Soils Data

"Long-term soil erosion is the average mass of soil lost per square kilometre per year (tonnes/km2/year) over a period of approximately 10 years. It is extrapolated from long-term measurements of sediment load in rivers. Extrapolation is based on mean annual rainfall, rock type, and land cover. The total sediment in rivers (tonnes/year) for a particular region is the sum of all soil erosion over the entire region (Dymond et al, 2010). Soil-erosion rates were calculated to 2012.

This data set relates to the "Estimated long-term soil erosion" measure on the Environmental Indicators, Te taiao Aotearoa website."

"Long-term soil erosion is the average mass of soil lost per square kilometre per year (tonnes/km2/year) over a period of approximately 10 years. It is extrapolated from long-term measurements of sediment load in rivers. Extrapolation is based on mean annual rainfall, rock type, and land cover. The total sediment in rivers (tonnes/year) for a particular region is the sum of all soil erosion over the entire region (Dymond et al, 2010). Soil-erosion rates were calculated to 2012.

This data set relates to the "Estimated long-term soil erosion" measure on the Environmental Indicators, Te taiao Aotearoa website."

This metadata record describes an image of land predicted to be at risk of severe mass movement erosion for the South Island. The image was produced using the Highly Erodible Land model that identifies land at risk to the main forms of mass-movement soil erosion in New Zealand: landsliding, gullying, or earthflow erosion. If the land has protective woody vegetation, then it is not at risk (Dymond et al., 2006). The Highly Erodible Land model identifies five classes of land at risk of erosion: (1) High landslide risk – delivery to stream; (2) high landslide risk – non-delivery to steam; (3) Moderate earthflow risk; (4) Severe earthflow risk; and (5) Gully risk. Landsliding occurs on steep slopes where the soils do not have protective tree roots. The slope angle at which land is considered at risk to landsliding depends on rock strength. Where land is steeper than this slope threshold and does not have woody vegetation, it is considered at risk to landsliding. There is no slope threshold for land at risk to gullying or earthflow erosion. Where land is at risk to gullying or earthflow erosion and does not have woody vegetation, it is considered at risk. The different types of mass-movement soil erosion are not ranked in severity, except for earthflow risk which has extreme and moderate classes of risk. Use: These data provide a regional perspective on land at risk of soil erosion.

More information on this dataset and how it relates to our environmental reporting indicators and topics can be found in the attached data quality pdf.

"This data describes the location of the different types of soil in New Zealand using the New Zealand Soil Classification.

This data set relates to the "Soils" measure on the Environmental Indicators, Te taiao Aotearoa website."

"This data records estimated erosion risk for different areas in the North Island.

New Zealand experiences high rates of soil erosion. In the North Island, this is mostly due to the historical clearance of forest for agriculture (see also Estimated long-term soil erosion). In contrast, erosion in the South Island is mostly due to natural processes, primarily high rainfall and steep mountain slopes.
Highly erodible land comprises land at risk of landsliding, gullying, or earthflow erosion if it does not have protective woody vegetation (Dymond et al, 2006). Landsliding occurs on steep slopes where the soils do not have the support of tree roots.
Gullying and earthflow erosion can occur on all slopes, irrespective of steepness, but the land is only considered at risk if it does not have woody vegetation.
Landslide erosion is the shallow (approximately 1m) and sudden failure of soil slopes during storm rainfall. Gully erosion is massive soil erosion that begins at gully heads and expands up hillsides, over decadal time scales. Earthflow erosion is the slow downward movement (approximately 1m/year) of wet soil slopes towards waterways.

This data set relates to the "Estimated highly erodible land in the North Island" measure on the Environmental Indicators, Te taiao Aotearoa website."