scholarly journals Long-Term Impacts of Reservoir Operation on the Spatiotemporal Variation in Nitrogen Forms in the Post-Three Gorges Dam Period (2004–2016)

2021 ◽  
Author(s):  
Bei Nie ◽  
Yuhong Zeng ◽  
Lanhua Niu ◽  
Xiaofeng Zhang
Keyword(s):  
Water Quality ◽  
Reservoir Operation ◽  
Yangtze River ◽  
Ammonia Nitrogen ◽  
Three Gorges ◽  
The Yangtze River ◽  
Engineering Construction ◽  
Nitrogen Concentrations ◽  
Essential Nutrient

Abstract Nitrogen (N) is an essential nutrient limiting life, and its biochemical cycling and distribution in rivers have been markedly affected by river engineering construction and operation. Here, we comprehensively analyzed the spatiotemporal variations and driving environmental factors of N distributions based on the long-term observations (from 2004 to 2016) of seven stations in the Three Gorges Reservoir (TGR). In the study period, the overall water quality status of the river reach improved, whereas N pollution was severe and tended to be aggravated after the TGR impoundment. The anti-seasonal reservoir operation strongly affected the variations in N forms. The total nitrogen (TN) concentration in the mainstream of the Yangtze River continuously increased, although it was still lower than that in the incoming tributaries (Wu and Jialing rivers). Further analysis showed that this increase occurred probably because of external inputs, including the upstream (76%), non-point (22%), and point source pollution inputs (2%). Besides, different N forms showed significant seasonal variations; among them, the TN and nitrate nitrogen concentrations were the lowest in the impoundment season (October–February), and the ammonia nitrogen concentrations were the highest in the sluicing season (March–May). These parameters varied likely because of internal N transformation. Redundancy analysis revealed that the water level regulated by the anti-seasonal operation was the largest contributor. Our findings could provide a basis for managing and predicting the water quality in the Yangtze River.

scholarly journals Changes in Tundra Swan Cygnus columbianus bewickii distribution and abundance in the Yangtze River floodplain

2011 ◽  
Vol 21 (3) ◽  
pp. 260-265 ◽  
Author(s):  
PEIHAO CONG ◽  
LEI CAO ◽  
ANTHONY D. FOX ◽  
MARK BARTER ◽  
EILEEN C. REES ◽  
...  
Keyword(s):  
Water Quality ◽  
Yangtze River ◽  
Poyang Lake ◽  
Submerged Vegetation ◽  
Three Gorges ◽  
The Yangtze River ◽  
Vegetation Productivity ◽  
River Floodplain ◽  
Cygnus Columbianus ◽  
Tundra Swan

Approximately 75% of the East Asian Flyway Tundra Swan Cygnus columbianus bewickii population winters in the Yangtze River floodplain, China. Historically the species was more widely distributed throughout the floodplain but now most of the population is confined to five wetlands in Anhui Province and to Poyang Lake in Jiangxi Province, where the majority (up to 113,000 birds) occur. Within-winter counts suggest that swans congregate at Poyang Lake before dispersing to other sites later in the winter. Counts show large between-year fluctuations, but suggest declines at Shengjin and Fengsha Lakes (both in Anhui) during the last five years. Declines at Shengjin Lake are likely due to decreases in submerged vegetation (particularly tuber-producing Vallisneria, a major food item) perhaps linked to eutrophication. Range contractions throughout the floodplain may also be linked to reductions in submerged vegetation coverage elsewhere. Changes in water quality and lake hydrology post-Three Gorges Dam may have adversely affected submerged vegetation productivity. Key information needs for the effective implementation of conservation measures for Tundra Swans include: (1) annual surveys of all major wintering sites throughout each winter to establish the importance of different sites during the non-breeding period; (2) more information on swan diets at important sites; and (3) an assessment of adverse effects of water quality and lake water levels post-Three Gorges Dam on submerged vegetation productivity at Poyang Lake and other important sites.

scholarly journals Water Environmental Capacity Calculation Based on Control of Contamination Zone for Water Environment Functional Zones in Jiangsu Section of Yangtze River, China

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 587
Author(s):  
Qiuxia Ma ◽  
Yong Pang ◽  
Ronghua Mu
Keyword(s):  
Water Quality ◽  
Yangtze River ◽  
Water Quality Management ◽  
Water Environment ◽  
Ammonia Nitrogen ◽  
The Yangtze River ◽  
Environmental Capacity ◽  
Water Environmental Capacity ◽  
Functional Zones ◽  
The Government

In recent years, due to unsustainable production methods and the demands of daily life, the water quality of the Yangtze River has deteriorated. In response to Yangtze River protection policy, and to protect and restore the ecological environment of the river, a two-dimensional model of the Jiangsu section was established to study the water environmental capacity (WEC) of 90 water environment functional zones. The WEC of the river in each city was calculated based on the results of the water environment functional zones. The results indicated that the total WECs of the study area for chemical oxygen demand (COD), ammonia nitrogen (NH3-N), and total phosphorus (TP) were 251,198 t/year, 24,751 t/year, and 3251 t/year, respectively. Among the eight cities studied, Nanjing accounted for the largest proportion (25%) of pollutants discharged into the Yangtze River; Suzhou (11%) and Zhenjiang (12%) followed, and Wuxi contributed the least (0.4%). The results may help the government to control the discharge of pollutants by enterprises and sewage treatment plants, which would improve the water environment and effectively maintain the water ecological function. This research on the WEC of the Yangtze River may serve as a basis for pollution control and water quality management, and exemplifies WEC calculations of the world’s largest rivers.

Impact of the Three Gorges reservoir operation on downstream ecological water requirements

2012 ◽  
Vol 43 (1-2) ◽  
pp. 48-53 ◽  
Author(s):  
Qiongfang Li ◽  
Meixiu Yu ◽  
Jianhua Zhao ◽  
Tao Cai ◽  
Guobin Lu ◽  
...  
Keyword(s):  
Flow Regime ◽  
Reservoir Operation ◽  
Yangtze River ◽  
Three Gorges Reservoir ◽  
Three Gorges ◽  
The Yangtze River ◽  
Water Requirements ◽  
The Three Gorges Reservoir ◽  
The Three Gorges ◽  
Ecological Water Requirements

With population increase and economic growth, the flow regime of the Yangtze River has been altered to some extent by human activities, particularly dam construction. Dam-induced alterations in the flow regime of the Yangtze River will unavoidably influence water allocation among different water users and instream ecological water requirements may not be guaranteed during some months, particularly during phases of reservoir storing water. To assess the impacts of the Three Gorges reservoir operation on the downstream minimum instream ecological water requirements, this paper selected the Three Gorges reservoir and Yichang hydrological station below the reservoir as case study sites. On the basis of long-term time series of daily discharge data, the reservoir outflow was simulated under two water storing schemes and the degree to which the downstream minimum ecological flow was satisfied was computed. The results of this paper could provide references for the integrated management of the Yangtze River water resources and the assessment of dam-induced impacts on the Yangtze River ecosystem health.

scholarly journals Characteristics and Causes of Long-Term Water Quality Variation in Lixiahe Abdominal Area, China

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1694
Author(s):  
Chenjuan Jiang ◽  
Jia’nan Zhou ◽  
Jingcai Wang ◽  
Guosheng Fu ◽  
Jiren Zhou
Keyword(s):  
Water Quality ◽  
Quality Improvement ◽  
Yangtze River ◽  
Water Diversion ◽  
The Yangtze River ◽  
Water Quality Improvement ◽  
Water Quality Variation ◽  
Quality Variation ◽  
Regional Water

The Lixiahe abdominal area is a representative plain river network in the lower reaches of the Huai River, being an upstream section of south-to-north water diversion from the Yangtze River in Jiangsu Province, China. The assessment of long-term water quality variation and the identification of probable causes can provide references for sustainable water resources management. Based on the monthly water quality data of 15 monitoring stations in the Lixiahe abdominal area, the periodic characteristics and tendency of water quality variation were studied by combining wavelet analysis, the Mann–Kendall trend test, and Sen’s slope estimator, and the correlation between water quality variation, water level, and water diversion was discussed with cross wavelet transform and wavelet coherence. The results show that the comprehensive water quality index (CWQI) included periodic fluctuations on multiple scales from 0.25 to 5 years. The CWQI of 7 out of 15 monitoring stations has a significant decreasing trend, indicating regional water quality improvement. The trend slope ranges from −0.071/yr to 0.007/yr, where −0.071/yr indicates the water quality improvement by one grade in 15 years. The spatial variation of water quality in the Lixiahe abdominal area was significant. The water quality of the main water diversion channels and its nearby rivers was significantly improved, while the improvement of other areas was not significant or even became worse due to the increasing discharge of pollutants. The CWQI of the main water diversion channels and its nearby rivers was inversely correlated with the amount of water diversion. The greater the amount of water diversion, the better the water quality. The water diversion from the Yangtze River has played an important role in improving the regional water environment.

How polluted is the Yangtze river? Water quality downstream from the Three Gorges Dam

2008 ◽  
Vol 402 (2-3) ◽  
pp. 232-247 ◽  
Author(s):  
Beat Müller ◽  
Michael Berg ◽  
Zhi Ping Yao ◽  
Xian Feng Zhang ◽  
Ding Wang ◽  
...  
Keyword(s):  
Water Quality ◽  
River Water ◽  
Yangtze River ◽  
River Water Quality ◽  
Three Gorges Dam ◽  
Three Gorges ◽  
The Yangtze River ◽  
The Three Gorges ◽  
The Three Gorges Dam

Experimental investigation on water quality standard of Yangtze River water source heat pump

2012 ◽  
Vol 66 (5) ◽  
pp. 1103-1109 ◽  
Author(s):  
Zenghu Qin ◽  
Mingwei Tong ◽  
Lin Kun
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
River Water ◽  
Heat Pump ◽  
Yangtze River ◽  
Water Source ◽  
Quality Standard ◽  
Heat Pumps ◽  
The Yangtze River ◽  
Water Conditions

Due to the surface water in the upper reaches of Yangtze River in China containing large amounts of silt and algae, high content of microorganisms and suspended solids, the water in Yangtze River cannot be used for cooling a heat pump directly. In this paper, the possibility of using Yangtze River, which goes through Chongqing, a city in southwest China, as a heat source–sink was investigated. Water temperature and quality of the Yangtze River in the Chongqing area were analyzed and the performance of water source heat pump units in different sediment concentrations, turbidity and algae material conditions were tested experimentally, and the water quality standards, in particular surface water conditions, in the Yangtze River region that adapt to energy-efficient heat pumps were also proposed. The experimental results show that the coefficient of performance heat pump falls by 3.73% to the greatest extent, and the fouling resistance of cooling water in the heat exchanger increases up to 25.6% in different water conditions. When the sediment concentration and the turbidity in the river water are no more than 100 g/m3 and 50 NTU respectively, the performance of the heat pump is better, which can be used as a suitable river water quality standard for river water source heat pumps.

Sign in / Sign up

Export Citation Format

Share Document