Canterbury Wetland Monitoring Programme Design

Client: Environment Canterbury (ECan)

Environment Canterbury needed a long-term programme to track the condition of wetlands across the region and the pressures affecting them. The challenge: nobody knew exactly how many wetlands existed or where they all were, so the monitoring design had to account for that uncertainty from the start.

ECan first identified wetlands from aerial imagery. We then applied a grid-based sampling design to that full set, randomly selecting a representative sample for monitoring. This ensured every wetland had an equal chance of being included, and gave a result that fairly represented the whole region.

We then tested how well this design would perform over time, running simulations to determine how many wetlands needed to be surveyed each year to reliably detect real regional trends.

Outcome: ECan gained a flexible, statistically sound monitoring framework that could adapt as new information about wetland locations came to light.

Method: Grid-based spatial sampling design with balanced sampling, supported by simulation-based power analysis.