不同采样设计对长江口海洋环境监测效果影响的评价

长江口作为我国生物多样性最丰富的河口，海洋环境变化对水生生物种群的分布和数量波动都会有重要影响。但在目前该水域的综合监测调查中，多数监测项目缺少采样优化设计的过程。为评价不同采样设计对长江口海洋环境监测结果的影响，本研究使用普通克里金法（ordinary Kriging，OK）对不同海洋环境要素的空间分布进行插值，在此基础上比较定点采样（stationary sampling，SS）、简单随机采样（simple random sampling，SRS）和分层随机采样（stratified random sampling，StRS）3种调查站点设计对长江口中华鲟自然保护区及周边水域的水温、盐度、溶解氧及化学需氧量（COD）等要素的采样效果，结果显示:（1）各环境要素插值结果与实际调查值相近，普通克里金插值能够较好地模拟研究区域的海洋环境状况；（2）3种采样设计的平均采样效果（design effect，DE）为分层随机采样>定点采样>简单随机采样；（3）分层随机采样对水温、盐度和溶解氧的采样效果最好，而对COD的采样效果差别较小。由于长江口水域盐度要素存在明显的空间分布差异，因此，建议在今后的监测设计中，优先采用分层随机采样的方法，以同时满足多数要素的监测需要。

Evaluation of the effect of different sampling designs on marine environmental monitoring in the Yangtze River Estuary

As the estuary with the richest biodiversity in China, the marine environment of the Yangtze River Estuary is very important to study the effects on distribution and abundance of aquatic living resources. However, in the current comprehensive monitoring survey of the Yangtze River Estuary, there is a lack of optimization process in the design of monitoring stations. In order to evaluate the impact of different sampling designs on the monitoring results of marine environment in the Yangtze River Estuary, the ordinary Kriging (OK) was used to interpolate the spatial distribution of different marine environmental factors. And sampling effects of stationary sampling (SS) , simple random sampling (SRS) and stratified random sampling (StRS) on water temperature, salinity, dissolved oxygen and chemical oxygen demand (COD) of the Yangtze River Estuary were compared. The results show that: 1) the environmental factors of interpolation results were similar to survey value, OK can better simulate the study area of the "true" Marine environmental conditions; 2) the average design effect (DE) of the three sampling designs was as follows: StRS>SS>SRS; 3) the sampling effect of the three sampling designs for COD has little difference, and the StRS is the best among the water temperature, DO and salinity. Salinity has obvious spatial distribution characteristics in the Yangtze River Estuary. In order to meet the monitoring needs of most factors, it is recommended to using StRS in the future comprehensive investigation and monitoring.