Identifying and Evaluating Impacts - Mining and the Environment: From Ore to Metal - page 412

are involved. A pictorial, poster-style conceptual model is useful to introduce ecological
relationships. A box and arrow diagram can follow, detailing relationships among stres-
sors, receptors, and intermediate processes. To ensure the model does not become too
complicated to be helpful, only pathways and causes relevant to a specii c analysis should
be considered. Separate diagrams for each stressor or pathway will help to keep the focus
on the analysis steps that follow. See Jorgensen (1994), Suter (1993), Cormier et al . (2000),
or USEPA (1998) for additional advice on developing conceptual models. As well as clari-
fying relationships among multiple causes and effects, the SPR concept is a powerful tool
for discussing environmental change processes among the assessment team and for obtain-
ing additional insights from external stakeholders.

9.5 IDENTIFYING PROJECT IMPACTS

In this text we differ between identifying and evaluating environmental impacts. Impact
identii cation methods recognize how and where impacts or impact interaction may occur.
Evaluation methods quantify impacts based on context and their signii cance attributes.
Some methods are capable of both, identifying and evaluating impacts and often combina-
tions of various techniques are used ( Figure 9.5 ). Regardless of which method is selected,
the method should be practical and adequate given available data, time and i nancial
resources, and impact signii cance. Flexibility, data requirements, and cost are always
important criteria when deciding on a particular methodology.
Identifying impacts is essentially an objective exercise answering the question 'Which
environmental changes are associated with mine development?' To i nd answers, two data
sets are necessary ( Figure 9.6 ).
Firstly, the receiving environment needs to be dei ned. Environmental assessment is a
site-based approach and baseline conditions provide the context for evaluating project-
induced effects. More data are required in terms of quantity, area coverage, and time
horizon, when assessing indirect impacts compared to direct impacts. It is important to
identify data needs early in the assessment process and to consider how data will be used
before they are collected. Data collection should consider current and likely future status
of potentially impacted environmental resources, so that project-induced changes can be
differentiated from changes that would occur in the absence of the project. Information on
historical trends, existing regulatory standards, and established regional planning are also
relevant.
Secondly, information on mine development is required. Key project characteristics are
ore type and reserve (such as coal, metals, or non-metals), scale of mine (annual average and

Regardless of which method
is selected, the method should
be practical and adequate
given available data, time and
fi nancial resources, and impact
signifi cance.

FIGURE 9.5
Methods and Tools for Identifying and
Evaluating Impacts

IMPACT
IDENTIFICATION

IMPACT
EVALUATION

Impacts identifi cation methods recog-
nize how and where impacts or impact
interaction may occur. Evaluation
methods quantify impacts based
on context and their signifi cance
attributes.
Source:
Based on Walker and Johnson 1999

Matrices
Expert opinions
Spatial analysis

Modelling

Checklist

Threshold analysis

Consultation
Network analysis
Flow chart