Study area at low-water period (2011 orthophoto, from IRDAT FVG). The springs of the karst Lake Doberdò are concentrated in the West sector of the basin, with the two major spring pools visible to the NW (1-2); a stream flows through the polje, with a large pool (3) at the confluence of various spring-fed channels located in the central-eastern sector of the basin; the stream disappears in the swallow hole pools in the East sector (4: main swallow hole pool). The dashed yellow line corresponds to the seasonal highest water level.