finished annual run can be viewed as any of its statistics without being recalculated.
Annual mean, hourly maximum and daily-mean maximum
Percentile maps and exceedance hours
Limit values from Law 104/2011 (RO), Directive 2008/50/EC, STAS 12574-87 and WHO
Reports and exports
One command writes a Word report with the scene, the settings, a concentration map for each emitted pollutant and the receptor tables.
Word report (.docx), with a PDF copy where Microsoft Word is installed
Scene, receptor and deposition-grid CSV
KML for Google Earth and PNG snapshots
AUSTAL interoperability
Any project can be checked in the official AUSTAL 3.3 without re-entering it.
Writes austal.txt from the current scene
Imports AUSTAL DMNA output as a map overlay
Every run also writes austal.log and DMNA grids of its own
How it calculates
Two models, one set of inputs
Both engines use the same VDI 3783 Part 8 boundary layer (friction velocity, Obukhov length and mixing height) and the same PLURIS plume rise (AUSTAL 3.3’s own model, Janicke & Janicke 2001), so the two can be compared directly for the same scene and weather. Every model is specified, with its equations and references, in the program’s user guide.
GaussianSimilarity dispersionσy and σz computed from the boundary-layer profile, using AERMOD’s effective-parameter scheme.
GaussianConvective boundary layerAERMOD’s three-plume formulation: direct, indirect and penetrated sources.
GaussianBuildings and convective riseBuildings act through Schulman–Scire downwash; in convective conditions the plume rises along AERMOD’s distance-dependent path.
GaussianLight windsA meander component gives realistic, finite values at low wind speed and at upwind and crosswind receptors.
LagrangianParticle trajectoriesLangevin velocity updates with the AUSTAL scheme, on a 2 m vertical profile and a 2 s time step; the plume is lifted gradually, as AUSTAL lifts its particles.
LagrangianConcentration as doseParticle mass is binned cell by cell, as AUSTAL does, and evaluated in the AUSTAL 0–3 m ground layer.
LagrangianDeposition and decayDry deposition, sedimentation and first-order decay; the deposition flux can be mapped as well.
LagrangianQuality levelN = 216+qs particles: 65 536 at qs = 0. Runs are seeded, so identical inputs give identical results.
ScreeningThe Gaussian model runs a year of weather in a couple of minutes: good for trying layouts, stack heights and emission rates.
AssessmentThe Lagrangian model follows AUSTAL’s turbulence physics for low-noise maps once the scene is settled.
VerificationExport the scene as austal.txt, run it in AUSTAL 3.3 and import the result for a side-by-side comparison.
DisPolAir models flat terrain with a horizontally uniform wind field. It does not compute flow over orography, and the particle model does not yet include flow around buildings. For those sites, use AUSTAL through the built-in export, or DisPol, our AUSTAL 3.3 front end.
Applications
Where DisPolAir fits
Any study that has to show what an installation, a road or a storage area adds to the air around it.
01
Environmental permits
Compare annual means, daily maxima and exceedance hours with the limit values, pollutant by pollutant, for the permit application.
02
Impact assessments
Model the air-quality impact of a project, with concentrations at the nearest homes, schools and hospitals entered as receptors.
03
Design decisions
Try stack heights, exit conditions and source layouts in minutes, before committing to a design or to a full AUSTAL study.
Inside the tool
A look at DisPolAir
The example project: two boiler stacks and a road, run with a year of hourly AKTerm data. Click any screenshot to see it full size.
Location — site centre and extent, map source and projection, with the annual mean PM10 map.
Meteorology — a year of hourly AKTerm data, binned into weighted situations; the map shows the SOx hourly maximum.
Calculation — Gaussian or Lagrangian model, roughness, grid resolution and per-pollutant deposition and background; the map shows the PM10 hourly maximum.
Display — the PM10 daily-mean maximum, shown from the same run without recalculating.
Objects — every source and receptor in a list, with the selected stack’s geometry, exit conditions and emission rates below.
Results — concentrations of every pollutant at each receptor, also drawn on the map.
Lagrangian model — the two stacks for a single weather situation, over Google satellite imagery.
AUSTAL export — the scene written as austal.txt, ready to run in AUSTAL 3.3.
Report — title page, a concentration map for each pollutant and the calculation log.
User guide — a built-in guide to every tab, model and export, available offline with F1.
A modelling aid, not a permit. DisPolAir is a screening and assessment tool for flat terrain with a horizontally uniform wind field. It does not model flow over orography or around buildings in the particle model, so results for complex sites should be confirmed with AUSTAL or the model your competent authority requires. The limit values built into the program are provided for orientation; always check them against the legislation in force.
Signum Data