The contribution of resilience assessment to impact assessment

ABSTRACT Resilience describes the ability of complex systems to withstand disturbance or recover from disturbance while maintaining structure and function. Resilience assessment identifies potential failure pathways due to disturbances, critical variables, and their thresholds in relation to system failure. It provides the basis for identifying management interventions to reduce system vulnerability to disturbance and enhance recovery of system structure and function. Case studies successfully applying resilience assessment are provided. For impact assessment of Ord River Irrigation Scheme, resilience assessment provided the basis for a conservation strategy for flora and fauna threatened by project clearance. Resilience analysis of policies for managing public health risks for water quality identified strengths and weaknesses of these policies for sustainable management of health risks. In assessing environmental programmes for lakes in Greater Wellington, resilience assessment identified critical variables for managing lake values. In multi-objective planning for Te Waihora/Lake Ellesmere, resilience analysis identified rehabilitation priorities without adversely affecting other lake values. A resilience approach to protecting Christchurch from flooding led to a scheme to accommodate flood flows greater than design criteria. KEY POLICY HIGHLIGHTS An approach to resilience assessment is provided comprising adaptive cycles, failure pathways, multiple spatial scales, and management interventions. Examples are discussed of applications of resilience assessment to project assessment, environmental policy, environmental programmes, rehabilitation priorities, and project design. The value added by resilience assessment to impact assessment and environmental management is discussed.