Badwater's True Lowest Point (2013)

[GowerGulch42]

There's another thread discussing using lidar (light detection and ranging) to determine more accurate elevations for high mountain peaks. Someone also mentioned that application being used to find the true low point of Badwater Basin, so I did.

Here's how.

There is no high-resolution lidar data for Badwater Basin. There is some elsewhere in Death Valley, along the Furnace Creek Fault and the Panamint-Saline Valley Faults, but none of those cover the salt flats out from the parking lot. So I got the next-best thing (or rather, the only thing). The highest-resolution elevation model for Badwater Basin is a 2013 1/3 arc-second radar map. This is made by satellites, so it's much lower resolution than can be gotten from an aircraft. Since Badwater Basin is a low-relief surface, this is OK since the lowest point is likely to be a flat area rather than a single point. The ground resolution of 1/3 arc-second is 10 meters, a little over 32 feet. 

I downloaded this digital elevation model (DEM) from The National Map, the spatial data repository managed by the USGS. It covers most of the basin between Salt Creek and Foundry Canyon, so that's all the important low area. I first clipped out everything above sea level - this reduces the range of elevations from well over 6,000 feet to only 282 feet. This makes the next analysis much easier and faster. 

I generated 5 ft contours for the whole salt pan below sea level, and then created more 1 ft contours for the salt flat itself below -279 feet, the elevation of the boardwalk. I didn't save a screenshot of what that map looked like, so I'll have to redo it and post later. I found that the lowest 2 feet, ranging -280 to -282, covers a huge area of the playa. The old coordinates at [ 36.241921°, -116.825441° ] fall squarely at -281 feet. The contours highlighted an area about 1.4 miles to the south of all the land below -282. Here they are in relation to one another:



This lowest - low area is about 0.4 acres, about 220 feet by 94 feet, in size. It is also much closer to the boardwalk than the previous point. It is a mere 1.9 miles straight out from the trodden area! The lowest point on the DEM is located within this area at [  36.233001°, -116.802648° ].  



The playa is, however, a dynamic place. This true low point may move around year-to-year, or even season-to-season. It's nearly impossible to say how far it might move without newer or more frequent data of this type, and I'll jump right on it when it gets created! So I present to you… the 2013 True Lowest Point per Satellite Radar Mapping of Badwater Basin!