Services | Flood Analysis

 

Combination Method for Flood Assessment


The combination method for flood assessment involves following methodology:


Water mask from remote sensing
Wetland mask from remote sensing
DEM and contour analysis in combination with soil, water, and wetland datasets

Water Mask - Using satellite imagery, all the water bodies are mask into a single layer for the normal water level. In addition, a wet seasonal or a flooded seasonal satellite image is used to extract the flood boundary. This process will delineate the normal flood levels.

Wetland Mask - Similar to water mask, satellite imagery is used to mask out wetland vegetation around streams and rivers. Normally these vegetations work as buffer for seasonal floods.

DEM and Contour Analysis - Once the flooded water mask and wetlands are extracted, DEM is used to create contour lines around the streams and rivers. Depending on geologic complexity, value for contour lines will be incremented. After the contour lines are produced, an analyst thresholds the contour lines with respect to flooded water mask, wetland mask, breakage in soil type adjacent to the wetland mask.