In arid areas, rural communities can be affected by erosive phenomena caused by intense rainfall. By involving such communities in participatory mapping over the last few decades, our ability to analyse the effects of these phenomena has been enhanced. The aim of this study was to evaluate participatory mapping as a tool for spatially analysing agricultural variations caused by erosive phenomena, using local people to identify chronologies of physical events so we could analyse their effects on agriculture. The study was conducted in Laonzana, Tarapacá Valley, in northern Chile. We selected the participants for the participatory mapping using speci c criteria, and carried out eld activities in different phases, which allowed the identi cation, georeferencing and registration (through participatory mapping) of the information collected in the eld and from the collective memories of the participants. Three periods were studied: 1) "before 1977" with 26 sites and covering 234,273 m 2 ; 2) "between 1977 and 2012" with 6 sites and an area of 92,941 m 2 ; and 3) "after 2012' with three sites, covering 29,852 m 2 . This provided evidence for a decrease in the number of productive sites, these being limited to the vicinity of the village. The participatory mapping technique has become a useful tool in desert and mountainous areas with low population densities for recovering experiential information from communities. This participation contributes to the provision of examples for researchers, communities and government agencies to use in arguing for the need for cartographic information.