Browse Data

This dataset reports erosion modelling results regarding annual mean sediment load reductions required to meet proposed suspended sediment attribute bottom lines. For more detail on the modelling process and methods, see Neverman et al. (2019). Impact testing of a proposed suspended sediment attribute: identifying erosion and sediment control mitigations to meet proposed sediment attribute bottom lines and the costs and benefits of those mitigations. Maanaki Whenua Landcare Research Client Report. Prepared for the Ministry for the Environment.

Results of modelled mitigations are reported at catchment scale and at the REC2 river reach scale. The modelled on-farm mitigations (per economic optimisation as reported in Neverman et al. (2019) are also mapped.

This dataset includes three “packages” of information, each with multiple variables. The packages include:

1. Load – results on mean annual suspended sediment load reported by REC 2 river reach scale for various model scenario variations.
2. Lakes – results on sediment inflow, outflow, and entrapment in lakes and reservoirs
3. Coastal – results on sediment inflows, trap efficiency, and sedimentation rates in coastal hydrosystems (estuaries)

For further detail on the modelling methods and discussing results, see Hicks, M., Semademi-Davies, A., Haddadchi, A., Shankar, U., Plew, D. (2019) Updated sediment load estimator for New Zealand. NIWA Client Report No. 2018341CH, prepared for Ministry for the Environment. January 2019. Available online: www.mfe.govt.nz/publications/fresh-water/updated-s...

Note that some portions of this dataset refine and update 2011 modelling on suspended sediment loads across New Zealand, whereas other components, especially the coastal package, report new modelling results.

This dataset reports modelled reference and current state of streambed deposited fine sediment at the REC1 stream segment scale. It provides predicted reference state from a boosted regression tree model trained on 1.) reference site data defined by land cover rules, 2.) all available deposited sediment. It also shows predicted current state trained on all available deposited sediment data.

See Clapcott & Goodwin (2017) for further information on the relevant model rules and data inputs.

This dataset reports modelled mean annual suspended sediment load reduction required to meet proposed suspended sediment attribute bottom lines. Results are reported for the REC 2 river reach scale as well as at the “catchment pourpoint average” scale. The dataset includes masks for the DoC estate as well as glacial mountain source of flow. For further information, see Hicks et al. (2019) Sediment load reductions to meet suspended and deposited sediment thresholds. NIWA Client Report No. 2019100CH. Prepared for the Ministry for the Environment.

Note that the river segment and pour point catchment results provided here (in the attached folders with the same names) form the basis for the erosion and economic modelling assessment of proposed sediment attributes as reported in Neverman et al. (2019). Impact testing of a proposed suspended sediment attribute: identifying erosion and sediment control mitigations to meet proposed sediment attribute bottom lines and the costs and benefits of those mitigations. Maanaki Whenua Landcare Research Client Report. Prepared for the Ministry for the Environment.

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.

The dataset maps areas of winter forage cropping and intensive winter grazing occurring in hill country areas during 2018. Hill country is defined as areas where paddocks have an average slope of greater than 7 degrees. Paddocks are classified into crop type and a measure is provided of the proportion of bare ground within the paddock after grazing.

This layer provides sea-draining river catchments, extracted from the Freshwater Ecosystems of New Zealand (FENZ) v1.0 geodatabase.

​

www.doc.govt.nz/our-work/freshwater-ecosystems-of-...

Note: Metadata relates to the mosaicked imagery. This layer has been provided to enable users to explore coverage and capture dates of the imagery. To enquire about ordering the imagery, please e-mail lucas[at]mfe.govt.nz.

This imagery is a 10m, ten-band multispectral, cloud-minimised mosaic of Sentinel 2A and 2B satellite tiles over Chatham Islands made from scenes captured late-2017/early-2018.