鱼类产卵敏感期河流生态流速的分区分类阈值研究

Zoning and classification of ecological flow velocity thresholds required by river fish during sensitivity spawning periods

敏感生态流量目标的合理制定是生态流量管理的重难点问题。针对目前敏感生态流量目标制定中存在的计算方法繁杂、关键参数缺乏等问题,本文以鱼类产卵期为重点,提出了分区分类河流敏感期生态流速和生态流量核算方法,制定了不同区域(东北、黄淮海、西南、长江中下游和东南沿海)、不同类型(按集水面积、山区河段和平原河段等划分)河流敏感期生态流速阈值。结果显示,全部分区分类推荐流速平均值为0.66 m/s,其中山区大站平均值为0.94 m/s、山区小站平均值为0.62 m/s、平原大站平均值为0.63 m/s、平原小站平均值为0.46 m/s。基于阈值核算了全国217个鱼类产卵生境保护河段的敏感期生态流量目标,并结合部分断面湿周法结果对阈值合理性与适应性进行了验证,验证结果表明相关阈值和方法适应于不同类型、不同规模河流,可为我国现阶段河流敏感生态流量管控提供参考。

The reasonable formulation of sensitive ecological flow targets is a challenging issue in ecological flow management in China.To address the existing problems of complicated calculation methods and lack of key parameters in the establishment of sensitive ecological flow targets,this paper focuses on the fish spawning period and proposes a method for calculating ecological flow velocity and flow volume during sensitive periods in river segments categorized by region.Different threshold values for ecological flow velocity during sensitive periods are established for different regions(Northeast,Huang-Huai-Hai,Southwest,Middle and lower Yangtze River,South-East coastal areas,and Northwest regions)and different types of rivers(by catchment area,mountain reach,plain reach,etc.).The results indicate that the recommended average flow velocity for all categorized regions is 0.66 m s,with mountainous large stations averaging 0.94 m s,mountainous small stations averaging 0.62 m s,plain large stations averaging 0.63 m s,and plain small stations averaging 0.46 m s.Based on this thresholds,ecological flow targets during sensitive periods are calculated for 217 river segments designated for fish spawning habitat protection nationwide.An analysis of the rationality and adaptability of the thresholds is conducted in conjunction with results from wetted perimeter method for certain sections.The verification results demonstrate that the applicable thresholds and methodology are suitable for diverse river types and scales,thereby offering valuable insights for managing and controlling sensitive ecological flow in Chinese rivers.