Publicaciones

Cómo citar este artículo: Marcer, Arnald; Pons, Xavier. "Park GIS Implementation," dentro Proceedings of GIS PlaNET'98 International Conference and Exhibition on Geographic Information. 7-11 Setembre 1998. [CD-ROM]. Lisboa: [s.n.], 1998

PARK GIS IMPLEMENTATION

A GIS implementation model which takes advantage of Internet technology to embed the system into the organization of a protected area organization. The case of "Zona Volcànica de la Garrotxa" Natural Park GIS.

Arnald MARCER and Xavier PONS

KEYWORDS: Protected area, Management, Planning, Organization, GIS, Internet technology, intranet, Open system.

INTRODUCTION

The Cartographic Institute of Catalonia (ICC) has provided high quality base cartography in digital format: topographic maps at 1/5000 and 1/50000 scales in vector format, colour orthophotography at a resolution of 2.5m, black and white orthophotography at 0.5m resolution and a Digital Elevation Model at 15m resolution. The ICC also participates in some aspects of project implementation and in project evaluation [4].

METHODOLOGY AND DISCUSSION

Division of the system into modules

Management of the park is divided into clearly defined fields of action: water, soils, geology, fauna, vegetation, etc. Each of these fields of action is the responsibility of a given management unit of the park's organization, which is also under the responsibility of the head of the unit. The above mentioned fields of action have been grouped into several modules to structure the whole system. The staff member of the park responsible for each field of action is also the person in charge of the corresponding system module. The aim was not to add a GIS unit within the park organization and hire a GIS specialist but to embed the GIS within the functioning of the park. Each park staff member needs to know the system well enough to carry out all his or her duties and the staff member in charge of the module needs to know how to apply the GIS to the field of action of his or her responsibility.

During the design phase, several meetings with the park staff were organized in order to clearly define the modules into which the system had to be divided and the management objectives for each one. Existing analogic and digital datasets were also analyzed and their adequacy for each module evaluated. Required capture (acquisition) of new data was also evaluated.

The system finally consists of five modules: water and soil management, vegetation (forest and flora) management, fauna and hunting management, public use management and legal aspects and reports management. The order in which the modules would be developed was determined on the basis of data availability and park needs.

Such modules would be designed as sets of well-structured data with the established protocols to perform all necessary operations on the data. This allows, in principle, not only to develop new modules in the same way as new management needs arise but also to train the park staff in their use and maintenance.

Therefore, modules would not be self-contained, closed applications but a set of organized graphical and alphanumerical datasets with their metadata and the protocols for their maintenance and update. Although they can be very adequate for static and repetitive tasks, customized applications impose a dependency of the park on external software developers, and one of the aims of the project was precisely the opposite.

The whole system, data and applications, is located in a computer server in the park and can be accessed from any computer in the park Local Area Network (LAN). The size of all data and information, excluding software, handled by the system is of 1.5+ Gb contained in over 9000 files. This data and information are in several diferent formats: text files, tabular data, raster files, structured and non-structured vector files, html files, images, etc.

Groundwater Control as an Example. The park is situated in the watershed of the Fluvià river, almost at its uppermost part. Between the park and the top of the watershed lies "La Vall d'en Bas", a valley whose lands are mainly used for agriculture and grazing. Controlling the quality and quantity of waters within the aquifer is not only a problem of environmental concern but also of public health. Over 30000 people in the park area make use of these waters for different purposes, including drinking. Due to the use of fertilizers (both artificial and natural) over the years and its progressive leaking through the soil there exists a problem of nitrogen pollution in the aquifer's waters.

The park has set a program to monitor the quality and quantity of groundwater. This program has been set under the direction of the Department of Geology of the UAB. A network of 80+ wells and springs have been chosen where water-level depth is periodically measured as well as water samples are analysed in search of nitrates, nitrites, ammonia and their electrical conductivity is measured. Once the monitoring programme reached the state in which its methodology was clearly established and the parameters to be measured determined, it was integrated within the GIS. As with the rest of the modules the aim for the park is to be self-sufficient and independent in carrying out the monitoring programme (data gathering, analysis and handling) and only have external assessment for punctual matters.

The implementation of the monitoring programme with the GIS consists of a set of graphical layers and tables organized in a set of subdirectories within the directory of the Water and Soils Management Module, a data entry form and the protocols for update and maintenance specified in the intranet (see below). Graphical layers consist of a point layer representing all sampled wells and springs with a linked database for all measurements made at each point and a series of raster maps representing the spatial variability for each measured parameter (nitrate, nitrite, amonia, electric conductivity and water-level depth) for each date of measure. A continous hydrological arc layer at 1/5000 scale was built out of the 1/5000 topographic maps and a derived polygon layer of buffers along the water courses was built. These buffers represent also areas on which uses and activities are regulated due to their proximity to a water course. Tabular data consist of a table containing all parameter measures, a table containing the physical characteristics of each sample point and a table containing measures for other known wells and springs that were sampled at some time in the past.

Park staff users need to be able to maintain and update this dataset. They need to be able to add and eliminate sample points, to produce representation maps of the spatial variability of a given parameter for a given date and they need to make graphics of the evolution of a given parameter for a given point over time. They also need to make simple reports that are given to the owners of the well that has been measured.

Access to the layers can be done either from within the GIS or from the intranet (see below). By appropriately configuring the GIS startup file, access to the graphical layers can be very fast and easy. The map format of MiraMon, MMM-file types, allow to open any type of layer (vectorial non-structured or structured point, arc/node and polygon, raster (bit, byte, integer, float and RGB composites) without having to know beforehand to which type the layer belongs to and without having to specify visualization conditions (zoom level, symbology, colour palette, etc.). The user only needs to choose the option "File|Open map..." and choose the appropriate map in the file-dialog box and the layer will be open. MiraMon maps can contain any number of layers without having to duplicate any information since they are simple text files which specify which layers are to be open and under which visualization conditions.

All data collected in the field, measures from the wells and springs, can be entered to the system by means of a customized data entry form. This data entry form allows the manager to enter the data directly into the tables linked to the graphical layers. The form organizes the data entered in a set of related tables and controls that data are entered correctly. In this case, a closed and customized application, the data-entry form, has been developed since the task to be performed is a well-established and repetitive one (a long-term monitoring program).

Protocols for adding or eliminating points from the network of sampling points are detailed on a page in the intranet. Adding or eliminating points from the graphical layer means digitizing, rebuilding the topology of the vector layer and reestablishing the appropriate database links. An application helps the park manager in reestablishing all those links.

From the data entry form, graphical representations of the evolution over time of any measured parameter can also be produced. Data can be easily imported from a spreadsheet and then all its graphical power utilized. Also, raster layers representing the spatial variability of any given measured parameter for a specific sample date can be generated from another form. The form just implements the interpolation method chosen in the monitoring program. Finally, the form allows to produce the above mentioned reports that are given and to the owner.

Other information such as the legal documents that regulate water issues can also be found in the appropriate page of the intranet.

Combining GIS and intranet

Internet technology (i.e., web browsers and hypertext language (HTML)) has been used to build an intranet on the park's LAN. This intranet allows access to all GIS information and metainformation, legal texts, system specifications and protocols for system configuration and maintenance. In addition, some information within the intranet can be made public in Internet in the near future with very little extra effort.

Park managers can access any type of data or information through the intranet on self-explanatory pages. Besides accessing any information in text format, from within an HTML page, a link can also be made to any file type. When clicking on an hyperlink the web browser asks the operating system which application is associated with the file type specified in the hyperlink and then opens that file with the appropriate application. In the case of graphical layers of the GIS, when the user clicks on a hyperlink to a graphical layer, the web browser launches the GIS associted with them, MiraMon in our case, and opens that layer.

In order for a GIS to be able to be integrated in an intranet in such a manner, it is highly recommended that the executable be small in size and fast to respond. MiraMon executable file is only about about 800Kb. Its code is entirely written in ANSI C and makes use of the Windows API, which makes it small and fast. Its response to a call made by a web browser after a user has clicked on an hyperlink in an HTML page is very fast.

Some web browsers make a copy of the file to be opened in a temporary directory and then call the application to open them. This is a problem that needs to be overcome for two reasons. First, files need to be small in size, otherwise it would not be possible to operate this way since disk space would be rapidly wasted and speed would be very low since the file would first have to be copied. Second, possible relative paths contained within the files would be wrong. In order to solve this problem, MiraMon uses a very small application that serves as a bridge between the browser and itself. This application, which operates invisibly to the user, launches itself before MiraMon does and gives to MiraMon the file to be opened with the correct relative paths. Also, MiraMon maps, described above, are used to make the hyperlinks. Since they are very small text files no problem of wasting disk space and slowing down the process appears.

One of the shortcomings of using this methodology is that each time a click on a hyperlink to a file is made, a different instance of its associated application is opened and therefore each different file is opened in a different instance of the application. In the case of GIS this is an important handicap in its use since visual overlaying is made impossible. However, MiraMon overcomes this difficulty by "listening" to user input. If one instance of the program is already opened and there is a call from the web browser (or from any other application) to open a given file, the program can open the file in the already open instance or in a new one, depending on user needs. Which the option chosen is depends on system configuration or on user choice in a dialog box. The intranet, then, can serve not only as a quick and easy access to all data but also as an interface for the GIS itself.

Moreover, since HTML editors are currently an easy to use tool and no need of HTML programming is needed to produce simple HTML pages, park managers can easily use them to maintain the system, the interface or to build their own private interfaces.

User profiles

Ease of use and maintenance is important when trying to guarantee a success implemention of an information system as explained by Alexander (1995) [2]. The task is not easy since GIS is quite a new technology and has only been present in academic curricula since very recently. GIS concepts and use need, therefore, to be taught from scratch. However, the effort proves worthwhile if the adequate tools are provided and if they are provided in such a manner that can be made easy to understand and where each different user can progress up to his or her will or necessities in a gradual manner. This can be achieved by carefully structuring all data and information and by using technologies such as intranet (see above) and a GIS that can be easily customized to different user needs. Indeed, there is no need to provide to all users with all available tools. Instead, if tools can be gradually introduced as needs arise the system will be more easily learned. Park staff can be highly occupied people with tasks that can arise in a single day. In order to introduce a new way of dealing with the information it is necessary to do it in a gradual manner that can be assimilated over time.

Each different user can have the same GIS system tailored to his or her specific needs. This can be made by allowing to define user profiles which determine which GIS capabilities are available and which are not for a given user. These profiles can be defined in the system startup file or they can be even dynamically changed from within the program. In this way, an advanced user and a beginner can be using exactly the same system but with very different levels of complexity. There are users that may only need to visualize information and query it by location, others that will almost only digitize, others which will need all system capabilities. MiraMon can be adequately configured to suit these different needs. Furthermore, users can progressively complexify it as they learn more on the system and as new needs arise.

If the park is to have a system that can be self-maintained and updated without or almost without outside contribution a GIS culture and know-how needs to be developed inside the park. Although not an easy task, the combination of an easy to use GIS, whose degree of complexity can be configured, with an intranet with all protocols for data handling written plus an effort in staff training can act synergistically in accomplishing this task.

Hardware and Software