Soil water content probes installed!

Another phase of the C-111 project was completed this week with the installation of soil water content probes in agricultural areas along the C-111 canal.

Part I: installing access tubes

The first part of the installation focused on laying down the infastructure for probe insertion. To this end, the Water Resource Engineering team, with invaluable assistance from special guests Bruce and Manny, drilled holes adjacent to the monitoring wells at six sites.

Once a hole is ready, the probe access tube is inserted and cemented in place – ideally with a thin coat of cement lining the tube and the hole’s interior.

One research site was so water-logged, the team decided to delay equipment installation until late fall, south Florida's dry season.

Probe head-unit stands were also installed and painted bright orange to protect equipment from errant heavy machinery.

Part II: inserting and launching probes

Despite unwavering companionship from feisty mosquitoes, the Water Resource Engineering team set about inserting and launching the soil water content probes.

This task involved mounting the probe head-unit (power source) to the stand and then running its wire into the access tube and connecting it to the probe.

Once powered, the probe is connected to the laptop. The current date/time is updated, and the probe data collecting launch time is set.

In all, ten probes were installed – two for each of five sites characterized by the dominant soil types in the C-111 area: Biscayne (gravelly marl), Krome (very gravelly loam), and Chekika (very gravelly loam). Every 15 minutes, probes will take soil water content readings at depths of 10, 20, 30 & 40cm.

Next stop: tensiometers!

Working hard

I just want to thank everyone for all the hard work. I know we had a very busy summer and it looks like a busy fall... but I think we will all be proud of what we have accomplished. Thanks to Mike and Tina for their continued support. I would also like to thank Isaya for his efforts. The results from the summer REU and the C111 so far are great! I think we all have something to celebrate.

Before installation? Configuration!

In preparation for the next step in the C111 project, the EnviroScan soil water content probes were calibrated this week. Next week, two of these probes will be installed at each of the six C111 project study sites (adjacent to the groundwater wells).



The configuration process


Configuring the soil water content probes consists of establishing, for each indiviual sensor:
-high and low points
-depth in the ground
-poistion on the probe
-sampling interval
The final step is naming the specific probe based on study necessity.

Below are pictured all the tools for successful configuration of these particular probes (Solo).

1. a laptop with configuration software installed

2. a configuration USB cable (allows laptop and probe to communicate)

3. a probe head unit (to power the probe)

4. a probe access tube (for air readings)

5. a water-filled container bisected by an access tube (for water readings)

Let's begin

For configuration to begin, the probe is connected to the head unit (for power) and the USB cable (to communicate with the laptop).

Once communication is achieved, the probe is then inserted into the access tube. The tube is then held in the air and each sensor is read individually to establish the high point reading.

For the low point reading, the probe is inserted into the access tube bisecting the water-filled container. When read, the sensor in question should be approximately in the center of the underwater access tube.

Following the high/low points, sensor depth is assigned and the sampling interval is established. The final step is naming the probe, synchronizing the date and time, and writing all this information to the probe.

Next stop, installation!

C-111 Project wells are now operational!*

Initiated early this month and finished last week, the monitoring wells component of the C-111 project is now online!

Drilling

Earlier this month, the entire Water Resource Engineering team (with special guests Kiah and Robert) installed 4 wells in agricultural areas along the C-111 canal. Well construction in a shallow water table, as we learned in the field, is a rather messy and labor intensive process.

The first step involved making a 4 inch borehole into which a 2 inch well casing was inserted.

The annular space around the well screen was filled with coarse sand up to a depth of 5 feet. The annular space above the coarse sand was filled with fine sand and cement, each to 7 feet.

To prevent vandalism, the top portions of the wells were protected using water proof 12 inch cast iron manholes.

Surveying

In order to obtain precise data on water table elevation, it is necessary to accurately determine the elevation of the wells above sea level.

The elevations of the wells were obtained using differential surveying based on a benchmark located at S-177 along C-111. The surveying was done using a laser level.

Leveloggers

The final step in the process involved the programming and deploying of Solinst leveloggers. The leveloggers were installed at an elevation of -2 meters below sea level (NGVD 29) and were programmed to log water table levels every 15 minutes. A barologger was installed in one of the wells in order to provide for atmospheric corrections. The leveloggers are currently in a testing period.

Soil Water Monitoring

In the coming weeks, we will install EnviroScan probes near the well locations to monitor soil water in the different soil types (i.e., Krome, Chekika and Marl) of the agricultural areas along the C-111 canal. Stay tuned!

* Isaya Kisekka contributed to this blog post.

Great team work

The last few weeks have been so busy here! I would like to thank everyone for all of their hard work and dedication. I know it has been a tough summer... but we have accomplished much!

New video online - irrigation retrofit benefits!

I recently produced a short video for Miami-Dade Extension's Urban Conservation Unit.

The video briefly discusses the shortcomings of mechanical irrigation systems and how these issues can be addressed by switching to digital irrigation systems in general, and soil water sensor systems in particular. It features a sampling of the wonderful variety of irrigation systems we encounter in our work throughout Miami-Dade County.

The video is a short slideshow with narration originally produced for use on the FYN/UCU facebook page. However, despite conforming to size and length restrictions, it was rejected by the site. This version is full-HD.

Check it out!

http://www.youtube.com/watch?v=352llkBYbWs