Isochrones: Isochrones is a line on the map which connects points having an equal time of travel of the surface runoff to the catchment outlet. These are some property of Isochrones: ● Isochrones vary with time, It's most commonly used to depict travel times, such as drawing a 30 minute travel time perimeter around a start location. ● The isochrone below joins up all points within a 45-minute drive from the origin. ● Isochrones depict the variation of the pore water pressure along with the depth of the soil sample. ● Isochrones are mainly used for transport planning, property search, sales territory planning, etc.