Rivers in the Critical Zone

Wohl, Ellen

doi:10.1016/b978-0-444-63369-9.00009-4

Cited by 5 publications

(2 citation statements)

References 124 publications

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“…The hyporheic zone is an important ecosystem control point (Bernhardt et al, 2017) where ground water and river water mix (Boulton et al, 1998;White et al, 2015;Wohl, 2015). DOM plays an especially important role in the hyporheic zone, and its origins and bioavailability have been extensively shown to drive microbial activity and organic matter turnover in these control points (i.e., hyporheic zones).…”

Section: Introductionmentioning

confidence: 99%

Coupled Biotic-Abiotic Processes Control Biogeochemical Cycling of Dissolved Organic Matter in the Columbia River Hyporheic Zone

et al. 2021

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A critical component of assessing the impacts of climate change on watershed ecosystems involves understanding the role that dissolved organic matter (DOM) plays in driving whole ecosystem metabolism. The hyporheic zone—a biogeochemical control point where ground water and river water mix—is characterized by high DOM turnover and microbial activity and is responsible for a large fraction of lotic respiration. Yet, the dynamic nature of this ecotone provides a challenging but important environment to parse out different DOM influences on watershed function and net carbon and nutrient fluxes. We used high-resolution Fourier-transform ion cyclotron resonance mass spectrometry to provide a detailed molecular characterization of DOM and its transformation pathways in the Columbia river watershed. Samples were collected from ground water (adjacent unconfined aquifer underlying the Hanford 300 Area), Columbia river water, and its hyporheic zone. The hyporheic zone was sampled at five locations to capture spatial heterogeneity within the hyporheic zone. Our results revealed that abiotic transformation pathways (e.g., carboxylation), potentially driven by abiotic factors such as sunlight, in both the ground water and river water are likely influencing DOM availability to the hyporheic zone, which could then be coupled with biotic processes for enhanced microbial activity. The ground water profile revealed high rates of N and S transformations via abiotic reactions. The river profile showed enhanced abiotic photodegradation of lignin-like molecules that subsequently entered the hyporheic zone as low molecular weight, more degraded compounds. While the compounds in river water were in part bio-unavailable, some were further shown to increase rates of microbial respiration. Together, river water and ground water enhance microbial activity within the hyporheic zone, regardless of river stage, as shown by elevated putative amino-acid transformations and the abundance of amino-sugar and protein-like compounds. This enhanced microbial activity is further dependent on the composition of ground water and river water inputs. Our results further suggest that abiotic controls on DOM should be incorporated into predictive modeling for understanding watershed dynamics, especially as climate variability and land use could affect light exposure and changes to ground water essential elements, both shown to impact the Columbia river hyporheic zone.

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Section: Introductionmentioning

confidence: 99%

Coupled Biotic-Abiotic Processes Control Biogeochemical Cycling of Dissolved Organic Matter in the Columbia River Hyporheic Zone

et al. 2021

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“…As the main carrier of surface runoff, river plays an indispensable role in the water cycle, which is the main water source for human life and ecosystem [1]. At the same time, river water resources significantly regulate regional climate, balance ecosystem and protect biodiversity.…”

Section: Introductionmentioning

confidence: 99%

Feasibility and Potential Study of Yarlung Tsangpo River Power Generation Based on Optimization Model

Liu¹,

Guo²,

Zhang³

2023

HSET

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The Yarlung Zangbo River is not only the longest plateau river in China, but also one of the highest rivers in the world. This paper studies ecology, geology, investment and benefits respectively. Based on the data of the elevation, drop and fish abundance of the Yarlung Zangbo River, combined with its geographical location, a multi-objective optimization model is established. To analyzes the number of hydropower stations built on the Yarlung Zangbo River from the perspective of maximum energy utilization, this paper use the dynamic programming method to find the maximum output energy of each hydropower station. The conclusion is that the total output of 16 hydropower stations is 51358600KW, which reaches a high level. It is estimated that the potential power generation capacity of the Yarlung Zangbo River is about 55 million KW.

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