Method for marking terrain

Method for determining changes in a terrain comprises: (a) treating the terrain with an agent; and (b) irradiating the treated terrain and/or the adjoining untreated areas by means of UV light and the deviation; where the agent is an aqueous dispersion containing (a1) at least one binder, (a2) at least one substance emitting visible light when irradiated with UV light and (a3) an optional dispersant. Method for determining changes in a terrain comprises: (a) treating the terrain with an agent; and (b) irradiating the treated terrain and/or the adjoining untreated areas by means of UV light and the deviation; (b1) the light intensity of the emitted light of a partial area of the terrain from the average intensity of the emitted light of the area of the terrain; and/or (b2) the light intensity of the emitted light of a portion of the adjoining, untreated area from the average intensity of the emitted light of the adjoining untreated areas; and/or (b3) the light intensity of the emitted light of the terrain immediately following the treatment with the agent from the intensity of the emitted light at a later point in time; and/or (b4) the light intensity of the emitted light of the adjoining untreated area immediately following the treatment of the terrain with the agent from the intensity of the emitted light of the adjoining, untreated area at a later point in time is determined; where the agent is an aqueous dispersion containing (a1) at least one binder, (a2) at least one substance emitting visible light when irradiated with UV light and (a3) an optional dispersant. An independent claim is also included for a terrain treated with the agent.