Effects of river regulation on water quality in the lower Mokelumne River, California

2005 ◽  
Vol 21 (6) ◽  
pp. 651-670 ◽  
Author(s):  
Dylan S. Ahearn ◽  
Richard W. Sheibley ◽  
Randy A. Dahlgren
Keyword(s):  
Water Quality ◽  
River Regulation ◽  
Mokelumne River

scholarly journals Study on the Causes of Water Environmental Pollution of Important Rivers in Haihe River Basin and Countermeasures

2021 ◽  
Vol 261 ◽  
pp. 04023
Author(s):  
Xu He ◽  
Hou Siyan
Keyword(s):  
Water Quality ◽  
Point Source ◽  
Environmental Pollution ◽  
River Basin ◽  
River Regulation ◽  
Haihe River Basin ◽  
Point Source Pollution ◽  
Haihe River ◽  
The Impact

The water quality of six important rivers in Haihe River Basin, including Yongding River, Luanhe River, North Canal, Daqing River, South Canal and Chaobai River, was evaluated. The influence of point source and non-point source on water quality was analyzed. The causes of water environmental pollution in the major rivers were preliminarily revealed. The results show that the water quality of Chaobai River is good, and the impact of point source and non-point source discharge on the water body is small. Other rivers are affected by different degrees of point source and non-point source pollution. Based on the analysis results, the engineering measures and management countermeasures for river regulation are put forward.

Water quality response to a pulsed-flow event on the Mokelumne river, California

2007 ◽  
Vol 23 (2) ◽  
pp. 185-200 ◽  
Author(s):  
Solomon S. Henson ◽  
Dylan S. Ahearn ◽  
Randy A. Dahlgren ◽  
Erwin Van Nieuwenhuyse ◽  
Kenneth W. Tate ◽  
...  
Keyword(s):  
Water Quality ◽  
Pulsed Flow ◽  
Mokelumne River ◽  
Quality Response

scholarly journals A century scale human-induced hydrological and ecological changes of wetlands of two large river basins in Australia (Murray) and China (Yangtze): development of an adaptive water resource management framework

2015 ◽  
Vol 12 (8) ◽  
pp. 8247-8287 ◽  
Author(s):  
G. R. Kattel ◽  
X. Dong ◽  
X. Yang
Keyword(s):  
Water Quality ◽  
20Th Century ◽  
Human Disturbance ◽  
Water Resource Management ◽  
River Basins ◽  
River Regulation ◽  
Large River ◽  
Management Framework ◽  
Biological Communities ◽  
Large River Basins

Abstract. Recently, the provision of food and water resources of two of the world's large river basins, the Murray and the Yangtze, has been significantly altered through widespread landscape modification. Long-term sedimentary archives, dating back to past centuries, from wetlands of these river basins reveal that rapid, basin-wide development has reduced resilience of biological communities, resulting in considerable decline in ecosystem services, including water quality. In particular, large-scale human disturbance to river systems, due to river regulation during the mid-20th century, has transformed the hydrology of rivers and wetlands, causing widespread disturbance to aquatic biological communities. Historical changes of cladoceran zooplankton (water fleas) were used to assess the hydrology and ecology of three Murray and Yangtze River wetlands over the past century. Subfossil assemblages of cladocerans retrieved from sediment cores (94, 45 and 65 cm) of three wetlands: Kings Billabong (Murray), Zhangdu and Liangzi Lakes (Yangtze) strongly responded to hydrological changes of the river after the mid-20th century. River regulation caused by construction of dams and weirs, and river channel modifications has led to hydrological alterations. The hydrological disturbances were either: (1) a prolonged inundation of wetlands, or (2) reduced river flow, which caused variability in wetland depth. These phenomena subsequently transformed the natural wetland habitats, leading to a switch in cladoceran assemblages preferring poor water quality and eutrophication. An adaptive water resource management framework for both of these river basins has been proposed to restore or optimize the conditions of wetland ecosystems impacted by 20th century human disturbance and climate change.

scholarly journals Assessment of water quality and pollutant loading of the Rajang River and its tributaries at Pelagus area subjected to seasonal variation and river regulation

2019 ◽  
Vol 22 (5) ◽  
pp. 4101-4124 ◽  
Author(s):  
Angela-Sanoh Tawan ◽  
Teck-Yee Ling ◽  
Lee Nyanti ◽  
Siong-Fong Sim ◽  
Jongkar Grinang ◽  
...  
Keyword(s):  
Water Quality ◽  
Seasonal Variation ◽  
River Regulation ◽  
Pollutant Loading

scholarly journals Effect of climate change on long-term river geometric variation in Andong Dam watershed, Korea

2020 ◽  
Author(s):  
Jong Mun Lee ◽  
Jungkyu Ahn ◽  
Young Do Kim ◽  
Boosik Kang
Keyword(s):  
Climate Change ◽  
Water Quality ◽  
Environmental Changes ◽  
River Regulation ◽  
Large River ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Output Analysis ◽  
Integrated Method ◽  
Geometric Variation

Abstract Because of multifunctional weirs installed as part of large river regulation works in Korea, water quality problems have arisen from environmental changes in tandem with decreased flow rates. However, there has been limited research into the green algae removal effect, water quality improvement in congested waters, dam and weir operations, and consequential riverbed changes. Studies regarding outflow in a basin, the application and development of sediment load output analysis methods, feasibility of related dam operations, and riverbed patterns have been separately performed. However, basins and rivers should be analyzed by an integrated method instead of an individual one. Therefore, in the present study, the effect of congestion on a river connected to a dam/weir and estuary bank was analyzed based on climate change scenarios HadGEM3-RA RCP 4.5 and 8.5, with the aim of integrating individual studies using watershed and river models. Flow was controlled by dam- and weir-related discharge simulations. Variations in the riverbed caused by the transfer of suspended load in the downstream region were analyzed for both long and short durations. The results of this analysis suggest that given future climate change scenarios, the width of the river and riverbed variations in the riverbed are expected to rise.

scholarly journals A century-scale, human-induced ecohydrological evolution of wetlands of two large river basins in Australia (Murray) and China (Yangtze)

2016 ◽  
Vol 20 (6) ◽  
pp. 2151-2168 ◽  
Author(s):  
Giri R. Kattel ◽  
Xuhui Dong ◽  
Xiangdong Yang
Keyword(s):  
Water Quality ◽  
Ecosystem Services ◽  
20Th Century ◽  
Large Scale ◽  
River Flow ◽  
River Basins ◽  
River Regulation ◽  
Past Century ◽  
Biological Communities ◽  
Landscape Modification

Abstract. Recently, the provision of food and water resources of two of the world's largest river basins, the Murray and the Yangtze, has been significantly altered through widespread landscape modification. Long-term sedimentary archives, dating back for some centuries from wetlands of these river basins, reveal that rapid, basin-wide development has reduced the resilience of biological communities, resulting in considerable decline in ecosystem services, including water quality. Large-scale human disturbance to river systems, due to river regulation during the mid-20th century, has transformed the hydrology of rivers and wetlands, causing widespread modification of aquatic biological communities. Changes to cladoceran zooplankton (water fleas) were used to assess the historical hydrology and ecology of three Murray and Yangtze river wetlands over the past century. Subfossil assemblages of cladocerans retrieved from sediment cores (94, 45, and 65 cm) of three wetlands: Kings Billabong (Murray), Zhangdu, and Liangzi lakes (Yangtze), showed strong responses to hydrological changes in the river after the mid-20th century. In particular, river regulation caused by construction of dams and weirs together with river channel modifications, has led to significant hydrological alterations. These hydrological disturbances were either (1) a prolonged inundation of wetlands or (2) reduced river flow, both of which caused variability in wetland depth. Inevitably, these phenomena have subsequently transformed the natural wetland habitats, leading to a switch in cladoceran assemblages to species preferring poor water quality, and in some cases to eutrophication. The quantitative and qualitative decline of wetland water conditions is indicative of reduced ecosystem services, and requires effective restoration measures for both river basins which have been impacted by recent socioeconomic development and climate change.

Effects of a gradient in river regulation on the longitudinal trends in water quality and benthic algal and macroinvertebrate assemblages in the Hunter River, Australia

2012 ◽  
Vol 63 (6) ◽  
pp. 494 ◽  
Author(s):  
Daniela P. Cortez ◽  
Ivor O. Growns ◽  
Simon M. Mitrovic ◽  
Richard P. Lim
Keyword(s):  
Water Quality ◽  
New South ◽  
River Regulation ◽  
Regulated River ◽  
Downstream Site ◽  
Macroinvertebrate Assemblages ◽  
Dimensional Scaling ◽  
South Wales ◽  
Lotic Ecosystem ◽  
Algal Assemblages

River regulation impacts lotic ecosystem processes; however, the effect of a gradient of regulation on these attributes has rarely been studied. This study examined the effects of a river regulation gradient on longitudinal trends in water quality and benthic algal and macroinvertebrate assemblages in three tributaries of the Hunter River, New South Wales, Australia. Longitudinal patterns were expected to differ across rivers, with recovery being proportional to its regulation gradient. Significant differences in longitudinal trends were tested using permutational multivariate analysis of variance (PERMANOVA) through exploration of the river by distance from source interaction. Multi-dimensional scaling (MDS) ordination plots identified sites responsible for any significant interaction observed. Similarity percentage analysis (SIMPER) analyses identified variables/taxa responsible for differences at sites below dams. BEST analyses identified environmental variables best explaining biological assemblage patterns. Significant differences in longitudinal trends were observed for all attributes. Increases in the regulation gradient most affected macroinvertebrate assemblages, followed by water quality and benthic algal assemblages respectively. Downstream recovery was absent in the heavily regulated river at its most downstream site, whereas recovery was observed on corresponding sites of the moderately regulated river. The study suggests that a gradient in river regulation increases the magnitude of disruption of lotic ecosystems, with recovery dependent on this gradient.

scholarly journals Prewhitened causality analysis for the chlorophyll-a concentration in the Yeongsan River system

2018 ◽  
Vol 54 (2) ◽  
pp. 161-177 ◽  
Author(s):  
Eunhyung Lee ◽  
Sanghyun Kim ◽  
Eunhye Na ◽  
Kyunghyun Kim
Keyword(s):  
Water Quality ◽  
Factor Analysis ◽  
Chlorophyll A ◽  
Cross Correlation ◽  
River System ◽  
River Regulation ◽  
Principal Factor ◽  
Principal Factor Analysis ◽  
Chl A ◽  
The Impact

Abstract Blooming of algae has been a primary issue of concern for heavily polluted aquatic ecosystems. The chlorophyll-a (Chl-a) concentration depends on various hydrological, biochemical and anthropogenic components, which makes prediction of algal blooms complicated. A river regulation project in Yeongsan River, South Korea, involving the construction of a weir, had substantially altered the flow regime. A prewhitened time series analysis is a useful method for delineation of a causal relationship between two environmental variables. This study explores the impact of river regulation on algal blooming using both the prewhitened cross-correlation method and principal factor analysis. Both individual and comprehensive causality structures were configured for the variation in Chl-a concentration. A prewhitened cross-correlation analysis indicates that the water quality response patterns of the river system were changed to those of a reservoir after the river regulation project. A principal factor analysis of correlations indicates that the weir construction had a stronger impact on algal concentration than both the hydro-meteorological factor and difference in sampling location. Variation in stochastic structures from nutrients and water quality factors to algal bloom was substantially reduced by the construction of a weir, which can be explained by the relatively uniform flow pattern throughout the river regulation practice.

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