Tutorial manual for CLUES 1.4
Project background
The Ministry of Agriculture and Forestry (MAF), in association with Ministry for the Environment (MfE), has engaged NIWA and five subcontractors (Lincoln Ventures, Harris Consulting, AgResearch, HortResearch, Landcare Research) to develop a modelling system to assess the effects of land use change on water quality and socio-economic factors at a regional or national level. The system is called CLUES - Catchment Land Use for Environment Sustainability.
CLUES is intended to provide a “sustainable development” context allowing for community, social and economic inputs in assessing the effects of land use and land use change on water quality. It was created because there was no quantitative method available to link these factors at the level of detail required.
The CLUES catchment modelling framework allows users to easily develop and simulate the effects of land use change on stream water quality and integrates the following components:
• OVERSEER® nutrient budget model for nitrogen loss from pastoral land uses. Five farming scenarios are available; dairy, sheep/beef lowland, sheep/beef hill country, sheep/beef high country, and deer.
• SPASMO predictions of nitrogen leaching for combinations of crop, fertiliser, climate and soil.
• HARRIS Consulting (HC) economic models for simulating the relationships between economic output and nutrient loss from different land use types. Triple bottom line effects of land use change.
• SPARROW model for phosphorus and other sources of nitrogen (such as point sources and forest sources), and for nutrient losses in the stream network.
• Ensus nitrogen leaching risk model.
The modelling framework, illustrated below, has been discussed fully by Woods et al. (2006).
Manual layout
This manual is presented as a tutorial. The tutorial uses the files provided with the CLUES 1.4 CD for Waikato (Clues_waikato9.2.mxd) with Raglan Harbour as a case study and has been prepared using ArcMap v. 9.2. The extent and location of the display can be adjusted using the standard ArcGIS zoom and pan tools. Users will need beginner to intermediate GIS skills to run CLUES 1.4
Data requirements
CLUES requires the following spatial data either provided as map layers or incorporated into the model framework:
• Current land use.
• Stream network and river reaches (sub-catchments).
• Climate (e.g., annual rainfall).
• Slope.
• Soil order and drainage class (from the Land Resource Inventory).
• Point sources and lakes.
This data is provided as part of the CLUES system, although land use can be modified by the model user by creating new scenarios.
Land uses simulated in CLUES are in order:
DAIRY - dairying
SBHILL - hill country sheep and beef
SBINTEN - low land intensive sheep and beef
SBHIGH - high country sheep and beef
DEER - deer
OTHER_ANIM - other types of farm animals
CROPS - arable crops (e.g., maize and barley)
VEG - market gardens, vegetables
BERRY - berries
KIWI - kiwifruit
SUM_FRUIT - “summer” stone fruit (e.g., plums, peaches, nectarines)Tr
TROP_FRUIT - tropical fruit
PIP_FRUIT - pip fruit (e.g., apples, pears)
FLOWERS - flowers
VITI - viticulture, vineyards
PLANT_FOR - planted exotic forest, forestry
NAT_FOR - native forest
SCRUB - scrubland
URBAN - urban areas
OTHER - other land covers (e.g., ice, bare soil etc.)
TUSSOCK - tussock
UNGR_PAST - ungrazed pasture
These classifications were produced by Landcare Research Ltd and are defined by Woods et al. (2006). New land use layers created for land use change simulations must have the same fields in their respective attribute tables (Sections 6.1.2 and 6.1.3).
Results generated
Both nutrient (N and P) transport and economic factors are calculated within the CLUES framework, these are listed below:
• Nutrient loads (tonnes/year) – stream load for a particular river reach, including the load from upstream tributaries.
• Nutrient yield (kg/ha/year) – stream load divided by the area of the catchment.
• Total nitrogen loss risk (scale from very low to very high) – the leaching risk for nitrogen based on land use. This is displayed as a raster dockable window with pixel resolution of 100 m.
• GDP (gross domestic product, $ / year) - an estimate of the total value arising from the farming, horticulture, and pine plantation land uses.
• FTE (full time equivalents) – This is an indication of total employment for farms where employment is work done by employees and self-employed persons.
• CFS (cash flow surplus) – this is the output from the land use after farm working expenses have been deducted, but before interest, leases, wages of management, and capital expenditure. CFS is used an indicator of on farm welfare – but should not be taken as a direct measure of on farm welfare.
All loads and yields are cumulative, that is, each river reach value represents the sum for all the upstream river reaches. More information on the Triple Bottom Line indicators can be found in Harris Consulting (2007).
Types of display
CLUES 1.4 allows the user to choose between a number of displays both to show the results of particular land use scenario simulations and to allow comparison between the default (current) land use scenario and changed land use.
Maps
CLUES 1.4 displays model results in map format (Section 5.1) for the following:
• Nitrogen load (river lines or watershed option)
• Phosphorus load (river lines or watershed option)
• Nitrogen yield (river lines option)
• Phosphorus yield (river lines option)
• Total nitrogen loss risk (dockable window raster map)
River lines (N Load)
Watershed (N Load)
Bar charts
Bar charts (Sections 5.2 and 6.2.3) allow quick comparisons between the default land use and simulations made with changed land use scenarios. Charts are available for:
• Nitrogen load
• Phosphorus load
• GDP
• FTE
• CFS
Default GDP
Scenario 1 GDP (comparison)
Tables
CLUES 1.4 provides two types of table that can be used to summarise and compare water quality and economics for individual river reaches (sub-catchment) and for all the river reaches selected in a model run. Tables are covered in Sections 5.3 and 6.2.4.
Sub-catchment summary
Selected river reach summary
Contact for Enquiries
MAF Information Services
Pastoral House
25 The Terrace
PO Box 2526
Wellington, NEW ZEALAND
Fax: +64 4 894 0721
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