Freshwater Data

Full report: Memorandum on implementing a national index for susceptibility to streambank erosion: environment.govt.nz/publications/national-index-st...

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This dataset contains predictions of the susceptibility to streambank erosion for every stream link in the RECv2.5 digital river network. Streambank erosion susceptibility is computed as a dimensionless index (range 0-100) for each stream link based on factors that may influence reach-scale bank erosion. These factors comprise stream power, the extent of riparian woody vegetation, valley confinement, channel sinuosity, and the erodibility of stream banks based on soil texture. The approach for determining streambank erosion susceptibility is described by Smith & Betts (2021) and based on the bank erosion model developed by Smith et al. (2019).

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***Smith HG, Spiekermann R, Dymond J, Basher L 2019. Predicting spatial patterns in riverbank erosion for catchment sediment budgets. New Zealand Journal of Marine and Freshwater Management 53: 338–362.

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***Smith HG, Betts H 2021. Memorandum on implementing a national index for susceptibility to streambank erosion. Technical memorandum prepared for the Ministry for the Environment by Manaaki Whenua – Landcare Research.

The StockEx LSL 2021 proposed layer identifies proposed areas of "low slope land" where the Resource Management (Stock Exclusion) Regulations 2020 would apply if the low slope land map was updated as proposed in the "Stock exclusion regulations: Proposed changes to the low slope map" (MfE, 2021) discussion document. The layer shows the area of land defined as low slope land. These areas have a local mean slope is less than or equal to 5 degrees and are below 500m in altitude. Areas of lakes and ponds, estuarine open water, built-up areas, transport infrastructure, depleted grass, tall tussock grassland and urban parkland, as defined in Land Cover Database 5, are also excluded.

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Note: The current regulation layer is 'Stock Exclusion Low Slope Land 2020'

data.mfe.govt.nz/layer/104827

The StockEx LSL 2021 proposed layer identifies proposed areas of "low slope land" where the Resource Management (Stock Exclusion) Regulations 2020 would apply if the low slope land map was updated as proposed in the "Stock exclusion regulations: Proposed changes to the low slope map" (MfE, 2021) discussion document. The layer shows the area of land defined as low slope land. These areas have a local mean slope is less than or equal to 5 degrees and are below 500m in altitude. Areas of lakes and ponds, estuarine open water, built-up areas, transport infrastructure, depleted grass, tall tussock grassland and urban parkland, as defined in Land Cover Database 5, are also excluded.

The Stock Exclusion Low Slope Land 2020 layer identifies areas of "low slope land" as defined in the Resource Management (Stock Exclusion) Regulations 2020. The layer shows the land parcels, or part parcels, defined as low slope land. These areas have a mean slope is less than or equal to 10 degrees. Parcels with a parcel intent of "ROAD" are excluded. Areas of lakes, ponds, settlements and urban parkland, as defined in Land Cover Database 5, are also excluded. Areas of low-slope grassland and annual cropland within high-slope parcels are also included in the Stock Exclusion Low Slope Land extent.

This dataset shows land parcels within grassland and annual cropping areas which have an average slope of less than 10 degrees. Polygons are attributed into 3 slope classes: less than 5 degrees mean slope; 5 - 7 degrees mean slope; 7 - 10 degrees mean slope.