光纤布拉格光栅用于海水盐度监测初探

海水入侵问题已波及中国沿海的9个省份，其中海水入侵最为严重的山东、辽宁两省入侵面积超过2000 km2。在气 候变化和人类活动等作用因素的加剧影响下，海水入侵问题不可避免，因此，海水入侵的监测和防治是解决问题的关键， 具有十分重要的意义。本文针对目前海水入侵监测技术存在的问题，提出了一种可大范围实时原位监测海水盐度的光纤布 拉格光栅（FBG） 方法，并设计试验对三种FBG盐度测试方案的可行性进行了对比研究。试验结果表明：FBG技术应用于 海水盐度监测具有一定可行性；利用能量补偿技术的两点串FBG测试效果最佳，灵敏度及稳定性在三种方案中均最好。基 于FBG的海水盐度监测方法可以弥补目前常用的水化学法和物探法存在的不足，为海水入侵的监测和预防提供了一种先 进、高效的手段。

Preliminary Study on Monitoring the Salinity of Seawater with Fiber Bragg Grating

Seawater intrusion problem has spread to the nine coastal provinces of China, the invasion areas of Shandong province and Liaoning province have exceeded 2000 km2. The problem of seawater intrusion is unavoidable under the influence of climate change and human activities. Therefore, the monitoring and prevention of seawater intrusion are significant to solve the problem. In this paper, the fiber Bragg gratting (FBG) method for large-scale real-time in-situ monitoring of seawater salinity is proposed, and the feasibility of three FBG salinity test plans is compared and studied by the designed experiment. The experimental results show that FBG technology is feasible for seawater salinity monitoring; The FBG test with energy compensation technique is the best, and its sensitivity and stability are the best in the three plans. The salinity monitoring method based on FBG can make up for the shortcomings of water chemistry and geophysical methods, and provide an advanced and efficient way for monitoring and preventing seawater intrusion.