all right hi everyone my name is Gigi Pavur and I'm an undergraduate senior
at Georgia Tech majoring in Earth that Atmospheric Sciences I'm so excited to
be here today with you all at AGU to tell you about a project I did this
summer through NASA DEVELOP, so NASA DEVELOP is a program within the Applied
Sciences program at NASA which is designed to increase participants like
me. Our capacity to use NASA earth observations so we do 10-week
feasibility projects, so with the help of my teammates Chelsey Dandridge, Robyn Kim
and Sarah Aldama, um, we were able to use NASA earth observations to improve
landslides situational awareness in the Dominican Republic
okay so imagine that
we are three thousand three hundred and eighty nine miles away from where you're
sitting right now at AGU you'll find a small country on the island of
Hispaniola and the Caribbean Sea the Dominican Republic so with its location
in the hurricane belt of the tropics the Dominican Republic is frequently exposed
to very heavy rainfall events which can trigger landslides
so my DEVELOP team partnered with a geological service in the Dominican
Republic to help improve their situational awareness of landslides and
our project partners were really interested in understanding how to limit
the loss of life and protect infrastructure for landslides and then
also our project supported an international agreement between the NASA
earth science division and the Central American integration system and that
agreement was designed to increase collaborations between NASA and Central
American countries, so I was really exciting to get to work on a project of
this international scale and calibre and then also I'd like to point out that I
too went bananas when I saw that fruit also has landslide risk so NASA has
about 30 satellites that are constantly orbiting Earth and collecting
environmental data and this data is really useful to study environmental
challenges like landslides so for a project we use two earth
observations the first was from the shuttle radar topography mission or SRTM
which provides elevation data and we use that to determine slope and then we also
used global precipitation measurement from GPM which is the satellite right
here
okay so landslide experts at Goddard Research Center at Space Flight Research
Center created a model called LHASA and yes you guessed it LHASA is another
NASA acronym so it stands for a Landslide Hazard Assessment for
Situational Awareness so this model is publicly available online through github
as both a Python script and an R script so my team worked to use this model and
take it from a global scale and cater it specifically for the Dominican
Republic and we did this by incorporating local data from our
project partners
so a really important component of the LHASA model is a
susceptibility map so this shows the landslide susceptibility in the
Dominican Republic and my team created this by using a fuzzy overlay model to
determine the correlations between landslide factors like elevation slope
distance to active fault lines clay percentage lithology
and forest covered loss and so when the static map is combined in LHASA with
precipitation measurements it will output near real-time nowcast so when
the rainfall the historical rainfall exceeds the 95th percentile it will
issue a high hazard nowcast if your susceptibility map says it's a
very susceptible region to landslides so since GPM rainfall data is available
every 30 minutes you could realistically make new outputs for this every half
hour so you might be wondering landslides are a natural process for
altering topography so why are they considered a natural disaster what makes
them a natural disaster and what I learned through this project
is that it really becomes a natural disaster when it affects people so once
again our project partners were really interested in knowing where landslides
impact people so we created this bivariate map on which depicts the
intersection of landslide susceptibility and and population so the regions but
you want to pay attention to are this deep red color up there which represent
high population and high landslide susceptibility and now fortunately
you'll see there aren't actually that many pixels of that color which is a
good thing and then you can see as well but Santiago and Santo Domingo and then
Bayer hona all have high populations because those are their main cities but
they aren't located in susceptible regions the central area has very high
landslide susceptibility but not a lot of people living there because it's
actually a national park so the idea is that this bivariant map can be used fore
quick heuristic identifications of regions on where people are at risk
all right then lastly a big final outcome of our project was we wanted to increase
our project partners capacity to actually use NASA the earth observations
so we wrote a tutorial so that they could do everything that we did over the
summer and one thing that we also showed them was how mapping landslides from
space can help them better understand where landslides occur even if they
don't have the budget necessarily to do ground mapping or like field research so
the three images on the right wait left so an interesting story about a
landslide that happened so we have a forest with the road going through it in
2012 and then by 2014 wait 2016 all the trees are gone and then by 2018 we have
evidence of a landslide so once again our project partners can use this to go
back and improve their historical landslide inventory and then our
tutorial also went through how to use LHASA
and how to make their own susceptibility map and then lastly it was translated
into Spanish and shared with other Central American countries so that they
can hopefully use this as a start point to use LHASA in their country
okay
,um so I'd like to end with a quote that was in the NASA calendar last year which
judging from the line over there I'm sure you guys are all familiar with it
but the quote I think it perfectly captures the value of applying NASA
earth observations to combat environmental challenges so the quote is
from Nelson Mandela and it says action without vision is only passing time
vision with action is merely daydreaming but vision with action can change the
world so quite literally earth observations
give us the perspective and vision we need to take action and according to
Nelson Mandela that's how we change the world so here we can see the night
lights of Earth and we know that from this perspective of space. Disasters
don't they aren't confined by country borders and from my DEVELOP project this
summer I learned that the applications of earth observations can also transcend
these boundaries so lastly thank you to the moon and back to all the people who
helped me do this project including our project partners in the Dominican
Republic our science advisors Dr. Ross and Dr.
Dalia Kirschbaum and then of course to my wonderful team Sarah and Robin and
Chelsea they put up with a lot of landslides jokes for me which as you
know is a very slippery slope thank you