Workshop on Strategic Environmental Assessment Tools for SEA

Workshop on Strategic Environmental Assessment Tools for SEA Freeman Cheung Chairman, Hong Kong Institute of Environmental Impact Assessment 18 June 2005 Delivering sustainable solutions in a more competitive world

Introduction • More sophisticated assessment techniques are now available for environmental assessment • The recent development of the computer modelling techniques using Geographical Information System (GIS) has assisted the development of assessment tools for EIA • Regional Air Quality Model • Noise Mapping Software • GIS-based Habitat Map Delivering sustainable solutions in a more competitive world

Air quality models for EIA • simple Gaussian dispersion models • other numerical models (plume/puff models of various complexity) • physical modelling (wind tunnel) • regional photochemistry air dispersion model Delivering sustainable solutions in a more competitive world

Pollutants in the Atmosphere and their Transport over Hong Kong (PATH) • PATH Modelling System commissioned by EPD in 1996 and delivered in 2001 • state-of-the-art system, custom-built for HK from existing US components and thoroughly validated Delivering sustainable solutions in a more competitive world

AIVS Aircraft Inventory Verification Study • Airborne meteorological and air quality measurements • A total of 14 flights in November 1997 • Results used in PATH verification • Comparison of pollutant fluxes on the inflow and outflow SAR borders provides a check on the total HK emissions Delivering sustainable solutions in a more competitive world

Delivering sustainable solutions in a more competitive world

PATH modelling domains • five nested domains • grid spacing of 0. 5, 1. 5, 4. 5, 13. 5, 40. 5 km • 49 x 49 grids and recently extended to 97 x 97 grids • unequally spaced vertical layers extend up to 25 km a. g. l. The lowest layer only 20 m deep Delivering sustainable solutions in a more competitive world

SAQM 49 x 49 nested grids Delivering sustainable solutions in a more competitive world

Emissions • comprehensive HKSAR and regional emissions databases • separate datasets for: • • • point sources motor vehicles marine emissions biogenic emissions all other area sources Delivering sustainable solutions in a more competitive world

Delivering sustainable solutions in a more competitive world

Delivering sustainable solutions in a more competitive world

Example: wind field & O 3 concentrations 20 August 1996 4. 5 km grid Delivering sustainable solutions in a more competitive world

Examples of Regional Air Quality Modelling for SEA • Site search and EIA for the proposed HEC 1800 MW power plant at Lamma Extension • CTS-3 SEA: Assess impacts of different vehicular emissions control measures, and different transport and population development scenarios by means of comprehensive air quality modelling • PATH was used to assist in the development of emission control strategy for the Pearl River Delta Region Delivering sustainable solutions in a more competitive world

HEC 1800 MW Power Station EIA Study • PATH modelling of HKSAR air quality impacts • several emissions scenarios developed • AQO compliance demonstrated for the worst case meteorological scenario (1 hr and 24 averages) and by means of the PATH ‘annual average episodes’ Delivering sustainable solutions in a more competitive world

Base case SO 2 time series for 26 -28 June 1995, assumed as the worst-case scenario for the HEC power station EIA Delivering sustainable solutions in a more competitive world

SEA for the Third Comprehensive Transport Study (CTS-3) • many transport and population development scenarios tested • detailed, 10 vehicle-class traffic forecast for each model grid cell used to estimate vehicular emissions under different growth scenarios • separate scaling up or down of other emissions (power stations, area sources, marine) • innovative use of model results for assessment: modelled increments (2016 scenario – 1997 base case) added to actually measured 1997 concentrations Delivering sustainable solutions in a more competitive world

NO 2 annual conc. 2016 – 1997 high growth (high end) CTS-3 scenario Delivering sustainable solutions in a more competitive world

Noise Exposure System • ERM was commissioned by EPD in 2000 to undertake a two years Study “Investigation Study for Review of the Acoustical Environment Due to Infrastructure Projects in Hong Kong (Contract 39/2000)” • The worldwide trend to communicate environmental noise information to the public Delivering sustainable solutions in a more competitive world

Requirements of the Noise Exposure Model · Collate noise information for the territory · Identify and quantify the scale of noise problems · Evaluate the effectiveness of mitigation measures Delivering sustainable solutions in a more competitive world

Data Inventory for the NES • • • Digital Elevation Model (DEM) Road Network (Linked to BDTM and ATC data) Building Locations and Heights Podiums Enclosures Barriers Ground Surface Weather Stations Noise Grids for 4 heights for Lden, Ld, Le and L 10 Delivering sustainable solutions in a more competitive world

Some Statistics…. • 2, 000 km trafficable road (>2, 000 AADT) • ~1, 100 km 2 study area • 6. 8 M inhabitants • 80, 000 residential buildings • 0 – ~1, 000 m elevation Delivering sustainable solutions in a more competitive world

Road Treatment Illustration Delivering sustainable solutions in a more competitive world

Road Treatment (Traffic Composition) Delivering sustainable solutions in a more competitive world

Model Delivering sustainable solutions in a more competitive world

Reality Delivering sustainable solutions in a more competitive world

Processing Overview Input Processing Output Obstacles Building footprints Podiums Barriers Enclosures G Spot heights Contour lines Rivers I • • • Slope tops/bottoms Emitters • Railway tracks • Road centreline • Airport Level of exposure estimated for various areas S Vegetation (ground absorption) Noise Exposure Software Calculates noise levels in different areas using inputs Traffic Model • # of vehicles • Speed • Vehicle weight Delivering sustainable solutions in a more competitive world Decisions made on mitigation/planning based on results

Road Noise Contour @ 4 m above ground level Delivering sustainable solutions in a more competitive world

Delivering sustainable solutions in a more competitive world

Conflict Map Delivering sustainable solutions in a more competitive world

4 m above ground 18 m above ground 40 m above ground 80 m above ground Delivering sustainable solutions in a more competitive world

Noise Exposure • Project requirement to estimate percentage of population exposed to excessive noise • Assigning noise levels to each building facades • Data used include Census Map and Building Type Dataset • Use street block population data and building block volume to estimate number of people affected Delivering sustainable solutions in a more competitive world

Histogram of Noise Levels vs Population Delivering sustainable solutions in a more competitive world

No. of People Exposed to Road Traffic Noise Levels > 70 d. B(A) Delivering sustainable solutions in a more competitive world

Summary • One of the largest scale noise mapping exercises in the world • Integrated GIS and Noise Model for better visualisation of the noise environment • A very useful tool/platform to develop 3 D graphical presentation of information to encourage public participation Delivering sustainable solutions in a more competitive world

GIS-based Habitat Map Delivering sustainable solutions in a more competitive world

Habitat Type Freshwater/Brackish Wetland Fung Shui Forest Fishpond/Gei Wai Lowland Forest Delivering sustainable solutions in a more competitive world Mangrove Seagrass Bed Intertidal Mudflat Natural Watercourse

Delivering sustainable solutions in a more competitive world

Ecological Assessment for NENT Study • • Determine amount of habitat lost Refer to total habitat in area of Hong Kong Ecological value of habitat Presence of rare species Delivering sustainable solutions in a more competitive world • • Effects on Species of Conservation Concern Habitat fragmentation/ isolation Noise/ human disturbance Water quality

Delivering sustainable solutions in a more competitive world

Conclusions • GIS based assessment tools are non-dispensable tools in strategic environmental assessment and planning • PATH is a useful tool to compare air quality impact from different development scenarios and to develop control strategies • Noise exposure system is capable of producing population exposure forecast for different districts for future land use planning • GIS-based habitat map is used to provide calculation of habitat loss for assessment of the potential ecological impact for strategic environmental assessment Delivering sustainable solutions in a more competitive world