Posts tagged aster-gdem
Silvia Estrada-Flores is a Depiction user and an expert in the food industry supply chain who lives in Australia. Naturally, she has been very concerned about the major flooding occurring in the state of Queensland–and, specifically, about the way the flooding is affecting grocery stores in the area.
Silvia used Depiction to first run rough simulations of the flooding and potential flooding in and around Brisbane, Queensland, using ASTER-GDEM elevation data (because she was unable to get access to the higher quality data generated by the government), and then to depict the situation facing the grocery stores in the area. She also used Depiction’s geoaligning capability to show the official flooding predictions in relation to grocery stores.
Silvia writes, “Today, I can just reassure consumers in Brisbane that there will be stores open around you. I am hoping that this map shows the areas where consumers can purchase supplies in these confusing times.” She will be writing more in the near future on the challenges of maintaining the supply chain in this situation, so pay attention to her blog, Chain of Events, if this information is important to you.
Even if you are not specifically concerned with the response of the food industry supply chain to disasters (though if you eat any food yourself, you may want to think on it at least a little!), I think Silva’s work illustrates a couple broader points. First, this is exactly the kind of thing Depiction was built for–giving powerful tools to subject-matter experts like Silvia, who may not have any experience with or access to GIS technology, but who have a need to depict the world around them in rapidly changing situations. Very few people have both the skills and resources to use high-end GIS and modelling software and the expert-level knowledge and experience in something like food industry supply chain management. And yet that field, and many others like it, have a real and abiding need for location-based knowledge, situational awareness, and the ability to ask “what if” about their community. We are very proud that Silvia was able to use Depiction to gain insights into the situation in Brisbane, and that Depiction users across the world are doing similar things within their own fields of expertise, without having to be mapping technology experts.
Second, the situation reminds us of the need for collaboration across boundaries. In her first blog post, Sylvia mentions her frustration with the unavailability of good quality elevation data:
It was difficult to find freely available information on elevation data. This can create difficulties for those planners dealing with emergency preparations that are not necessarily acting on behalf of the Government. I am aware of the National Elevation Data Framework portal, but I could not find elevation data for Queensland that is readily accessible. The process for downloading information (even in those cases where data happens to be free) is slow, due to the requirements of data licensing and so on. Not really useful when you are in a hurry to see flood damages and impact…
Here in the States, we are fortunate to have the USGS, which provides a relatively user-friendly method of obtaining good quality elevation data at multiple resolution levels through the Seamless Data Warehouse. This has allowed us to make US elevation data available as a Quickstart data set in Depiction. However, that is not the case in most parts of the world, and even here in the USA, many other crucial datasets are out of reach, depending on the locality. As Silvia notes, this presents major problems for people who are attempting to prepare for or respond to a disaster, among other things. Governments who are looking for an easy way to bolster the assistance that can be provided by the private sector during a disaster might think about making their GIS data easily accessible by the public.
One question we get frequently from folks who are just seeing Depiction for the first time is “Is it just the US, or is it worldwide?” Depiction is certainly worldwide–wherever you have data for, Depiction will happily plot it.
Of course, one of the most useful parts of Depiction is our Quickstart data, and much of that, admittedly, is limited to the United States. NASA Landsat imagery is worldwide, and OpenStreetMaps is most definitely worldwide, enabling our routing and route-based simulation to function all over the planet.
But one thing noticeably lacking from our Quickstart list is elevation data outside the US and Canada. Fortunately, there is a relatively simple way to get data just as good as our US data for anywhere on Earth.
It’s called ASTER-GDEM, and it is a joint project of the Japanese Ministery of Economics, Trade and Industry (METI) and NASA. As it happens, the Japanese site is much, much easier to use.
There are four ways to choose tiles–you can simply click on 1 degree by 1 degree tiles to select them (click ’start’ to begin); you can draw a polygon (again, click start), you can upload a shapefile, and it will bring in the associated areas, or you can manually enter the coordinates of the area you want. However you do it, you will recieve a visual representation of the tiles you will be downloading, and you can use the “manually select tiles” option to add or remove tiles. Up to 100 tiles can be easily downloaded at a time, in a zip file full of zip files. The data itself is in GeoTIFF format, which loads nicely into Depiction.
One note–you will have to register (which is free) and commit to using the files in particular ways, but the restrictions are very broad.
I can’t promise that we will add this to the Quickstart menu, in part because of the restrictions just mentioned, but the website is the most user friendly way I’ve ever seen of retrieving elevation data–Seamless server, eat your heart out.
I hope to put up some sample depictions using this worldwide data soon–but in the meantime, you should try it out and submit your own!