The fundamental background to the physiographic approach is that water quality outcomes vary spatially across the landscape, even when there are similar land use pressures. These differences are often the result of natural spatial variation in the landscape, which alters the composition of the water through coupled physical, chemical, and biological processes.
The Physiographic Environments of New Zealand (PENZ) is a three-year project that links fresh water to the land. Understanding this relationship is crucially important as it is a major influence over water composition, and hence quality.
Land and Water Science are currently working on a Sustainable Farming Fund Project to provide a web based portal to bring Physiographic Science into the hands of the rural community so that they're empowered and able to make informed decisions regarding land management.
Over the past year we have been collaborating with Living Water (DOC/Fonterra Partnership) and local landowners to undertake high-resolution physiographic mapping of the Waituna Catchment, Southland.
Peak Runoff Control Mitigations
This project focuses on the catchment of Waituna Lagoon and identifies where small detainment dams could be constructed to control the surficial runoff of contaminants from the landscape. The sites are prioritised by capture zone size, the likelihood of overland flow, generated runoff volumes, and the possibility of contaminant load from various land uses.
This work looks at water movement and potential flow pathways at the paddock scale, identifying the locations where contaminants are leaving a property. This information can be used to inform better farm management decisions, or the placement of various mitigations or interventions, improving water quality.