- What does 0% mean in this chart?
- Why does it visually appear to water before hitting allowed depletion?
- I may be overlooking something stupidly obvious and hopefully someone corrects me.
Longer dorkier version...
In the moisture level charts there is the orange Allowed Depletion line going across the X-Axis of Time. Yet... I'm not sure what it is supposed to represent.
Take this chart for example.
If you go into the more detail area it tells me the zone is 33% on June 2nd. The zone is configured for 50% allowed depletion. Is where the black meets the white above 2nd supposed to represent 0%, or is it the orange line above Allowed Depletion supposed to be 0%?
If the zone is 17% under Allowed Depletion on June 2nd shouldn't the orange line be above the blue data point for the 2nd if the line were to represent 50% as the configured allowed depletion amount?
Overlaying a ruler and grind lines we can see...
- Field Capacity is at pixel row ~295
- Allowed Depletion down at pixel row ~840
- Black shaded area ends at pixel row ~895
From 895 (end of black shaded area) to 295 (field capacity) we have 600 rows of resolution.
33% of the way from the end of the black shaded area to field capacity would be pixel row 695.
50% of the way from the end of the black shaded area to field capacity would be pixel row 595.
Neither value really aligns with the blue dot's location for June 2nd which appears closer to 650-660.
However, from 840 (orange line) to 295 (field capacity) we have 545 lines of resolution.
33% of the way from the orange line to field capacity would be pixel row 658.
50% of the way from the orange line to field capacity would be pixel row 567.
658 is spot on for where the blue dot is represented. That seems to indicate the orange line is 0% moisture.
I guess that begs a further question. Does 0% represent zero moisture in the ground, or does it represent we have hit the floor of the configured allowed depletion value? In other words we can't go down more because we've arrived at the configured 50% allowed depletion. If the moisture level were 5% we'd actually be +5% from the configured allowed depletion rate, 55% in this instance.
I hope that made some ounce of sense.