1985~1986年长江口生态系统能流网络分析

中国近海基于北斗卫星导航系统的渔船监控系统(vessel monitoring system，VMS)，在渔船管理和应急救援中发挥了重要作用，同时北斗船位数据还包含位置、时间、航速、航行等信息，可进一步用于渔船航次信息挖掘与分析。文章首先把海陆边界划分成多个0.1°×0.1°的港口格网，然后根据格网与渔船轨迹相交关系，提取海南省2016年的全部航次。
海南省渔船以小型为主，航次时间1~5 d占全部航次数的71.8%，各作业类型航次时间平均都在5 d左右；受休渔期、节假日、台风等天气影响，航次频数各月变化有3个峰值和3个谷值；儋州、三亚、文昌3个海南省返回港的航次占航次总数的62.9%，海南省出港非海南省返港的航次主要集中在北海市、阳江市、惠州市等港口。文章基于北斗船位数据的航次提取方法具有普适性，可以直接应用到安装有北斗终端的近海其他省市的渔船。

Analysis of cost effectiveness on fishing trip cost by adopting photovoltaic power generation system in a small fishing vessel

China's offshore fishing vessel monitoring system which is based on the Beidou satellite navigation system (contains position, time, speed, navigation and other information) plays an important role in the management and rescue of fishing vessels. In this paper, the sea and land boundary was divided into a number of 0.1°×0.1° port grids. According to the relationship between the grids and the tracks of fishing vessel, we have determined the total number of voyages of fishing vessel in Hainan Province in 2016. Hainan fishing vessels are mainly small ones and 1–5 day voyages accounted for 71.
8% of the total number of voyages (average voyage time of each fishing type is about 5 d). Since moratorium, holidays, typhoons and other factors affect the number of voyages, the frequency of voyage in each month had three peaks and three valleys. The three Hainan return ports in Danzhou, Sanya and Wenchang accounted for 62.9% of the total number of voyages. The voyages departed from Hainan but not returned to Hainan are mainly in Beihai, Yangjiang, Huizhou and other ports. The extraction method of number of fishing vessel voyages based on Beidou position data is universal, which can be directly applied to the fishing vessels installing Beidou terminal in other provinces near the offshore.