Natural Disaster is natural destruction in a society in form of :
Earthquake: For earthquake post disaster study we need to have high
spatial resolution satellite image.
·
Earthquake
·
Forest
Fire
·
Hurricane
·
Volcanic
Eruptions
·
Landslides
·
Drought
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| Image by WikiImages from Pixabay |
High Spatial Resolution:
Small pixel size indicates high spatial resolution and greater details.
Reason: If we want to classify houses on basis of partially damaged,
fully damaged we need to closely observe our AOI, to see damaged bridge we need
to see it as close as we can ,as detailed as we can
Floods: For flood study, we need to have data with high temporal
resolution.
High Temporal Resolution:
How frequent an area is being observed is its temporal resolution.
Reason: Floods may be progressive or flash, let’s take example of
progressive flood first, after every small time period we need to know how much
and from where water is proceeding so we can study its impact. High temporal
resolution data will assist us in change detection due to flood, its extent etc.
Similarly for flash floods the case is same.
Forest Fires: For forest fires we need to have satellite image with high
spectral resolution.
High Spectral resolution: Greater number of wave lengths greater is
spectral resolution.
Reason: Forest fires have characteristic of light and heat, to detect
differences in both we need to have high spectral resolution data.
Landslides: For landslides study we need to have data with high
In order to study a landslide, you need to
be able to view the size and contrast of the landslide features and the
morphological expression of the topography within and around the
landslide. Parameters you might be interested in determining are the type
of movement that has occurred, the degree of present activity of the landslide,
and the depth to which movement has occurred, for all this you need to have
high spatial resolution data.
For monitoring the movement of a
landslide that involves the comparison of landslide conditions over time,
including the aerial extent of the landslide, the speed of movement, and the change
in the surface topography we need to have data with high spatial but for
analysis of land slide and for future prediction we need to have data with high
spatial and spectral resolution.
Volcanic Eruption: In order to study
volcanic eruption we need to have data with high radiometric resolution.
High Radiometric Resolution: It is no of levels,
higher levels or large different intensities indicate large radiometric
resolution.
Reason: As we know that Satellites have the advantage of being able to
cover a wide area in one pass. It allows us to understand events that cover
many square kilometers, such as pyroclastic flow, smoke and changes to the
terrain. Also, in the vicinity of volcanoes there are often openings in the
Earth’s crust called fumaroles, which emit very hot gases. Some fumaroles are
in mountainous areas with no road access, so they’re hard to keep track of with
high radiometric data differences can be assessed.
Hurricanes /Storms:
Multispectral images can also be used to
detect the moisture condition the clouds. Temporal imagery is required to find
the destination of the typhoon. So we need image with high temporal Resolution.
Droughts: Multispectral imagery can be used for droughts
prediction. NIR- bands can be used to detect soil moisture condition in an area
(water absorbs NIR) .Then upon these values we can prepare drought mapping. To
calculate (NDVI) to find out the plants greenery in the area. Data with high
spectral and radiometric resolution is needed.
Sources:
http://cwfis.cfs.nrcan.gc.ca/en_CA/background/faq/fm3
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