Where does runoff collide?

The part of rain or snowmelt that flows across the land into streams and rivers instead of soaking into the ground. Mulvaney's 1851 On the use of self-registering rain and flood gauges gave the first formula tying rainfall to the peak flow leaving a catchment (the rational method), and Horton's 1933 The role of infiltration in the hydrologic cycle explained runoff as the rainfall left over once the soil can no longer absorb it. The referent is moving water on the land, counted as a depth or a flow rate, and it has nothing in common with a second round of an election or a closed book of insurance claims.[1][2]

Unit

A depth or volume of water leaving a catchment, or a flow rate such as cubic metres per second

Recovery means

Water returns to the system by later infiltration and slow baseflow between storms

Measured by

Gauged at a stream cross-section, or estimated from rainfall, catchment area, and a runoff coefficient

A second round of voting held between the leading candidates when no one wins an outright majority in the first round, so the winner is chosen by a majority of a narrowed field. Duverger's 1951 Les partis politiques was the classic study of how this two-round majority rule shapes the number of parties, and Bouton's 2013 A theory of strategic voting in runoff elections modelled how voters behave when a runoff is expected. The referent is a voting procedure and its effect on parties and candidates, not water crossing a field or an insurer winding down its policies.[3][4]

Unit

One electoral contest decided in two rounds, per office and election

Recovery means

Not applicable

Measured by

Studied through the vote shares across the two rounds, turnout, and the number of candidates and parties