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Glacial Lake Windham

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I was fascinated by this post on Glacial Lake Windham by the Catskill Geologist and thought it would be ineresting to pull the LIDAR of the area.

Let’s learn some more this week. We would like you to drive west from Windham on Rte. 23. You may have done this before, perhaps many times. But, as always, we want you to be paying more attention to the landscape that you are passing. We, especially, want you to take heed of the flat landscapes down at the bottom of the valley. It would be easy to dismiss this as a floodplain, after all valley floors are supposed to display floodplains. But, you would be wrong; this flat landscape is the floor of an ice age lake. Lake deposits are almost always spread out as flat sheets. That’s what we see here.

These lake bottom landscapes continue at least as far west as Ashland. They speak to us of a glacial lake. It was a big one, extending at least five miles from the Windham moraine to a bit west of Ashland. Rte. 23 lies on a platform that runs parallel to the old lake. That platform also has an ice age origin. It is composed of sediments that were dropped down the northern valley wall and deposited as a lakeshore deposit called a glacial terrace. That terrace was irresistible to highway engineers when they were making Rte. 23. It lifted the highway up onto a well-drained surface.

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Little bags of dog shit 🐶 💩

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I saw another bag of dog shit walking the trail today. Seems silly to pick up your dog’s shit and then leave it in a little bag along the way.

I don’t like pets. While I’m all for raising livestock for meat, milk, eggs or even manure to fertilize the soil, I’ve always seen owning a dog or cat to be rather deprived. I can’t imagine having to scoop up and carry a bag of dog shit around town. Dogs and cats are omnivores and their poop is loaded with pathogens. If you need a friend maybe you should join a community organization or try online dating rather than subjectating a domestic animal.

Pet ownership is gross in my book. Livestock is fine in a barnyard, I have no problem tying a dog on a chain in a barn to keep away predators or a barn cat to control mice. But in the house, just yuck. Especially with my allergies. Maybe a dog is fine for hunting and duck retrieval but I can’t see being such an empty person that needs a dog for companionship.

Trains with Hazardous Materials That Derailed in 2022

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300 trains containing Hazardous Materials derailed in 2022 in America.
 
138 involved cars with hazardous materials derailing. 10 train derailments released hazardous materials.
 
2 hazardous material derailments required evacuations, 1 required more then 500 people evacuated.

 

Trains with Hazardous Materials That Derailed in 2022

Creating Digital Surface Models GeoTIFF Using National Map Downloader, LiDAR Point Clouds and PDAL 🗺

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Find LiDAR Point Clouds on the National Map Downloader: https://apps.nationalmap.gov/downloader/#/

Select Find Elevation Source Data (3DEP) – Lidar, IfSAR

Search for LiDAR Point Cloud (LPC)

Click Export all results as a TXT file and save to a directory.

Then run this Unix command on the text file to download point clouds:

cat data.txt | tr -d '\n' | xargs -d '\r' -I {} wget -c -nc '{}'

Next create a pipeline.txt for pdal with the classification (For DSM, 1 are unclassified points like buildings and treetops, while 2 are ground points, if you want a DEM, you can also make them this way too with Classification of 2:2):

{ 
    "pipeline": [
        { 
            "type": "readers.las"
        },
        {
            "type": "filters.range",
            "limits": "Classification[1:1]"
        },
        {
            "gdaldriver":"GTiff",
            "resolution": 1.0,
            "output_type": "max",
            "type":"writers.gdal"
        }
    ]
}

Next convert the point clouds into digital surface model (GeoTIFF), you can use this shell command with xargs to go over each LAS file, using the above pipeline:

ls *.laz | xargs -I {} basename {} .laz | xargs -P3 -I {} pdal pipeline pipeline.txt --readers.las.filename={}.laz --writers.gdal.filename={}.tif

The above command can be somewhat slow depending on how many LAZ point clouds you need to go through and your selected resolution. -P3 sets the number of parallel process (3) which can help speed things up a bit.

Now we have the digital surface models raster that can be used in QGIS for hillshade for 3D.

Build a virtual raster (dsm.vrt) for easy loading into QGIS rather than loading separate files.

gdalbuildvrt dsm.vrt *.tif