Measurement error of police data to identify solid waste dumping sites

Abstract

The increasing number of illegal dumping sites in rural regions of Spain represents a worrying problem in terms of sustainable construction and demolition (C&D) waste management. Local and regional authorities should have an effective system to control this issue. In fact, the Nature Protection Service of the Civil Guard (known as SEPRONA) has data on administrative sanctions of illegal dumping. However, the lack of reliable official data increases the uncertainty and control of rubble. This study analyzes the administrative sanctions for C&D waste that took place in Extremadura (Spain) in 2018. A total of 1 238 geolocations about illegal dumping provided by SEPRONA were analyzed. The main objective was to analyze the reliability of police data to locate solid spills in Extremadura. A detailed verification of the presence of rubble was conducted through interviews with the Civil Guard agents, field survey and photo-interpretation using up-to-date orthophotographs. The main findings showed a low quality in the georeferencing of the complaints. Only 2 % were clearly located in sites where C&D waste could be observed, and 9 % of the complaint is not exactly located in places where waste can be observed, but this kind of rubble was observed in close proximity to the geolocation. There is a lack of police culture to take advantage of GIS data for crime studies, and field agents do not use accurate techniques for georeferencing. Therefore, a good training for field agents and the development of a good practice guide can be key to ameliorate this problem.