Small headwater lakes are common water features in northern environments. These small lakes are often reported to have an influence on downstream water quality; however, few studies have addressed the underlying hydrology of these systems and how small lakes influence downstream discharge or how far downstream these influences persist. We show that catchments with small lakes sustain baseflows compared to catchments without lakes. In addition, small lakes have limited influence on the magnitude and timing of peakflow events, except for immediately downstream of the lake where peakflow hydrographs are characterized by low magnitude and long duration. The relative contribution of lake water to downstream discharge can vary widely in time (between 0% and 75%) and be detectable when lakes make up as little as 0.5% of catchment area. This variability and persistence of lake water in stream networks may have important implications for how we interpret water quality patterns downstream of small lakes.

中文翻译：

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源头湖泊及其对下游排放的影响

在北部环境中，小型上游水库是常见的水域特征。据报这些小湖经常对下游水质产生影响。但是，很少有研究探讨这些系统的基本水文学，以及小湖泊如何影响下游流量或这些影响持续到下游的程度。我们表明，与没有湖泊的集水区相比，有小湖泊的集水区保持了基流。此外，小型湖泊对洪峰流量的大小和时间的影响有限，除了紧接在洪灾下游的洪峰水位低，持续时间长的特点之外。湖泊水对下游排放的相对贡献可能随时间变化很大（在0％到75％之间），并且当湖泊仅占集水区的0.5％时可以检测到。