Analyzing, Visualizing, and Predicting the Impacts of Various Natural
Disasters Through Geospatial Applications
Abstract
Using population grid datasets, satellite imagery, and geospatial data
accessed through Google Earth Engine, we identified patterns between
natural disasters, their causes, and their impact on communities in
order to predict and identify ways to reduce their effects. Techniques
used include resampling, grid manipulation, mapping of datasets, and
trend examination by creating time-series graphs and visualizations. For
wildfires, population data was overlapped by burn scar data to calculate
the yearly California population directly affected by wildfires
(residing in burn areas) from 2000 to 2020. A line of best fit based on
the calculated values showed an increase in population affected over
time, and notable outliers revealed years with conditions that
contributed to wildfire vulnerability, including high vegetation, high
wind speeds, high temperatures, low relative humidity, and sloped
topography. Scoring and combining data based on these five factors
resulted in a fire risk map that visualizes the susceptibility of
California to wildfires. For floods and tropical storms, the
hurricane-heavy Florida-Caribbean region was analyzed by processing
surface soil moisture (SSM) and precipitation (GPM) datasets to create
time series line charts that revealed an upward trend in both SSM and
precipitation in the fall of 2017. To examine how susceptible SSM,
precipitation, and dense populations were to flooding, we overlapped
maps of the various datasets by masking higher values with areas of the
map that had flooded. A significant overlap existed with these flood
factors, allowing us to generate a map that visualizes areas susceptible
to flooding. For extreme heat, San Francisco was chosen as the area of
study. We created land surface temperature (LST) and normalized
difference vegetation index (NDVI) images of the city to determine the
effect of vegetation on extreme heat events in urban areas. Our
observations showed that while greenbelts — large vegetated areas
dispersed throughout the city — do have a significant cooling effect,
this effect does not spread far beyond the limits of the area. A
possible solution is to distribute a greater number of smaller green
areas evenly throughout the city instead.