On a small screen this shows only the part of the island where the locations are, so the numbers can be read.
Open the whole map at full size
Land outside the mapped park boundary is shown paler. Where a mapped river and a modelled valley line run side by side, the model agrees with the map; where a modelled line has no mapped river beside it, either the river is unmapped or the model is wrong.
Where the modelled flow paths lead
7 modelled drainage groupsFollowing the modelled flow paths from each location towards the coast groups the 18 locations by their modelled outlet. These groups may help plan field visits, although access and actual river connections need to be checked on the ground.
Each location
18 locations · numbered in visit order, as in the priority list. On the map, 10 to 18 are the small on-hold dotsElevation is estimated from a 30 m surface model; under forest it may reflect the canopy rather than ground level. Slope is the typical slope across the location (the median), with the steepest part in brackets.
Modelled upstream land is the area of land that the terrain model routes through the location. It is not a measure of rainfall, water volume or stream flow. A larger area suggests that more of the surrounding terrain contributes to that point in the model.
How well does the model match mapped waterways?
We compared the modelled valley lines with 77 km of rivers and streams mapped in OpenStreetMap. These waterways were not used to build the model.
63% of the mapped waterway length lies within 60 metres of a modelled line, compared with 24% of all land.
This is an encouraging indication that the model captures broad valley patterns in the landscape. It gives a useful starting point for identifying where streams or drainage channels may be found.
The comparison does not confirm the exact location of individual channels. Some waterways may be missing from the map, and the elevation data cannot always distinguish a real stream from a modelled downhill route.
In practice, the model helps identify places worth checking in the field. A visit can establish whether a channel exists and whether the modelled route matches the terrain. A location marked “valley line” is a place to look for a channel, not a place where one is known to exist.