In eutrophic waterways, aquatic plants can cause large diurnal fluctuation in DO concentration through respiratory activity and photosynthesis. Using the DO fluctuation, DORM model and diurnal curve method calculate the metabolic rates of river ecosys...
In eutrophic waterways, aquatic plants can cause large diurnal fluctuation in DO concentration through respiratory activity and photosynthesis. Using the DO fluctuation, DORM model and diurnal curve method calculate the metabolic rates of river ecosystems.
In this study Namdae River data are used to investigate the applicability of these models. The results show that the ratios of R : P are generally high in this study area, and photosynthetic rates of lower reaches are higher than those of upper reaches. The ratios of atmospheric reaeration to gross photosynthesis show that by far the major source of DO replenishment in the Namdae River is atmospheric reaeration.
The DORM model differs from existing procedures for diurnal curve method. The model uses the complete DO transport equation, including DO surface exchange, longitudinal dispersion, dependence of respiratory rates on water temperature and dissolved oxygen. As a result the DORM model is expected to be more accurate than graphical or other methods.
And with these respiratory and photosynthetic rates, nonpoint source water quality is evaluated.