Week 10 - Cumulative Effects Assessment Flashcards
What is cumulative environmental effects?
effects of an additive, interactive, synergistic, or irregular nature, caused by individually minor but collectively significant actions that accumulate over time and space
- no universally accepted definition
What is an example of a cumulative effect?
Watershed.
- upstream there is forestry sedimentation, industrial caused flow alterations, agricultural and sewage runoff, and bank erosion
- altogether causes a cumulative effect
What are the scientific and technical requirements?
- boundaries: time and space
- quantification: quantitative study dominates
- modelling: conceptual and quantitative modelling useful
- prediction: EA impact prediction from baseline
- study design: clear direction on study strategy/framework
- qualitative approaches
- indigenous knowledge
- local knowledge
What is a significant impact?
Within specified time and space boundaries, it is a predicted or measured change in enviro attribute which should be considered in project decisions, depending on reliability and accuracy of prediction and magnitude of change
What are factors to consider in determining significance?
- exceedance of threshold
- effectiveness of mitigation
- incremental contribution of effects from action under review
- relative rarity of species
- magnitude of change relative to natural background variability
- degree of existing disturbance
What are the recommendations based on a basic set of criteria for conducting EA?
- joint planning of impact assessment b/w proponents and RA
- identify VECs
- define context fro impact significance
- establish clear temporal and spatial boundaries for study
- develop/implement study strategy
- specify nature of predictions
- require monitoring of project effects
Why did Rees take on the CEA and Global Change research in 1995?
- disenchantment project by project approaches
- no generally accepted defintions
- cumulative impact of development to date calls into question the prevailing pattern of global development
What did Rees conclude about CEA?
- little practical value unless tied to development limits
- regional carrying capacity
- implications for developed and developing countries
- major development projects should be assessed in terms of cumulative socioeconomic impacts
- effect on widening income disparity
- cumulative effects on natural capital
- biodiversity loss
- climate change
How does CEA differ from traditional EA?
- assesses effects over larger area
- assesses effects during longer time period
- considers effects on VECs due to interactions with other actions, and not just effects of single action under review
- includes other past, existing, and future actions
- evaluates significance in consideration of other than just local direct effects
What are CE mechanisms?
- time crowding: repeated so frequently that the ecosystem has no time to recover/assimilate effects
- space crowding: so close together that effects overlap
- synergistic effects: diff impacts combined
- indirect effects: delayed impact via complex pathways
- precedent setting: development leads to further development
- combination: of one or more effects
- other descriptors: fragmentation or patchiness effects, triggers and thresholds, time lags
Give some examples of CEA case studies
- Cheviot Coal Mine near Jasper National Park
• VECs: elk, grizzly bears
• Issues: development near large protected area & destruction of habitat
• Approaches: GIS-based habitat modelling and CEA for bears
• Lessons: need for region based mitigation - Trans-Canada Highway Twinning Phase near Banff National Park
• VECs: elk, moose, wolf, coyote, bears
• Issues: habitat loss, disturbance
• Approaches: spatial analysis with GIS
• Lessons learned: qualitative conclusions/ranking system useful to communicate results - Mackenzie Valley Gas Pipeline CEA Work
• Canadian Arctic Resources Committee (CARC)
○ Long standing interest in protecting North
• Applied Globio Impact Modelling
○ High terrestrial impact on birds, large mammals, and flora and fauna
