Small hydroelectric power (SHP) facilities are proliferating around the world, including in Brazil where legislation encourages SHP over other hydropower development, defining SHP as facilities with installed capacities of 3–30 MW and reservoirs <13 km². SHP facilities are often diversion designs with small or no reservoirs, while other SHPs have more conventional dams that create extensive reservoirs. This study seeks to understand the relative impacts of these two different designs on downstream water quality, comparing a conventional SHP system on the main stem to a complex of smaller SHPs with diversion designs in lower‐order reaches of the São Lourenço River. This river delivers nutrients and sediments to the Pantanal, one of the world's largest floodplain ecosystems. Samples collected upstream and downstream of each set of facilities over a range of flows revealed that the conventional SHP reservoir significantly reduced pH, dissolved oxygen, total iron, suspended solids, and turbidity consistent with observations in many other reservoirs. In contrast, water quality changes downstream of the smaller SHPs were less pronounced and could be attributable to natural variability. An analysis of energy production versus water quality impacts suggests that SHPs on the smaller tributaries are favorable compared to the conventional SHP in terms of water quality impacts. With the proposed addition of dozens of new facilities in the upland watersheds draining into the Pantanal, this study improves our understanding of the relative impacts of different designs of SHPs on downstream water quality, while recognizing that water quality is just one of several potential impacts to be considered.

中文翻译：

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小型水力发电厂对巴西潘塔纳尔河漫滩的支流的水质影响

小型水电（SHP）设施在世界范围内激增，包括巴西，在该国立法鼓励SHP超越其他水电开发，将SHP定义为装机容量为3–30 MW且水库<13 km ^2的设施。SHP设施通常是分水设计，水库很小或没有水库，而其他SHP则具有更常规的水坝，可形成大量水库。这项研究试图了解这两种不同设计对下游水质的相对影响，将传统的SHP系统在主干上与较小的SHP进行复杂比较，并在SãoLourenço河下游进行分流设计。这条河为全球最大的洪泛区生态系统之一的潘塔纳尔河（Pantalal）提供营养和沉积物。在一系列流量范围内，在每套设施的上游和下游采集的样品显示，常规SHP油藏显着降低了pH，溶解氧，总铁，悬浮固体和浊度，这与许多其他油藏的观察结果一致。相比之下，较小的小水电项目下游的水质变化不太明显，可能归因于自然变化。能源生产与水质影响的分析表明，就水质影响而言，较小支流上的SHP比常规SHP更有利。提议在排入潘塔纳尔湿地的山地流域增加数十个新设施后，这项研究使我们对不同设计的小水电对下游水质的相对影响有了更深入的了解，同时认识到水质只是对水体的若干潜在影响之一。被考虑。对能源生产与水质影响的分析表明，就水质影响而言，较小支流上的小水电比传统小水电有优势。提议在排入潘塔纳尔湿地的山地流域增加数十个新设施后，这项研究使我们对不同设计的小水电对下游水质的相对影响有了更深入的了解，同时认识到水质只是对水体的若干潜在影响之一。被考虑。对能源生产与水质影响的分析表明，就水质影响而言，较小支流上的小水电比传统小水电有优势。提议在排入潘塔纳尔湿地的山地流域增加数十个新设施后，这项研究使我们对不同设计的小水电对下游水质的相对影响有了更深入的了解，同时认识到水质只是对水体的若干潜在影响之一。被考虑。