The frequency and magnitude of storm events is expected to increase with climate warming. Tidal freshwaters may be particularly sensitive to these events owing to their proximity to riverine inputs. Continuous and synoptic water quality data from riverine and tidal freshwater segments of the James, Mattaponi, and Pamunkey Rivers (Virginia, USA) were analyzed to characterize their response to high discharge events. Water quality attributes subject to dilution effects (conductivity, pH) showed negative responses to increasing discharge, which were similar in magnitude among riverine and estuarine segments. Variables associated with sediment transport (turbidity, TSS, E. coli, TN, and TP) showed positive responses to discharge, stronger responses in riverine vs. estuarine segments, and relatively linear responses over the full range of discharge. Variables affected by internal biological processes (CHLa, DO) showed negative responses to increasing discharge, greater sensitivity in the low range of discharge, and stronger responses in estuarine segments. High discharge was associated with reduced chlorophyll-a (CHLa), lower dissolved oxygen, and more heterotrophic conditions (lower production relative to respiration). During unusually high discharge in 2018, annual GPP was reduced to 38% (Pamunkey) and 78% (James) of long-term average values. Inter-estuarine differences in their sensitivity to high discharge reflect differences in forms of primary production, as the phytoplankton-dominated James exhibited rapid recovery in CHLa and GPP between storm events.

风暴事件的频率和强度预计会随着气候变暖而增加。由于潮汐淡水靠近河流输入，因此它们可能对这些事件特别敏感。分析了詹姆斯河，马塔波尼河和帕蒙基河（美国弗吉尼亚州）的河流和潮汐淡水段的连续和天气水质数据，以表征它们对高排放事件的响应。受到稀释作用（电导率，pH）影响的水质属性显示出对排放量增加的负面反应，在河流和河口段的幅度相似。与沉积物迁移相关的变量（浊度，TSS，大肠杆菌，TN和TP）显示出对排泄的积极响应，河道与河口段的响应更强，并且在整个排泄范围内具有相对线性的响应。受内部生物过程（CHLa，DO）影响的变量显示出对流量增加的负面反应，在低流量范围内的更大敏感性以及在河口段的较强反应。高放电与叶绿素-a（CHLa）降低，溶解氧降低和异养状况（与呼吸作用相比产量降低）有关。在2018年异常高的放电期间，年度GPP降低至长期平均值的38％（潘蒙基）和78％（詹姆斯）。河口间对高排放物的敏感性差异反映了初级生产形式的差异，