Pigs, people, points and polygons: the development of a GIS-based decision support tool for intensive animal industry siting
AGWISE Project Officer
EDROC Inc. (Eastern Downs Regional Organisation of Councils Inc.)
PO Box 3021, Village Fair PO, Toowoomba, QLD 4350
(076) 4688-6639, (076) 4688-6779
Funded by the Natural Heritage Trust (NHT), with in-kind contributions from participating agencies, the AGWISE Project is administered by the Eastern Downs Regional Organisation of Councils Inc. (EDROC). The Project is particularly timely within the eastern Darling Downs region in that we are currently faced with the dilemmas of increasing intensive agricultural activities, increasing human population and the requirement for scientifically based land use planning techniques and strategies. A major part of AGWISE Project is to provide a sound basis for the planning and siting of new and expanding Intensive Animal Industries (IAIs) within the eastern Downs region. These industries include piggeries, feedlots, poultry farms and dairies.
The paper details the development, and application, of an ArcView-based Decision Support Tool (DSS) to assist decision-makers in providing a sound basis for planning the locations for new and expanding IAIs on the eastern Darling Downs. Using the Spatial Analyst extension and with Avenue-based scripts and the Dialog Designer, the tool uses a diversity of spatial datasets to define both “No Go” areas and a Catchment suitability ranking for piggeries/feedlots of varying sizes. Finding locations that are environmentally sustainable, as well as being both economically viable and socially acceptable, is a real challenge when there is a limited “land pool” available. The ArcView-based DSS can greatly assist regulatory agencies, producers and community in meeting this challenge.
The AGWISE Project, covering the eastern Darling Downs region of southern Queensland, is timely in that this single Project has two primary and inter-related goals:-
- To provide a sound basis for planning of new and expanding Intensive Animal Industries (IAIs) within the eastern Downs (EDROC) region. These industries include piggeries, feedlots, poultries and dairies; and,
- To develop sub-catchment waste re-use management strategies to maximise the re-use of organic wastes produced by rural and related industries within the Queensland Murray-Darling Basin (QMDB).
Funded by the Natural Heritage Trust (NHT), with in-kind contributions from participating agencies, the AGWISE Project is administered by the Eastern Downs Regional Organisation of Councils Inc. (EDROC). The Project calls on the expertise and resources of EDROC, the National Centre for Engineering in Agriculture (NCEA), the Department of Primary Industries (DPI), the Department of Natural Resources and Mines (DNRM), the Environmental Protection Agency (EPA), and the Department of Local Government and Planning (DLGP). This exciting concept of many agencies “working together” is ground-breaking and means that research synergies developed throughout the life of the Project are multi-disciplinary, resulting in sound research findings. Further details on the scope and research progress of the AGWISE Project can be found in the Progress Report 1998 – 1999 (Eastern Downs Regional Organisation of Councils Inc., 1999).
This paper describes the development of a methodology, and associated spatially-based Decision Support Tool (DSS), to assist decision-makers in providing a sound basis for planning the locations for new and expanding IAIs on the eastern Darling Downs, at the northern extent of the Murray-Darling Basin. Although the case here is restricted to piggery siting, the tool can also be used for feedlots, poultries and dairy siting.
The eastern Darling Downs region is ideally suited for intensive animal production with its large grain supply and the proximity to markets. Within the next five years demand for pork products from the region is expected to at least double – hence the requirement to find suitable locations for piggery expansion. Finding locations that are environmentally sustainable, as well as economically viable and socially acceptable is a real challenge when there is a limited available “land pool”. The AGWISE DSS tool will assist producers, regulatory agencies and community in meeting this challenge.
GIS (Geographic Information Systems) provides a very effective tool for assisting decision-makers in instances such as “where can we site this industry to have a minimal environmental footprint and have negligible social impacts?” The development of GIS to combine geographic spatial layers with non-spatial data and provide both spatial analysis and modelling routines, in a user-friendly framework, giving the decision-maker reliable results on which to base a decision. Although decisions relating to piggery siting are often controversial, GIS provides a logical way to “narrow down” to a list of potentially suitable piggery sites throughout a region. Sunday Tim et al. (1998) developed a GIS-based Decision Support System, using a ranking of environmental parameters, to assist in the siting of Intensive Animal Industries in the Midwest region of the USA. However, further computing tools are then needed to rank the remaining acceptable sites, from most desirable to least desirable for piggery establishment, for which a Multi-Criteria Decision Analysis (MCDA) can be used. MCDA methods are specifically designed to choose the best alternative from a number of alternatives, based on which can be calculated to overall best meet any number of often conflicting criteria.
The GIS used on implementing the AGWISE DSS is the ESRI product ArcView 3.2 with a menu system developed using ArcView customisation tools, the Dialog Designer extension and Avenue programming tools. The simple MCDA was developed within ArcView using the programming tools. The basis of this system is that it be user-friendly and provide meaningful results for the decision-maker (whether producer, regulator or community).
When using the AGWISE Decision Support Tool, two major site selection suitability operations are performed. In the first phase, ArcView GIS tools are used to create buffers and “screen out” sites that fail to meet specified minimum criteria. These are termed “No Go” areas. Criteria used to define these unsuitable areas include:
- Separation Distances (from receptors) – based on an empirical (S Factor) formula developed by DPI for odour-based separation from IAIs (see McGahan et al., 2000 or McGahan et al., 2001 for further details on the calculation factors). As many complaints with regard to piggery siting concern odour, this is a critical parameter;
- Unsuitable tenure (ie. National Parks, Declared Catchment Areas, Reserves, urban/residential designation, unsuitable designations on Local Authority Strategic Plans);
- Unsuitable topography (ie steep slopes >20%; Upper Condamine Floodplain designation; or within 200 metres of designated streams and roads).
The second phase involves the system user assigning an “order of importance” to the potential suitability criteria, following which the DSS tool assigns a suitability index (from least to most suitable) against each sub-catchment unit (the EDROC region is subdivided into 264 sub-catchment units, the finest scale of spatial analysis undertaken in this study). Criteria used in the suitability assessment include:
- Groundwater vulnerability zones (composite layer derived by DNRM);
- Groundwater availability zones;
- Slope (% based) – averaged for each sub-catchment unit;
- Vulnerability to Flooding – averaged for each sub-catchment unit;
- Soil Suitability Index – averaged for each sub-catchment unit;
- Remnant Vegetation Status – averaged for each sub-catchment unit;
- Cumulative IAI nutrient generation estimates levels – for each sub-catchment unit
Following this the system builds a composite suitability index (least to most suitable), based on the user weighting of suitability criteria, and displays the suitability index for all sub-catchment units (see Figure 2).
Both phases of the GIS analysis are then displayed in graphic, and tabular form, to assist decision-making in potential siting of such industries.
Figure 1. “No Go” Areas, unsuitable for a 5,000 SPU piggery with pond-based waste treatment are shaded. This area is southwest of Toowoomba.
Figure 2. Sub-catchment Composite Suitability Ranking for the 5,000 SPU Piggery (most suitable = lighter shading; least suitable = darker shading). Combined with “No Go” areas from Figure 1, which are still shaded.
The combination of both the “No Go” areas and the sub-catchment suitability ranking (least to most suitable) provides the system user with certainty, at a regional level, as where to site an Intensive Animal Industry operation with x number of Standard Animal Units and a specified waste treatment method.
Using The Tool To Assist With Piggery Site Selection
In the ideal situation a potential applicant would approach the Intensive Livestock Environmental Management Services unit (ILEMS) of DPI. The applicant wants to establish a piggery with, in this case, 5,000 Standard Pig Units (SPU) with a pond-based effluent disposal system and is open to suggestions of where it can be located. The AGWISE DSS is then run for the scenario for 5,000 SPU and conventional housing and effluent disposal methods. The first phase of the Tool displays the “No Go” areas within the eastern Downs region (ie buffers from residential areas; unsuitable tenure; Declared Catchment Areas; and Local Authority Strategic Plan designations that do not permit IAIs). Figure 1 displays the results of running the AGWISE Tool for a piggery of 5,000 SPU ( “No Go” areas are hatched).
After viewing these graphics, the applicant may well ask the question, “of the remaining ‘available’ land pool, are any areas more suitable for the establishment of a 5,000 SPU piggery than others?”. At this stage the second stage of the process, the suitability ranking operation can be performed. The applicant can “rank” the suitability criteria in order of relative importance to build a scenario that is relevant to the producer. Likewise, Local Authorities and DPI can rank the suitability criteria to build a scenario that best fits their future regional planning priorities. By running varying scenarios, based on differing “rankings”, a picture can be built as to which areas on the eastern Downs are most suitable for a 5,000 SPU piggery (see Figure 2).
As the land pool available for piggery development is quite limited on the eastern Downs (ie. many urban/rural residential areas; restricted areas), the AGWISE DSS tool provides prospective producers and regulatory authorities with a large degree of certainty on where to locate new/expanding IAIs. Although primarily aimed as a regional planning aid, the AGWISE DSS tool can be used as an initial way to assist in locational decision-making. For instance, if a prospective producer wishes to see what difference using a more advanced waste treatment method will have on the potential siting of a piggery the AGWISE tool can demonstrate such scenarios. Figure 3 illustrates (at a more detailed scale) the ‘No Go’ areas if a 5,000 SPU facility uses the older pond technology, whereas if a more advanced waste treatment measure were to be adopted (ie solid separation; covered ponds) then Figure 4 illustrates the much contracted “No Go’ areas. Such scenario modeling would assist the applicant in choosing waste treatment methods if a piggery were to be sited closer to residential areas. At a later stage detailed site reports and Environmental Impact Studies may need to be undertaken.
Figure 3. Linear Shaded Areas depict ‘No Go’ Zones for a 5,000 SPU piggery with Standard ‘Pond-based’ waste treatment (Sub-catchment mapping scale)
Figure 4. Linear Shaded Areas depict ‘No Go’ Zones for a 5,000 SPU piggery With advanced waste treatment (solids treatment). Sub-catchment scale as for Fig. 3. Note that the ‘No Go’ buffer is reduced compared with that in Figure 3.
Currently the AGWISE tool is being incorporated into the regional Local Government planning scheme legislation – IPA (Integrated Planning Act), and will become one of a number of tools to aid in regional decision-making and assist in developing regional sustainable agriculture. The old phrase, “try before you buy”, is illustrated by the AGWISE Project. The prospective producer will be able to use this tool prior to purchasing the appropriate land required. However, current producers can also use the system to ascertain if their current land holdings are potentially suitable for piggery expansion.
If you are a producer who is considering establishing a piggery on the Darling Downs it may be advantageous to run the AGWISE tool prior to purchasing land for industry placement, or before expanding an existing operation.
Eastern Downs Regional Organisation of Councils Inc. (1999). AGWISE PROJECT PROGRESS REPORT for the period 1 August 1998 to 31 July 1999. EDROC Inc., Toowoomba, Queensland.
McGahan, E., Casey, K., Nicholas, P., and A. Skerman. (2000). Odour Modelling Used To Improve Landuse Planning For Piggeries. Paper presented to Enviro2000: Towards Sustainability Conference, Sydney, 2000. (Proceedings on CD-ROM).
McGahan, E., Skerman, A., Casey, K., and Streeten, T. (2001). Separation Guidelines for Queensland Piggeries. Intensive Livestock Environmental Management Services, Department of Primary Industries, Toowoomba, Queensland.
Sunday Tim, U., Prato, T., and Fulcher, C. (1998). Integrated Spatially Explicit Decision Support System For Livestock Production Planning And Environmental Protection. In Animal Production Systems and the Environment, Volume 1: Oral Presentations, Iowa State University, pp. 437 – 442.