Abstract:
Wetland hydrology is the driving force of wetland formation, "water stage-duration-frequency" (
S,
D,
F) are the characteristic indexes of wetland hydrology. Aimed to promote the development of the theories and methods for determining (
S,
D,
F) thresholds, the agreed conclusions derived from (
S,
D,
F) threshold studies were summarized, which include: The principle of determining
S threshold is "saturate to the earth's surface"; the principle of determining
D threshold is "the lag time from the onset of saturation to the formation of anaerobic condition"; and
F threshold should be≥50%. Through the analysis of these agreed conclusions, the results suggested: ① There are scientific problems in using the principle of determining
D threshold; ② The present theories and methods for determining (
S,
D,
F) threshold were built for the wetlands of "normal condition", and can not be used to determine the (
S,
D,
F) threshold of "abnormal condition". In order to get (
S,
D,
F) thresholds scientifically, new scientific theories and methods for determining (
S,
D,
F) threshold should be built, which should include: The (
S,
D,
F) threshold theories and methods for wetlands of both "normal condition" and "abnormal condition", and the theories and methods of scientific testing for (
S,
D,
F) thresholds.