A Wind-Driven Gas Exchange Rate Model

摘要

The dissolved oxygen is a major factor influencing the water quality of a water body. The gas exchange rate determines the speed that the low soluble gases, including dissolved oxygen, transfer from atmosphere to water. The wind-driven gas exchange rate model is important for the water quality modeling in water bodies such as lakes and estuaries when the wind is the predominant factor. Although empirical formulae have been developed for wind-driven gas exchange rate, they cannot explain the mechanisms of wind-driven gas exchange rate. The empirical formulae are normally limited in their applicability due to the specific experimental conditions under which they were established. This study is to develop a mechanistic wind-driven gas exchange rate model for the general application ranges. This mechanistic wind-driven gas exchange rate model correlates the gas exchange rate with the hydrodynamic parameters based on the surface renewal mechanism and the two-film transfer mechanism. The gas exchange rate values predicted with this model show reasonable agreements with the experimental data in the wind-driven gas exchange systems. This model can be applied for water bodies with wind blowing over the water surface as the predominant factor influencing the exchange rate of the low soluble gases.