This work aims to evaluate the hydrologic changes caused by a small hydropower plant on the watercourse in which it is installed. Since hydrologic research with data of temporal frequencies less than a day is less common than daily measurements, there are few indicators and methodologies capable of treating such records. For this reason, 17 indicators are proposed which describe the magnitude, duration, frequency and rate of changes in hydrologic conditions occurring in a watercourse at a sub-daily frequency. These 17 indicators were used to assess changes in the flow regimes at sub-daily scales across the Itiquira hydroelectric facility in Mato Grosso, Brazil. During the dry season the river was more susceptible to hydroelectric operations than during the wet season. Eighty-eight percent of the proposed indicators were significantly altered during the dry season compared to 71% during the rainy season. In addition to the number of indicators that changed between the seasons, the magnitude of the change was different. During the dry season, 53% of the magnitudes of the proposed indicators were classified as having a high magnitude of change, while in the rainy season only 6% of the indicators were characterized as having a high magnitude of change.

中文翻译：

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由小型水力发电设施引起的次日尺度的水文变化评估

这项工作旨在评估由安装水道的小型水力发电厂引起的水文变化。由于时间频率小于一天的数据的水文学研究比日常测量少见，因此很少有指标和方法能够处理此类记录。因此，提出了17个指标，它们描述了次日频率在水道中发生的水文状况的变化幅度，持续时间，频率和变化速率。这17个指标用于评估巴西马托格罗索州Itiquira水力发电站日流量范围内流量变化的变化。与干旱季节相比，干旱季节的河流更容易受到水力发电的影响。与干旱季节的71％相比，干旱季节的拟议指标有88％发生了显着变化。除了季节之间变化的指标数量外，变化的幅度也不同。在干旱季节，拟议指标的幅度的53％被归类为变化幅度大，而在雨季，仅有6％指标的变化幅度被归类为高变化。