The Spatiotemporal Variation of Water Quality in Incheon Coastal Area

Hourly variation of water quality in the Hwangsan-do sea area was high. The highest and lowest concentrations of salinity, DO, pH, Temp, TN, TP and COD were shown two times in the 24 hours. The correlation coefficient of salinity and COD was -0.83, salinity and TN -0.73, salinity and TP -0.75. When the salinity was low, COD, TN and TP were high. Therefore organic matter and nutrient are coming into the Incheon coast sea from Han-river fresh water during ebb tide. Salinity was high at flood tide but low at ebb tide in Shiwha-ho sea area. COD was not specifically varied by the change of salinity, but TN and TP was high at ebb tide and low at flood tide contrary to salinity in Shiwha-ho sea area. COD, TN, TP and salinity were not particularly varied by the change of tidal movement in Palmi-do sea area, because it is relatively located far from the coast. Sequential measurement which can cover the variation of water quality is recommended to assure the representative water quality in estuary affected by the tidal movement.