Aquatic Pollution and Coastal Management

Unit 12 : Environmental impact assessment

12.6.Detailed Assessment
Assessment of Impacts or Baseline Studies
EIA predictions depend on understanding cause effect relationships and the status and trends of environmental characteristics. The assessment of impacts consists of a number of key stages.
Compilation of baseline data

Identification of impacts
A number of methods have been developed to assist in impact identification.
Predicting the magnitude of changes: a number of techniques have been developed to predict the magnitude of environmental impacts.

Determining the significance of impacts
some standards exist by which the significance of impacts can be judged.
An impact is the change from the natural “base line” state resulting from a particular activity.

Impacts can be adverse or beneficial

• Have both temporal and spatial dimensions
• Can be primary (direct) or indirect (secondary), can occur throughout the life of the project

Aims of Prediction
To identify and present
The time in the future at which impact is predicted to occur
The area over which the impact will have an effect
The magnitude of the impact (quantified)
Significance of predicted changes
Limitations of the techniques used and the data on which predictions are based

Compilation of Data Base

Comprehensive Format
A. Natural resources

• Soil characteristics
• Type of vegetation
• Extent of mangroves/coral/wetlands
• Wild life resources
• Ground water aquifers
• Coastal resources fish / mangroves/seaweed
• Physico-chemical characteristics of waters

B. Natural process

• Soil erosion
• Sedimentation
• Volcanic eruption
• Earthquakes
• Floods
• Coastal erosion
• Sea level rise

C. Environmental parameters

• Waves
• Tides
• Wind
• Physico-chemical characteristics of waters

D. Anthropogenic process

• Deforestation
• Sewage
• Soiled waste
• Dredging
• Beach mining
• Oil spills
• Coastal erosion
• Habitat degradation
• Agriculture/land use pattern
• Population growth

E. General Information

• Population
• Literacy
• Communication and transport
• Basic amenities