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Critical Pathways

Understanding water flow on catchment scale

Lincoln Agritech, New Zealand is leading a five-year Critical Pathways Programme (CPP) a research programme funded by the Ministry of Business, Innovation and Employment (MBIE), New Zeland. Responding to a well-recognised knowledge gap, it aims to elucidate the relatively shallow and short pathways operating at the sub-catchment scale, and to represent them in water flow and contaminant transfer models.

Two contrasting Waikato catchments, the Waiotapu Stream catchment (approx. 300 km2) and the Piako River headwater catchment (approx. 100 km2) were surveyed using SkyTEM, which took only seven flight days to complete. Using parallel flight paths (200 m apart) enabled us to get high-resolution data across the entire catchment areas. This starkly contrasts with the conventional approach that uses a limited number of point-scale lithology data (colour, texture, and composition) from the installation of groundwater bores.

The Hydrogeophysics group are a partner in the project and has assisted with optimal SkyTEM setup with respect to mapping the shallow subsurface environment. Furthermore HGG have assisted in the processing and interpretation of the big-data SkyTEM dataset. Researcher from HGG and Lincoln Agritech will also collaborate closely on how to take all the big data and transform it into realistic modellong of the water and contaminant  flow on a catchment scale. The Critical pathways project should hence be seen as a “sister” project to Mapfield.