Mikroplastik merupakan partikel plastik berukuran mikro (<5 mm). Mikroplastik membutuhkan waktu yang lama untuk terdegradasi sehingga sulit dihilangkan di perairan.Tujuan dari penelitian ini adalah menganalisis perbandingan  kepadatan dan jenis mikroplastik di perairan muara Banjir Kanal Barat dan Banjir Kanal Timur, Semarang. Pengambilan sampel air laut dilaksanakan pada bulan April dan Mei 2021 di 3 titik yang berbeda di setiap stasiun dengan  menggunakan plankton net. Pengamatan mikroplastik dilakukan di Laboratorium Fakultas Perikanan dan Ilmu Kelautan, Universiats Diponegoro. Hasil penelitian menemukan bentuk mikroplastik dalam sampel air laut adalah fiber, fragment, film, dan pellets. Warna mikroplastik yang ditemukan adalah hitam, biru, merah, cokelat, kuning, tranparant, dan hijau. Hasil Uji FT-IR jenis polimer mikroplastik yang ditemukan adalah Nylon, Nitrile, PVC,  PET, dan  PC. Kepadatan mikroplastik paling tinggi terdapat di perairan muara Banjir Kanal Timur sebesar 179,09 Partikel/m3 dengan kepadatan total bentuk fiber (37,80 partikel/m3), bentuk fragment (34,14 Partikel/m3), bentuk film (18,29 Partikel/m3), dan bentuk pellets (85,85 Partikel/m3). Kepadatan  mikroplastik di perairan muara Banjir Kanal Barat yaitu sebesar 79,51 Partikel/m3 dengan kepadatan total bentuk fiber (20,73 partikel/ m3), bentuk fragment  (28,09 Partikel/m3), bentuk film (5,36 Partikel/m3), dan bentuk pellets (25,12 Partikel/m3). Hasil independent t – test menunjukkan p(0,169) > 0,05 bahwa kepadatan mikroplastik di perairan muara Banjir Kanal Barat dan Banjir Kanal Timur tidak berbeda nyataMicroplastics are micro-sized plastic particles (<5 mm). Microplastics take a long time to degrade making them difficult to remove in the water. The purpose of this study is to analyze the comparison of abundance and type of microplastics in the estuary of the Banjir Kanal Barat and Banjir Kanal Timur, Semarang. Sampling was conducted in April and May 2021 at 3 different points at each station using net plankton. Microplastic observations were conducted in the Laboratory of the Faculty of Fisheries and Marine Sciences, Universiats Diponegoro. The results found the types of microplastics in seawater samples are fiber, fragments, film, and pellets. The microplastic colors found are black, blue, red, brown, yellow, tranparant, and green. FT-IR test results of microplastic polymers found are Nylon, Nitrile, PVC, PET, and PC. The highest microplastic abundance is found in the estuary of the Banjir Kanal Timur of 179.09 Particles/m3 with a total abundance of fiber types (37.80 particles/m3), fragment types (34.14 Particles/m3), film types (18.29 Particles/m3), and pellets types (85.85 Particles/m3). The abundance of microplastics in the estuary of the Banjir Kanal Barat is 79.51 Particles /m3 with a total abundance of fiber types (20.73 particles / m3), fragment types (28.09 Particles / m3), film types (5.36 Particles / m3), and pellets types (25.12 Particles / m3). The results of independent t-test show p(0,169) > 0.05 that the abundance of microplastics in the estuary of the Banjir Kanal Barat and Banjir Kanal Timur is no different

利用台湾海峡中部2号大浮标2017年全年的实测波浪资料, 对海浪的基本波要素及其与风的相关性、波谱特性进行统计分析, 得出了重要特征波参数之间的回归关系和适合台湾海峡中部的海浪谱形式。研究结果显示: 1) 台湾海峡中部的常浪向是NE向, 强浪向是NNE向, 月均有效波高的变化范围为0.87~2.98m, 7月波高最小, 12月波高最大, 波周期与波高有着相似的月际变化趋势; 2) 主要波浪类型是以风浪为主的混合浪, 谱型上以单峰为主, 波高与风速整体上呈正相关关系, 大浪主要由台风和强劲的东北季风引起; 3) 波浪的平均周期与大部分特征波周期之间具有良好的线性相关性, NNE、NE方向的波浪有效波高和有效波周期线性相关性较强; 4) 相比于Jonswap谱, 规范谱一是更符合本区域的海浪谱模式, 给出了基于有效波高和谱峰周期拟合的规范谱一形式。这些研究成果可为海洋工程设计和波浪数值模拟提供参考。

Using the measured wave data in 2017 in the central Taiwan Strait, we analyze the basic features of wave, including spectral features, and their relationships with wind. The regression relationship among important characteristic wave parameters and the appropriate wave spectrum form are also investigated. The results are as follows. 1) The most frequently occurring wave direction is NE, and the strong wave direction is NNE. The monthly average significant wave height varies from 0.87 to 2.98 m. The wave height is the smallest in July and the highest in December. The wave period has similar inter-month change to wave height. 2) Mixed waves dominated by wind wave and single-peaked spectra make up the majority. The wave height is positively correlated with the wind speed as a whole. Strong wave is mainly generated by typhoons and strong northeast monsoon. 3) There are good linear correlations between mean wave period and most characteristic period parameters. The significant wave height and its corresponding wave period are strongly linearly related in the directions of NNE and NE. 4) Compared with the Jonswap spectrum, the Code spectrum 1 is more reasonable for the fitting of sea wave spectrum in this area. A spectrum in the form of Code spectrum 1 is given, which is fitted by significant wave height and spectral peak period. These results can provide references for ocean engineering design and numerical simulation of wave.

利用海南东方近岸海域2014年至2015年间一整年的海浪观测资料, 分析了海浪的时间变化特征。观测时间段内, 有效波高最大值为4.03m, 平均值0.79m; 平均周期最大值为6.32s, 平均值为3.58s。该海域冬季波高较大, 秋季最小, 常浪向为SSW方向, 强浪向为WSW向。基于该长期观测数据, 文章亦研究了平均周期、有效波高之间的关系, 同时还确立了该海域波高与平均持续时间之间的关系。最后讨论了观测时间段内波浪能流密度的变化特征, 发现一年中能流密度大于2kW·m^-1的频率为26%, 且从全年的计算结果来看, 观测位置处12月的波浪能较适宜开发, 但总体波浪能资源不够丰富。文章对于认识海南东方近岸海域波浪特征以及工程设计都具有重要的意义。

Temporal variation characteristics of ocean waves in the coastal area of Dongfang, Hainan are analyzed based on observations of ocean waves for a whole year from Aug 1, 2014 to Jul 31, 2015. During the observation period, the maximum height of the significant wave height was 4.03m, the average was 0.79m; the maximum value of the mean period was 6.32s, and the average was 3.58 seconds. In this sea area, the wave height was higher in winter, with minimum in autumn. The normal wave direction was SSW, and the strong wave direction was WSW. Based on the one-year observation data, the relation between the mean period and significant wave height was studied, and the relation between the significant wave height and its mean duration was also established. Finally, the variation characteristics of wave energy density in the observation period were discussed. We found that the frequency of wave energy density above 2kW·m^-1 in one year was 26%, and the wave energy at the observation location increased faster in December, but the total wave energy resources were not rich enough. The results obtained in this study are of great significance for understanding the wave characteristics and engineering design of the coastal area of Dongfang, Hainan.

以2000年为例,采用SWAN波浪数值模型对浙江近海海域的波浪进行了全年模拟计算,并计算获得年、月平均波功率密度分布。研究表明,浙江近岸海域年平均波功率密度约为2~6 kW·m^-1,往外海逐渐增大;同时季节变化明显,秋、冬季节波功率密度较大,春、夏季节较小。另外,通过对浙北、浙中和浙南3个近海海区的波浪出现频率和波功率密度随波高和周期变化的分析可知,浙北海域波功率密度比较高的波高及周期范围和波浪出现频率较高范围较为接近,而其对应平均波功率密度相对较低;浙南海域波功率密度比较高的范围所对应的平均波功率密度较高,而与波浪出现频率较高的范围则略有差异;浙中海域居两者之间。总体而言,浙江近海波浪能资源丰富,且全年中可开发与利用的波浪能出现频率较高。

Taking the year of 2000 as an example, the ocean waves in the sea adjacent to Zhejiang were simulated using SWAN model, and the wave power was calculated. Firstly, average annual and monthly wave power distributions were analyzed. The results show that the wave power is about 2~6 kW·m^-1 in the sea adjacent to Zhejiang,and increases seaward. Due to the effect of monsoon its seasonal variation is obvious far from the coast while it is not so obvious near the coast. Secondly, through analysis of wave joint distribution of wave height and period which corresponds respectively to wave occurrence frequency and wave power, we compare the wave power joint distribution of wave height and period in the sea area of northern,middle and southern Zhejiang. A parameter of ‘wave power ratio’ was introduced, which represents the proportion of cumulated wave power during one year within a range of wave height and period. Generally, the wave height and period range of big‘ wave power ratio’ and high wave occurrence frequency is very close but not completely the same. The range of big ‘wave power ratio’ and high wave occurrence frequency are relatively close in the sea area of northern Zhejiang,but the corresponding mean wave power is comparatively low, while the corresponding mean wave power of the rang of big ‘wave power ratio’ in the sea area of southern Zhejiang is high, but a little bit different from the range of high wave occurrence frequency. The situation in the sea area of middle Zhejiang is in between that off northern and southern Zhejiang. In general,there are abundant wave energy resources off Zhejiang, and the yearly wave occurrence frequency of exploitable wave energy is quite high.