Sunday, July 12, 2015

New and Updated Lake Maps

The lake wasn't quite there yet Tuesday with about 8" to go and by Thursday about 6" to go but had stopped going up. Rains Saturday along with rains on the way for Sunday and Monday should do the trick. Unfortunately it looks like only one day this week without rain so even if the lake does top off I likely won't get to start depth mapping for another week.

I redid all the maps mostly changing everything to WGS84 Web Mercator so all finished maps will be in that format which is the same format that Google Maps, Bing Maps, Open Street Map and other web based maps use. That means layers can be overlayed on a Google Earth Map.

The maps can be downloaded here. Links to mapping programs on the right ------->

README for maps:

Base Layers NAD83 UTM folder - contains the layers clipped from county sized layers in their original NAD83 UTM CRS (Coordinate Reference System) from the Iowa Natural Resources Geographic Information Systems Library. Also contains 2ft contour Shape file as well as the mask used to clip them from a county-wide Shape file.

Base Layers WGS84 WM folder - This contains the NAD83 layers 'warped' (re-projected) to WGS84 datum and a Web Mercator projection EPSG 3857 (Also known as Spherical Mercator and Pseudo Mercator) These maps have all been processed through GIMP For better color balance and sharpness as well as editing of the LIDAR layer to clean up the old creek and road under the dam as well as the parking lot areas. It's also had the brightness and contrast darkened so as to show up better and not fade out the color as badly when overlayed with a transparent photo or topo map. The base layers all have a .gtf file which is the GeoTIFF header information pulled using GeoTFF Tools. Programs like GIMP and other graphics/photo editing program strip out the Geo information in the header so you have to use GeoTIFF Tools to reinsert the Geo information that calibrates the maps. These are text files and can be viewed in notepad or other programs

Most GPSes use the WGS84 Web Mercator and although many programs such as OziExplorer, and Fugawi can handle re-projection 'on the fly' Google maps, Open Street Map, Bing and other online maps are in WGS84 Web Mercator format and both of my depth mapping packages need WGS84 WM background maps. I recommend the WGS84 WM layers be used for any editing or custom maps you may want to make or if you want to use one as an overlay in Google Earth

Finished Maps folder - All maps in this folder will be in WGS84 WM format. This will hold a variety of finished background and and later depth maps in several formats

Finished Maps sub-folder - Orux Map Tiles -  contains zipped folder tiled maps for OruxMaps (Android). To use just download the free OruxMaps app from the Google Play store and unzip in the default directory. Usable as just a map with about any Android device and those with built-in GPS can make tracks and waypoints to mark and find fishing spots. 

Tuesday, July 7, 2015

Well That Should Certainly Do It

Our 1/2" of predicted rain turned into over 3.5" with over 3" in less than 4 hours here in east Davenport. Although they didn't get as much north of town they still got at least 2" in the watershed feeding the lake So I suspect it will be topped off by morning. I would think it would also create some current in the main lake and sweep out some of the excess duck work. Unfortunately the rains start up again Wednesday afternoon with rain everyday through the weekend  I suspect we'll blow away the 4.1" average rain for July by the end of the week ....

Sunday, July 5, 2015

Getting Closer But Still Not Quite There

I went out there Friday the 3rd with my boat for the first time just to check things out and do a little test run for the maps and mapping software. That all went well, the maps and my GPS look to be in perfect calibration. Only problem I had was the wireless mouse/keyboard hanging up on me twice after starting the motor (out of maybe a dozen starts) despite being on separate batteries. Lots of trees and brush both above and just below the surface but I only 'bumped a stump' once going up one of the 'fingers' on the west end of the lake. Lots of duck work covering many areas so you can't see below the surface but even though it looks tough it's a lot easier to navigate most of it safely than one of the back water sloughs on the Mississippi.because of the depth. Water quality and clarity is off the charts, I filled my livewell and it looked like drinking water.

I went up to the dam spillway and measured from the top of the concrete and the lake surface and got 14"  so there should be only 14-15" to go. A few pictures of the spillway structure

After I pulled the boat out I drove up to the west end boat ramp and took some pictures looking back at the causeway and the concrete culvert small boat passageway. Then I went up and chatted with the guy fishing there and I asked how deep it was in there and he said about 18".  When the lake is full the water is supposed to be between 30" and 36" deep in the passage and 18" + 14" = 32" so 14-15" to go looks like a valid estimate. Some rains are coming Monday night but I don't think they'll quite be enough to top the lake off. Shouldn't take more than a couple of average rains to fill it up to the top, maybe in a couple of more weeks

Thursday, June 25, 2015

Pictures of New Maps

I forgot to include these in the last post. The first is zoomed out to show the entire lake and the other is at full 1 pixel per meter resolution. You can zoom in even more and they still look pretty good.

Wednesday, June 24, 2015

Less Than 3 ft To Go !

As of last Tuesday I estimated 3ft to go and this was confirmed by the DNR on Wednesday. Although last night's big storms that hit the area split and missed us they are forecasting 1-2 inches for tomorrow night and that should top it off.

I also have new map layers and some basic finished maps available on my GitHub site as well as a tiled map for Android devices using the free OruxMaps app available at the Google Play Store. This is a 1 pixel per meter map that can be easily sized to 200% or larger and still looks good. With this map and an Android device with GPS you are all set to navigate the lake and make your own waypoints and tracks for fishing. If you like the map and the Orux app I strongly suggest purchasing the Donate version for just $2.62 ... a real bargain for the average fisherman that can't afford a $500-$1000 chartplotter. These maps will only get better as I add a layer showing the locations of structure and the depth isolines made from actual measurements at the lake.

Here's a few pictures from last Tuesday June 16 after the last hard rain

Tuesday, June 16, 2015

New Background Maps Just About Done

Since the last photos I took I have gotten 5.55" of rain at my location. Although it's been spotty the lake's watershed should have gotten about the same give or take an inch. We are getting a break in the rain today so later I'm going out to check and I expect it to be close to if not fully filled. So instead of early July I should be able to start taking actual depth measurements early next week weather permitting.

So now I'm am going to have to hustle up on finishing my map layers but that is mainly the projected depth layer which I am just about done with, the shoreline (0ft) definition layer and data for the depth mapping programs and the layer with all the natural and man made structure. Only the shoreline layer is necessary for me to start and it is derived from the projected depth layer and should go fairly quickly.

Here are some examples of the new map layers. First up the LIDAR base

Then I added the 2014 photo layer on top with 25% transparency

Here it is with the full 2ft contour overlay which was derived from the LIDAR layer (Not by me, IA state employees)

And this one shows it with the edited contour file for lake only

Here is a zoomed in photo. You can see where they changed some things for the dam and boat ramp since the LIDAR data was taken (2008-2010)

Here is a succession of maps off the lower 2 miles of the lake taken in 2009, 2011, 2013, and 2014 showing the changes made.

That's it for now. I'll post the photos I take today and give a report on lake level later in the week.