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于2013年4月及6月,针对DIDSON的特点设计了携带声呐的船舶走航式及定点式两种方法,对葛洲坝下游近坝区水域(大江、三江至下游镇江阁处江段)进行水声学调查,观察鱼类资源的时空分布特点。观测数据经去噪处理,获得鱼类资源结果。结果表明:葛洲坝下游近坝区鱼类资源分布呈明显的空间差异,大江水域鱼类密度显著高于三江水域,且近坝区高于下游江段,最大值为69.24ind./1 000m3,位于大江电站下游约1km处,最小值为1.53ind./1 000m3,位于宜化大楼江段。鱼类资源在时间上没有显著的统计学差异,6月份鱼类活动昼夜差别比4月份更明显,主要集中在上层水域,傍晚至凌晨鱼类活动较少。进一步分析发现,船闸的运行方式、水体中食物可获取程度、各鱼类种群生活习性差异等,均对鱼类资源时空分布产生影响。此外,开展适逢葛洲坝禁渔期,禁渔措施维持了近坝区水域春、夏季鱼类资源量的稳定性,是保护鱼类资源的有效而直接的方法。
In April and June 2013, two approaches to ship navigation and fixed-point carrying sonar were designed according to the characteristics of DIDSON. Water was applied to the waters near the dam (from Dajiang and Sanjiang to the downstream of Zhenjiang Pavilion at the downstream of Gezhouba) Acoustic survey to observe the spatial and temporal distribution of fish resources characteristics. The observations are denoised to obtain fish resource results. The results showed that the spatial distribution of fish resources in the dam area near the lower reaches of Gezhouba was significantly different. The fish density in the big river was significantly higher than that in the Sanjiang area, and the near dam area was higher than the downstream river with a maximum of 69.24ind./1 000m3 About 1km downstream of the Dajiang Power Station, the minimum value is 1.53ind./1000m3, which is located in the river section of Yihua Building. There was no significant statistical difference in fish resources. The difference between day and night in fish activities in June was more obvious than in April, mainly in the upper waters, with less fish in the early evening and early morning. Further analysis found that the operation mode of the lock, the degree of food accessibility in the water body and the differences in the living habits of different fish species all have an impact on the spatial and temporal distribution of fish resources. In addition, during the closure period of the Gezhouba Dam, the closed fishing measures maintained the stability of fish resources in spring and summer near the dam area, which was an effective and direct method to protect fish resources.