Quelles sont les meilleures pratiques pour identifier les friches industrielles à l’aide d’un SIG dans les zones urbaines ?

In the definition of scope, it is important to take into account classical definitions such as central place and hierarchy of services. As an example, if a brownfield has the potential for a higher hierarchy retail development, or if it is large enough to accomodate more than one level of hierarchy, site selection criteria of the desired units might be suitably adopted to assess the current accessibility of the brownfield. On the other hand, alternative analyses may be also useful. Most brownfield areas' accessibility may be improved if there is an infrastructure intervention. So, an alternative scenario where accessibility would be highly improved could be taken into account to shift the point of view, and setting the initial scope.

I would suggest the following points to be considered for identifying brownfield sites using GIS in urban areas.  Fuse data layers: history, environment, land cover.  Go beyond location: consider past use, soil, sensitivities.  See from above: use high-resolution imagery for precision.  Work with locals: tap their knowledge, enrich your data.  Dig into the past: property records reveal hidden uses.  Leverage GIS tools: model suitability, overlay layers efficiently.  Stay legal: follow environmental regulations.  Mine public data: environmental agencies are your allies.  Keep data fresh: continuous monitoring is key.  Document & report: clear communication builds trust.

Any data can be collected and wasted, if they are not collected to establish some level of information base that can be connected with our know-how of redevelopment. In line, our know-how of redevelopment will then be connected to our spatial strategies. Thus, before starting data collection, a structured interview with redevelopment experts should be held to delineate the types of data to be collected, and their scope and temporal extension, before jumping into collecting all data. On the other hand, usual redevelopment applications, zoning revisions or other interventions may require standard analysis which has to be done based on legislation. But these analyses are often of little strategic value. Sometimes small data is more important.

An origin-destination matrix makes more sense from an accessibility perspective than usual buffers. If there is a legal constraint and the buffer is clearly indicated, or if there is scientific evidence for the validity of the buffer, use it. As an example, proximity to green fields is generally accepted as important, but in different localities quality of green spaces may be more important than proximity. Kernel density maps, hot-spot analysis or other things may not be very useful if applied straightforward, in the case of brownfield development. Competitive buffers may be applied based on real estate market analysis taking into account competing pipeline projects and proximity to premium services, and infrastructures.

More synthesis should clarify simpler and neater options, targeting specific decision-makers, i.e. such as investors, developers, or others who have to take into account different factors for decision-making.

A post synthesis expert opinion or internal evaluation may help in ordering the potentials and risks of brownfield areas from different perspectives. The perspectives could vary based on potential approaches to intervention, such as different public-private partnership models. A difficult part is to assess the change in the relative position of the brownfield site among a set of peer areas, since it requires a selection: Is the brownfield area desired to reach a standard, or be elevated to the most competitive position within a set of peers.