香溪河库湾水质特征与非回水区水华响应关系

为探究香溪河在受倒灌影响较弱的河段水华暴发征兆及机理，于水华高发期5~8月对香溪河进行监测，分析电导率、水温、叶绿素a（Chl-a）以及流速.结果表明，在6~8月，香溪河倒灌现象于XX05点（峡口镇）处基本结束，XX06~XX09受倒灌来水影响较弱；香溪河于7月暴发水华，各个监测点位上Chl-a含量均值达到100μg/L以上，XX05~XX06与XX07-XX09点位上暴发不同种水华；在水华暴发前后，水体温度无显著变化，且并无明显分层现象，说明水温分层是水华暴发的主要原因这一理论并不能很好的适用于非回水区；通过对电导率数值的研究发现，数值在垂向上出现显著拐点，而拐点出现在临界层与光补偿层之间，同时与叶绿素a含量分布呈现显著负相关性.香溪河总氮（TN）、总磷（TP）平均值为1.849mg/L和0.157mg/L，均超过富营养化的阈值，水体氮磷含量与Chl-a浓度无显著相关性，水体中除N、P营养盐外的其它离子对香溪河水华的暴发起着重要作用.在水华消退后，电导率数值又逐渐恢复表层高底层低的垂向线性分布特性，与水华的暴发、消退有着明显的响应.

Relationship between water quality of Xiangxi River Reservoir and the algal blooms in non-return area in the Three Gorges Reservoir Area

In order to explore the signs and mechanisms of the algal blooms in the river where the backwater of the Xiangxi River are weak. Based on field data during the high-period, such as temperature, conductivity, Chl-a and the flow rate, the Xiangxi River backflow phenomenon basically ended at XX05(XiaKou Town), so the study was conducted at XX06-XX09; the algal blooms happened in July, Chl-a was above 100μg/L, and different kinds of algal blooms on XX05-XX06 and XX07-XX09; in the study area, the water temperature stratification was not obvious. The theory that water temperature stratification was the main cause of blooms was not very suitable for this water area. The study of conductivity showed that there was a significant inflection point in the vertical direction, and the inflection point depth was between the critical layer and the light compensation layer, and had a significant negative correlation with the distribution of chlorophyll a content. The average values of total nitrogen (TN) and total phosphorus (TP) in Xiangxi River were 1.849mg/L and 0.157mg/L, which exceeded the criterion of the eutrophication. The nitrogen and phosphorus content had no significant correlation with Chl-a. Other ions except N and P nutrients played an important role in the algal blooms. After the algal blooms, the conductivity gradually recovered lower from the surface to the bottom vertically, and had obvious response with the bloom and regression of algal blooms.