利用遥感技术估算南海北部表层异养细菌丰度*

常规异养细菌监测方法精度高但费时费力且不能连续观测, 而卫星遥感成本低、可以大面积同步、长时间周期观测, 可与常规方法互补。文章利用南海北部10个航次采集的表层异养细菌丰度和卫星遥感反射率, 采用统计回归的方法建立了异养细菌丰度的遥感模型, 其模型决定系数为0.81, 均方根误差为2.44×10⁸个·L^-1, 平均相对误差为21%, 具有较好表现。利用该模型估算南海北部表层异养细菌丰度, 结果显示: 从珠江河口到南海北部开阔海域, 异养细菌丰度逐渐减小。夏季河口地区平均异养细菌丰度最高, 春季最低; 近岸海域靠近珠江河口西侧的平均异养细菌丰度高于东侧; 冬季陆架地区平均异养细菌丰度最高, 夏季最低; 开阔海域的异养细菌丰度变化幅度较小。

Estimating the spatial distribution of heterotrophic bacteria abundance in the Northern South China Sea using remote sensing*

Heterotrophic bacteria play an important role in using organic matter, and their abundance indicates eutrophication of water. The conventional methods of monitoring heterotrophic bacteria abundance are highly accurate but time-consuming and laborious; measurements are discrete. Satellite remote sensing technology, characterized by low-cost, large-area synchronization, and long-term repeated observations, is complement with conventional methods. In this study, we use the abundance of heterotrophic bacteria observed during 10 cruises in the northern South China Sea and satellite remote sensing reflectance data to develop an algorithm to estimate heterotrophic bacteria abundance using statistical regression methods. The coefficient of determination of this model is 0.81, the root-mean-square error is 2.44×10⁸ cells·L^-1, and the average relative error is 21%. The established model is used for retrieving the abundance of heterotrophic bacteria on the surface of the northern South China Sea. The abundance of heterotrophic bacteria gradually decrease from the Pearl River Estuary to the open sea. The average abundance of heterotrophic bacteria in the estuary area reaches the highest in summer and the lowest in spring. The average bacterial abundance in the coastal waters near the Pearl River Estuary is higher on the west side than on the east side. Bacterial abundance in the shelf area is the highest in winter and lowest in summer; bacterial abundance in the open sea has little variation from season to season.