南淝河叶绿素a时空分布特征及环境因子影响分析

THE SPATIAL AND TEMPORAL DISTRIBUTION OF CHLOROPHYLL-A AND ITS CORRELATION WITH ENVIRONMENTAL FACTORS IN THE NANFEIHE RIVER

2009年8月至2012年4月,采样测试了南淝河上游8个位点的水质状况等,分析了南淝河叶绿素a(Chl.a)的时空分布特点及其与环境因子的关系。结果表明,南淝河研究河段Chl.a平均值为83.46μg/L,已处于严重富营养化状态。南淝河Chl.a浓度与总磷(TP)、化学需氧量(COD)、酸碱度(pH)、总固体悬浮物(TSS)、水温(WT)显著性正相关(P<0.05),与透明度(SD)、氨氮/总磷比值(4NH+–N/TP)、水深(WD)、降雨(Rain)及风速(Wind)显著性负相关(P<0.05)。逐步回归分析表明,影响南淝河上游河段Chl.a浓度的主导环境因子依次为水温、风速、降雨、总磷和氨氮。对南淝河与其他富营养化水体Chl.a的主要影响因子进行比较,结果表明水温是影响Chl.a的最重要因子,氮磷比、营养盐、降雨、风速、生物因子均对富营养化水体Chl.a有影响。

We collected water samples at eight sites in the Nanfeihe River from August 2009 to April 2012 every month in order to analyze the temporal and spatial distribution of chlorophyll-a in the river and its correlation with environmental fac-tors. Results showed that the average concentration of Chl.a in the Nanfeihe River was 83.46 μg/L, which indicated that the water is highly eutrophic. The concentration of Chl.a significantly increased along with the increase in the concentration of TP, COD, TSS, pH and the water temperature;while decrease along with the increase in SD, 4NH＋-N/TP, the water depth, rainfall and the wind speed. We applied step-wise regression analysis to the data and found that the key environmental factors affecting the concentration of chlorophyll-a were the water temperature, the wind speed, rainfall, and the concentration of TP and 4NH＋-N. By comparing the major impact factors that affect the concentration of Chl.a in the Nanfeihe River and other eutro-phic water bodies, we concluded that the water temperature was the most important factor affecting the concentration of Chl.a, In addition, N/P ratio, nutrients, rainfall, wind speed and biological factors were also critical factors.