scholarly journals Effects of dimensionality on the performance of hydrodynamic models

2021 ◽  
Author(s):  
Mayra Ishikawa ◽  
Wendy Gonzalez ◽  
Orides Golyjeswski ◽  
Gabriela Sales ◽  
J. Andreza Rigotti ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Temperature ◽  
Flow Velocity ◽  
Numerical Models ◽  
Mixed Layer Depth ◽  
Water Reservoir ◽  
Density Currents ◽  
Hydrodynamic Models ◽  
Subtropical Zone ◽  
Drinking Water Reservoir

Abstract. Numerical models are an important tool for simulating temperature, hydrodynamics and water quality in lakes and reservoirs. Existing models differ in dimensionality by considering spatial variations of simulated parameters (e.g., flow velocity and water temperature) in one (1D), two (2D) or three (3D) spatial dimensions. The different approaches are based on different levels of simplification in the description of hydrodynamic processes and result in different demands in computational power. The aim of this study is to compare three models with different dimensionality and to analyze differences between model results in relation to model simplifications. We analyze simulations of thermal stratification, flow velocity, and substance transport by density currents in a medium-sized drinking water reservoir in the subtropical zone, using three widely used open-source models: GLM (1D), CE-QUAL-W2 (2D) and Delft3D (3D). The models were operated with identical initial and boundary conditions over a one-year period. Their performance was assessed by comparing model results with measurements of temperature, flow velocity and turbulence. Results show that all models were capable of simulating the seasonal changes in water temperature and stratification. Flow velocities, only available for the 2D and 3D approaches, were more challenging to reproduce, but 3D simulations showed closer agreement with observations. With increasing dimensionality, the quality of the simulations also increased in terms of error, correlation and variance. None of the models provided good agreement with observations in terms of mixed layer depth, which also affects the spreading of inflowing water as density currents, and the results of water quality models that build on outputs of the hydrodynamic models.

Turning Routine Data into Systems Insight: Multivariate Analysis of Water Quality Dynamics in a Major Drinking Water Reservoir

2020 ◽  
Vol 25 (4) ◽  
pp. 565-579
Author(s):  
Azadeh Golshan ◽  
Craig Evans ◽  
Phillip Geary ◽  
Abigail Morrow ◽  
Zoe Rogers ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Multivariate Analysis ◽  
Water Reservoir ◽  
Routine Data ◽  
Drinking Water Reservoir

Sediment record of mining legacy and water quality from a drinking-water reservoir, Aztec, New Mexico, USA

2020 ◽  
Vol 79 (17) ◽  
Author(s):  
Johanna M. Blake ◽  
Jeb E. Brown ◽  
Christina L. Ferguson ◽  
Rebecca J. Bixby ◽  
Naomi T. Delay
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
New Mexico ◽  
Water Reservoir ◽  
Sediment Record ◽  
Drinking Water Reservoir

Hydrology and Water Quality Survey Near the Gezhouba Dam in the Winter

2013 ◽  
Vol 726-731 ◽  
pp. 3256-3261
Author(s):  
Jia Fei Zhou ◽  
Cong Feng Wang ◽  
De Fu Liu ◽  
Jing Wen Xiang ◽  
Ping Zhao ◽  
...  
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Water Temperature ◽  
Flow Velocity ◽  
Water Column ◽  
Quality Data ◽  
Chinese Sturgeon ◽  
Water Quality Data ◽  
Gezhouba Dam ◽  
Survival Condition

Filed hydrology and water quality data were collected near the Gezhouba Dam early December of 2012 to analyze the response of Chinese Sturgeon survival condition to water temperature, dissolved oxygen (DO), pH, transparency (SD) and bottom flow-velocity. The results showed that water temperature lag is unconspicuous. The water temperature of Gezhouba Dam Sanjiang (GDS) was lower than that of Gezhouba Dam River (GDR), and it hindered propagation of sturgeon eggs. DO decreased fast in the vertical water column of GDS, pH ranged from 7.5 to 7.71. The hydrology and water quality were suitable for the life condition of sturgeon eggs and fry, except index of bottom flow-velocity.

scholarly journals Field Research on Mixing Aeration in a Drinking Water Reservoir: Performance and Microbial Community Structure

2019 ◽  
Vol 16 (21) ◽  
pp. 4221 ◽  
Author(s):  
Zizhen Zhou ◽  
Tinlin Huang ◽  
Weijin Gong ◽  
Yang Li ◽  
Yue Liu ◽  
...  
Keyword(s):  
Drinking Water ◽  
Microbial Community ◽  
Water Temperature ◽  
Water Reservoir ◽  
Field Research ◽  
Pollutant Removal ◽  
Chl A ◽  
Drinking Water Reservoir ◽  
Aeration System ◽  
Significant Difference

Field research on the performance of pollutant removal and the structure of the microbial community was carried out on a drinking water reservoir. After one month of operation of a water-lifting aeration system, the water temperature difference between the bottom and the surface decreased from 9.9 to 3.1 °C, and the concentration of the dissolved oxygen (DO) in the bottom layer increased from 0 to 4.2 mg/L. The existing stratification in the reservoir was successfully eliminated. Total nitrogen (TN), total phosphorus (TP), and total organic carbon (TOC) concentrations were reduced by 47.8%, 66.7%, and 22.9%, respectively. High-throughput sequencing showed that Proteobacteria, Bacteroides, and Actinomycetes accounted for 67.52% to 78.74% of the total bacterial population. Differences in the bacterial changes were observed between the enhanced area and the control area. With the operation of the water-lifting aeration system, the populations of bacteria of the main genera varied temporally and spatially. Principal component analysis pointed out a clear evolution in the vertical distribution of the microbial structure controlled by the operation of the aeration system. Permutational analysis of variance showed a significant difference in the microbial community (p < 0.01). Redundancy analysis showed that physical (water temperature, DO) and chemical environmental factors (Chl-a, TOC, TN) were the key factors affecting the changes in the microbial communities in the reservoir water. In addition, a hierarchical partitioning analysis indicated that T, Chl-a, ORP, TOC, pH, and DO accounted for 24.1%, 8.7%, 6.7%, 6.2%, 5.8%, and 5.1% of such changes, respectively. These results are consistent with the ABT (aggregated boosted tree) analysis for the variations in the functional bacterial community, and provide a theoretical basis for the development and application of biotechnology.

An Assessment of the Physicochemical Parameters of Mananga River, Cebu, Philippines

2012 ◽  
Vol 4 (1) ◽  
Author(s):  
Mary Joyce L. Flores ◽  
Macrina T. Zafaralla
Keyword(s):  
Water Quality ◽  
Water Temperature ◽  
Flow Velocity ◽  
Physicochemical Parameters ◽  
Oxygen Demand ◽  
Anthropogenic Sources ◽  
Positive Correlation ◽  
Water Currents ◽  
Significant Spatial Variation ◽  
Water Quality Status

The Mananga River today is a source of potable water to meet the demands of a fast growing Cebu metropolis. The physicochemical parameters of Mananga River were studied to assess its water quality status. Six sample collections were done from February to December 2006 in 3 monitoring stations covering the upstream (S1), midstream (S2) and downstream (S3) of Mananga River. Results showed significant spatial variation (p<0.05) in the studied physicochemical parameters except for alkalinity, total phosphates and nitrate-nitrogen (NO3-N). Significant temporal variation (p<0.05) was also observed for the factors except for stream width, biological oxygen demand (BOD5) and total suspended solids (TSS). Flow velocity showed significant positive correlation with discharge, pH, DO and NO3-N, and negative correlation with water temperature and TSS. Water temperature correlated negatively with DO and pH, and positively with TSS, with the latter showing a positive correlation with BOD5. The results implied that water currents play a major role in the distribution of dissolved substances and the suspension of sediments. Water quality of the studied segments of Mananga River progressively decreased downstream and was more pronounced during the dry periods. Results also indicated that the river was receiving loads of organic matter from natural and anthropogenic sources.   Keywords - ecology, Mananga River, water quality, flow velocity, Cebu City, Philippines

scholarly journals Prioritizing riparian corridors for ecosystem restoration in urbanizing watersheds

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8174 ◽  
Author(s):  
Samuel F. Atkinson ◽  
Matthew C. Lake
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Ecosystem Services ◽  
Watershed Management ◽  
Water Reservoir ◽  
Riparian Restoration ◽  
Surface Slope ◽  
Management Options ◽  
Riparian Corridors ◽  
Drinking Water Reservoir

Background Riparian corridors can affect nutrient, organic matter, and sediment transport, all of which shape water quality in streams and connected downstream waters. When functioning riparian corridors remain intact, they provide highly valued water quality ecosystem services. However, in rapidly urbanizing watersheds, riparian corridors are susceptible to development modifications that adversely affect those ecosystem services. Protecting high quality riparian corridors or restoring low quality corridors are widely advocated as watershed level water quality management options for protecting those ecosystem services. The two approaches, protection or restoration, should be viewed as complementary by watershed managers and provide a foundation for targeting highly functioning riparian corridors for protection or for identifying poorly functioning corridors for restoration. Ascertaining which strategy to use is often motivated by a specific ecosystem service, for example water quality, upon which watershed management is focused. We have previously reported on a spatially explicit model that focused on identifying riparian corridors that have specific characteristics that make them well suited for purposes of preservation and protection focused on water quality. Here we hypothesize that focusing on restoration, rather than protection, can be the basis for developing a watershed level strategy for improving water quality in urbanizing watersheds. Methods The model described here represents a geographic information system (GIS) based approach that utilizes riparian characteristics extracted from 40-meter wide corridors centered on streams and rivers. The model focuses on drinking water reservoir watersheds that can be analyzed at the sub-watershed level. Sub-watershed riparian data (vegetation, soil erodibility and surface slope) are scaled and weighted based on watershed management theories for water quality, and riparian restoration scores are assigned. Those scores are used to rank order riparian zones –the lower the score the higher the priority for riparian restoration. Results The model was applied to 90 sub-watersheds in the watershed of an important drinking water reservoir in north central Texas, USA. Results from this study area suggest that corridor scores were found to be most correlated to the amount of: forested vegetation, residential land use, soils in the highest erodibility class, and highest surface slope (r2 = 0.92, p < 0.0001). Scores allow watershed managers to rapidly focus on riparian corridors most in need of restoration. A beneficial feature of the model is that it also allows investigation of multiple scenarios of restoration strategies (e.g.,  revegetation, soil stabilization, flood plain leveling), giving watershed managers a tool to compare and contrast watershed level management plans.

scholarly journals Occurrence of cyanobacteria, actinomycetes, and geosmin in drinking water reservoir in Korea: a case study from an algal bloom in 2012

2020 ◽  
Vol 20 (5) ◽  
pp. 1862-1870
Author(s):  
Jung Eun Lee ◽  
Seok-Jae Youn ◽  
Myeongseop Byeon ◽  
Soon-Ju Yu
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Cell Density ◽  
Algal Bloom ◽  
Water Reservoir ◽  
Primary Source ◽  
High Concentration ◽  
Drinking Water Reservoir ◽  
Peak Value

Abstract In 2012, a large concentration of geosmin was found in the Paldang reservoir, which is the primary source of drinking water in Seoul, Korea. In June and September 2012, we measured the concentrations of cyanobacteria and actinomycetes, and geosmin, to identify the source of geosmin in the Paldang reservoir. A total of 68 water samples were collected from two sampling sites (Sambong, Paldang), and used to analyze the correlation between cyanobacteria, actinomycetes, and geosmin. The cell density attained a maximum of 24,722 cells/mL on August 11, 2012 and geosmin occurred at a high concentration of 3,934 ng/L on August 13 in Sambong. After July 31, 2012 a rapid increase in growth and cell density occurred with a peak value of 11,568 cells/mL on August 6, 2012. At the same time, the geosmin concentration increased to 3,157 ng/L in Paldang. The number of cyanobacteria positively correlated with geosmin concentration (R2 = 0.84, P &lt; 0.0001), while actinomycetes were not significantly correlated with geosmin (R2 = 0.01, P = 0.709). In addition, the number of actinomycetes was associated with increased turbidity (R = 0.507). Among the various water quality constituents, temperature affected cyanobacteria in the Paldang reservoir (R = 0.803). These results suggest that cyanobacteria are the main source of geosmin in the Paldang reservoir, which might be providing useful information for managing the unpleasant taste of its drinking water.

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