基于底栖动物响应特征的洮儿河生态流量目标适应性分析

Adaptability analysis of ecological flow based on response characteristics of benthos in the Taoer River

以洮儿河为研究对象,基于其底栖动物采样监测数据,构建流量因子与生物因子之间的响应关系,以评价生态流量保障成效和生态流量目标的适应性。结果表明:以当前生态流量目标(冰冻期、平水期、丰水期分别多年平均径流的5%、10%和15%)泄放后,生态流量达标率时间上逐渐提升,空间上自上游至下游递减,底栖动物多样性、生物量等指数递变趋势类似;底栖动物多样性指数与生态流量达标率相关性最显著并可据此建立线性回归关系;结合该回归关系和情景分析,发现冰冻期、平水期、丰水期目标分别为7%、14%和27%时线性拟合度最高(R^(2)=0.998),表明该目标下底栖动物多样性的维持效果最好。建议逐步提高生态流量目标,促进已受损生态系统恢复。

In order to evaluate the effectiveness of ecological flow support and the adaptability of ecological flow target,the response relationship between the flow factor and the biological factor was constructed based on the sampling data of benthos in Taoer River.The results show that under the current ecological flow target,which is settled as 5%,10%,15%of the annual average runoff for frozen,normal,and wet period,the compliance rate of ecological flow improved gradually in temporal.And the compliance rate of ecological flow decreased from upstream to downstream in spatial,which like the change trend of benthic diversity and biomass.Then,the Pearson analysis showed that the correlation between the benthic diversity index and the compliance rate of ecological discharge is the most significant and the linear regression relationship was established accordingly.Finally,combined with the regression relationship and scenario analysis,it was found that the linear fitting degree was the highest(R^(2)=0.998)when the targets of the frozen,normal,and wet periods were setting as 7%,14%,and 27%,respectively,indicating that the target was most suitable with the best effect on maintaining benthic diversity.Thus,it is suggested to gradually increase the ecological flow target and promote the restoration of damaged ecosystem in Taoer River.