scholarly journals The application of metacommunity theory to the management of riverine ecosystems

2021 ◽  
Author(s):  
Christopher J. Patrick ◽  
Kurt E. Anderson ◽  
Brown L. Brown ◽  
Charles P. Hawkins ◽  
Anya Metcalfe ◽  
...  
Keyword(s):  
Riverine Ecosystems

scholarly journals Environmental Flow Assessment Considering Inter- and Intra-Annual Streamflow Variability under the Context of Non-Stationarity

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1737 ◽  
Author(s):  
Kang Ren ◽  
Shengzhi Huang ◽  
Qiang Huang ◽  
Hao Wang ◽  
Guoyong Leng
Keyword(s):  
Kendall Test ◽  
Environmental Flow ◽  
Mean Value ◽  
Test Method ◽  
Stationary Condition ◽  
Annual Streamflow ◽  
Riverine Ecosystems ◽  
Study Results ◽  
Wide Range ◽  
Streamflow Variability

A key challenge to environmental flow assessment in many rivers is to evaluate how much of the discharge flow should be retained in the river in order to maintain the integrity and valued features of riverine ecosystems. With the increasing impact of climate change and human activities on riverine ecosystems, the natural flow regime paradigm in many rivers has become non-stationary conditions, which is a new challenge to the assessment of environmental flow. This study presents a useful framework to (1) detect change points in runoff time series using two statistical methods (Mann-Kendall test method and heuristic segmentation method), (2) adjust data of the changed period against the original flow series into a stationary condition using a procedure of reconstruction; and (3) incorporate inter- and intra-annual streamflow variability with adjusted streamflow to evaluate environmental flow. The Jialing to Han inter-basin water transfer project was selected as the case study. Results indicate that a change point of 1994 was identified, revealing that the stationarity of annual streamflow series is invalid. The variations of reconstructed streamflow series are roughly consistent with original streamflow series, especially in the maximum/minimum values and rise/fall rates, but the mean value of reconstructed streamflow series is increased. The reconstructed streamflow series would further serve to eliminate the non-stationary of original streamflow, and incorporating the inter- and intra-annual variability would upgrade the ecosystem fitness. Selecting different criteria for the conservation of riverine ecosystems can have significantly different consequences, and we should not focus on the protection of specific objectives that will inevitably affect other aspects. This study provides a useful framework for environmental flow assessment and can be applied to a wide range of instream flow management approaches to protect the riverine ecosystem.

scholarly journals Assessment of Automatically Monitored Water Levels and Water Quality Indicators in Rivers with Different Hydromorphological Conditions and Pollution Levels in Greece

Hydrology ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 86
Author(s):  
Angeliki Mentzafou ◽  
George Varlas ◽  
Anastasios Papadopoulos ◽  
Georgios Poulis ◽  
Elias Dimitriou
Keyword(s):  
Water Quality ◽  
Time Series ◽  
Quality Indicators ◽  
High Frequency ◽  
Automatic Monitoring ◽  
Water Levels ◽  
High Temporal Resolution ◽  
Water Quality Indicators ◽  
Pollution Levels ◽  
Riverine Ecosystems

Water resources, especially riverine ecosystems, are globally under qualitative and quantitative degradation due to human-imposed pressures. High-temporal-resolution data obtained from automatic stations can provide insights into the processes that link catchment hydrology and streamwater chemistry. The scope of this paper was to investigate the statistical behavior of high-frequency measurements at sites with known hydromorphological and pollution pressures. For this purpose, hourly time series of water levels and key water quality indicators (temperature, electric conductivity, and dissolved oxygen concentrations) collected from four automatic monitoring stations under different hydromorphological conditions and pollution pressures were statistically elaborated. Based on the results, the hydromorphological conditions and pollution pressures of each station were confirmed to be reflected in the results of the statistical analysis performed. It was proven that the comparative use of the statistics and patterns of the water level and quality high-frequency time series could be used in the interpretation of the current site status as well as allowing the detection of possible changes. This approach can be used as a tool for the definition of thresholds, and will contribute to the design of management and restoration measures for the most impacted areas.

Utility of field-based artificial streams for assessing effluent effects on riverine ecosystems

1996 ◽  
Vol 5 (2) ◽  
pp. 117-124 ◽  
Author(s):  
Joseph M. Culp ◽  
Cheryl L. Podemski ◽  
Kevin J. Cash ◽  
Richard B. Lowell
Keyword(s):  
Artificial Streams ◽  
Riverine Ecosystems

scholarly journals Characteristics and Practices of Ecological Flow in Rivers with Flow Reductions Due to Water Storage and Hydropower Projects in China

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1091 ◽  
Author(s):  
Lejun Ma ◽  
Xingnan Zhang ◽  
Huan Wang ◽  
Changjun Qi
Keyword(s):  
Calculation Method ◽  
River Flow ◽  
Water Storage ◽  
Engineering Calculation ◽  
Water Diversion ◽  
Western China ◽  
Flow Management ◽  
Riverine Ecosystems ◽  
Management Scheme ◽  
Ecological Flow

Water and flow reductions in the channels downstream of water storage and hydropower projects have significant impacts on aquatic ecosystems. Understanding and analyzing the ecosystem status is of great significance to facilitate the protection of riverine ecosystems. A database was established based on the 2000–2017 environmental impact assessment (EIA) reports on water storage and hydropower projects in China, and corresponding analysis software was built based on an ArcGIS spatial analysis platform. The projects in China are mainly found in the Yangtze and Pearl River basins and in south-western China. The hydropower projects have a larger influence than the water storage projects on the flow of downstream rivers sections, and most of the hydropower projects, especially the water diversion projects, cause flow reductions in the downstream rivers. An ecological flow management mechanism in China implemented in 2006 provided a promising method to alleviate river flow reductions. However, there is still only one kind of ecological flow calculation method and few ecological flow regulation measures in use. Based on the advantages and problems of the existing ecological flow management system, this paper proposes a management scheme based on a regional-engineering calculation method. The results can facilitate decision making in ecological flow management.

scholarly journals Impact of sulfamethoxazole on a riverine microbiome

2021 ◽  
Author(s):  
Chiara Borsetto ◽  
Sebastien Raguideau ◽  
Emma R Travis ◽  
Dae-Wi Kim ◽  
Do-Hoon Lee ◽  
...  
Keyword(s):  
River Flow ◽  
Wastewater Treatment Plants ◽  
Antibiotic Resistance Genes ◽  
Resistant Bacteria ◽  
Water Fraction ◽  
Riverine Ecosystems ◽  
Short Term Exposure ◽  
Bacterial Microbiome ◽  
The Impact

The continued emergence of bacterial pathogens presenting antimicrobial resistance is widely recognised as a global health threat and recent attention focused on potential environmental reservoirs of antibiotic resistance genes (ARGs). Freshwater environments such as rivers represent a potential hotspot for ARGs and antibiotic resistant bacteria as they are receiving systems for effluent discharges from wastewater treatment plants (WWTPs). Effluent also contains low levels of different antimicrobials including antibiotics and biocides. Sulfonamides are antibacterial chemicals widely used in clinical, veterinary and agricultural settings and are frequently detected in sewage sludge and manure in addition to riverine ecosystems. The impact of such exposure on ARG prevalence and diversity is unknown, so the aim of this study was to investigate the release of a sub-lethal concentration of the sulfonamide compound sulfamethoxazole (SMX) on the river bacterial microbiome using a flume system. This system was a semi-natural in vitro flume using river water (30 L) and sediment with circulation to mimic river flow. A combination of 'omics' approaches were conducted to study the impact of SMX exposure on the microbiomes within the flumes. Metagenomic analysis showed that the addition of low concentrations of SMX (<4 μg L-1) had a limited effect on the bacterial resistome in the water fraction only, with no impact observed in the sediment. Metaproteomics did not show differences in ARGs expression with SMX exposure in water. Overall, the river bacterial community was resilient to short term exposure to sub-lethal concentrations of SMX which mimics the exposure such communities experience downstream of WWTPs throughout the year.

Designing sustainable energy plans for the Greater Mekong Subregion

2021 ◽  
Author(s):  
Stefano Galelli ◽  
Kais Siala ◽  
AFM Kamal Chowdhury ◽  
Thanh Duc Dang
Keyword(s):  
Power Supply ◽  
Fossil Fuels ◽  
Sustainable Energy ◽  
Solar Pv ◽  
Economic Sectors ◽  
Planning Period ◽  
Riverine Ecosystems ◽  
The Many ◽  
Greater Mekong Subregion ◽  
The Impact

&lt;p&gt;Fossil fuels and hydropower dams have long been at the backbone of power supply systems in the Greater Mekong Subregion (GMS), an energy policy catalyzed by the direct availability of these resources, the backing of foreign investments, and the limited coordination among the many decision-makers. Such policy has resulted in large externalities: gas and coal-fired plants contribute to the carbon footprint of all GMS countries, particularly Thailand; dams have affected the riverine ecosystems, impacting entire economic sectors. According to the official energy plans, coal will be soon sidelined, but dams will keep playing an important role. That is despite the availability of solar and other renewable resources. Is it possible to design more sustainable energy plans for the GMS? Can we limit the number of dams that will be built in the near future? What are the main technologies and policies that should be prioritized? To answer these questions, we developed a spatially-distributed numerical model that co-optimizes capacity expansion as well as hourly dispatch of generation, transmission, and storage. The model is applied to Thailand, Laos, and Cambodia, over a planning period spanning from 2016 to 2037. Optimization results show that the generation capacity planned by these countries could be met in a more sustainable manner by relying on solar PV, which could supply about one third of the projected electricity demand. Investments in renewable energy should be supported by cross-border grid interconnections, which would connect load centers to more production sites, easing the supply-demand balancing. To put the analysis in a broader water-energy context, we also assess the impact of current and proposed energy plans on river connectivity and flows. Overall, our analysis demonstrates that there are untapped opportunities for untying the fate of the Mekong River basin from that of power supply and economic development.&lt;/p&gt;

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