In the interests of simplifying the data entry requirements for creating a new analysis, the Overseer team are focused on enabling more effortless ingress of data. In line with this focus, we have identified the availability of multiple topographic datasets for New Zealand. Evaluation of those datasets suggested it is feasible for the topography of pasture blocks to be automatically derived. This means it is no longer necessary to manually add slope data to pasture blocks. This will save data-entry time and reduce the possibility of data-entry error.
When a pasture block is drawn, the topography of a block is automatically derived using a spatially referenced slope dataset.
This slope dataset available from the Landcare Research New Zealand Land Resource Inventory (NZLRI) was originally created from aerial photogrammetry and is comprised of a polygonised layer that delineates the physiographic areas of relatively homogenous average slope class.
To align the NZLRI slope data with Overseer model requirements, post-processing was applied to classify the slope data in to the Overseer slope categories: flat, rolling, easy hill and steep hill.
When creating or editing a pasture block, users can select show modelled topography to show the proportion of different slopes within the polygon e.g. :
The NZLRI dataset is mapped at a 1:63 360/1:50 000 scale. If slope differs at a farm-level scale then users can manually change a blocks topography.
If topography is changed to a slope different to the modelled topography then an orange warning message pops up to notify you which topography is recommended.