Drone-based, airborne sensory system for flood elevation and flood occurrence probability measurements and return periods by proxy measurements and method thereof

A drone-survey measurement based inundation probability forecast and flood hazard vulnerability measuring system, wherein location-specific elevation data are measured by drones of the measuring system, the measured location-specific elevation data being transmitted to an inundation engine for measuring and/or measurement-based forecasting of flood hazard vulnerabilities for different units and/or sub-units based on said measured location-specific elevation data, the system comprising:

• a geo-tagging graphical user interface for selecting perimeter points of a definable polygon on a geographical and/or topographical map provided by the geo-tagging graphical user interface, the polygon segregating a defined geographical area of the geographical and/or topographical map falling with said polygon,
• one or more of the drones having at least one optical sensor or camera for optical image sensing, different subareas of the geographical area defined by the polygon being captured by optical images and each possible location within the polygon being sensed by at least two of the optical images measured by the optical sensor or camera of the one or more of the drones,
• a 3D data extractor linked via a data transmission interface to the one or more of the drones, the captured optical images being transmitted from the one or more of the drones to the 3D data extractor, a drone measurement-based 3D digital twin of the geographical area defined by the polygon being extracted by three-dimensional measurements from the captured optical images, three-dimensional coordinates of points on the geographic area being measured based upon the at least two of the optical images of a location taken from different positions of one or more of the drones, common points being identified on each of the at least two of the optical images, a ray being generated from a location of the at least one optical sensor or camera to a measured point on the geographic area, and an intersection of these rays triangulation determining a three-dimensional location of a point,
• a calibration module to capture at least two ground control points within the geographic area defined by the polygon, a ground control point being a defined mark on a target surface of the geographic area linked with geographical and/or topographical coordinates, and the at least two ground control points providing georeferencing and geo-calibration for the at least two of the optical images within the polygon and the 3D digital twin by assigning geographical coordinate data to the 3D digital twin, and to achieve an accuracy of 5 cm or less for elevation and surface inclination drone-based measurements, root mean square error values at the at least two ground control points is in a range of 15-40 mm,
• a progressive morphological filter, root mean square error values of the 3D digital twin or a digital terrain model being adjusted to be in a required range by calibration of parameters of the progressive morphological filter, and
• a flood hazard aggregator for generating flood hazard vulnerability measures for one or more of the units and/or sub-units situated within the polygon depending on forecasted or user-specifically selected return periods and/or inundation heights based on flood hazard damage impacts to the one or more of the units and/or sub-units associated for different of the inundation heights and/or the return periods depending on the 3D digital twin.