Groundwater, soil, and trees work together to dampen extreme water cycle fluctuations

The oscillations of water at the atmosphere level are faster than the oscillations at the land level, which are faster than the oscillations at the aquifer level. That’s because rain gets slowed when it hits land. And surface water gets slowed when it becomes groundwater. In the atmosphere, water vapor can get blown around quickly. On the surface of the earth, soil can hold onto water for weeks. In aquifers, water can sit for centuries.

Groundwater can feed surface water if tree roots bring it up. Groundwater can thus dampen the fluctutation of surface water. Rivers that would otherwise run only seasonally, can run year round if the groundwater levels are high enough. The river level thus fluctuates less. Soil moisture fluctuate less into dry season if groundwater is being brought up by tree roots and mycelia. If trees transpire surface water during the dry season they then create more atmospheric water, which means the atmospheric water does not fluctuate so much from season to season. Thus groundwater dampens surface water fluctuations which dampens atmospheric water fluctuations.

The slow water movement is about building the soil sponge, and using earthworks and forests to slow the water. The ‘Slow it, sink it, spread it’ slogan that Brock Dolman coined explains the ethos of this movement. When the slogan is followed, more water will move from the surface to the aquifer level. Large storms, and atmospheric river events will replenish aquifers if the landscape is able to slow the water enough. In so doing flooding which may have occurred during these large storms is diminished.

If we have trees to lift the water, then the groundwater can rise into the air, and then get blown downwind across the continent. Moisture can thus hop across the continent.

I’ve added to Brock Dolman’s slogan to create an extended slogan: ‘Slow it, sink it, spread it, lift it, hop it’. The lift refers to trees bringing up the water through the roots and also to the act of transpiring it. (Its important that we sink enough, so that we have enough to lift. If we don’t then we dry out aquifers.) The hop refers to moisture hopping (otherwise known as the small water cycle).

The groundwater, the soil, and the trees work together to better couple the water between the three levels of aquifer, surface, and atmosphere. In so doing they dampen extreme water cycle fluctuations.