【摘要】 文章以横江流域pH值为研究对象，分析了pH值的时空变化特征，以及浮游植物群落对pH值的影响，探讨了pH值变化的影响因素以及内在的机理。研究结果表明：横江流域pH值从上游到下游逐渐升高的趋势，7、8月份pH值最高为9.1,4-6月份最低为7.5。影响pH值变化主要因素是溶解氧、叶绿素a、水温。横江流域主要的浮游植物的种属7门60属，其中硅藻门最为丰富，优势种也是以硅藻门为主；春季以硅藻为主，夏季以蓝藻为主，秋季以绿藻、硅藻为主，可以看出浮游植物群落变化导致了水体pH值的季节性的变化，因此，生物作用是横江流域pH值变化的主要因素。更多还原

【Abstract】 Taking Hengjiang River Basin as the research object, this study analyzes the temporal and spatial variation of pH value, and the influence of phytoplankton community structure characteristics on pH value. Meanwhile, this work discussed the influencing factors and internal mechanism of pH value variation ofHengjiang River Basin. The results show that the pH value of Hengjiang River Basin gradually increases from the upstream to the downstream, which exhibits the highest pH value in July and August while the lowest from April to June.The main water quality factors affecting the variation of pH value in Hengjiang River Basin are dissolved oxygen, chlorophyll α and water temperature. There are 7 genera and 60 species of phytoplankton in Hengjiang River Basin and diatom is the most abundant and the dominant species. In Hengjiang River Basin, diatom, cyanobacteria are the dominant species in spring and summer, respectively. In autumn, green algae and diatoms are the dominant species. It can be seen that variation of algae species results from the seasonal changes of pH value in Hengjiang River Basin. Thereafter, the change of carbon dioxide carbonate balance buffer system caused by biological effect is the main factor for the pH variation in Hengjiang River Basin.更多还原