Digital Networks: challenges, solutions, and case studies to inform nationwide integrated freshwater-land mapping.
- Author
- Doug Booker, Clare Wilkinson, Matt Wilkins
- Year
- 2024
- Journal / Source
- NIWA report for ministry for the Environment
- Pages
- 90 pp
- Summary
- Digital Networks (DNs) are virtual representations of spatially explicit connections across coupled freshwater-land systems. DNs are an important tool for many aspects of freshwater policy, planning, reporting, management, and research because they are a fundamental input to classifications, typologies, models, simulations, and quantitative analysis. A nationally consistent DN is needed to ensure consistency between regions for nationwide applications such as environmental reporting, policy analysis, and flood forecasting. The generation of DNs is challenged by technical constraints, data availability, and because requirements for DN characteristics differ between uses. A DN is characterised by its level of spatial detail (resolution), accuracy of object positioning (alignment), and spatial extent (coverage), which are determined by a combination of input data, technical methods, and developer decisions. Large rivers are usually represented within DNs, but fine resolution DNs can include small streams, drainage ditches, or ephemeral channels along which surface water may flow for short-lived periods. This is important because biophysical modelling may benefit from detailed spatial representation inside and outside of river channels whereas river management and policy development purposes may not require representation of surface flow pathways outside of river channels.