海河流域河道最小生态流量研究

Calculation of minimum ecological flux of rivers for Haihe River Basin

应用基于河流形态的河道最小生态流量计算方法,选取潘家口、滦县、石匣里、官厅、观台、楚旺及称钩湾7个控制断面对海河流域河道最小生态流量进行计算.该方法立足河流形态,将水位水面宽曲线突变点与维持一定生境(主要包括平均水深、流速等)综合考虑来确定临界流量.计算结果表明:7个控制断面的最小生态流量均值为5.84 m3/s,占多年平均流量的5.8%～10%;在最小生态流量下的水面宽率为43%～70%(平均为61%),平均水深为0.24～0.59 m,流速为0.24～0.34 m/s.这些计算结果与国际上已有的计算结果相符.根据流域相似性原理进行外推,计算了海河流域其他河道的最小生态流量.

The minimum ecological flux of rivers for seven hydrological control sections in the Haihe River Basin was calculated by use of the minimum flux method based on river geomorphology. The method determined the critical flux by consideration of both breakpoint on the water level-river width curve and the maintenance of the original habitat （mainly including average water depth, average velocity, et al） to a certain extent. The results show that the average minimum ecological flux of the seven control sections is 5.84m^3/s, which accounts for 5.8%-10% of the long-term average value, and that under the minimum ecological flux, the ratio of river width is 43%-70% （the average value being 61% ）, the average water depth is 0.24-0.59m, and the flow velocity is0.24-0.34 m/s. The calculated results are in accordance with those previously obtained and recognized at aboard. By extrapolation of the calculated results according to the similarity principle, the minimum ecological flux of other rivers in the Haihe River Basin can be obtained as well.