Work or play? Field work on the Wasatch Plateau.

I am a lucky geologist this week because my coworker, Paul, is really a go-getter.  For the second year, he secured funding to do a project for Manti-La Sal National Forest managers that involves some of the most enjoyable field work imaginable.

The project involves taking inventory of "groundwater dependent ecosystems" (GDEs), a.k.a spring-fed wetlands, in an area of the Wasatch Plateau in central Utah.  We focus on coal mine lease tracts that have or likely will soon have new coal mining underneath them. The idea is to assess the status of the GDEs now so that future changes, possibly due to piracy of groundwater into the coal mines, can be assessed.

What that boils down to for me and my co-worker Janae for two weeks is hiking around the forest looking for and documenting springs. Paul and our other coworker, Rich, were doing the same thing a few miles south of us.

The Terrain

Yeah, so this part of the job is really hard.  Ha ha.  Fall colors on the Wasatch Plateau were lovely.

Me with a pack of gear, the large weir plate, and the soil core auger above a wetland.  Normally Janae and I split up carrying the gear, but for some reason I had more of the heavy stuff in this photo.

Janae above a lovely little wetland.

Sometimes the GDEs are near roads.  This one has been developed for stock watering.

Other times the GDEs are harder to get to.  The area has been hit hard by pine bark beetle, which makes for tough hiking through dead fall. The spring flow we were mapping goes right down the hill through the center of this photo under the downed trees.

There is some pretty steep terrain in places.

But other times the GDEs are just spread out there before you!

The Housing

Our lodging is a 14-foot travel trailer.  We were one of two campers at a remote Forest Service campground.

Living in style.

With the propane heater, little fridge, and gas stove, were were comfy and cozy at night.  Our coworkers working a few miles south of us were camping in tents.  Lucky us.

 

Field work is tough on clothes.  I ripped two pair of pants this week!

The Work

The FS has this really long, detailed inventory assessment they want us to do on each GDE.  There are 10 field sheets worth of notes.  We draw a map, describe a soil core, measure flow and water quality, identify plants (as best us geologists can), collect plant samples (since we are horrible at identifying plants), identify fauna if we can, and answer a bunch of questions about the health and status of the GDE.

One of our site sketch maps.  The GDE looks like a skewered amoeba in this map.

Soil Cores

Soils are a very important indicator of the health of a wetland.  Ground that is trampled by cattle gets churned up and doesn't develop the soil structure needed to support plants.

Janae collecting a core in a fen, which is an area of spongy organic soil.  This soils in this area were relatively intact.

Me collecting a core in a sedge-dominated wetland.

Me extracting soil from the auger. Janae actually did a lot more of the soil coring and describing than I did because she was way better at the soils part.

A soil core.

Flow

My favorite part is measuring the flow.  For this we have two weir plates that we temporarily install in the spring brook, if present.  We inventoried 8 GDEs this week.  Only one had flow large enough to need the larger weir plate.

Large weir plate installed 15 feet downgradient from the spring head.  The height of water flowing through the notch is proportional to the flow.  This was about 22 gallons per minute. 

Down the hill from the previous photo, we measured flow again to see if more flow was gaining on this large landslide-complex GDE.  It wasn't.

The size of my smile is proportional to the enjoyment factor for this work. :-)

All the other springs had only diffuse, unmeasurable flow, or flow that would fit though this smaller (and lighter!) weir.  The plate is supposed to be installed facing upgradient so you can read the level of the pool, but because of the geometry of this channel, I had to flip it around.

It's a dirty job!

Weir installed and quantifying flow.

Another way to measure the flow is volumetrically.  That is a fancy word using a stopwatch to time the duration it takes to fill a container of known volume.  

Measuring flow volumetrically: Directing the flow from a culvert into a 500 milliliter bottle.

 

The Geologic Setting

Of course, Janae and I both loved figuring out the geologic setting of each GDE.  Part of the area we were covering is underlain by the Cretaceous-Tertiary North Horn Formation, a unit of mudstone, claystone, sandstone, and conglomerate that is infamous for landslides. The largest GDE we inventoried (4 acres in size) was at the head of a very large landslide.  The water is instrumental in lubricating the sediments and facilitating movement on the slide.  We saw several fresh headscarps and this area:

Can the geologist in you figure out what is going on here?  Flow comes off the elevation we are standing on in a little stream channel to our right.

The area outlined in green is a back-rotated slide block; it has rotated so that the upslope area is lower than the higher ground with trees, and therefore is creating a wet area - not quite a sag pond, but if rotation continues, a pond might form.  Because there are two out flow areas and because the vegetation in the wet area, outlined in red, looked unhealthy, I suspect there has been recent movement.  If this area had been stable for a long time, the drainage would most likely evolve to one outflow and the vegetation would adjust to the amount of water available, but it looks like perhaps the veg is being drowned.  There were huge storms in late September which added water to the already unstable ground. Landslide!

Water Quality

Another assessment tool is to measure the temperature, pH, and electrical conductance of the water.

Sometimes the best pool of water is hard to get to.

Other times we captured the water in a basin.

Animals

Cattle grazing is allowed in most of the Manti-La Sal NF, and it takes a pretty severe toll on the wetlands.

This GDE was on a steep hill slope and completely trashed by trampling.

While we were there, Bessy came to drink. 

A nearby wetland was in slightly better shape, but cattle use this one heavily too.

Only in very limited places that are off limits to cattle, did we find healthy GDE.  This 20x30-foot area was "fenced" by large dead fall, which protected it from grazing.

Besides cattle, we didn't experience much animal life except we heard elk bugling, saw a few deer and squirrels, and lots of these guys...

Spiders are our friends.

Not sure what critter made this track, but we really were not surprised, since wetlands are important for the wild ones too.

We had mostly good weather this week, despite being at between 8,000 and 10,200 feet elevation.  We got a little rain and snow on the last day, but we were on our way out and managed find two springs close to the road so we had the truck to use to warm up when needed. Let's hope for similar weather next week!