Modelling of suspended sediment in a weir reach using EFDC model

2015 ◽  
Vol 73 (7) ◽  
pp. 1583-1590 ◽  
Author(s):  
Gijung Pak ◽  
Kristine Joy B. Mallari ◽  
Jongrak Baek ◽  
Deokwoo Kim ◽  
Hwansuk Kim ◽  
...  

Construction of hydraulic structures often leads to alteration of river dynamics and water quality. Suspended solids entering the upstream of the weir cause adverse effects to the hydroecological system and, therefore, it is necessary to build a modelling system to predict the changes in the river characteristics for proper water quality management. In this study, the discharges and total suspended solids upstream and downstream of the Baekje Weir installed in Geum River, Korea, was modelled using the environmental fluid dynamics code (EFDC) model. The resulting trend of four rainfall events shows that as rainfall increases, the total suspended solids (TSS) concentration increases as well. For the two larger events, at the upstream of the weir, TSS was observed to decrease or remain constant after the rainfall event depending on the lowering of the open gate. At the downstream, TSS supply was controlled by the weir during and after the rainfall event resulting in decline in the TSS concentration. The modelling produced good results for discharge based on %Diff. (4.37–6.35), Nash–Sutcliffe efficiency (NSE) (0.94–0.99) and correlation coefficient (r) (0.97–0.99) values as well as for TSS with acceptable values for %Diff. (12.08–14.11), NSE (0.75–0.81) and r (0.88–0.91), suggesting good applicability of the model for the weir reach of the river in the study site.

2021 ◽  
Vol 49 (1) ◽  
pp. 188-192
Author(s):  
Mario Manzano ◽  
Eduardo Jaramillo ◽  
Mario Pino

The effects of a sudden rainfall (40 mm d-1) event on the surface waters covering muddy tidal flats were studied during April 2016 at the estuarine Cruces River wetland in south-central Chile (~40ºS). The study area included flooded vestigial tree trunks, which is evidence of coseismic subsidence associated with the 1960 Valdivia earthquake as a source of environmental variability. The tidal flat with vestigial tree trunks registered the fastest and highest depth of inundation. In contrast, the tidal currents velocity and total suspended solids' concentrations were higher at the flat without trunks. Sudden rainfall events can significantly modify the characteristics of surface waters above sedimentary intertidal surfaces, where structures such as flooded trunks are present.


1996 ◽  
Vol 47 (6) ◽  
pp. 763 ◽  
Author(s):  
EG Abal ◽  
WC Dennison

Correlations between water quality parameters and seagrass depth penetration were developed for use as a biological indicator of integrated light availability and long-term trends in water quality. A year-long water quality monitoring programme in Moreton Bay was coupled with a series of seagrass depth transects. A strong gradient between the western (landward) and eastern (seaward) portions of Moreton Bay was observed in both water quality and seagrass depth range. Higher concentrations of chlorophyll a, total suspended solids, dissolved and total nutrients, and light attenuation coefficients in the water column and correspondingly shallower depth limits of the seagrass Zostera capricorni were observed in the western portions of the bay. Relatively high correlation coefficient values (r2 > 0.8) were observed between light attenuation coefficient, total suspended solids, chlorophyll a, total Kjeldahl nitrogen and Zostera capricorni depth range. Low correlation coefficient values (r2 < 0.8) between seagrass depth range and dissolved inorganic nutrients were observed. Seagrasses had disappeared over a five-year period near the mouth of the Logan River, a turbid river with increased land use in its watershed. At a site 9 km from the river mouth, a significant decrease in seagrass depth range corresponded to higher light attenuation, chlorophyll a, total suspended solids and total nitrogen content relative to a site 21 km from the river mouth. Seagrass depth penetration thus appears to be a sensitive bio-indicator of some water quality parameters, with application for water quality management.


2015 ◽  
Vol 41 (1) ◽  
pp. 13-19
Author(s):  
Kaniz Fatema ◽  
Wan Maznah Wan Omar ◽  
Mansor Mat Isa

Water quality in three different stations of Merbok estuary was investigated limnologically from October, 2010 to September, 2011. Water temperature, transparency and total suspended solids (TSS) varied from 27.45 - 30.450C, 7.5 - 120 cm and 10 -140 mg/l, respectively. Dissolved Oxygen (DO) concentration ranged from 1.22-10.8 mg/l, while salinity ranged from 3.5-35.00 ppt. pH and conductivity ranged from 6.35 - 8.25 and 40 - 380 ?S/cm, respectively. Kruskal Wallis H test shows that water quality parameters were significantly different among the sampling months and stations (p<0.05). This study revealed that DO, salinity, conductivity and transparency were higher in wet season and TSS was higher in dry season. On the other hand, temperature and pH did not follow any seasonal trends.Bangladesh J. Zool. 41(1): 13-19, 2013


2021 ◽  
Vol 25 (3) ◽  
pp. 34-43
Author(s):  
Tamarah A. Adnan ◽  
◽  
Eman A. Mohammed ◽  
Abdul-Sahib T. Al-Madhhachi ◽  
◽  
...  

Tigris River is the only potable source in Baghdad city therefor many water treatment plants were built on the banks such as Al-Karkh, Sharq Dijla, Al-Sadr, Al-Wathba, Al-Karama, AlQadisia, Al-Dora, Al-Wahda, and Al-Rashed project. Tigris River suffers from the pollution that comes from various sources such as Industry, domestic sanitation, and farming activities therefore several indices were used to calculate water quality within Baghdad to convert physicochemical parameters of water to a single value that represents the river status (good, bad, very bad, etc..).The aim of this review paper to show the results of previous studies about the water quality for the Baghdad region. Most results showed that water quality was good in the north of the city of Baghdad and bad in the south of Baghdad. The deterioration of water quality was due to many reasons such as the discharge of wastewater directly into the river without pretreatment, increase in (Electic conductivity, Turbidity, and total suspended solids, total hardness, Iron ion, the fecal coliform)concentrations, and Climate change, therefore, Tigris River needs intensive treatment before using by humans.


2017 ◽  
Vol 16 (1) ◽  
pp. 75-85
Author(s):  
O. E. OMOFUNMI ◽  
J. K. . ADEWUMI ◽  
A. F. ADISA ◽  
S. O. ALEGBELEYE

Catfish production is one of the largest segments of fish culture in Lagos State, Nigeria. However, catfish effluents, which usually deteriorate the environment, need to be controlled. The effect of paddle-wheel aerator in catfish effluent was evaluated. The volume of catfish effluent was collected into two basins and diluted at given ratios. The paddle-wheel aerator was installed in one basin, while another basin served as control in determining the impact of paddle wheel aerator on catfish effluents. Water qualities such as Total Suspended Solids (TSS), Total Nitrogen (TN), Total Phosphorus (TP), Total Ammonia (TNH3) and Nitrite (NO2-N) and Biochemical oxygen demand (BOD5) examined and ana-lysed. Results indicated that paddle-wheel aerator reduced TSS (24.4±1.5 %), TN2-N (53.3±1.2 %) , TNH3-N (65.2±1.2 %) , NO2-N (97.1±1.1 %) , TP (61.8±1.1 %) and BOD5 (54 ±1.5 %). com-pared with natural purification 33.9±1.6 % of TSS, 22.7±1.4 % of TN2-N, 29.3±1.6 % of TNH3-N, 53.9±1.2 % of NO2-N, 21.6±1.5 % of TP and 15.4±1.6 % of BOD5 at the same dilution ratio There were significant different (P ≤0.05) between paddle wheel aerator and natural purification in concen-trations reduction. The paddle wheel aerator was found to be relevant in the water quality improve-ment and thus recommend for small and medium scale fish farmers in controlling effluents.


2018 ◽  
Vol 52 (4) ◽  
pp. 19-31
Author(s):  
Christopher Buzzelli ◽  
Zhiqiang Chen ◽  
Peter Doering ◽  
Amanda Kahn

Abstract Coastal water bodies are impacted by watershed alterations, increased population density, modifications to inlets and shorelines, climatic periodicity, and increases in external material loads. Estuaries such as Lake Worth Lagoon (LWL) in south Florida possess all these attributes. The LWL watershed extends from the southeastern portion of Lake Okeechobee through Palm Beach County, where it meets the lagoon. Palm Beach County Department of Environmental Resources Management recognizes the social and ecological importance of the ~36 km lagoon and aims to maintain suitable water and habitat quality for all stakeholders. Recent declines and shifts of seagrass distribution along the lagoon prompted a step toward better understanding the water quality patterns of the system. In support of these efforts, this study assessed bathymetry, inflow, flushing, and water quality attributes (chlorophyll a, salinity, total nitrogen, total phosphorus, total suspended solids, turbidity) using data collected along a series of 14 midlagoon stations from 2007 to 2015. Salinity in the North Segment was higher and less variable because of proximity to Palm Beach Inlet. Although concentrations of chlorophyll a, total nitrogen, and total phosphorus correlated with freshwater inflow, turbidity and total suspended solids were not. Fast flushing of the lagoon on a scale of days likely precludes water quality issues common to many estuaries with higher resident times. However, the combination of landscape-scale water management, a shoreline that is almost 70% modified by hard structures, and changes in essential nearshore habitats, introduces new levels of uncertainty to both the understanding and management of LWL. From this study, increased knowledge of relationships among water quality parameters and their spatial and temporal variability in LWL provides points of reference from which targeted studies can be developed to explore links between environmental parameters and responses of key organisms in this unique system.


2020 ◽  
Vol 12 (7) ◽  
pp. 2992 ◽  
Author(s):  
Kongmeng Ly ◽  
Graciela Metternicht ◽  
Lucy Marshall

Population growth and economic development are driving changes in land use/land cover (LULC) of the transboundary Lower Mekong River Basin (LMB), posing a serious threat to the integrity of the river system. Using data collected on a monthly basis over 30 years (1985–2015) at 14 stations located along the Lower Mekong river, this study explores whether spatiotemporal relationships exist between LULC changes and instream concentrations of total suspended solids (TSS) and nitrate—as proxies of water quality. The results show seasonal influences where temporal patterns of instream TSS and nitrate concentrations mirror patterns detected for discharge. Changes in LULC influenced instream TSS and nitrate levels differently over time and space. The seasonal Mann–Kendall (SMK) confirmed significant reduction of instream TSS concentrations at six stations (p < 0.05), while nitrate levels increased at five stations (p < 0.05), predominantly in stations located in the upper section of the basin where forest areas and mountainous topography dominate the landscape. Temporal correlation analyses point to the conversion of grassland (r = −0.61, p < 0.01) to paddy fields (r = 0.63, p < 0.01) and urban areas (r = 0.44, p < 0.05) as the changes in LULC that mostly impact instream nitrate contents. The reduction of TSS appears influenced by increased forest land cover (r = −0.72, p < 0.01) and by the development and operation of hydropower projects in the upper Mekong River. Spatial correlation analyses showed positive associations between forest land cover and instream concentrations of TSS (r = 0.64, p = 0.01) and nitrate (r = 0.54, p < 0.05), indicating that this type of LULC was heavily disturbed and harvested, resulting in soil erosion and runoff of nitrate rich sediment during the Wet season. Our results show that enhanced understanding of how LULC changes influence instream water quality at spatial and temporal scales is vital for assessing potential impacts of future land and water resource development on freshwater resources of the LMB.


RBRH ◽  
2016 ◽  
Vol 21 (4) ◽  
pp. 653-665
Author(s):  
Rubia Girardi ◽  
Adilson Pinheiro ◽  
Edson Torres ◽  
Vander Kaufmann ◽  
Luis Hamilton Pospissil Garbossa

ABSTRACT Studies carried out over short time intervals assist in understanding the biogeochemical processes occurring relatively fast in natural waters. High frequency monitoring shows a greater variability in the water quality during and immediately after heavy rainfall events. This paper presents an assessment of the surface water quality parameters in the Atlantic Forest biome, caused by heavy rainfall events. The work was developed in two fluviometric sections of the Concordia River watershed, located in the state of Santa Catarina, southern Brazil. The spatial distribution of land use shows the predominance of Atlantic Forest in fluviometric section 1 (FS1) and pasture, forestry, agriculture, and Atlantic Forest in fluviometric section 2 (FS2). In each selected heavy rainfall event, the evolution rainfall height, the water level, and physicochemical parameters of water were analyzed. In all events, the water quality changed due to the heavy rainfall. After the events, an increase in water level and turbidity in both fluviometric sections were detected. In addition, the ammonium ion concentration increased in the river, and the pH value and nitrate concentration decreased. The electrical conductivity presented different behavior in each section. The dissolved oxygen concentration increased in 19 of 27 events. The principal component (PC1) correlated with the turbidity in FS1, and it correlated with level, turbidity, and pH in FS2.


KIMIKA ◽  
2019 ◽  
Vol 30 (2) ◽  
pp. 49-60
Author(s):  
Ann Selma Morata ◽  
Jeff Tristan Caligan ◽  
Trixie Babes Capio ◽  
Kyle Dymer Regatalio

Malihao river was reported to have a decline in water quality over the years due to the increasing human activities surrounding the river. Various pollutants were present in the river such as suspended and dissolved solids, copper, lead, cadmium, and oil/grease; and their concentration levels are beyond the set limit by the national guidelines. The removal of these compounds was studied using waste bivalve shells is a suggested remedy, as they are locally available and abundant in the region. Total suspended solids were removed using chitosan from Perna viridis up to 81%; copper and lead were removed using Polymesoda erosa in a packed column; and oil/grease was efficiently removed using Crassostrea spp. up to 80-100%. Additional monitoring efforts in the locality should be done to properly manage this body of water to prevent from further deterioration.


Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2618
Author(s):  
Johann Alexander Vera Mercado ◽  
Bernard Engel

Land use influences water quality in streams at different spatial scales and varies in time and space. Water quality has long been associated with agricultural and urban land uses in catchments. The effects of developed, forest, pasture, and agricultural land use on nitrogen, nitrate, and nitrite (NNN); total phosphorus (TP); total suspended solids (TSS); chemical oxygen demand (COD); dissolved oxygen (DO) and total Kjeldahl nitrogen (TKN) concentrations and their sensitivity were quantified to spatial pattern differences. The linear mixed modeling framework was used to examine the importance of spatial extent on models with water quality parameters as the response variable and land use types as the predictor variable. The results indicated that land use categories on different water quality parameters were significant and dependent on the selected spatial scales. Land use exhibited a strong association with total phosphorus and total suspended solids for close reach distances. Phosphorus is not highly soluble, and it binds strongly to fine soil particles, which are transported by water via runoff. Nitrogen, nitrate, and nitrite, dissolved oxygen, chemical oxygen demand, and total Kjeldahl nitrogen concentrations were better predicted for further reach distances, such as 45 or 50 km, where the best model of nitrogen, nitrate, and nitrite is consistent with the high mobility of NO3−.


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