EVS-Islands

Two small chunks of real estate in the middle of the Pacific Ocean. I would image the shipwrecked sailor would be ecstatic to land on either of them. That would be for a short while. Once that sailor determined that neither island has any water, their joy would turn to desperation. As I teach my students, the absolute first prerequisite people require to sustain life is water. Sure, you can drink filtered urine. You can even drink unfilter urine. But that is a temporary measure. This is a part of the Pacific that doesn't generate much moisture laden clouds.  No rain, no water.

The islands are great for seabirds, they can discover water where you and I wouldn't. Consequently, these islands are for the birds, literally. They are both classified as a National Wildlife Refuge maintained by the US Fish and Wildlife Service.

Both Howland Island and Baker Island have great Wikipedia entries. They require special permission to visit. About the only people traveling to the islands today, besides the shipwrecked sailor, are ornithologists, radio amateurs and Amelia Earhard researchers.

Posted by Mr Minton at 9/09/2006 04:27:00 PM | Permalink | Comments | links to this post

Darnley Island (9°35'S., 143°46'E.) lies 7.5 miles S of Brown Reef. The island rises to a height of 181m and, in clear weather, may be seen from a distance of 25 to 30 miles from seaward. A coral reef, approximately 0.5 mile in diameter, lies 3.2 miles W of Darnley Island.

Anchorage.—Anchorage may be taken in Treacherous Bay, on the N side of the island, in 26 to 27m, about 0.5 mile offshore. The anchorage is protected from SE winds.

(SD Pub-128)

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Darnley Island (aka Erub Island) has a small population that earns it's living from farming and fishing.  The island is part of the Torres Strait Islands, a group of 274 small islands that form stepping stones between New Guinea to the north and Australia to the south.  Darnley Island is located near New Guinea.  You can learn more about the Torres Islanders by checking out this Wikipedia link.

The mapping was relatively fast.  Nothing really complex about the project.  I do enjoy mapping the reefs the ring the islands in this area.

Enjoy!

Posted by Mr Minton at 9/09/2006 10:53:00 AM | Permalink | Comments | links to this post

Still many of you are cruising onto this site wondering what Islands has to do with the Aussie slang expression "Evs".  So, if you want to see island maps and images or discuss mapping topics you are at the right place.  If you want to know all about Aussie slang, Like roo or dingo or "Evs", this ain't the place.

Posted by Mr Minton at 9/08/2006 08:07:00 AM | Permalink | Comments | links to this post

I mentioned in previous posts that the best global river shorelines that I have encountered are Navteq shorelines. It looks like they might have used Landsat imagery to create their river shorelines. If someone associated with these river creations wishes to comment, go for it. The rivers are good, but they do not compare to EVS precision. My river shorelines and island details are excellent and extremely precise compared to Navteq's efforts. See for yourself.

Posted by Mr Minton at 9/06/2006 05:19:00 PM | Permalink | Comments | links to this post

About 25 curious folks from throughout the United States have visited EVS-Islands over the last 3-days.  They searched for "EVS, Australia" and ended up visiting "EVS-Islands".  I am not sure if they were actually hunting for Electric Vechicles or the EVS Knee Brace Company.  I do know that they stopped in and most of them visited my post about Australian Estuaries.  I hope if you were or are one of the visitors you enjoyed you visit at my site.  Come again!

By the way, does anyone know what they would have been hunting for in the first place?  Just curious. 

Posted by Mr Minton at 9/06/2006 04:37:00 PM | Permalink | Comments | links to this post

This is a very old project. It predates my EVS-Islands blog. Why post it now and on an islands blog site? I just felt that it would be interesting. This lake is one of the largest in the world. At the western end of the lake is a dam that helped to dry up the river to the north of it. Not a good thing. The river that flows to the north is the Ili River. I mapped the river as well as the lake. It was very time-consuming to complete both the lake and the river.

Enjoy the slideshow. It shows the lake from 1:400,000 down to 1:50,000 at three sites within the lake.

Posted by Mr Minton at 9/06/2006 12:50:00 AM | Permalink | Comments | links to this post

This looks like Thomas the Train's island of Sodor. Look at all of the plots of land. This island is heavily cultivated. It has some interesting features - the windbreaks made up of trees that form two concentric rings around the island, the remnant of the lagoon, that is now small lakes (not sure if they are brackish or not). This looks like a nice, tidy island that most probably gets beat to death from the typhoons that rip into Japan and China from the south.

Enjoy the island!

Posted by Mr Minton at 9/04/2006 10:29:00 PM | Permalink | Comments | links to this post

How do you make a map of a river?  The same way you create a map of an island, carefully and with precision.  I have made river maps before and they are challenging. Riverine shorelines are more dynamic then island shorelines.  They have these swampy shores that are half river and half shore.  Where does the river end and the shoreline begin?   Rapids offer a different challenge.  Are you mapping rapids formed by below water features or above water features?  How many of the above water features should you digitize?  And riverine islands are most often half river and half shore continuing the challenge of river mapping.

My real objective was to determine a reasonable length of river that I might be able to digitize in a typical work day.  It turns out that this 150-kilometer stretch of river took one work day to complete.

Now for the "How To" part.  First you must determine the resolution you will work from to create the maps at the scale your client requires.  Working from Landsat ETM+, I determined that 1:12,500 was a good resolution to work from to create 1:25,000 scale river shorelines.  For some features I work at 1:6,250.  The digitizing is a slow steady progression of vectors being placed on the shoreline image.  The order of feature digitizing is one shoreline and then the other moving in down-river direction.  Finally, the riverine islands and above water features are digitized.  The secret is to work steady and not try to do too much with the shoreline.

If the digitizing line (yellow line), which is about 5-meters thick (on-screen), covers the indentation make a straight line.  If the shoreline indentation extends beyond the digitizing line, follow the indentation.

Do you realize how poorly mapped most rivers are?  The only consistent river mapping that I am aware of at 1:25,000 scale is country topographics. Few of these are digitized and the costs are prohibitive.  The Digital Chart of the World (DCW) rivers consist of thin blue lines, not good for detailed studies.  Navteq shows rivers that are roughly approximations of the underlying rivers as depicted on Landsat. However, they aren't EVS precision.  However, rivers, such as the one in this post mapped at EVS precision are as good as the base imagery they are taken from.

Posted by Mr Minton at 9/03/2006 07:05:00 PM | Permalink | Comments | links to this post