Systems and methods for flood zone modeling

One or more non-transitory tangible computer-readable storage media storing computer-executable instructions for performing a computer process on a computing system, the computer process comprising:

• identifying one or more relevant stream segments from an input stream network;
• defining one or more cross profiles for one or more selected points on the relevant stream segments, the selected points located within a flood hazard area;
• generating a high resolution flood level elevation map by interpolating flood level elevation from the selected points, wherein the flood level elevation is calculated using a multivariate adaptive regression spline function;
• generating a flood depth map having a flood depth value for each of the selected points computed as a difference between the interpolated flood level elevation and a terrain elevation;
• and
• defining one or more flood zones in the flood depth map, the flood zones having a positive flood depth for a return period.

A method for flood hazard modeling, the method comprising:

• identifying one or more relevant stream segments from an input stream network using at least one computing unit, wherein the one or more relevant stream segments include at least one of:
• segments of named streams;
• downstream segments of the segments of named streams;
• or unnamed segments having a relevant classification and an accumulation area exceeding a threshold value;
• defining one or more cross profiles for one or more selected points on the relevant stream segments using the at least one computing unit, the selected points located within a flood hazard area, wherein one or more parts of the one or more cross profiles are at least truncated (i) where the parts intersect a stream segment with an equal or greater accumulation area than an original stream segment or (ii) according to a horizontal distance buffer depending on a Strahler Order and an accumulation area;
• generating a high resolution flood level elevation map using the at least one computing unit, the high resolution flood level elevation map generated by interpolating flood level elevation from the selected points;
• generating a flood depth map using the at least one computing unit, the flood depth map having a flood depth value for each of the selected points computed as a difference between the interpolated flood level elevation and a terrain elevation;
• and
• defining one or more flood zones in the flood depth map using the at least one computing unit, the flood zones having a positive flood depth for a return period.