The characteristics of wind waves in Lake Chaohu in 2018

Abstract

基于实测数据，利用验证良好的SWAN风浪模型开展了2018年巢湖风浪变化及分布特征研究.巢湖2018年平均有效波高和波周期分别为0.16 m和1.22 s，整体春季风浪大，秋季风浪小.月均最大值出现在4月，分别为0.22 m和1.36 s，月均最小值出现在11月，分别为0.11 m和1.06 s，变化幅度分别为最大值的52%和22%.月均值整体中巢湖最大，东巢湖次之，西巢湖最小.巢湖月最大有效波高和波周期主要出现在东巢湖或中巢湖，各值月间差异显著，最大变化幅度分别为最大值的61%和27%.不同湖区计算的月均有效波高和波周期较大值分布范围所占湖区的比例不同，中巢湖与东巢湖较大，西巢湖最小.不同月份及湖区较大有效波高出现的时间占比是不一致的，9-11月份时间占比较小，将有利于蓝藻水华的出现.;In this study, the wind-wave model SWAN was used to simulate the characteristics of variations and distributions of wind waves in Lake Chaohu for the year 2018. The model was calibrated and evaluated using observational data. Results suggest that the annual mean significant wave height and wave period of Lake Chaohu during 2018 were 0.16 m and 1.26 s, respectively. The wind wave was strong in spring and weak in autumn. The monthly mean values exhibit great variations. The largest monthly values of 0.22 m and 1.36 s were obtained in April, while these values were 0.11 m and 1.06 s in November, which were the lowest during 2018 and whose variation ranges were 52% and 22% of the maximum values, respectively. Among different lake basins, monthly mean wave height in the east basin and central basin were the highest, followed by the west basin. The highest value of monthly maximum significant wave height and wave period appeared in the east basin or the central basin. The values of monthly maximum significant wave height and wave period varied significantly during different months, whose variation ranges were 61% and 27% of the maximum values, respectively. The distribution ratio of the high values of monthly significant wave height and wave period computed by model in different lake zones were large in the east basin or central basin, but it was small in the west basin. The proportion of time when the high significant wave height appeared was different during different months in different lake zones, and it was small from September to November, which would be beneficial to the emergence of cyanobacteria blooms.