三沙湾海上水产养殖面积遥感监测与评价

针对三沙湾海域的海上养殖区域不断扩张问题，监测海水养殖面积在海洋渔业管理中发挥着重要作用，也为海水养殖业的发展强度评估提供了有效的手段。在此基础上，本文利用不同期的Landsat TM/OLI遥感影像，通过支持向量机分类法提取和统计2003、2005、2008、2011、2013、2014和2016年三沙湾海域的海水养殖面积，并使用不同的面积扩张指标来评估研究区海水养殖的扩张强度。结果表明:（1）2003-2016年间，三沙湾海域的网箱和藻类养殖区面积扩张迅速，扩张速度分别为1.7 km2/a和9.3 km2/a；（2）2016年三沙湾海上养殖总面积达160 km2，超过三沙湾海域计划海水养殖量的21.2%；（3）2003-2016年间，网箱、藻类养殖区面积不同时期的扩张强度差异较大，且网箱养殖区范围由大陆、岛屿沿岸向深水区域发展，而藻类养殖区扩张范围几乎覆盖整个海域。

Detection of marine aquaculture in Sansha bay by remote sensing

In view of the continuous expansion of marine aquaculture in Sansha bay, the monitoring of marine aquaculture plays an important role in the management of marine fisheries and also provides a valid method to evaluate the expansion intensity of the mariculture.Based on Landsat TM/OLI remote sensing images from different periods, the mariculture area of Sansha bay in 2003, 2005, 2008, 2011, 2013, 2014, 2016 were extracted and counted in this study by using the support vector machine classification method, and the the expansion intensity of mariculture in the study area were evaluated through different expansion indicators.The results showed that:(1) during the period from 2003 to 2016, the area of cage and algae culture in Sansha bay expanded rapidly, the rates of expansion were 1.7 km2/a and 9.3 km2/a, respectively; (2) In 2016, the total area of marine aquaculture in Sansha bay reached 160 km2 in 2016, exceeding 21.2% of the planned mariculture in Sansha bay; (3) Between 2003 and 2016, the expansion intensity of cage and algae culture varied greatly in different periods.The scope of cage culture developed from the mainland and the coastal of islands to the deep sea, the expansion scope of algae culture covers almost the entire sea.