SGEvT: Verified from wild deposit space

Created in 2015, the General Society for Territorial Evaluation (SGEvT) has developed a platform that brings together dozens of indicators and decision-making tools intended to assist local authorities in managing their territories. Among these tools, we recently found a solution to detect, qualify, but prevent illegal dumping of waste.

An “indicatheque”. This is what the General Society for the Evaluation of Territories (SGEvT), in particular Nancy Oliveto, lawyer, urban planner and a Toulouse-based company born in 2015, has created – and it is going to prosper. Former consultant on sustainable development. Baptized Terreval, this library of indicators and decision support tools now includes around sixty, intended to guide local authorities in their regional development projects. The birth of this true “dashboard”, like the company, is closely linked to the Grenelle de l’Environment. Arnaud André, co-founder and president of SGEvT, spoke about it: “The Grenelle de l’environnement gave rise to the obligation for local authorities to develop plans for the sustainable development of the region.[1]. The number of factors to be included in these plans has increased sharply, to take into account aspects such as energy efficiency, soil artificialisation, etc. Other obligations were for these local authorities to evaluate the effectiveness of their plans. The company was therefore founded on the idea of ​​providing local authorities with tools to build a dashboard so that they can monitor the impact of projects carried out over time”.

Scalable, this platform continuously thrives on the needs expressed by SGEvT’s customer community. “As the projects progressed, various issues appeared, such as the urban envelope, i.e. the boundaries of the city. So we developed algorithms to help establish this envelope, but also to verify compliance with the prescriptions that were created., explains Arnaud André. Recently, SGEvT has also tackled an issue of increasing importance: illegal dumping.

Detect, qualify, but prevent illegal dumping

Led by Adem, a survey conducted in 2018 among 2,652 local authorities revealed that almost 90% of them were then facing the problem of illegal dumping. However, the agency noted in the report published after the completion of this investigation[2], “There is no comprehensive list of situations of illegal deposits (amount and nature of deposits) on a national scale”. A tool developed by SGEvT, however, could change the situation. The company has in fact developed a remote sensing solution aimed at identifying, but also identifying these deposits (extent, date of appearance, risk to the environment, etc.) and even before the waste appears, especially in areas at risk of illegal dumping.

Some French communities are not affected by the problem of illegal dumping. However, establishing an inventory on a national scale remains difficult. © SGEvT

“Thanks to our long-standing links with CNES, we proposed to them to set up an offer based on Pleiades satellite photos, crossed with our relevant knowledge of the area: relief, plot occupation, transport network… “, reveals Arnaud André. The process, which began in late 2019, culminates in 2021 with the launch of this unique remote sensing tool. “Development takes time. It is really necessary to identify in satellite images forms that may be wild deposits, but also simple rocks or rivers for example. So algorithms need time to learn, gradually correcting their errorsSGEvT president notes.

A solution that has already proven itself in the field

The spatial resolution of the images captured by the Pléiades satellite allows the detection of deposits from about fifty square meters. © SGEvT

Once identified, each deposit is scored according to criteria such as proximity to a watercourse, a groundwater table, schools or other sensitive locations. “The tool we developed provides priority elements, making it possible to answer the question “Which filing should be processed first?”. », emphasizes Arnaud André. An interest has been added to the identification of sensitive areas, which are helpful for the presence of wild deposits. Areas, once demarcated, can thus be subject to stronger surveillance. “We also provide intervention tools, Adds the company’s co-founder. In late 2021, we helped the police conduct an intervention operation in Aude covering several hundred km². We have prepared sheets for them specifying the size of depots, conditions of access to reach them etc. Thanks to this, the gendarmes went into the field, and in one afternoon, they were able to do a job that would have taken them several days, perhaps more than a week, without our tools. »

An initial campaign of intervention, conducted at the end of 2021 by the Aude gendarmerie using data and indicators provided by the SGEvT, proved particularly fruitful. © SGEvT

In terms of reliability, the tool offered by SGEvT is able to achieve a detection rate of at least 90% according to the company’s president, who nevertheless admits: “If the deposit disappears from the satellite, obviously we won’t detect it. This is the case, for example, under the cover of plants. That said, it depends on the season.”. In addition to this limitation, the size of the deposit is also important: with a resolution of 50×50 cm, the images provided by the Pléiades satellite allow the detection of deposits from several tens of square meters. “A simple plastic bag full of waste will not be caught”, thus cited by Arnaud André as a counterexample. The future Pléiades Neo constellation, with its spatial resolution of 30 cm, promises to lower the detection threshold even further.

Available through the TEREvAL platform, the tool significantly generates intervention sheets to guide actions performed in the field. © SGEvT

Expanding the range of its tools: SGEvT’s raison d’être

Following the success of the project carried out in Aude, SGEvT now hopes to offer its solution to other local authorities. “There is a lot of interest, and the subject will be studied. Not only from local authorities, but also from collection builders, who see new opportunities in this.”Arnaud Andre is delighted.

For a subscription of several thousand euros per year – depending in particular on the size of the area covered – the definition of detection functionality, rating or access means is already available. Through the TEREvAL platform “And of course there will be elements to complete these functions along with other ideas.”The president of the company provides.

An additional string is thus added to the arc of the “indicathèque” developed by SGEvT. A platform that should be expanded a bit more soon, with the addition of other tools, as Arnaud André finally revealed: “We have a complete offer in terms of proximity and we are working, for example, on local health contracts[3]which has become imperative for many regions.”. And the manager concludes: “Our mission is to provide communities with the widest possible collection of tools”.


[1] Territorial Climate-Air-Energy Plans (PCAET), mandated by Grenelle 2 legislation for communities of more than 50,000 inhabitants, and now mandatory for all inter-municipalities with more than 20,000 inhabitants (threshold lowered in 2018).

[2] ADEME, ECOGEOS. 2019. Characteristics of the litter problem. Report. 84 pages.

[3] Tools jointly carried out by Regional Health Organizations (ARS) and local authorities to reduce regional and social inequalities in health.

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