Blog - LEO - posts for July 2020

Gravity flow experiment

Gravity flow experiment, July 2020

Prior to the experiment the NovaLynx tipping buckets were calibrated (see this post).

The experiment was repeated separately for each hillslope, since the storage tanks cannot hold enough water for a 12h rain with the Multi 1 circuit on all 3 hillslopes simultaneously.

For each hillslope a 1h rain event was performed to calibrate the rainfall distribution followed by a 12h rain event on the following day to reach a gravity flow regime down to a depth of 50cm.

Details on the rainfall calibration: rainfall_calibration.xlsx

Schedule: 

Date Task Comment 
 CENTER 
 2020-07-06 Spanned ropes on Center hillslope to mark cup locations for rainfall calibration. Masts were raised in the morning. Kept raised until after the 12h rain event.
 Ropes spanned upslope-downslope with pre-labeled marks every 2m from 0-30m.
 2020-07-07 Placed cups on Center hillslope and removed ropes. 
 2020-07-08 Issues with Tipping Bucket counts, switched to cumulative counts to reduce impact. See also NovaLynx calibration
 2020-07-09 Rainfall calibration, Multi 1, Center hillslope.
 Collected and weighed cups after 1h of rain (08:30-09:30).
 Details in attached excel file. Air handler off during the rain.
 2020-07-10 12h rain event (8:30-20:30), Multi 1, Center hillslope.  Air handlers were turned off during rain.
Discharge collection for Center -1 (PE102 and NovaLynx) was leaking. Fixed at 19:40.
 Mast lowered after the rain event.
 EAST 
 2020-07-13 Spanned ropes on East hillslope to mark cup locations for rainfall calibration. Masts were raised in the morning. Kept raised until after the 12h rain event.  
 Ropes spanned upslope-downslope with pre-labeled marks every 2m from 0-30m.
 2020-07-14 Placed cups on East hillslope and removed ropes. 
 2020-07-15 Rainfall calibration, Multi 1, East hillslope.
 Collected and weighed cups after 1h of rain (08:30-09:30).
 Details in attached excel file. Air handler off during the rain.
 2020-07-16 12h rain event (8:30-20:30), Multi 1, East hillslope. Air handlers were turned off during rain.
 Mast lowered after the rain event. 
 WEST 
 2020-07-20 Spanned ropes on West hillslope to mark cup locations for rainfall calibration. Masts were raised in the morning. Kept raised until after the 12h rain event.  
 Ropes spanned upslope-downslope with pre-labeled marks every 2m from 0-30m.
 2020-07-21 Placed cups on West hillslope and removed ropes. 
 2020-07-22 Rainfall calibration, Multi 1, West hillslope.
 Collected and weighed cups after 1h of rain (08:30-09:30).
 Details in attached excel file. Air handler off during the rain.
 Gantry malfunction caused an interruption of several hours during the cup collection.
 2020-07-23 12h rain event (8:30-20:30), Multi 1, West hillslope. Air handlers were turned off during rain.
 Mast lowered after the rain event. 

After the experiment, cups, labeled ropes and cardboard transport boxes used for the cup collection during the rainfall calibration were stored in upper habitat office 10.

NovaLynx calibration and switch to cumulative counts

Prior to the gravity flow experiment, the NovaLynx tipping buckets were calibrated in June/July 2020.

For details of the calibration see here: novalynx_calibration_2020.xlsx

During the calibration we noticed that duplicate counts can occur.

To reduce the issue, the counting of the NovaLynx tipping buckets and PE102 flow meters was switched to cumulative counts on 2020-07-08.

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