Dams and Climate Interact to Alter River Flow Regimes Across the United States
Dams and Climate Interact to Alter River Flow Regimes Across the United States
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DOI：
10.1029/2020ef001816
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发表时间：
2021-04-01
期刊：
影响因子：
8.2
通讯作者：
Ruhi, Albert
中科院分区：
文献类型：
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作者：
Chalise, Dol Raj;Sankarasubramanian, A.;Ruhi, Albert
通过水库储存和管理河流流量可以抑制或增加气候引起的河流流量波动，但对大坝和气候之间的相互作用知之甚少。在这里，我们研究了大坝的属性如何控制不同方面的流量改变整个美国（CONUS），并比较大坝影响和参考流计之间的变化趋势。我们使用730个站点的长期日流量数据量化了偏离自然流态的情况。大坝的大小和目的解释了水流变化的高度变化，在水资源紧张的地区，变化尤其严重。重要的是，水坝对河流流量的调节通常会抑制气候驱动的变化（占流量指标的48%），特别是在具有积极流量趋势的流域;而在其他情况下（44%），甚至具有双重影响（8%）。我们的结果表明，需要根据各种水流状况方面（例如，事件的规模和持续时间、频率和时间），而不是仅仅是平均年流量。通过对美国地质勘探局的径流记录，可从上游和下游的209个大坝在美国本土，我们提出的概念，大坝放大流量变化，但也改善了一些流量变化指标。了解这种潜力和局限性是重要的，鉴于气候的非平稳性和新一波的筑坝在发展中经济体，并将成为未来进一步推进环境流科学的关键。
Storing and managing river flows through reservoirs could dampen or increase climate-induced fluctuations in streamflow, but interactions between the effects of dams and climate are poorly understood. Here, we examined how dam properties control different facets of flow alteration across the coterminous United States (CONUS), and compared alteration trends between dam-affected and reference stream gages. We quantified departures from the natural flow regime using 730 stations with long-term daily discharge data. Dam size and purpose explained high variation in flow alteration, and alteration was particularly severe in water-stressed regions. Importantly, regulation of river flows by dams often dampened climate-driven alteration (48% of the flow metrics), particularly in watersheds with positive flow trends; while worsening climatic impacts in other cases (44%), or even having dual effects (8%). Our results show that dam and climate impacts on streamflow need to be assessed jointly, and based on a diverse range of flow regime facets (e.g., event magnitude and duration, frequency, and timing) instead of mean annual flows only. By pairing the USGS streamflow records available from upstream and downstream of 209 dams across the CONUS, we advance the notion that dams amplify flow alteration, but also ameliorate some flow alteration metrics. Understanding such potential and limitations is important in light of climate non-stationarity and a new wave of damming in developing economies, and will be key to further advancing environmental flow science into the future.