Identifying and Evaluating Impacts - Mining and the Environment: From Ore to Metal - page 417

cumulative impacts are identii ed. Feedback loops can also be incorporated into network
and l owchart analyses by including a series of loops with information on existing feed-
back mechanisms.
The basic component of network and systems analysis is the impact chain, which illus-
trates the process of cause and effect including the knock-on effects to other environmen-
tal receptors ( Figure 9.8 ). Linked together, complex diagrams or l owcharts are developed
which include a wide range of indirect impacts and more impact interactions. There are,
however, limits to the complexity that can be readily understood by reviewers. Highly
complex diagrams may look impressive but may not be easily understood. Accordingly,
it is preferable to produce multiple, simple l ow charts or diagrams, rather than a single
complex diagram that purports to identify all project interactions.
Since a direct project impact often results in a series of indirect effects, the chain
becomes increasingly complex with each additional project activity. The method can be
expanded to include impact interactions between environmental sub-systems. If appropri-
ate and available data allow, it is also feasible to include some quantitative analysis in the
network. The network analysis then constitutes a simple form of modelling, a quantitative
impact evaluation.

Highly complex diagrams may
look impressive but may not be
easily understood.

FIGURE 9.8
An Example of how Impact Chains
can be used to Illustrate Indirect
Impacts and Impacts Interaction

OPERATION STAGE

Recruitment and
training

Ore haulage
and processing

Mining Mine dewatering

Employment and
business opportunities

Air quality
and noise

Vibration

Micro climate

Income
opportunities

Demography

Local and regional
economy

Norms, values
and lifestyle

Environmental
sanitation

Community perception
and attitude