20260225
16030100
1.0
TRUE
150000000
5000
ItemDescription
Northland’s Erosion and Sediment Risk map – property scale
Erosion Risk
Susceptibility
Northland
SPAL
NRC
OpenData
Composite erosion susceptibility raster combining 50% regolith activity (geological risk) and 50% overland flow or OLF index (runoff risk), scaled to a continuous 1–5 index (higher values = higher susceptibility).
<DIV STYLE="text-align:Left;"><DIV><DIV><P STYLE="margin:0 0 0 0;"><SPAN><SPAN>This raster represents a continuous composite susceptibility surface based on two SPAL indicators: MADZ-derived regolith activity (i.e. landscape structural instability indicating geological risk) and the OLF (indicating sediment runoff) index. Equal weighting was applied to both inputs:</SPAN></SPAN><SPAN /><SPAN /><SPAN><SPAN>Composite Score = 0.5 × Activity + 0.5 × OLF</SPAN></SPAN><SPAN /><SPAN /><SPAN>The resulting surface was scaled from approximately 1.32 to 4.95 (higher values = higher susceptibility), yielding a continuous measure of erosion susceptibility across the landscape. This supports prioritisation and interpretation at fine spatial resolution.</SPAN></P><DIV STYLE="font-size:12pt"><P><SPAN>For details see the Land & Water Science report (Gunn and Rissmann 2025) - </SPAN><A href="https://www.nrc.govt.nz/media/tr4ng33g/northlands-landscape-driven-erosion-map-lws-2025.pdf" target="_blank" STYLE="text-decoration:underline;"><SPAN>Northland’s Landscape Driven Erosion Map: A Resource for Decision-Makers and Communities</SPAN></A></P><P /><P><SPAN>Author: Dr Clint Rissmann (Land & Water Science)</SPAN></P><P><SPAN /></P><P><SPAN>Extent: Whole Northland</SPAN></P><P><SPAN /></P><P><SPAN>Projection: NZTM (EPSG:2193)</SPAN></P><P><SPAN /></P><P><SPAN>Coarsest Scale of Component Dataset: 1:63,000 resampled to 5m</SPAN></P><P><SPAN /></P><P><SPAN>Version: Version 2.0</SPAN></P><P><SPAN /></P><P><SPAN>Date Created: July 2025</SPAN></P><P><SPAN /></P><P><SPAN>Date Modified: N/A</SPAN></P><P><SPAN /></P><P><SPAN>NRC Team (if applicable): Natural Resources Science Team</SPAN></P><P><SPAN /></P><P><SPAN>Subject Matter Expert: Clint Rissmann – Landscape Scientist</SPAN></P><P><SPAN /></P><P><SPAN>File Size: 1.91 GB</SPAN></P><P><SPAN /></P><P><SPAN>Raster Metadata Summary:</SPAN></P><P><SPAN>CRS: NZGD2000 / New Zealand Transverse Mercator (EPSG:2193)</SPAN></P><P><SPAN>Pixel Size: 5 m × 5 m</SPAN></P><P><SPAN>Raster Dimensions: 35,661 (width) × 44,551 (height)</SPAN></P><P><SPAN>Extent: 1567222.5000, 5971572.5000 to 1745527.5000, 6194327.5000</SPAN></P><P><SPAN>GDAL Driver: GTiff (GeoTIFF)</SPAN></P><P><SPAN>Compression: LZW</SPAN></P><P><SPAN>Statistics: Min = 1.3167, Max = 4.9504, Mean = 4.0059, StdDev = 0.1441</SPAN></P><P><SPAN>Valid Data Coverage: 31.27%</SPAN></P><P><SPAN /></P><P><SPAN>Data Provided By: Manas Chakraborty (Freshwater Resource Scientist)</SPAN></P><P><SPAN /></P><P><SPAN>Data Published By: Bhawana Kafle (Geospatial Analyst)</SPAN></P><P><SPAN /></P><P><SPAN>Published Date: 19/02/2026</SPAN></P><P><SPAN /></P><P><SPAN>Last Updated By: Jordon Corston (Geospatial Analyst)</SPAN></P><P><SPAN /></P><P><SPAN>Last Update Date: 19/05/2026</SPAN></P></DIV></DIV></DIV></DIV>
Land & Water Science; NRC
<DIV STYLE="text-align:Left;"><DIV><DIV><DIV STYLE="font-size:12pt"><P><SPAN><SPAN>This continuous susceptibility surface reflects relative composite scores based on weighted inputs. Values are scaled but not classed into discrete categories. Use is intended for sub-catchment to regional landscape interpretation.</SPAN></SPAN></P><P><SPAN STYLE="font-weight:bold;font-size:14pt">Licencing</SPAN></P><P><SPAN><SPAN>This dataset was developed by Land & Water Science under agreement with NRC. NRC is licensed to use the product, but Land & Water Science retains intellectual property and full reuse rights.</SPAN></SPAN></P></DIV></DIV></DIV></DIV>
20260519