Exploring the world of free tools for GIS, GPS, Google Earth, neogeography, and more.
Matt Perry posts on the release of a 4-year effort he’s been part of to map the effects of mankind on the marine ecosystems of the world. Links on his page point to the announcement article in Science Magazine, media coverage, and the UCSB Global Map of Human Impacts to Marine Ecosystems website that has downloadable KML and raster data for this information. This is incredibly important work, and the results are sobering:
The World Weather Map lets you click on a location, and get a plot by month of temperature (max/average/min), rainfall, and average number of hours of sunshine. A fourth tab supposedly gives you “Experiences”, a link list of things to do at that location, but the list sometimes includes activities a long distance (> 100 miles) from that location. You can also add an overlay showing what areas are “Hot”, “Warm” or “Wet” for a particular month.
The main website’s map is also flawed in that there’s no zoom feature, so for areas where the climate can change dramatically over a short distance (like the American Southwest), getting the climate for the exact location you want can be difficult to impossible. (1/24/2008: Fixed by the good folks at WorldReviewer; see the comment below) Oddly enough, there’s a widget version of this map that does include a zoom feature, and which can be embedded in any website, as below. Click and drag to move the map; click on +/- to zoom in and out; click on any point to get the climate data for that location:
Portland State University’s Glaciers Online site has maps, photos and data for glaciers of the American West. Contents include:
From the people who brought you Hey, What’s That? and two Google Mapplets for adding contour lines and terrain profiling to Google Maps comes the Sea Level Rise Visualization mapplet, more advanced than the Flood Maps website mentioned in a previous post. You can set three different flooding levels, and assign different colors to them (red, orange, and yellow):
For those diehards out there, you can choose English units (feet) instead of meters, and modify the flooding level numbers and update the map quickly by clicking on the “Go” button. Leaving a level blank omits that color from the map. Here’s an image from south Florida that uses the numbers above:
As the mapplet and my earlier post on Flood Maps point out, there are limitations to this approach deriving from the data. The SRTM data used for this has a spatial resolution of 90 meters, so the results will have a comparable spatial resolution. And SRTM data includes the heights of building and vegetation in the terrain, so urban areas like Miami will have SRTM terrain heights that are higher than the true terrain level, and the flooding level there will be undermapped by this mapplet. You’ll need to use higher resolution data with building/vegetation effects for more accurate results, as is done in this post. But for a quick estimate, this Mapplet does a nice job.Two additional tips on Google Mapplets:
- Google Mapplets aren’t currently accessible from the main Google Maps page; use this Preview link to reach a Google Maps page with an Mapplets tab
- You can reach any Mapplet with a single link like this one:http://maps.google.com/ig/add?moduleurl=http://www.heywhatsthat.com/mapplets/sealevel.xml&pid=mpl&synd=mplTo create a direct link to any other Mapplet, just replace the text “www.heywhatsthat.com/mapplets/sealevel.xml” with the address of the Mapplet you want to reach. Thanks to Mike Kosowsky of HeyWhatsThat.com for this tip.
LIDAR (Light Detection and Ranging) can be used to create high-resolution terrain data (sub-meter), detail good enough to show individual man-made features like buildings and bridges. It’s especially useful for analyzing terrain in areas that are in constant change, like coastlines. High-resolution coastal LIDAR data is available at this NOAA website for the entire US ocean coastline, and parts of the Great Lakes coastlines, for times ranging from 1996 to the present.
Continue reading ‘LIDAR Data Coastal Erosion And Flooding Analysis Using MicroDEM’
Last week, I posted the last in my series on animating sea level rise in Google Earth using raster overlays (the “Inconvenient Truth Effect”), and ended with the comment that I would do the same thing with vector overlays, and that doing it that way had some advantages over using raster overlays. Uh, maybe not.
For this effort, I decided to do a vector overlay animation that showed flooding in San Francisco instead of the previous one in Manhattan. Creating a raster animation was pretty straightforward:
Yesterday’s post showed how to create a sea level rise flooding animation in Google Earth, like this one:
And there’s a problem with the accuracy of this image: there’s no actual depth to the flooding, i.e. the lower levels of the buildings aren’t covered with water. In fact, some of the buildings you can see in the view above would be completely covered with water if this were a more realistic depiction. That’s because no absolute altitude was assigned to the image overlays used in creating the animation, so they are “clamped” to the terrain level. But by assigning a height to every overlay image in the animation, one can create a realistic effect where the flooding doesn’t just cover more area as the sea level rises, but covers the bottom levels of some buildings, and completely covers other ones. This would be similar to the animations shown in the movie “An Inconvenient Truth”, and in one sense even better. In that movie, the flooding was show in overhead views, while the Google Earth animation can be viewed at an oblique angle of your choosing, with 3D buildings. Continue reading ‘The "Inconvenient Truth" Effect In Google Earth: Animated Sea Level Rise Flooding Of Lower Manhattan With An Added Depth Effect’
The National Solar Radiation Database offers solar radiation data and limited meteorological data for 237 sites in the US over the period 1961-1990, and expanded data for 1454 sites from 1991-2005 (click on image for larger view):
Data includes:
User manuals in PDF format can be downloaded. Data is in text format, but can be converted to spreadsheet format with a bit of work.
