三峡库区回水区叶绿素a的分布及影响因素分析

为探讨三峡水库蓄水以来竺溪河-澎溪河回水区叶绿素a的分布及其影响因素,2013年1月1日至2014年12月,在竺溪河-澎溪河河段设置了8个采样点,对叶绿素a及相关环境因子进行了监测。依据监测信息和资料,对竺溪河-澎溪河河段富营养化状态、叶绿素a和相关环境因子的空间分布特性及其相关性进行了分析。结果表明:竺溪河和澎溪河均处于不同程度的富营养化状态,且受干流倒灌的影响,回水区首端的富营养化程度具有季节性变化特点;竺溪河和澎溪河回水区各采样点叶绿素a和TN,TP的相关性系数均值分别为澎溪河-0.014,-0.014,竺溪河为0.154,0.244,而干流为0.469,0.449。该结果也说明,TN和TP对支流回水区藻类生长的影响比较小,而与干流的叶绿素a浓度呈相对明显的相关关系。

Study on distribution law and influencing factors of chlorophyll a in backwater area of Three Gorges Reservoir

In order to explore the distribution and influencing factors of chlorophyll a in Zhuxi-Pengxi river backwater area after the impoundment of Three Gorges Reservoir, eight sampling points were set in Zhuxi-Pengxi river section and chlorophyll a and its related environmental factors were monitored from January, 2013 to December, 2014. Based on monitoring data, eutrophic state, distribution and correlation of chlorophyll a and its related environmental factors were analyzed. The results show that Zhuxi River and Pengxi River are in varying degrees of eutrophic state, and present a seasonal variability in the head of backwater area under the effect of the intrusion of mainstream; average correlation coefficients of chlorophyll a and TN, TP in backwater area are -0.014,-0.014 in Pengxi River, and 0.154, 0.244 in Zhuxi River while in mainstream are 0.469, 0.449. The results also demonstrate that TN and TP are not strongly correlated to the growth of algae in tributary backwater area, but have a significant impact on chlorophyll a in the mainstream of Yangtze River.