Luigi Garretti
Regione Piemonte, Direzione Regionale Pianificazione e Gestione Urbanistica, v. XX Settembre 88, 10121 Torino, tel (+39-11) 4324160, Luigi.Garretti@regione.piemonte.it

Marco Cavagnoli
CSI Piemonte, Settore Sistemi Territoriali, c. Unione Sovietica 216, 10134 Torino, tel. (+39-11) 3168204, marco.cavagnoli@csi.it

Stefano Giorgi
CSI Piemonte, Settore Sistemi Territoriali, c. Unione Sovietica 216, 10134 Torino, tel. (+39-11) 3168204, marco.cavagnoli@csi.it

Marina Grattapaglia
CSI Piemonte, Settore Sistemi Territoriali, c. Unione Sovietica 216, 10134 Torino, tel. (+39-11) 3168204, marco.cavagnoli@csi.it

Abstract

The geographic information system of Regione Piemonte is setting up a series of data distribution services. In this paper we present a prototypal application to display and query data via the web. The application deals with urban plans data of the regional Urban Planning Information System, stored in a SDE database.

INTRODUCTION

The Sit (Sistema Informativo Territoriale) of Regione Piemonte is a well-established geographic information system used, since 1982, in order to manage Urban and Regional Planning, Geological Survey, Environment and Parks, Agriculture, Civil Defence and Public Transport, to name a few of the better-known regional government tasks supported by GIS. Services and geographic information are available to the public, aimed at the user’s technical, administrative and decision-making requirements. The system has been set up using Esri tools (ArcInfo, ArcView, SDE, MapObjects, IMS).
Essential topographic information, as well as similar information vital to land monitoring has been produced, catalogued, integrated and updated since the system’s introduction twenty years ago. The region has been observed as a unique entity with its own natural anthropical features. Its past and current topography has been studied from both a descriptive and prescriptive point of view, identifying its visible and hidden characteristics at both a local and regional scale (1:250.000, 1:100.000, 1:50.000, 1:25.000, 1:10.000) etc.

BEYOND THE DATA

Beside the traditional concept of data per se, used in a local and corporative way, the idea of shared data managed by various and composite processes in territorial government is gradually increasing and developing. It means that the first step to take by public administrations is to publicize their informative heritage to different kind of users. Up to today the issue has not been completely achieved, because it involves not only technical and organization aspects, but cultural and institutional factors too. As a matter of fact, the use of geographical information is rapidly spreading, even out of its traditional application fields, and data offer is increasing. Nevertheless that does not automatically mean that any user can get useful, meaningful and right information for his purposes.
In particular, government officials use GIS to support decision making activities, so they generally do not need raw data, but synthetic information, at different processing levels. Data refinement, either in descripting terms or in processing terms, is particularly important in the well-developed cultural context of the Regional Public Administration in Regione Piemonte: the more GIS use is becoming a de facto standard way of working, the more data interchange among local departments and tools provided for it get crucial. Many geographic data used and managed by a local administration can be in fact very important to other administrations too, even if they look at them from different "points of view", according to their knowledge domain. Therefore it becomes strategical to promote and assure the proper data knowledge and interchange, encouraging sharing and reuse to the greatest extent. The Sit of Regione Piemonte provides different tools to achieve the information discovery, that is the ability to browse the metainformation about the available data, and to identify the data of interest. The main tools are: the Cartographic Inventory, the Sit Access Interface and the Territorial Data Base.
The Cartographic Inventory is a tool for querying and retrieving metainformation about available cartography and related data, via Internet. The Sit Access Interface is a tool for distributing public geographic data via the regional geographic network: fully implemented with ArcView and Internet Map Server software, it provides advanced functions for spatial and thematic browsing. The Territorial Data Base is a first level tool for querying and displaying heterogeneous territorial data, based on municipal areas, provided with simple statistical and cartographical functions.
These tools have been designed for the sake of setting the "unified work place", that is a general access desktop service aimed at making regional officials able to surf? all over the Regional Information System. These general principles also inspire and regulate the departmental Information Systems such as the Urban Planning Information System: originally planned to meet peculiar requirements, now they are developing towards distributing, exchanging and integrating services for data management in territorial government.

THE URBAN PLANS INFORMATION SYSTEM CASE

The Urban Planning Information System is a well-developed system in regards to the storage of existing urban plans, based on municipal areas. It adopts a specialized methodology for standardizing urban plans, which has been improving in the course of ten years.
In a few words, the methodology uses a series of glossaries collecting in a gerarchical structure all the prescribing rules which constitute the urban plan. Each plan can then be disassembled in its primary and lowest rules, stored in a coded format, related to geographical zones within the municipality ("normative areas"). The normative areas constituting the geographical component in the Information System are georeferred on the highest available cartographic data, that is the Regional Topographic Map at the scale 1:10000. The disassembled plan can then be assembled again, using GIS functions and capabilities, depending on the peculiar user’s requirements, to perform various type of analysis, produce new maps and processed data.
At present about 400 urban plans have been managed and stored, covering the whole provinces of Turin and Vercelli and parts of the other provinces in Regione Piemonte, that is approximately one third of the whole region (see fig. 1). The increasing system complexity requires the information spread and distribution among different administrative departments: for that purpose CSI is setting up a series of various tools and services, which are currently studied and undertaken for supporting the regional administrative processes involving the urban plans. The most important goal is to achieve the integrated management of the whole information which can be useful for checking an urban plan with reference to neighbouring and overlapping plans, existing environmental, cultural, geological constraints, socio-economical data, etc.

THE PROTOTYPAL TOOL

A starting component of this tools system has been implemented as a prototype, which is at present restricted to data query. It has been planned to be the lowest level means of knowing urban planning rules and cartography. The prototypal application deals with these features associated as items in a SDE layer of normative areas, which can be represented using a pre-classified thematic layout, with raster image of the Regional Topographic Map as a geographical background. The prescribing aspects are represented by two fundamental features in urban planning: the predominant use designation (residential, productive, agricultural, tourist, natural and service areas) and the building saturation degree.
The simplification level adopted in this prototypal application is admittedly remarkable, compared to the complexity of the information system, and the amount of data at present has been reduced to a portion of urban plans, just for testing: but the chosen scale and the available functions meet the regional and provincial requirements, that is the information level is suitable. Moreover, as soon as all available plans are included in an accessible form, the user will be able to query more than 100,000 normative areas.
To make the maps reachable on the net, the application is based on the following components:

• Web Server: Microsoft Personal Web Server, supported by Arcview in Windows 95.
• Map Server: the Arc View extent Internet Map Server and the Java Based Applet Mapcafè
• Browser: Netscape 3.0

The ArcView project includes the following layers:

• raster background of the Regional Topographic Map
• municipal and provincial boundaries
• selection of municipalities with stored urban plans
• boundaries of normative areas
• a thematic map of normative areas, referring to a representative urban plans classification

The following functions are supported:

• zooming (in and out, next and past) over the map
• panning over the map
• switching on and off the displaying of available layers
• automatic selection in drawing layers, depending on the scale
• interactive query on the normative areas layer
• string search into the items values
• map printing

Fig.1 - Urban plans stored (July 1998)