Earth's Systems / Biological processes / Terrestrial ecosystem functioning / Living soil system / Soil export to rivers and ocean: sediment, dissolved carbon and nutrients

Soil export to rivers and ocean: sediment, dissolved carbon and nutrients

Water leaving soil carries particles, dissolved organic carbon, nitrate and phosphorus to streams, rivers and the coast, linking the soil to the ocean carbon and nutrient cycles.

Boundary: where this process starts

Starts with: Rain beyond infiltration capacity or on saturated soil produces runoff and subsurface drainage

Boundary: where it ends

Ends after: Drainage leaches dissolved organic carbon from organic horizons; rivers carry about 0.2-0.4 Gt C per year to the ocean; Nitrate and particulate phosphorus reach the coast and drive eutrophication and hypoxia

Line thickness = size of impact (1 to 5)% on a line = chance a fork takes that branch📄 = pieces of evidence on a stepNegative effectLoops backHypothesisResource used up (arrow into the step)Resource used, not used upResource made or released (arrow out of the step)

What am I looking at? The concepts on every map

Participant: Someone or something that takes part in a process or influences it: a plant, a microbe, a river, a machine, a force. Participants are the rows of a map.
Resource: Something a step uses or uses up: water, oxygen, sunlight, a tool. Each step has an arrow down to the resources it uses.
Step: One thing that happens in a process. Every step has at least one participant and carries evidence.
Decision fork: A step where the process can go several ways. Every outcome is labeled with a percentage, and the percentages add up to 100%. It is not limited to yes or no.
Loop: A line that carries the process back to an earlier step. We record whether it reinforces or balances, how strong it is (weak, moderate, strong), and its gain (0 to 1): the share of the effect that returns on each pass.
Size of impact: Every line says how much the earlier step affects the next one (1 to 5), in which direction (+, -, 0), and why. Thicker lines mean bigger impact.
Evidence: The support for a claim: a source and what it shows. Every step, line, change and vote needs it. Click any step or line to read its evidence.
Boundary: Where a process starts and where it ends. Every process, and every subprocess, has a start and an end.
Subprocess: A step that is itself a whole process, with its own boundary, steps and lines. Click a step marked ↘ to open it. Subprocesses nest as deep as the evidence goes.
Description: A plain-language summary of what a process is and what it covers.
Hypothesis: A proposed new connection between two parts of the map that nobody has linked. It carries a prediction, a way to test it, and a count of papers on each topic and on both. It is an unverified idea until someone tests it.

Every step, with its evidence

The same information as the map, as a list you can search and share. Click a participant or resource to see everywhere it appears.

Rain beyond infiltration capacity or on saturated soil produces runoff and subsurface drainage

Rain Runoff Soil Water Soil