摘要
通过对2008-2010年三峡水库主要泄水过程香溪河水动力和水华的时空动态特征进行统计分析,建立了香溪河库湾水动力与水华的响应式,当水深5m时,以对数方式进行拟合香溪河流速与chl-a浓度效果较好,故选用y=-11.711ln(x)-7.754为香溪河流速大小与chl-a浓度的响应关系式,综合考虑拟合结果和香溪河库湾水华的藻类组成,保守取定控制水华爆发的临界流速为0.04m/s。通过CE-QUAL-W2对三峡水库主要泄水期初始水位165m时的日泄水调度工况进行模拟。结果表明,水库干流水体基本以中层异重流倒灌进入香溪河库湾,上游来流则主要从底部和表层流出库湾。库湾河口附近XX00表层流速达到抑制水华发生的临界流速0.04m/s。工况3中水位日降幅最大达到2.24m/d时库湾表层流速显著大于其他2种工况,XX00、XX03、XX04和XX07表层流速均达到抑制水华发生的临界流速。因此,初始水位165m时进行日调节泄水调度时抑制典型支流库湾水华的效果可能较好。
According to hydrodynamic characteristics and spatial-temporal characteristics of water bloom in outpouring operation process between 2008 and 2010, the response relation between water bloom and hydrodynamic conditions has been established. At depth of 5 m, there is a better fitting between flow velocity and chlorophyll-a concentration, so the model of y=-11. 7111n（x）- 7. 754 is chosen as the response relationship model. Based on an overall analysis of results and algae species, the velocity of 0. 04 m/ s is selected conservatively as the critical flow velocity inhibiting algal bloom of tributaries. According to the model hydrodynamic characteristics of Xiangxi Bay on the different scheduling methods of TGR and initial water level of 165 m is simulated. The results show that the mainstream of reservoirs basically intruded into Xiangxi bay in the form of middle layer density currents, the upstream of Xiangxi River plunged through the bay from its bottom and surface. When the water level is stable, only the surface velocity of XX00 reaches the critical velocity of 0. 04 m/s inhibiting bloom. Under discharge conditions, the more the discharge is, the greater the surface velocity is. When the lowering of water level is up to 2. 24 m/d, surface velocity of bay is significantly larger than the other conditions. Especially, the surface velocity of XX00, XX03, XX04 and XX07 are all up to the critical velocity of 0. 04 m/s un- der the condition of 3. For this reason, the outpouring operation in the initial water level of 165 m is better for inhibiting bloom.
出处
《中国农村水利水电》
北大核心
2013年第11期1-6,10,共7页
China Rural Water and Hydropower
基金
国家自然科学基金面上项目(51179095
51179205)
国家自然科学基金青年基金项目(51009080
51009081
51209123)
