基于改进Tennant法的小清河生态基流计算

为拓宽Tennant法的适应性,针对北方地区部分河流丰枯期径流差异大的特点,提出了在一般用水期(11-次年3月)生态基流的确定方法;同时,为满足鱼类生存繁衍要求,确定了鱼类产育期(4-10月)所需的逐月最低流速,选取最低流速所对应的流量与传统Tennant法生态基流量较大者为最终生态基流量,更好地保障了鱼类的生存繁衍要求。以小清河为例,选取人类干扰较小的历史数据对生态基流量进行计算,并与其他计算方法的结果进行对比验证。结果表明:改进的Tennant法计算结果更为合理,同时兼顾了多方面需水要求,有利于生态保护和维持河道持续健康发展。

Calculation of ecological base flow in Xiaoqing river based on improved Tennant method

In order to broaden the adapibality of Tennant method,the paper proposed the determination method of ecological base flow in general period of using water (from November to next March) according to the feature of large difference between wet season and dry season; at the same time, in order to meet the survival and reproduction requirements of fish, the paper determined the required monthly minimum velocity in the fish-birth period (April to October) to select the larger flow which corresponding to the minimum flow velocity and traditional Tennant method ecological base flow as the final ecological base flow so as to safeguard the survival requirement of fish.Taking Xiaoqing River for example,the paper chose the historical data with less human interference to calculate the ecological base flow and verify it with the result of other calculation method. The results show that the improved Tennant method is more reasonable and takes into account the many aspects of water requirement.The method is helpful for the ecological protection and the sustained and healthy development of the river.