基于DIDSON的水库鱼类资源探测与时空分析

为获取上海市陈行水库鱼类时空分布特征，分别于2019年4月17日、8月15日和11月13日，采用双频识别声呐（Dual-frequency Identification Sonar，DIDSON）对陈行水库进行鱼类资源探测，利用ECHOVIEW水声数据处理软件构建鱼类目标分析模型，开展鱼类目标的提取与计数，分析并绘制鱼类资源密度的水平和垂直分布图，揭示水库鱼类数量和时空分布特征。结果表明：1）陈行水库中小型鱼类（其体长<0.6 m）居多，占比达80.9 %；2）春季至秋季库区鱼类体长逐渐增加，密度不断增大，数量和总重量也在增加；3）水平空间尺度上，库区鱼类个体主要集聚在水库南部，夏季分布相对集中，秋季相对分散；4）垂直空间尺度上，库区鱼类主要分布在水深2～6 m区间，占比达84.85 %，春季鱼类分布平均水深为3.89 m，夏季为4.34 m，秋季为5.12 m，库区鱼类垂直分布随季节有向底层移动趋势。本文所研究的水声探测方法和鱼类目标分析模型，为类似的鱼类资源调查分析工作提供了有益参考，探测结果为水库采取合理的鱼类资源管理提供了依据。

Detection of fish resources in reservoir and spatial and temporal analysis based on DIDSON

In order to obtain the characteristics of the temporal and spatial distribution of fish in Chenhang Reservoir,Shanghai, dual-frequency identification sonar(DIDSON)was used in fish resource on April 17th, August 15th, and November 13th, 2019. Fish target analysis model for carry out the extraction and counting of fish targets was established by ECHOVIEW underwater acoustic data processing software. To draw the horizontal and vertical distribution maps of fish resources density and further analyze the spatial and temporal distribution of fish quantity in reservoirs.The result showed:The proportion of small and medium-sized fish (length <60 cm) in Chenhang Reservoir was 80.9%; The body length, density, number and total weight of fish in the reservoir increased from spring to autumn; on the horizontal spatial scale, fish mainly gathered in the southern part of the reservoir, with relatively concentrated distribution in summer and relatively scattered in autumn; on the vertical spatial scale, fish in the reservoir area were mainly distributed in water depth between 2-6 m, proportion is 84.85%. The average depth of fish distribution was 3.89 m in spring, 4.34 m in summer, and 5.12 m in autumn,the vertical distribution of fish in the reservoir area tended to move to the bottom with the seasons. The underwater acoustic detection method and fish target analysis model studied provide useful reference for similar fish resource investigation and analysis, and the detection results provide useful assistance for fish stock management.