形成湿地的“淹埋深-历时-频率”阈值研究进展

湿地水文是形成湿地的发生学因素,“淹埋深-历时-频率”(S, D, F)是表征湿地水文的特征指标。为了推进(S, D, F)阈值研究理论和方法的发展,总结了(S, D, F)阈值研究的一致结论:S阈值确定的原则是水饱和至地表;D阈值确定的原则是从水饱和开始到厌氧环境形成的时滞;F阈值应取≥50%。通过对这些一致结论的分析后认为:D阈值确定的原则存在着科学性问题;目前(S, D, F)阈值研究理论针对正常情况下湿地类型,不适合非正常情况下的湿地类型。为了科学地解决(S, D, F)阈值问题,必须构建新的(S, D, F)阈值确定的理论和方法,包括正常情况下和非正常情况(S, D, F)阈值确定的理论和方法以及(S, D, F)阈值科学性检验的理论和方法。

Review on the study of "water stage-duration-frequency" thresholds for forming wetlands

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.