Goodbye Field Season, Hello Data Analysis

A newly installed station. Image credit: AGCI, 2014.

It's been a busy summer here on the soil moisture front! Since March, two new soil monitoring sites were scouted and tested, and two new stations are now on the ground, courtesy of Pitkin County Parks and Open Space!

Both of the new stations differ slightly from the two previous stations. The existing stations, at Smuggler Mountain and Sky Mountain, are sited in relatively undisturbed natural areas. The two new stations, by contrast, are both sitting on heavily disturbed land--land that has been altered from its natural state by prolonged human activities. The Glassier site overlooks the Roaring Fork River from a riparian zone on a former ranch, and the much of the surrounding property will still be used for agricultural purposes in the future.  The Brush Creek site is in a high mountain meadow formerly used for grazing. The Brush Creek meadow is currently dominated by an invasive species of brome grass that was commonly planted by early ranchers in the Roaring Fork Valley because it is good for grazing.

Observations of site hole. Image credit: AGCI, 2014.

The property at Brush Creek is currently owned by Pitkin County Parks and Open Space and is under consideration for some form of restoration to a more native species composition. The soil monitoring station at this site, therefore, has a few extra sensors installed: there are soil moisture probes located at 2in, 8in, and 20in depths both immediately below the tower, and 50 feet away. The intention is that one location will serve as a control and the other location will serve as a variable site once restoration begins. In this way, we will be able to observe what impact a change in dominant plant species may have upon soil moisture.

Another new addition this summer is the variable of soil temperature. Soil temperature probes have been included at both of the two new stations, added to the station at Smuggled Mountain, and will be soon added to Sky Mountain site as well.

Installing a soil monitoring and weather station is a multi-step process.

The first step is site selection. Ideally, the ground should be relatively level, soil moisture of the exact site should be comparable to other soil moisture readings taken nearby, and it needs to be high enough above any local rivers or creeks that high spring flows won't flood the area.

Conducting a perc test. Image credit: AGCI, 2014.

The second step is to conduct a percolation test and collect several gallons on soil samples.

Then, the soil samples have to be dried and sifted to remove large stones or clods. The dried soil is used to calibrate the soil moisture sensors to make certain that they are functioning properly before we put them into the ground.

Once the equipment has been tested, it's time for an installation! The tower must be erected and the sensors attached or inserted into the ground. After everything is grounded, attached, and plugged in comes the tense moment of checking the online database to make sure that everything is operating properly.

After the installation is complete, that doesn't mean that site visits are done. Equipment has to be checked periodically, and site visits can help build background information about any changes that are occurring at the site in terms of plant composition.

There's still work to be done back in the office as well! The months where it is too snowy and the ground too frozen for us to do site installs or updates are "data season" back in the office. This indoor time is used to look for interesting relationships in our data and to conduct background investigations on soil moisture research being conducted elsewhere.

If you want to take a look at some of our existing data yourself, visit the iRON's Downloadable Data page.