On the basis of the “Environmental quality standard for surface water” (GB 3838-2002) in China, eight water quality indexes were measured in M River, including pH, water temperature (T), transparency (SD), dissolved oxygen (DO), chemical needs Oxygen (COD), ammonia nitrogen (NH3-N), total nitrogen (TN), total phosphorus (TP). Using the single factor index method, it is concluded that the water pollution of M River is serious and the water quality is beyond Grade V of water environment standard. Moreover some indexes of the water quality meet with the standard level, including COD, NH3-N, TN and TP. The Pearson correlation analysis is conducted between water quality indexes and phytoplankton community parameters. After phytoplankton qualitative and quantitative analysis, the phytoplankton community characteristics in Minxin River were analyzed by Dominance index (Y), Shannon-Wiener diversity index (H’), Margalef Species diversity index (d) and Pielou evenness index (J). H’ and TN was a significant positive correlation (r = 0.923, P <0.05); J and COD was a significant positive correlation (r = 0.918, P <0.05); There was a very significant negative correlation between d and water temperature (T), COD, NH3-N, TN (r =-0.881, P <0.01; r =-0.983, P <0.01; r =-0.893, P <0.01; r=-0.962, P<0.01). The result of the research indicates that T, COD, NH3-N and TN are main water quality indexes affecting phytoplankton community structure.

Environmental factors of projects in the sea area, such as tidal current characteristics and sediment transport patterns, play a decisive role in the safe operation of the harbor. Based on the observation data of tide level, tidal current, suspended sediment, and surface sediment in the Port of Shenquan, this paper focuses on the study of the characteristics of tidal current and sediment of projects in the sea area. According to the measured tide hydrograph, it can be concluded that the tide in the Port of Shenquan is irregular diurnal, and the flow of rising and falling tides is basically rectilinear. The velocity of the neap tide is higher than that of spring tide, which is mainly related to the strong winds and waves. The sand source is limited, and the sediment concentration in the water is very low. The hourly sediment concentration in each station fluctuates within a narrow range, independent of hourly velocity change. The sediment is coarse and fine, with a distribution pattern of coarse near shore, fine in deep water, coarse in East and West, and fine in the middle, and the sorting coefficient of sediment is medium to well.