scholarly journals Simulating the Impact of Water Quality Improvement Measures for Nutrient-Sensitive River Basins with the Aquatox Model

10.29007/5q94 ◽  
2018 ◽  
Author(s):  
Alper Elçi ◽  
Selma Ayaz ◽  
Sebnem Aynur
Keyword(s):  
Water Quality ◽  
Quality Improvement ◽  
River Basin ◽  
Multiple Models ◽  
Water Quality Improvement ◽  
Diffuse Source ◽  
The Future ◽  
Improvement Measures ◽  
The Impact

Water quality modelling studies are effective tools for the prediction of the impact of water quality improvement measures. This study aims to predict the future water quality of a nutrient-sensitive river basin assuming the implementation of water quality improvement measures by setting up and executing multiple models. The rationale behind the use of multiple models is the better suitability of each model for its relevant objective. Hydrodynamics of the river are simulated using the WASP model. Following the estimation of diffuse-source nutrient loadings in the river basin with the SWAT model, water quality of the river is simulated with a multi-segment Aquatox model. All models are calibrated to one year of observed data. Models are first executed to obtain the current water quality status and then to predict the water quality for the period of 2016-2040. For the future persion, it is assumed that measures are taken to reduce point-source and diffuse-source pollutant loadings. Model results suggest that load reductions are expected to be effective and that improvement in water quality can be predicted for all water quality indicators. TKN concentrations vary between 0.11-2.13 mg/l with the highest mean concentration occurring during the months of January. TP concentrations are expected to have a higher variability (0.032-0.65 mg/l).

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.

What Price for Ecosystem Services in China?

2017 ◽  
pp. 176-198
Author(s):  
Haixia Zheng ◽  
Stale Navrud ◽  
Shiran Shen
Keyword(s):  
Water Quality ◽  
Quality Improvement ◽  
Ecosystem Services ◽  
Water Resources ◽  
River Basin ◽  
Contingent Valuation Method ◽  
Policy Instrument ◽  
Miyun Reservoir ◽  
Water Quality Improvement ◽  
Value Of Water

Payment for Environmental Services (PES) in the watershed has been widely adopted as an important policy instrument to compensate upstream water users for providing water quality improvement for the whole river basin. In this paper, we use three independent valuation methods to determine the price of ecosystem service (ES), particularly water quality, in Miyun Reservoir, the main surface water source for Beijing. We find that the value of water quality is lowest using opportunity cost of limitation of development rights (OCLDR), highest with contingent valuation method (CVM), and water resources benefits assessment (WRBA) gives an in-between value. OCLDR determines the size of subsidies from those that benefit from water quality improvement from upstream. WRBA is a reference for compensation criteria to the upstream government and farmers when water resources are transferred across jurisdictional boundaries. CVM not only captures the direct value of water quality improvement, but also the indirect value of improvement in other ecosystem services as a result of improvement in water quality. Based on the results, we propose a multi-level ecological compensation system for the Miyun Reservoir river basin. We use OCLDR to determine subsides/ compensation to upstream farmers and other suppliers of the ES; WRBA set the price of water transfer; and CVM to figure out the size of payments for integrated water quality improvement.

scholarly journals Effects of Opened and Closed Spillway Operations of a Large Tropical Hydroelectric Dam on the Water Quality of the Downstream River

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Fiona-Annilow Wera ◽  
Teck-Yee Ling ◽  
Lee Nyanti ◽  
Siong-Fong Sim ◽  
Jongkar Grinang
Keyword(s):  
Water Quality ◽  
River Basin ◽  
Aquatic Organisms ◽  
Quality Parameters ◽  
Regulated River ◽  
Land Uses ◽  
Hydroelectric Dam ◽  
Water Ph ◽  
The Impact

Water quality downstream of a hydroelectric dam is potentially affected by dam operations and other land uses in the river basin. Previous short-distance studies below the large Bakun Dam indicated poorer water quality during closed spillway. However, the extent of the impact is still unknown. Such knowledge is essential for mitigating the impact of the dam. Thus, the objectives of this study were to determine the water quality up to a distance of 210 km under two spillway operations, namely, closed and opened spillways, and also to determine the changes in water quality from the predam condition. Physicochemical parameters were measured at 15 stations along the Rajang River. Results of this preliminary study indicated that there were significant differences in eight out of nine water quality parameters between opened and closed spillway operations with opened spillway showing better water quality. During closed spillway, as we approached the dam, there was an increasing acidity and a decreasing oxygen content. Furthermore, as the water flows downstream, the unhealthy DO level (<5 mg/L) extended up to 165 km and the linear model showed an increasing DO rate of 0.09 mg/L per km. With opened spillway, DO decreased exponentially from 9.74 mg/L towards the downstream direction to 7.67 mg/L. The increasing turbidity and TSS in the downstream direction indicate contributions from erosion due to other land uses. The river is polluted with organics as indicated by COD of Class IV or V with sources from the dam and the activities in the river basin. Compared to the predam condition, the regulated river is less turbid but warmer and higher in ammonia. Closed spillway led to lower DO and acidic water. However, opened spillway water pH and DO were similar to those in the predam condition. Thus, it is recommended that DO be consistently high enough for the health of sensitive aquatic organisms downstream.

scholarly journals Spatial-temporal analysis of the surface water quality of the Pará River Basin through statistical techniques

2019 ◽  
Vol 14 (1) ◽  
pp. 1
Author(s):  
Josiani Cordova de Oliveira ◽  
Kelly Prado Maia ◽  
Nara Linhares Borges de Castro ◽  
Sílvia Maria Alves Corrêa Oliveira
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
River Basin ◽  
Statistical Tests ◽  
Surface Water Quality ◽  
Minas Gerais ◽  
State Legislation ◽  
Historical Series ◽  
The Impact

Water quality issues are a growing concern due to the the recent intensification of urbanization and industrialization. This paper evaluates and compares the surface water quality of the ten sub-basins of the Pará River, located in the São Francisco River Basin, Minas Gerais, and evaluates the impact of seasonality and the compliance with the current limits of state legislation. The surface water quality monitoring database of the Institute of Water Management of Minas Gerais (Igam) was used, and 18 parameters were analyzed from a historical series from 2008 to 2016, totaling 16,651 observations. First, the descriptive statistics of the parameters were calculated, considering each sub-basin separately. Then, for the temporal and spatial analysis, the Kruskal-Wallis nonparametric statistical tests were applied, followed by the multiple comparison test, with an alpha level of 5%, due to the asymmetric behavior of the data. Thus, it was possible to compare water quality of the sub-basins in rainy and dry seasons and to identify which parameters were responsible for the greater degradation. In the compliance analysis to the current limits of state legislation, it was identified that all of the sub-basins were out of the specified range for at least one of the evaluated parameters. Finally, the seasonality analysis exposed significant differences in the parameters of dissolved oxygen, turbidity, total suspended solids, total solids and water temperature, where it was shown that there was a worsening of water quality in the rainy season for most sub-basins.

Water Quality Improvement of a Reservoir Invaded by an Exotic Macrophyte

2012 ◽  
Vol 5 (2) ◽  
pp. 290-299 ◽  
Author(s):  
Mariana Rodríguez ◽  
Jacques Brisson ◽  
Guillermo Rueda ◽  
Manuel S. Rodríguez
Keyword(s):  
Water Quality ◽  
Invasive Species ◽  
Quality Improvement ◽  
Ecological Risk ◽  
Secchi Disk ◽  
Water Quality Improvement ◽  
Ecological Service ◽  
Quality Assessments

AbstractThe aim of this study was to evaluate the effect of the macrophyte waterhyacinth on the water quality of a reservoir in Colombia. Postinvasion water quality assessments were performed during three different hydrological periods and compared with preinvasion data. The results show that water quality has improved, especially in terms of transparency, showing an increase in Secchi disk values from 0.3 to 2 m (1 to 6.6 ft). The analysis strongly suggests that the improvement in water quality is due to the filtering and precipitation effects provided by waterhyacinth. This case highlights the dilemma of managing an invasive species that provides a beneficial ecological service while posing a high ecological risk.

Long-Term Trends in Intertidal and Subtidal Benthic Communities in Response to Water Quality Improvement Measures

2010 ◽  
Vol 33 (6) ◽  
pp. 1314-1326 ◽  
Author(s):  
Paula Chainho ◽  
Gilda Silva ◽  
Michael F. Lane ◽  
José L. Costa ◽  
Tadeu Pereira ◽  
...  
Keyword(s):  
Water Quality ◽  
Quality Improvement ◽  
Benthic Communities ◽  
Water Quality Improvement ◽  
Improvement Measures ◽  
Long Term Trends ◽  
Response To Water

What Price for Ecosystem Services in China?

2017 ◽  
pp. 171-192
Author(s):  
Haixia Zheng ◽  
Stale Navrud ◽  
Shiran Shen
Keyword(s):  
Water Quality ◽  
Quality Improvement ◽  
Ecosystem Services ◽  
Water Resources ◽  
River Basin ◽  
Contingent Valuation Method ◽  
Policy Instrument ◽  
Miyun Reservoir ◽  
Water Quality Improvement ◽  
Value Of Water

Payment for Environmental Services (PES) in the watershed has been widely adopted as an important policy instrument to compensate upstream water users for providing water quality improvement for the whole river basin. In this paper, we use three independent valuation methods to determine the price of ecosystem service (ES), particularly water quality, in Miyun Reservoir, the main surface water source for Beijing. We find that the value of water quality is lowest using opportunity cost of limitation of development rights (OCLDR), highest with contingent valuation method (CVM), and water resources benefits assessment (WRBA) gives an in-between value. OCLDR determines the size of subsidies from those that benefit from water quality improvement from upstream. WRBA is a reference for compensation criteria to the upstream government and farmers when water resources are transferred across jurisdictional boundaries. CVM not only captures the direct value of water quality improvement, but also the indirect value of improvement in other ecosystem services as a result of improvement in water quality. Based on the results, we propose a multi-level ecological compensation system for the Miyun Reservoir river basin. We use OCLDR to determine subsides/ compensation to upstream farmers and other suppliers of the ES; WRBA set the price of water transfer; and CVM to figure out the size of payments for integrated water quality improvement.

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