Nevada Geo-Flood Hazard Map in kml

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Two sweet snippets of a new 15mb kml file that shows the distribution of piedmont and playa flood hazards in Ivanpah Valley, Nevada (just south of Vegas) as inferred from geomorphology. I think that the information content of these types of derivative characterizations of hazards is optimized in Google Earth (or similar virtual globe application). In this case, some arguably arcane geological characteristics are boiled down to a straightforward relative hazard scheme running from cool colors (low hazard) to warm colors (high hazard). The closeup is dominated by the 'Barbie' fan (almost too perfect in shape). It straddles the border of NV and CA. Note how the trunk stream just bisects the Lucy Gray Range...Note that the playa at lower left is the proposed site of a major airport. Yes. That is what I said...Airport.

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The other snip is a sky view of the entirety of the map area with Las Vegas just out of the frame at the top. Just look at that playa (Roach Lake...yes...that is right...Roach Lake). Nice and flat. Just begging for an airport. Such ideas are far from outrageous in Nevada. Go check out area 51 sometime.

Using the transparency slider in GE allows for the user to become familiar with the distinctive surface characteristics of Quaternary desert piedmont deposits (mainly alluvial fan deposits) that inform the hazard interpretation. The high-res imagery available for this area really helps in this regard and completely trumps the overall value of a flat, paper, colored map.
 
House, P.K., 2007, Assessment of piedmont and playa flood hazards in the Ivanpah Valley area, Clark County, Nevada. Nevada Bureau of Mines and Geology Map 158, 1:50,000.
 
House, P.K., Ramelli, A.R., and Buck, B.J., 2005, Surficial geologic map of the Ivanpah Valley area, Clark County, Nevada. Nevada Bureau of Mines and Geology Map 156, 1:50,000.
 
Online report coming soon...seriously.

 

 

Contour Exploitation...Reno / Truckee River map

I spent much of the day looking at an awesome morass of detailed contours of the Truckee Meadows...which is what we call the Pleistocene 'outwash' terraces and Holocene floodplain / swamp that hosts the Reno-Sparks metro area. I started tweaking the contour color ramps and contour thickness and accidentally achieved some interesting visualizations that reveal some interesting fluvial details. Several of us at NBMG are currently revising the geologic maps in the local area. Lots of data, but lots of development.

On the advice of a colleague, I will try to convert the data to a grid and look further into the details tomorrow. Right...no LiDAR (yet).

(download)

State of the Bill Williams River map, July 12, 2010

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Oh right...that map. Yes, it is also being completed ~soon. I have finally honed-in on a way to make a geologic map out of the voodoo-spaghetti-massacre of linework. Here is a tiny example of the geologic map resulting from alluvial channel change between (only) 1953 and 1976. The legend needs some work. Just wait until I add data from 1985, 1996, 2005, and 2009. 

 
Lots to do this week. Eventually I will post the steps I took in ArcGIS to make this map over on Geologic Frothings on this site..

Minimum mappable unit blues 2

For better context, here is a 1:1,000,000 map of Clark County showing where the area in the previous post is located. The map we are trying to complete as Phase 1 of the Nevada Digital Dirt Mapping Project will be approximately 1:150,000. The tiling evident in this image is because the data are divided into the appropriate 100k sheets. For more background on the project, check out the Nevada Digital Dirt Mapping blog. Yes, there is some cross-posting going on...how else could I manage all of this stuff?
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