S-map is a new digital soil spatial information system for New Zealand. It is being created by Manaaki Whenua with funding from central and local government.

S-map Online is one of a number of delivery services for S-map data and has been developed and is operated by Manaaki Whenua's Informatics team.

When complete across New Zealand, S-map will for the first time provide consistent and comprehensive national soil data layers to support applications at local, and regional to national scales. It builds on previous soil mapping by filling gaps with new mapping, and upgrading the information content and associated database to meet a new national standard. In time, S-map will have national coverage and contain predominantly new digital data at a scale that resolves soil variation on hill slopes (nominally 1:50 000 scale).

All outputs will have to meet specific S-map standards, which specify the soil attributes that are to be mapped and their level of description, including a measure of uncertainty. The primary map layer is soil classes, i.e. delineated areas that are labelled with the soil family name. Each soil family is defined as a unique combination of attributes (NZSC classification, parent material, rock type, dominant texture and permeability class). Soil classes are further characterised as siblings according to their depth to rock class, stoniness, land type, drainage, texture (more detailed), functional horizons and miscellaneous variant information. The uncertainty of each of these family and sibling attribute classes is specified.

Associated with the soil class layer will be additional map layers of fundamental and derived soil properties. The fundamental soil properties are depth (diggability), depth to slowly permeable layer, rooting depth, rooting barrier, horizon thickness, stoniness, clay and sand content. They are developed from sample information and expert knowledge. The derived soil layers are each based on a model (or pedo-transfer function). Some models are simple lookup tables that depend only on the soil class. Others combine various soil, land use, vegetation, climate or topographic attributes in a mathematical formula. Derived layers will include available water (mm), macroporosity, water retention, bulk density, total carbon, total nitrogen, phosphorus, calcium, cation exchange capacity, pH, and phosphorus retention.

You can find out more about S-map from the references on this web page: https://smap.landcareresearch.co.nz/support/citing-s-map

and on the Soils Portal website at https://soils.landcareresearch.co.nz/tools/s-map-online/

Funding

There are three types of funding. First, funding from the Ministry of Business, Innovation and Employment (MBIE) contract to Manaaki Whenua's Characterizing Land Resources Portfolio is allocated to maintaining the S-map information system and SmapOnline website. Second, additional funding from commercial clients is used to support and maintain the S-map infrastructure. Third, S-map coverage of New Zealand is extended through funding from central and regional government. This pays for soil surveys to be undertaken, mapped and uploaded to S-map. The location of additional coverage is driven by regional council needs.

Stakeholders

Groups with a particular interest in new soil data include:

  • Territorial authorities for policy development, monitoring programmes and consent rules
  • Rural servicing agencies, farm managers and land owners – to provide information for management, planning, and standards certification
  • Science research programmes in which soil data underpin modelling and scaling up of research results, e.g., development of hydrological models in NIWA.

Methods

The work is divided into two major land areas:

  • Lowlands, dominantly flat to rolling land. Landforms are of such low relief that digital elevation models (based on current 20-m contour data) cannot be used for soil modelling. Soil mapping uses conventional methods, based on air-photo interpretation and free-survey techniques.
  • Uplands, dominantly hill and mountain terrain. Relief allows application of soil–landscape modelling based on digital elevation models and other spatial information. The actual modelling used will depend on the land system and the sampling cost and availability of data. The predominant technique will be to derive soil distribution rules from available data, literature and new sampling, and to apply these to modelled landform land-elements.

 

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Last updated: 2 September 2024