MODULE 2
ENVIRONMENTAL IMPACT ASSESSMENT METHODOLOGY
Module 2 : Syllabus
Measurement of environmental impact - organization, scope and
methodologies of EIA - Six generic steps - descriptive checklists - simple
interaction matrix -stepped matrix - uniqueness ratio - habitat
evaluation system.
COMPONENTS OF EIA
EIA PROCESS
PARALELL STUDIES
DEFINE PROPOSAL
SCREENING (Prepare initial
environmental evaluation)
NO EIA EIA REQUIRED PREFEASIBLITY
REQUIRED STUDIES
PUBLIC PARTICIPATION
PUBLIC SCOPING FEASIBLITY
PARTICIPATE STUDIES
PREDICTION
PUBLIC AND
CONSULTATION MITIGATION
PREPARE
DRAFT (EIS)
REVIEW OF EIS BY PUBLIC
AND REGULATORY
AUTHORITY PREPARE
FINAL EIS
MANAGEMENT
AND
MONITORING
OPERATION
AUDIT AND
MANAGEMEN
TNT
MEASUREMENT OF ENVIRONMENTAL IMPACT
• Number of techniques are available for providing a comprehensive
identification of impacts and some of them are listed below.
Adhoc method
Checklists
Matrices
Networks
Overlays
Cost-benefit analysis
Simulation modeling
SIX GENERIC STEPS IN EIA PROCESS
• STEP 1: SCREENING
• STEP 2: SCOPING
• STEP 3: IMPACT ANALYSIS
• STEP 4: IMPACT MITIGATION
• STEP 5: EIA REPORTS
• STEP 6: AUDIT
SIX GENERIC STEPS IN EIA PROCESS
STEP 1: SCREENING STEP 2: SCOPING
This step determines Scoping begins once screening is
whether or not EIA is required for a completed
particular project Scoping identifies the most important
step in EIA
what level of EIA is required
Scoping establishes the content and
scope of an EIA report Outcome:
Screening Outcomes: Identifies key issues and impacts to be
Full or comprehensive EIA required considered
Scoping lays the foundation of an
Limited EIA required
effective process, saves time and
No EIA required money, and reduces conflict
SIX GENERIC STEPS IN EIA PROCESS
STEP 3: IMPACT ANALYSIS STEP 4: IMPACT MITIGATION
Type of Impact(Air, water, Noise) To avoid, minimize or remedy
Nature of Impact (Direct or Indirect adverse impacts
or combination)
Magnitude of Impact To ensure that residual impacts
Extent(Local, regional, global) are within acceptable levels
Timing(Short term, Long term)
Duration(Temporary, Permanent) To enhance environmental and
Reversibility(Reversible/Irreversible) social benefits
SIX GENERIC STEPS IN EIA PROCESS
STEP 5: EIA REPORTS STEP 6: AUDIT
Review the quality of the EIA
Environmental Impact report.
Assessment Report (EIA Report) Take public comments into
Environmental Impact account.
Statement (EIS) Determine if the information is
sufficient.
Identify any deficiencies to be
corrected.
CHECKLISTS
A checklist is a list of Environmental parameters to be investigated.
A typical checklist might contain entries such as
Earth: Mineral resources, construction materials, soils etc.
Water surface: Rivers, lakes, reservoirs, coastal seas, oceans etc.
Atmosphere: Gases, particles, climate, temperature.
Flora: trees, shrubs, grass, crops, micro fauna etc
Fauna: Birds, Land animals, benthic organisms, insects, micro fauna.
Land use: Residential, industrial, commercial, industrial, mining etc.
Check list--CONT
RESOURCES PARAMETERS Nature of impacts
A B C D E F
HYDROLOGY Low flow regime
Flood regime
Operation of dams
Fall of water table
Rise of water table
POLLUTION Solute Dispersion
Toxic Substances
Organic Pollution
Anaerobic effects
Gas emissions
Check list--CONT
A: Positive impact very likely
B:Positive impact
C:No Possible Impact
D: Negative Impact Possible
E:Negative Impact very Likely
F: No Judgement possible at present
MATRICES
Simple matrices combine checklist in to a diagrammatic representation which
allows area of cause and effects relationship or interactions between the
various project activities and its impacts on environmental components.
The approach is to full matrices by brainstorming people with the awareness
of the proposal.
MATRICES
• A simple graded matrix for a EIA of a reservoir
ENVIRONMENTAL Impact of project activities
FEATURES LIKELY TO GET
AFFECTED
Colony construction
Importing of labour
Canal construction
Blasting operation
Dam construction
Rehabilitation
Hydro-power
generation
Irrigation
Forestry & Vegetation +2P -1T -1P -1P -1p +3p +1p
Birds -2T -2T -1T +2p +2P
Fisheries -1T +4P +2P
Sedimentation -1T -1T +2p +2p +3P +3P
Floods -1P -1P +3P
MATRIX--CONTD
• LIKELY EFFECT IS SYMBOLIZED AS FOLLOWS
TYPE OF IMPACT MILD Considerable HIGH VERY HIGH
Beneficial/Permanent effect +1P +2P +3P +4P
Beneficial/Temporary effect +1T +2T +3T +4T
Detrimental/Permanent effect -1P -2P -3P -4P
Detrimental/Temporary effect -1T -2T -3T -4T
HABITAT EVALUATION SYSTEM
• Habitats are those environments or ecosystems that provide substantial
ecological values and services such as fish and wildlife populations,
nutrient cycling, water purification, and climate control.
• All-natural areas contain definable units that can be called either
ecosystems or habitats.
• The term habitat is equivalent to ecosystem and includes both the physical
and biological components of the environment.
• All habitats are important for the conservation of ecological values at their
specific location.
• However, certain habitats, and types of habitat, can be designated as “of
special concern” and hence habitats of concern are defined as those
sensitive environments whose degradation or loss results in significant
diminution of ecosystem integrity or ecological values.
Habitat Evaluation Methodology
The definition of habitat is based on ecosystem values and thier functions.
The evaluation of habitat system is measured in following steps namely.
Step 1 : Review the type, status and trends of habitats in the regions
under consideration.
Step 2 : Identify habitats of concern for the region that may occur at the
site.
Step 3 : Analyze the impacts of all activities on the functions and values
of these habitats.
Step 4 : Derive mitigation measures to eliminate or ameliorate the
impacts on habitats of concern.
