Winter is Coming

I have been going to Coweeta every one or two weeks for the past two months to monitor sprinkling events on the soil model. Although I am measuring only one thing, water, being precise is actually very difficult. There are 5 high-resolution tipping buckets on the hillslope to measure samples of input and one large tipping bucket at the bottom of the model to measure outflow.

I experimented with placement of PVC collectors that are designed to capture spatial variability of the input by expanding the collection areas and positions of each input tipping bucket. Then I experimented with acrylic collectors, which are longer and smoother. Finally, I put specimen cups out along a grid on the model to measure input by hand. It is a dependable low-tech, high-resolution solution.

On the last trip of this year I shut down and winterized the model. That means disconnecting the water supply to the irrigation system, shutting off the reverse osmosis pump, and draining the water from the lines and water tank, all in case of a hard freeze, which is uncommon but possible. My instruments, e.g., soil probes and tensiometers, are sitting in the shed, ready for installation in an upcoming trip.