Bringing the environmental and planning expertise

to maximise the value of your investment

Modelling bird behaviour to progress wind

farm development

Tom Hartley

Principal GIS Consultant

Atmos Consulting

Our service areas

Renewable energy

Sustainable Development

Biodiversity

Property and Construction

Marine and Coastal

Water resources

Environmental Management

Our specialisms

Environmental Impact Assessment

Town Planning

Ecology and Ornithology

GIS mapping and analysis

Noise and Acoustics

Hydrology

Project Management

Expert technical, environmental and planning support throughout the entire project

life-cycle, from feasibility to implementation.

Onshore Wind and GIS

• Historically a good match

• Data has a potentially long shelf life

• Spatial modelling often required to

assess impacts on sensitive receptors

• Maturing sector and recent changes to

subsidies have lead to increased

pressure to do more with less

Can’t see the birds?

Theoretical modelling of bird activity

Leadhills wind farm

• Turbines < 2km from Special

Protection Area

• Lack of activity recorded in Vantage

Point surveys

• Uncertainty over potential impacts on

key ornithological species – objection

from Scottish Natural Heritage

Random Collision Risk Modelling

SNH (2000)

Usually derived from Vantage Point surveys -how to substitute activity levels in the flight risk volume?

• Define the flight risk volume

• Calculate how much of this volume is swept by

turbine rotors

• Calculate activity levels within this volume for

each species

• Calculate the number of bird transits through

the swept rotor volume

• Calculate the probability of a bird being hit in

each transit

The Solution

• A model to predict the time spent

in the windfarm airspace based on

territory / nest locations and

ranging behaviour

• Species-specific information

derived in part from the Atmos

GIS database

The Solution

How to define nest locations?

1. Historical nest locations provided by

SNH and local raptor study group

2. Worst case nest locations based on

interpretation of aerial photography

3. Random nest locations within SPA

based on breeding populations

The Model

• Define nest locations

• Map the ranging behaviour per nest

• Combine overlapping buffers as a grid

• Calculate the time spent in the turbine

envelope

• Correct for time spent at risk height

• Substitute for observed activity levels

in existing random CRM

The Result

• Low risk of adverse impacts on

populations

• Provided sufficient information to allow

SNH to remove their objection and

pass appropriate assessment

Further use in Pre-planning

Cumberhead wind farm

• Turbines < 2km from same SPA

• Operational commercial forestry

• Low activity levels of SPA species

• Is survey data representative?

Additional Model Validation

• Incorporated active survey data to

appraise worst case locations

The Result

• Model predicted low risk of adverse impacts

on populations

• Case was made to reduce survey effort from 2

years to 1

• Rationale accepted by consultees and project

submitted June 2015 and consented February

2016

• Significant saving of time and money for client

SNH Guidance

• Work was undertaken in close contact

with SNH

• Modelling approach included in 2016

SNH guidance:

• Wind farm proposals on afforested

sites - advice on reducing suitability for

hen harrier, merlin and short-eared owl

Incorporating habitat preference

Lethans wind farm

• Forested site, with turbines < 2km from SPA

• Habitat Management Plan proposed for 25 year lifetime of wind farm

• Felling may increase attractiveness to raptor species

• Model revised to incorporate habitat suitability into ranging behaviour from each nest

• Submitted to planning August 2016

Further applications

• Assessing different species

(behaviour and distribution) for

different sites or regions

• Testing different future scenarios

• Re-powering of existing sites using

historic data?

Questions?