Abstract

Introduction

Land resource information is a key component of land management and planning, and access to it is vital if Australian farm communities are to remain viable (Groves and Da Rin 1999). For many years the availability and use of spatial information has been limited to government and academic organizations (Baker 1999). With continuing emphasis being placed on the responsibilities of individual land managers to contribute to sustainable use of natural resources, the information and data sets held by government departments need to become readily accessible, affordable, relevant and understandable by the community. Geographic Information Systems (GIS) are ideally suited to providing the information that land managers require in their decision making process. However, the uptake of GIS use in agriculture has tended to be limited. Limitations to this uptake include a lack of understanding of resource information and its availability, and the skills required to access and use a typical GIS. The costs associated with geographic data and software also limit the broader use of GIS in agriculture.

With the rapid expansion of the Internet and associated technologies in recent years, information and data suppliers now have the opportunity to disseminate geospatial information in a visual and interactive manner (Kähkönen et al. 1999). A broad range of users and interest groups can now be reached via the Internet. Increased interactivity can also be achieved through Web based GIS (Web GIS) technologies.

This paper provides an insight into the barriers that currently retard the broad scale dissemination of spatial information to the rural Australian community, and describes the development of the Burnett Land Resource Information System with respect to these barriers.

Traditional Methods and Geographic Information Systems

Traditional forms of spatial information, such as contemporary maps and associated technical reports are useful and accurate products (Walker et al. 2000), and depending on resources can be reproduced if required. Whilst having an important role to play in the supply of land resource information to the community, these products do have some disadvantages, such as the costs of mass production and distribution (Peterson 1996). Once printed, these products are unable to be readily updated, giving traditional information packages a limited useful life span. A paucity of knowledge of the existence of the products in the first instance may also be a barrier to the use of these products by the community.

The mapping industry has always striven to adapt new technology to create better products (Cartwright 1999). Geographic Information Systems (GIS) are possibly the most significant new technology to become readily accessible to the mapping world in the last two decades. A GIS is defined by Rhyne (1997) as ‘a combination of a database management system, a set of operations for managing data, and a graphic display system, tied to the process of spatial analysis’. GIS has lead to a more dynamic environment in which spatial information products can be developed, displayed and updated as required. The combination of editable databases and visual presentation allows information products to be produced in a timely, accurate and repeatable manner. The reproduction, presentation and update of products made from a GIS is also faster and cheaper than for traditional printed products.

A standard GIS could be a useful tool for most land managers if they were given the opportunity to become familiar with this type of information delivery. However, most individual land managers do not have this opportunity. The use of GIS is generally limited to those agencies that can afford the thousands of dollars needed for adequate software, hardware and training. The agencies that are able to utilise GIS are often constrained by institutional problems associated with data sharing, licensing and intellectual property rights. Many countries and organizations also consider their data to be proprietary (Su et al. 2000), restricting broad community access to these resources. Electronic data sets also face issues of becoming outdated once committed to a client.

For the purposes of giving land managers access to relevant spatial information, a standard GIS may also be unsuitable. Most rural land managers will not be able to justify the expense of required software and data sets, or of the training required to use a GIS effectively. The cost of data sets is of particular relevance, as most land managers wishing to access this spatial information will be doing so only sporadically. A standard GIS package may offer too many functions for the average user to be comfortable with. It is probably most likely that a community user of spatial information will only want to extract relevant, easy to understand information, and not run complex GIS processes.

Due to historical computing restraints, many GIS data sets exist as technical references and codes that are relevant only to specialists from technical fields. The average user would have difficulty in interpreting and putting this type of data into useful management practice. When the community is the target audience, spatial information needs to be presented in an interpreted and easily useable format that imparts to the user knowledge, not just data (Cartwright 1999). To help users gain maximum benefit from the spatial information they extract, it may be also advantageous to incorporate other data types into information systems. Multimedia components such as photographs could be used for this purpose where appropriate (Cartwright 1997).

The issues raised in this paper indicate that a spatial information system targeting land managers must attempt to fulfil the following objectives:

• It must supply spatial information of relevance to the user in a manner that is both easy to understand and use;
• Access to the information must be cost effective to the user;
• The user must not be overwhelmed by being exposed to too much information, nor should they be confused by an over abundance of GIS functions, and;
• The information system must also access its component data sets from one location, ensuring that all users have access to information of the same currency and accuracy.

Internet Technology and Web GIS

The wide spread use of the Internet is aiding the delivery of resource information to the community. The delivery of land resource information intended for rural land managers should benefit markedly as use of this medium grows, particularly as Internet use by Australian farmers is amongst the highest in the world (Groves and Da Rin 1999). However, a significant proportion of rural Australians will continue to suffer from poor communications links for some time (Groves 2000). This is a major consideration for production of Web based spatial information systems targeted at rural land managers in Australia. However, it is possible and desirable to produce information systems that are readily accessible and useable in areas with poor line speeds. The use of the Internet to disseminate spatial information will also benefit data providers, as the Internet offers the advantages of interactivity, availability and easy updating (Richard 2000).

The simplest form of spatial information is a printed map, and this can be emulated on the Web by presenting static images (Stevenson and Cartwright 2000). An image of a map needs to be of excellent quality in a Web environment if it is to portray as much detail as a printed map. High quality images require large file sizes, and this is an impairment to download speed for users with poor Internet connections. Even if a user can download a high quality image in a satisfactory time there is no guarantee that the digital map will be of use, as computer monitors are limited in size and resolution. However, the cost of placing colour graphics on the Web is smaller than that associated with printing and distributing traditional maps (Peterson 1996). This alone may make the use of Web based images more appealing to some suppliers of spatial information.

Stevenson and Cartwright (2000) also argue that maps presented on the Internet as static images only convey similar levels of information as traditional paper maps. To overcome this, maps made available through the Internet are typically more interactive than stand alone static images (Peterson 1997). One solution used on the Internet is to offer a series of maps that can be viewed in sequence to mimic a user zooming in to an area of interest. This strategy requires the author of the information system to determine what areas of interest will be available to the user, and what information will be displayed in each case.

A more useful interactive method allows the user to determine the areas of interest and data layers depicted. This is what Web based GIS packages do, and they have been commercially available for several years. Most of the commercially available Internet map servers have been found to differ in a number of aspects, including the use of map pre-publishing vs direct data access, and data and platform restrictions (Su et al. 2000). Each map server also provides the user with a myriad of GIS functions, many of which may be superfluous to the requirements of a simple, information dissemination tool. The difficult part of building an information system is deciding which of these technologies to use (Stevenson and Cartwright 2000).

The Burnett Land Resource Information System

Providing community access to land resource information with spatial relevance was the major goal of this project. The decision was made to utilise the distribution advantages provided by the Internet for this purpose.

The Burnett River catchment covers some 3.3 million hectares (ha) of south east Queensland (Donnollan and Searle 1999), with the Inland Burnett District taking up about 2.9 million ha of this (Maher 1993). The Queensland Department of Natural Resources and Mines (DNRM) has 14 land resource GIS data sets of relevance to the Burnett River catchment. However, to keep the information system from becoming too complex, the land resource information sets that are available to users in this system had to be limited. The data sets contained in this system consist of three broad scale land system surveys (each mapped at a scale of 1:250 000) and their associated field observations. Land systems are described as broad-scale mapping units, defined in terms of landform pattern, soils, and the dominant vegetation (Gunn et al. 1988). The spatial component of a land management manual is also included, giving access to Land Resource Area (LRA) management guidelines. An LRA is a pattern of soils, vegetation and landform on related geological units (Maher 1993). The major soil management groups likely to occur within each LRA have also been described. To give these data sets increased spatial relevance, the information system also includes GIS layers depicting coastlines, rivers, roads and other infrastructure.

It would be unreasonable for this information system to require the user to download data sets or GIS processing programmes. This may be acceptable for systems accessed by multiple users over a Local Area Network, but this information system is targeted at rural users, many of whom suffer poor communications links. Therefore the Internet map server had to be able to access data sets from the server side, and needed also to carry out all GIS processing server side. The Internet map server also had to come at very little cost.

Mapserver (http://mapserver.gis.umn.edu/) is a freeware Common Gateway Interface (CGI) application that meets all of the requirements outlined above. CGI is a set of standards by which servers communicate with external programs, allowing users to gain access to a wider range of functions than a web server alone could provide (Ladd et al. 1999). This allows Mapserver to receive and process requests from the user, and then return the results. It is also able to access and process ArcView shapefiles easily, making it compatible with most available DNRM data sets. As it is freeware, the use of Mapserver helped to keep the costs of establishing the information system to a minimum.

Due to the complex nature of the land resource data sets used in this system, it is also necessary to store many attributes in a relational format. For this data to be used in a Web based information system the relational database must be accessible in a Web environment. MiniSQL (mSQL, http://www.hughes.com.au/) was chosen, as it is accessible via CGI, removing processing from the client side. This database management system is also freeware, helping to keep overhead costs to a minimum.

Development of the Information System

The Burnett Land Resource Information System has an efficient ‘back end’ to allow storage of all data sets and associated databases. This back end conducts all processing of user requests on the server side, returning only the required results to the user’s browser. To access this information the user is provided a simple to use interface that is easily downloadable. This section will describe the development and implementation of the back end, followed by an explanation of the two different methods used to develop an adequate user interface.

Back End – Server Side

All data sets available in the Burnett Land Resource Information System are stored as ArcView shapefiles on the same Web server as the relevant interface documents. There are 14 individual shapefiles available combining to a total data file size of about 62 megabytes (mb). The three land resource data sets essential to the system comprise only about 8.5 mb.

ArcView shapefiles store attribute data in DBASE format, a non-relational table structure with fields limited to 256 characters. The intended interpretations of the land resource data often exceeded 256 characters, making this storage format unsuitable. The non-relational, or ‘flat’, structure of DBASE tables also meant that the land resource data sets would require a multitude of fields to accommodate records with complex data attributes. It was particularly important for the Burnett Land Resource Information System to be able to present all of this data as interpreted information in an efficient manner. The land resource data sets originally contained numerous coded attributes, with associated relational data stored in MS Access™ databases. To overcome this, a relational database structure has been developed to store all of the required land resource data as codes utilising mSQL. This structure incorporates the decode information required to present interpreted query results. The land resource data sets now store a minimum number of attributes in the shapefile format, resulting in smaller file sizes.

The mSQL database is able to receive and process queries from the user based on Mapserver functions, and return the results into templates. Only six of these templates are required by the information system, making storage and maintenance of these files simple. Maintenance of the data and information source is also simplified in this process, as it is all located in one database, with no data duplicated in other locations.

This database also stores the filenames of multimedia components that bear relevance to individual records. This gives the user the opportunity to view landscape and soil images that may help to give some relevance to the land resource information that they have just extracted, which in turn may aid in the visualisation of geographic data (Walker et al. 2000). The other multimedia components that can be accessed through this same mechanism are 360^o panoramic views from selected sites throughout the Burnett Catchment. These can be accessed as a GIS layer to give spatial relevance, and can be viewed in standard image format (JPEG), or in a virtual environment if the user has the QuickTime™ plugin. Whilst these are not related specifically to individual records from the land resource database, they do help in providing some visualisation of the data, and may also attract a new suite of users.

The use of both Mapserver and mSQL in the Burnett Land Resource Information System allows users access to some very powerful GIS and database interrogation functions without any major load placed on the client’s hardware. As there is never any exchange of data sets or database records, the information system does not discriminate against users with poor communications links. The apparent exchanges of data and information are simply the loading of small HTML templates, populated with either images from Mapserver or text from mSQL. While this exchange will be more rapid for those users with fast line speeds, there is little more that can be done to speed up access to information for users with slower line speeds.

Development of a User Interface

The user interface for this system has been designed to be intuitive and downloadable in a short time, whilst still providing all of the functions that can make use of the facilities built into the back end of the system. This interface is best viewed in screen sizes of at least 1024 x 768 pixels.

In its simplest form the Burnett Land Resource Information System could be presented to users in a standard HTML format, utilising a minimum of templates, documents and forms. Using this method it would be possible to create an information system that presents no graphics other than those produced by Mapserver. This has distinct advantages for users who suffer from poor communications links. However, the use of such a system would not be particularly intuitive to most users, nor would it be visually appealing. The functionality provided by this format may also frustrate some more advanced users, as all user interaction is limited to manually manipulating numerous form elements, and single point clicks on the map display image. Some more advanced levels of user interaction would benefit both intuitiveness and appeal.

The interface also utilises some elements that aid users in navigating the spatially represented data (Cartwright et al. 2000). One of the elements included in this interface is a reference map, depicting the location within the catchment boundary that is represented by the current field of view. Another component to aid users in interpreting the visual display of the map is the inclusion of a dynamic legend. The interface also gives the user access to help and feedback mechanisms.

To enhance the visual appeal and intuitive nature of the interface that has been developed, several small graphics have been added as substitutes for traditional form elements. In particular, these graphics give the user the ability to change the implied GIS function (pan, zoom, query etc.) by pressing a button, as opposed to selecting a less appealing radio button or menu item. The simulated button press associated with the graphics is handled by Javascript, as is the manipulation of hidden form variables as required. The graphics used for this function are of an extremely simple nature and small size, about 1 kilobyte (kb) each. Nevertheless, it is acknowledged that the use of these graphics does prolong the initial download speed of the interface, especially over slow line speeds. The user also needs to have the ability to select map layers to be exhibited and queried in an easy manner. The interface used for this system is able to achieve this by utilising a simple, static layer control area. It would be more difficult to implement such an easy to use layer control if there were more data layers available to the system.

Java™

Java (http://java.sun.com) can be used to create applications (applets) to be run in Web pages on the client computer (Stevenson and Cartwright 2000). Downloading these applets can provide an impressive interactive user interface (Kähkönen et al. 1999). The Java applet used by the Burnett Land Resource Information System offers the user functions that would be expected in a simple GIS package, such as the ability to conduct zooming exercises by dragging a box with a mouse. This system also gives the user a more ‘streamlined’ experience, as the only elements of the browser window to reload are those that have been updated by Mapserver. For instance, a request to zoom in results in new map and reference images in the browser window, however the main web document itself does not reload. The use of Javascript also allows the interface to be made more dynamic, intuitive and appealing to the user.

There are some instances of organizations placing restrictions on the download of Java applets through the use of corporate firewalls. Some older browsers are also unable to process Java applets. It may be necessary to provide an alternative for users who are restricted by such situations, or who choose to disable their browser’s Java capabilities for security reasons.

Frames and Javascript

Standard HTML and Javascript can also be combined to provide a ‘streamlined’ user experience, similar to that achieved through the combination of Java and Javascript. To achieve the same affect of reloading only those components of the browser window that Mapserver has updated, frames technology was utilised. The use of frames to control the reloading environment allows less data to be loaded over the Web and shorten waiting time for each user request. In place of the Java applet used in the previous example, Dynamic HTML (DHTML) is used to provide the GIS functions of panning, zooming and querying in an interactive manner.

DHTML is an extension of HTML and Javascript, and in this case results in numerous layers in the browser window that can be accessed, moved and manipulated dynamically using Javascript (Stevenson and Cartwright 2000). The dynamic layers are used by this system to detect the coordinates of mouse events, in particular the location of all mouse movements and actions over the main map image. As is noted by Stevenson and Cartwright (2000), the biggest problem with using DHTML in a spatial information system is the implementation ‘baggage’ that is associated with ensuring that it works properly on various browsers. To ensure cross-browser functionality this system requires two additional Javascript files.

Comparison of the user interfaces

The Java applet used in the first example was about 14 kb in size, whilst the extra two Javascript files required to implement the DHTML have a total size of around 15 kb. The initial download times of the two systems, then, is relatively similar. When additional graphics used for buttons and logos are included, the additional download time of the complete user interface may be lengthened by up to about 20 seconds for users with a line speed of 9.6 kb per second (Groves 2000). This delay may be unacceptable for some users.

Development and maintenance of the two interfaces are roughly similar in the skills and time required. Both front ends can be transferred and modified to suit other purposes relatively easily, however it is beneficial if those attempting such a shift have a good working knowledge of the interface. It is important also to have a familiarity with either Java or Javascript.

A major difference between the Java and the frames interfaces has only become relevant with the release of new browser technology. The Java system requires LiveConnect (Hoque 1999) to allow free communication between the Java applet and Javascript. The early release of Netscape 6™ has encountered significant problems with implementing LiveConnect, and therefore the Java based information system is unable to be accessed through this browser at this time. The frames interface does not require this connection, and is quite stable on most of the latest (and many of the earlier) release browsers.

Discussion

Groves (2000) advised that, amongst other issues, Web sites intended for use by rural Australians should be designed to provide minimum download times. It is acknowledged that some sacrifices to download times have been made in the endeavour to produce an intuitive and visually appealing information system. The addition of several graphics that could be removed in favour of traditional form elements may be criticised by other developers. However the system itself relies on Mapserver providing images of around 12-15 kb as a result of user requests. For this reason the addition of several highly compressed graphics to enhance the system seems a fair imposition.

The use of graphics as buttons in a clear, structured layout makes the information system relatively simple to learn and use effectively. The use of data layers depicting infrastructure and landmarks, such as roads and rivers, help users to locate areas of particular interest to them, allowing a rapid extraction of relevant information. More infrastructure layers, such as cadastral boundaries, also become available at appropriate scales to further develop the user’s ability to place their field of view in perspective.

The information that can be extracted from the system is easily interpreted and contains minimal technical jargon. This database possesses a structure that allows the user to further interrogate and access more detailed information that may not be apparent at the first level. For example, the land system data set contains unique mapping area (UMA) attributes that are accessible from the first query level. However, each of these UMA records also contain information relating to land units, areas within each UMA that can be described but are too small to be depicted on the map. The flexibility of the relational database design allows this quite complex series of data to be accessed and presented in a simple and effective fashion.

All of the information accessed through this system comes at no cost to the user, excluding the personal costs associated with Internet connections. The datasets that are utilised in this system are also stored in one location, the Web server. This benefits both users and system administrators. Users of this system are now able to access all of this information from any Internet capable location, such as their own home. Previously this information was only available as numerous maps and reports, and would often need to be gathered from long distances. Additionally, system administrators are now able to provide updates to the information more readily, all of which will be reflected to the user immediately.

The Burnett Land Resource Information System is intended only as a dissemination tool for existing data sets. Therefore it does not need to give the user the ability to conduct any complex analysis or processing of data sets. This restriction was applied to the development of the user interface and has enabled the production of a system that is as simple to use as possible. However, this system does give the user the ability to carry out simple exercises, such as zooming in and extracting information from a user defined area. This is more flexible than traditional spatial information formats, and can be utilised in a manner that suits each individual.

This information system also has a variety of multimedia components that can be used to enhance the relevance of information extracted. In addition, multimedia components may help to attract users that would not usually seek out land resource information, but may learn something new in the process.

Conclusion

Traditional forms of spatial information will remain the primary source of resource information utilised by many land managers for years to come. The networks of interest groups and government extension activities that have built up over decades provide land managers with a familiar structure and format of information dissemination. However, as information supply agencies continue to have budgets reduced through economic pressure, investigations into the use of more efficient information delivery mechanisms will need to continue. With the Australian Federal Government making commitments to improving communication links in rural areas, the Internet may soon become a major component of the standard information dissemination network.

The Burnett Land Resource Information System now gives all users access to data sets and information that previously existed in a variety of formats. The ability to access each of these data layers in an environment that allows the easy extraction of information is a luxury previously not available to rural land managers. The combination of the information from these data sets gives land managers the opportunity to make their land use decisions from a more well informed position. The ability to access this information in one location makes the process as tireless as possible for users, and also makes maintenance of this information simple from a provider point of view.

This information system overcomes many barriers affecting rural use of Web based information systems. The strategies used by this system to promote land resource information on the Web are applicable to other spatial data types, such as environmental and demographic data sets. The development of this information system gives future developers of Web based spatial information systems a platform of techniques and approaches available through a low cost approach. The user friendly interface and back end that allows server side processing of interpreted information is an appropriate mechanism for delivering useful land resource information via the World Wide Web.

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