Study on generation of oxygen-depleted water based on stochastically-changing solar radiation intensity

To examine the generation probability of oxygen-depleted sea water in Hakata Bay, possible 20 time-series of different hourly-solar-radiation intensities were generated stochastically, and a numerical simulation on dissolved oxygen was carried out for each time series. The results of the model calibration followed the seasonal variation of observed water quality well, and generated cumulative-frequency-distribution curves of daily solar radiation agreed well with the observed ones. The simulation results indicated that the exchange of sea water would have a great influence on the DO concentration, and that the concentration could change more than 1 mg/L in a day. This prediction method seems to be an effective way to examine a solution to minimize fishery damages when DO is depleted.