Widespread changes to forested watersheds affected by the mountain pine beetle (Dendroctonus ponderosae Hopkins) epidemic across western North America raised concerns about the effects of this climate-induced disturba...Widespread changes to forested watersheds affected by the mountain pine beetle (Dendroctonus ponderosae Hopkins) epidemic across western North America raised concerns about the effects of this climate-induced disturbance on drinking water and natural resources. Effective communication and knowledge exchange across scientists and stakeholders (i.e., drinking water managers) is essential for constructively responding to such landscape scale disturbances, providing improved adaptive capacity through knowledge sharing. An assessment of stakeholder knowledge levels, information needs, primary concerns, and suggested communication strategies were conducted via an online elicitation survey and World Science Café workshops. Knowledge levels, assessed via a survey of local water managers and experts, were relatively low with approximately half of the respondents reporting little to no knowledge of the effects of mountain pine beetle on drinking water quality and quantity, thereby indicating limited knowledge exchange between scientists and drinking water stakeholders. Increased accessibility and dissemination of research findings pertinent to the mountain pine beetle epidemic’s effects on drinking water quality and quantity is necessary for natural resource management. Recommendations for improved communication among scientists and drinking water stakeholders in particular and forest health in general include dispersal of non-academic research summaries, information exchange through existing media and community resources, demonstration projects, and information clearinghouses. This information provides a better understanding of the challenges, concerns, and first-hand experience of stakeholders of a landscape disturbance issue to apply this knowledge to enhance land management practice and how researchers on this overall project enhanced science communication efforts.展开更多
River-type reservoir is narrow and long in shape and has many reservoir bends and confluence of tributaries. On the basis of Saint-Venant equation and differential equation for longitudinal diffusion and in considerat...River-type reservoir is narrow and long in shape and has many reservoir bends and confluence of tributaries. On the basis of Saint-Venant equation and differential equation for longitudinal diffusion and in consideration of the influence of confluences and bends, in order to predict the water quantity and quality, an one-dimensional unsteady mathematical model was established in this paper. The model consists of a hydrodynamic model and a water quality model. The average hydraulic characteristics and water quality parameters were calculated for a reservoir with two confluences and four bends. Computed results are in good agreement with field observation data. The model can be applied to predict the water quantity, water level and water quality of the river-type reservoirs.展开更多
It is very important in pollution treatment to clarify the space-time distribution of water quality in Dianchi Lake. Based on the sample data obtained from 10 observation stations every month from 2008 to 2009, it use...It is very important in pollution treatment to clarify the space-time distribution of water quality in Dianchi Lake. Based on the sample data obtained from 10 observation stations every month from 2008 to 2009, it uses space-time semi-variogram and ordinary kriging method to simulate the space-time variance and distribution of water quality indictors (TN, TP, BOD, CODMn, DO, Chlorophyl-α, etc.). Because the space-time semivariogram also has a certain of ex-trapolation function. From the simulation results, the pollution is mainly concentrated at the North (Caohai) and the Southwest area (Haikou), and water pollution has a increase trend.展开更多
A Walnut Gulch rainfall simulator was used to determine runoff water quality and salt balance of a Sandy Loam moderately saline-alkaline site containing 0.27%of gypsum near Moab,Utah.Four rainfall intensities correspo...A Walnut Gulch rainfall simulator was used to determine runoff water quality and salt balance of a Sandy Loam moderately saline-alkaline site containing 0.27%of gypsum near Moab,Utah.Four rainfall intensities corresponding to 2,10,25 and 50-year storm return intervals were applied to dry soil.During each rainfall simulation,time-stamped runoff samples were also collected for the determination of ions concentration.Soil water and solute content by depth increments were determined before and after simulations.All correlation coefficients between the applied simulation water and the amounts of Cl-,SO42-,NO3-and sum of anions in runoff water were positive and ranged between 0.922 and 0.999.The correlation coefficients for Ca2+,Mg2+,Na+,K+and sum of cations ranged between 0.783 and 0.983.We concluded from the data analysis that:(1)The amounts of ions in simulation water and in runoff water represent less than 1%of sum of the soil soluble content before rainfall simulation.(2)The CEC contained about 250%the sum of cation in saturated extract.(3)The very small amount of gypsum in the soil contained 50%the sum of saturated extract ions.This means that special attention should be paid to CEC and gypsum content in the management of such soils.Moreover,when modeling runoff and water quality from soils with these properties the modelers must include suitable subroutines considering gypsum and CEC of the soil for accurate prediction of runoff water quality.展开更多
Struvite (MgNH<sub>4</sub>PO<sub>4</sub>?6H<sub>2</sub>O) can be produced from municipal wastewater and has been shown to be an alternative fertilizer-phosphorus (P) source for vari...Struvite (MgNH<sub>4</sub>PO<sub>4</sub>?6H<sub>2</sub>O) can be produced from municipal wastewater and has been shown to be an alternative fertilizer-phosphorus (P) source for various crops, but little is known about the runoff-water-quality implications from soil-applied struvite. The objective of this study was to evaluate the effects of soil [Creldon (Oxyaquic Fragiudalfs), Dapue (Fluventic Hapludolls), Roxana (Typic Udifluvents), and Calloway (Aquic Fraglossudalfs) series], fertilizer-P source [synthetically produced electrochemically precipitated struvite (ECSTsyn), real-wastewater-derived ECST (ECSTreal), chemically precipitated struvite (CPST), and monoammonium phosphate (MAP)], and water source (rainwater, groundwater, and struvite-removed real wastewater) over time on runoff-water-quality parameters from laboratory-conducted, rainfall-runoff simulations. Mesh tea bags containing each soil-fertilizer treatment combination were rained on with each water source (Trial 1), incubated for 6 months, and rained on again (Trial 2) to evaluate runoff-water quality. Struvite fertilizers had similar runoff-water-quality properties to those from MAP. In Trial 1, runoff total P (TP) concentration differences (i.e., soil-fertilizer-water-type response minus control response minus blank response) from ECSTsyn or ECSTreal were 1 to 5 times larger than MAP and CPST for all water-soil-fertilizer-P source treatment combinations, except for the Creldon-groundwater and Roxana-wastewater combinations. In both trials, runoff TP decreased over time in all water-soil and soil-fertilizer-P source treatment combinations, except for the Roxana-CPST combination where TP increased over time by 46%. The similar water-quality responses from the struvite fertilizers among the various soils and water types compared to MAP suggest that struvite has similar runoff-water-quality implications as at least one widely used, commercially available fertilizer-P source.展开更多
Instream aeration has been used as a supplement to secondary treatment or a substitute for tertiary treatment for meeting dissolved oxygen (DO) standards in rivers. Many studies have used water quality models to det...Instream aeration has been used as a supplement to secondary treatment or a substitute for tertiary treatment for meeting dissolved oxygen (DO) standards in rivers. Many studies have used water quality models to determine the number, location, and capacity of instream aeration stations (IASs) needed to meet DO standards in combination with other pollution control measures. DO concentrations have been improved in the North Shore Channel and North Branch Chicago River by the Devon Avenue IAS for more than 35 years. A study was initiated to determine whether it was better to rehabilitate or relocate this station and to determine appropriate operational guidance for the IAS at the selected location. A water quality model capable of simulating DO concentrations during unsteady flow was used to evaluate the proper location for an IAS and operational guidance for this IAS. Three test years, a dry year, a wet year, and an extreme year, were considered in the evaluation. The study found that the Devon Avenue IAS should be rehabilitated as this location performed as well as or better than any of 10 alternative locations. According to the new operational guidance for this IAS, the amount of time with blowers operating could be substantially reduced compared to traditional operations while at the same time the attainment of the DO standards could be increased. This study shows that a carefully designed modeling study is key to effective selection, location, and operation of IASs such that attainment of DO standards can be maximized while operation hours of blowers can be minimized.展开更多
In this article the meaning of the quantity and quality of environmental flows of river in dualistic water cycle is discussed, and compared with the meaning of unitary water cycle. Based on the analysis of the relatio...In this article the meaning of the quantity and quality of environmental flows of river in dualistic water cycle is discussed, and compared with the meaning of unitary water cycle. Based on the analysis of the relationship between environmental flows of river requirements, the efficiency of water resource usage, the consumption coefficient, and the concentration of waste water elimination, the water quantity and water quality calculation method of the environmental flows of river requirements in dualistic water cycle is developed, and the criteria for environmental flows of river requirements are established, and therefore the water quantity-quality combined evaluation of natural river flows requirements are realized Taking the Liaohe River as a model, the environmental flows of river requirements for Xiliao River, Dongliao River, mainstream Liaohe River, Huntai River and northeast rivers along the coasts of the Yellow and Bohai seas in unitary water cycle are calculated, each taking up 39.3%, 63.0%, 43.9%, 43.3% and 43.5% of runoff respectively. Evaluated according to Tennant recommended flow, the results show that: except Xiliao River is "median", the rest are all upon "good", the Dongliao River is even "very good". The corresponding results in dualistic water cycle are that, the proportion of natural flows for each river is 57.5%, 74.1%, 60.8%, 60.3% and 60.4%; while the combined evaluation results show that: considering "quantity", except Xiliao River, the rest rivers can all achieve the "quantity" criteria of the en- vironmental flows of river requirements, but if considering the aspect of "quality", only Dongliao River can reach the "quality" standard. By water quantity-quality combined evaluation method, only Dongliao River can achieve the criteria. So the water quality is the main factor that determines whether the environmental flows can meet the river ecosystem demands.展开更多
With respect to groundwater deterioration from human activities a unique situation of co-disposal of non-engineered Municipal Solid Waste (MSW) dumping and Secondary Wastewater (SWW) disposal on land prevails simultan...With respect to groundwater deterioration from human activities a unique situation of co-disposal of non-engineered Municipal Solid Waste (MSW) dumping and Secondary Wastewater (SWW) disposal on land prevails simultaneously within the same campus at Puducherry in India. Broadly the objective of the study is to apply and compare Artificial Neural Network (ANN) and Multi Linear Regression (MLR) models on groundwater quality applying Canadian Water Quality Index (CWQI). Totally, 1065 water samples from 68 bore wells were collected for two years on monthly basis and tested for 17 physio-chemical and bacteriological parameters. However the study was restricted to the pollution aspects of 10 physio-chemical parameters such as EC, TDS, TH, , Cl-, , Na+, Ca2+, Mg2+ and K+. As there is wide spatial variation (2 to 3 km radius) with ground elevation (more than 45 m) among the bore wells it is appropriate to study the groundwater quality using Multivariate Statistical Analysis and ANN. The selected ten parameters were subjected to Hierarchical Cluster Analysis (HCA) and the clustering procedure generated three well defined clusters. Cluster wise important physio-chemical attributes which were altered by MSW and SWW operations, are statistically assessed. The CWQI was evolved with the objective to deliver a mechanism for interpreting the water quality data for all three clusters. The ANOVA test results viz., F-statistic (F = 134.55) and p-value (p = 0.000 2, low RMSE and MAE values but in Cluster 3 only ANN model fared well. Thus this study will be very useful to decision makers in solving water quality problems.展开更多
Using the RMA4 water quality model to simulate the water quality of Neijiang river in Zhenjiang, the result showed that: in the dry season the ranges of the concentration of various pollutants simulation of Neijiang ...Using the RMA4 water quality model to simulate the water quality of Neijiang river in Zhenjiang, the result showed that: in the dry season the ranges of the concentration of various pollutants simulation of Neijiang were BOD5 3.2-5.2 mg/L, CODMn 4.7-6.8 mg/L, NH3-N 0.46-1.8 mg/L, TP 0.23-0.48 mg/L, and in the rainy period, the ranges of the concentration of various pollutants simulation of Neijiang were BOD5 0.69-0.73 mg/L, CODM, 1.9-2.3 mg/L, NH3-N 0.25-0.38 mg/L, TP 0.14-0.17 mg/L.These simulated values were closed to the monitoring values of pollution concentrations of Neijiang, which indicated that RMA4 was certain practical in the river water quality simulation, and simulation results have a certain degree of reliability, and it provides a scientific planning and management method for the river pollution control.展开更多
With the progress of computer technology, water pollution control and planning has been a hot topic in the scientific community. This paper discusses corresponding research on the applications of cyclic water quality ...With the progress of computer technology, water pollution control and planning has been a hot topic in the scientific community. This paper discusses corresponding research on the applications of cyclic water quality model and simulated annealing algorithm for water pollution control and planning. Environmental engineering education has been the focus of much attention in recent years. Teaching methods of water pollution control and sustainable teaching innovation and creation was explored by many scholars, and the majority of workers engaged in teaching the course. The simulation result proves the effectiveness of the method. We plan to conduct more research in the future research to obtain better research result.展开更多
[Objective] The aim was to study the coupling effect of water and phosphate on economic traits of sugarcane. [Method] Taking sugarcane variety ROC22 as tested material,coupling effects of different levels of water sup...[Objective] The aim was to study the coupling effect of water and phosphate on economic traits of sugarcane. [Method] Taking sugarcane variety ROC22 as tested material,coupling effects of different levels of water supply quantity and different levels of phosphorus fertilizer on the yield and quality of sugarcane were studied. Among them,water supply quantity had 3 levels,that was,the water supply quantity per 10 days from the early tillering stage of sugarcane to the end of elongation was 199.5 m3/hm2 (A1),400.5 m3/hm2 (A2) and 600.0 m3/hm2 (A3),respectively; Phosphorus fertilizer as basic fertilizer had 4 levels:P2O5 0 kg/hm2 (B1),120 kg/hm2 (B2),240 kg/hm2 (B3) and 360 kg/hm2 (B4). [Result] Treatment A3B2 in water-fertilizer coupling was more suitable to improve economic traits of sugarcane. [Conclusion] The research results provide theoretical basis for the efficient utilization of water and phosphorus fertilizer in production of Guangxi sugarcane and the cultivation of high-yield and high-glucose sugarcane.展开更多
The underwater topography in the offshore sea area of north Jiangsu is complicated, including the middle radial sand ridges and northern Haizhou bay underwater shoal. Therefore, it forms special marine dynamic conditi...The underwater topography in the offshore sea area of north Jiangsu is complicated, including the middle radial sand ridges and northern Haizhou bay underwater shoal. Therefore, it forms special marine dynamic conditions and typical shoal wetland ecosystem. Previous researches of these sea areas were mainly focused on the forms of morphogenesis and the characteristic of conformation of sand ridges. Few studies have done on three dimensional hydrodynamic and water quality simulation. This paper introduced EFDC (Environ-mental Fluid Dynamics Code) to study the tidal current fields, dilution and diffusion of the sewage outlet near Yangkou Port. Comparison between computation results and the observed data indicates that this model could reasonably simulate hydrodynamic fields. Based on the computed tidal current field, the distributions of COD concentration were simulated. The range of contamination diffusion derived from sewage outlet was very limited, and the influence range of sewage came to the maximum when ebb slacks in neap tide period.展开更多
A three-dimensional coupled physical and water quality model was developed and applied to the Jiaozhou Bay to study water quality involving nutrients, biochemical oxygen demand, dissolved oxygen, and phytoplankton tha...A three-dimensional coupled physical and water quality model was developed and applied to the Jiaozhou Bay to study water quality involving nutrients, biochemical oxygen demand, dissolved oxygen, and phytoplankton that are closely related to eutrophication process. The physical model is a modified ECOM-si version with inclusion of flooding/draining processes over the intertidal zone. The water quality model is based on WASP5 which quantifies processes governing internal nutrients cycling, dissolved oxygen balance and phytoplankton growth. The model was used to simulate the spatial distribution and the temporal variation of water quality in the Jiaozhou Bay for the period of May 2005 to May 2006. In addition, the effect of reduction of riverine nutrients load was simulated and evaluated. The simulated results show that under the influence of nutrients discharged from river, the concentrations of nutrients and phytoplankton were higher in the northwest and northeast of the bay, and decreased from the inner bay to the outer. Affected by strong tidal mixing, the concentrations of all state variables were vertically homogeneous except in the deeper regions where a small gradient was found. Obvious seasonal variation of phytoplankton biomass was found, which exhibited two peaks in March and July, respectively. The variation of riverine waste loads had remarkable impact on nutrients concentration in coastal areas, but slightly altered the distribution in the center of the bay.展开更多
`The application of sewage sludge(SS)to forested lands may lead to the downward migration of potentially toxic elements(PTEs)through rainfall and thus pose risk to the subsoil and groundwater.Batch column experiments ...`The application of sewage sludge(SS)to forested lands may lead to the downward migration of potentially toxic elements(PTEs)through rainfall and thus pose risk to the subsoil and groundwater.Batch column experiments were conducted using leaching water equivalent to the rainfall amount in the study area over 3 years to investigate changes in concentrations of PTEs,including copper(Cu),zinc(Zn),lead(Pb),cadmium(Cd),and nickel(Ni)in the leachate from the acidic forest soil.Water quality index of leachate,potential ecological risk and human health risk in soil at different leaching stages were compared.Sewage sludge was applied at SS/soil mass ratios of 0:100(controls),15:85(T1),30:70(T2),45:55(T3),60:40(T4),and 75:25(T5).All treatments resulted in increased PTEs concentration in the upper 20 cm soil,T3-T5 increased potential ecological risk from"low"(control)to"moderate"or"considerable".During first year leaching,PTEs concentration increased with increasing SS/soil ratios,but the water quality index of T1-T3 was"excellent"or"good".Pb,Cu,Cd,and Ni in the 20-40 cm soil depth,and Zn in the 60-80 cm soil depth were also enriched,but potential ecological risk was"low".In subsequent leaching,PTEs concentration of leachate gradually returned to the background value and water quality index was"excellent".There were no significant changes in PTEs and ecological risk observed.During the monitoring process,the health risk caused by the migration of PTEs to the human body was always within the acceptable range.Overall,this study provides a reference for the management of risks from the application of SS on forestlands,i.e.,SS/soil ratios<45:55 is recommended on forestlands,and special attention should be given to early leaching risk.In addition,it also provides an important assessment method for the risk of PTEs leaching and migration in forested land application.展开更多
Taking Liyang City of Jiangsu Province as the research object, a water pollution accident diffusion simulation and analysis system, taking WebGIS as the core, was established by taking finite difference method to do t...Taking Liyang City of Jiangsu Province as the research object, a water pollution accident diffusion simulation and analysis system, taking WebGIS as the core, was established by taking finite difference method to do the system dynamics water quality model solution. This paper introduces the construction process of the model, the integration of the model with GIS, the interactive application of the system and users and the visual dynamic expression of water pollution accidents. By combining the statistical analysis of the spatial and environmental database in the system, the scientific simulation of the temporal and spatial relationship of the development of water pollution accidents on the client side is realized and providing precise decision support for early warning and control of water pollution diffusion.展开更多
The purpose of the study is to enhance the watershed management for St. Tammany parish, LA through development of a model that will account for water quality impacts. Bayou Chinchuba in St. Tammany parish Louisiana is...The purpose of the study is to enhance the watershed management for St. Tammany parish, LA through development of a model that will account for water quality impacts. Bayou Chinchuba in St. Tammany parish Louisiana is selected for this water quality model. Developed with HSPF (Hydrologic Simulation Program in Fortran), the model is used to calculate NO3, PO4, and BOD loading rates for varying scenarios of land use development. GIS tools are used to determine, visualize, and compare the total loads generated within sub-basins of the watershed based on the model simulation results. With the GIS calculation of NO3, PO4, and BOD total load and visualization enhancement, this tool simulates existing conditions and compares the water quality impact to 2020 expectation values.展开更多
In order to establish economic development region at Mawei districtwhich is nearby downstream of Minjiang river and to answer the question of impact of economic development on water quality of Minjiang estuary, the an...In order to establish economic development region at Mawei districtwhich is nearby downstream of Minjiang river and to answer the question of impact of economic development on water quality of Minjiang estuary, the analyses of hydrologic and hydraulic characteristics of Mawei reach of Minjiang tidal river, a two-dimensional mathematical model has been established and simulation of water quality was studied. The results show that the flushing time of a conservative pollutant during dry and raining period are 12 and 7 days respectively from Mawei to Minjiang mouth, the decay rate constants of BOD and NH3-N are 0.1 to 0.4 and 0.18 to 0.45 d-1 respectively. The capacity of dilution and assimilation for pollutants is larger.展开更多
A one-dimensional BOD-DO coupling model for water quality simulation is presented, which adopts Streeter-Phelps equations and the theory of back-propagation artificial neural network. The water quality data of Yangtze...A one-dimensional BOD-DO coupling model for water quality simulation is presented, which adopts Streeter-Phelps equations and the theory of back-propagation artificial neural network. The water quality data of Yangtze River in the Chongqing region in the year of 1989 are divided into 5 groups and used in the learning and testing courses of this model. The result shows that such model is feasible for water quality simulation and is more accurate than traditional models.展开更多
Monitoring of environmental parameters is one of the highest priorities in the evaluation of environmental status of water resources and in environmental protection policy. The main objectives are to understand and ev...Monitoring of environmental parameters is one of the highest priorities in the evaluation of environmental status of water resources and in environmental protection policy. The main objectives are to understand and evaluate the water quantity and quality in order to provide water of appropriate quality to various water users. The water quantity was assessed by the measurement of runoff or discharge at specific river cross sections using floating method for surface water and bucket and stopwatch method for springs and boreholes. The quality of river water and spring was identified in terms of its physical, chemical, and biological parameters. The analyzed data were compared with standard values recommended by WHO. Macroinvertebrates were collected in the rivers using a plankton nets and 10 minutes of sampling. Identification was made at the laboratory of Malacology. Results revealed that the quality of water obtained from sampling points is generally good to use for different domestic purposes except the Idanta River and Rwembwe borehole, which need an appropriate treatment before use. All sampling points are located far from houses and latrines, which can contribute to fecal contamination. On the different sampling points, bathing and washing clothes were observed and could constitute the source of pollution of drinking water. In Idanta and Kamira Rivers animals used water for drinking while also people use this water for domestic and drinking. In the two sampling points high values of Escherichia coli were found. No pollutant-taxa tolerant were found in the two monitored rivers for macroinvertebrates. Since water quality and quantity remain a major challenge in rural areas, the government should provide safe water to the population around Mikeno sector after treatment using suitable techniques.展开更多
The Inohana Lake is a branch lake of the Hamana Lake. The Inohana Lake is an estuary rather than a brackish lake, and has suffered environmental problems such as eutrophication and bottom hypoxic water. In this study,...The Inohana Lake is a branch lake of the Hamana Lake. The Inohana Lake is an estuary rather than a brackish lake, and has suffered environmental problems such as eutrophication and bottom hypoxic water. In this study, the coupled hydrodynamic and ecological models (eco-hydrodynamic model) were used to construct the strategy for preventing the bottom hypoxic water and improving or recovering the water quality in the lake. Using the model input obtained from the summertime data over 1998-2002, the summer-average flow field and oxygen concentration and budget of the standard run were calculated. Remedial measures used in this study are divided into two parts: the biogeochemical and physical changes in the present situation. For the remedial measures including the biogeochemical changes in the present situation, the simulations considering the reductions of the nutrient inputs from the river, main lake (land) and bottom sediment, and the sediment oxygen demand (SOD) were carried out. For the remedial measures including the physical changes, the 50 and 100 m extensions of the inlet width were considered in the model runs. These simulated results were compared in terms of changes in the dissolved oxygen (DO) concentration and oxygen budget in the bottom layer in the Inohana Lake. There was no significant change in the DO concentration and oxygen stock in the simulations for the reduction of the nutrient inputs from the land and bottom sediment, however increases in those in the simulations for the reduction of SOD. When SOD was reduced by 50%, the bottom DO concentration increased by approximately 2 mg/L and the oxygen stock in the bottom layer increased by 47% comparing the present situation (the standard run) of the lake. The simulation results for inlet width extension showed that the extension of width makes the DO concentration and oxygen stock lower. The remedial measures for the sediment control were proposed to prevent the bottom hypoxia and manage the water quality.展开更多
文摘Widespread changes to forested watersheds affected by the mountain pine beetle (Dendroctonus ponderosae Hopkins) epidemic across western North America raised concerns about the effects of this climate-induced disturbance on drinking water and natural resources. Effective communication and knowledge exchange across scientists and stakeholders (i.e., drinking water managers) is essential for constructively responding to such landscape scale disturbances, providing improved adaptive capacity through knowledge sharing. An assessment of stakeholder knowledge levels, information needs, primary concerns, and suggested communication strategies were conducted via an online elicitation survey and World Science Café workshops. Knowledge levels, assessed via a survey of local water managers and experts, were relatively low with approximately half of the respondents reporting little to no knowledge of the effects of mountain pine beetle on drinking water quality and quantity, thereby indicating limited knowledge exchange between scientists and drinking water stakeholders. Increased accessibility and dissemination of research findings pertinent to the mountain pine beetle epidemic’s effects on drinking water quality and quantity is necessary for natural resource management. Recommendations for improved communication among scientists and drinking water stakeholders in particular and forest health in general include dispersal of non-academic research summaries, information exchange through existing media and community resources, demonstration projects, and information clearinghouses. This information provides a better understanding of the challenges, concerns, and first-hand experience of stakeholders of a landscape disturbance issue to apply this knowledge to enhance land management practice and how researchers on this overall project enhanced science communication efforts.
文摘River-type reservoir is narrow and long in shape and has many reservoir bends and confluence of tributaries. On the basis of Saint-Venant equation and differential equation for longitudinal diffusion and in consideration of the influence of confluences and bends, in order to predict the water quantity and quality, an one-dimensional unsteady mathematical model was established in this paper. The model consists of a hydrodynamic model and a water quality model. The average hydraulic characteristics and water quality parameters were calculated for a reservoir with two confluences and four bends. Computed results are in good agreement with field observation data. The model can be applied to predict the water quantity, water level and water quality of the river-type reservoirs.
文摘It is very important in pollution treatment to clarify the space-time distribution of water quality in Dianchi Lake. Based on the sample data obtained from 10 observation stations every month from 2008 to 2009, it uses space-time semi-variogram and ordinary kriging method to simulate the space-time variance and distribution of water quality indictors (TN, TP, BOD, CODMn, DO, Chlorophyl-α, etc.). Because the space-time semivariogram also has a certain of ex-trapolation function. From the simulation results, the pollution is mainly concentrated at the North (Caohai) and the Southwest area (Haikou), and water pollution has a increase trend.
文摘A Walnut Gulch rainfall simulator was used to determine runoff water quality and salt balance of a Sandy Loam moderately saline-alkaline site containing 0.27%of gypsum near Moab,Utah.Four rainfall intensities corresponding to 2,10,25 and 50-year storm return intervals were applied to dry soil.During each rainfall simulation,time-stamped runoff samples were also collected for the determination of ions concentration.Soil water and solute content by depth increments were determined before and after simulations.All correlation coefficients between the applied simulation water and the amounts of Cl-,SO42-,NO3-and sum of anions in runoff water were positive and ranged between 0.922 and 0.999.The correlation coefficients for Ca2+,Mg2+,Na+,K+and sum of cations ranged between 0.783 and 0.983.We concluded from the data analysis that:(1)The amounts of ions in simulation water and in runoff water represent less than 1%of sum of the soil soluble content before rainfall simulation.(2)The CEC contained about 250%the sum of cation in saturated extract.(3)The very small amount of gypsum in the soil contained 50%the sum of saturated extract ions.This means that special attention should be paid to CEC and gypsum content in the management of such soils.Moreover,when modeling runoff and water quality from soils with these properties the modelers must include suitable subroutines considering gypsum and CEC of the soil for accurate prediction of runoff water quality.
文摘Struvite (MgNH<sub>4</sub>PO<sub>4</sub>?6H<sub>2</sub>O) can be produced from municipal wastewater and has been shown to be an alternative fertilizer-phosphorus (P) source for various crops, but little is known about the runoff-water-quality implications from soil-applied struvite. The objective of this study was to evaluate the effects of soil [Creldon (Oxyaquic Fragiudalfs), Dapue (Fluventic Hapludolls), Roxana (Typic Udifluvents), and Calloway (Aquic Fraglossudalfs) series], fertilizer-P source [synthetically produced electrochemically precipitated struvite (ECSTsyn), real-wastewater-derived ECST (ECSTreal), chemically precipitated struvite (CPST), and monoammonium phosphate (MAP)], and water source (rainwater, groundwater, and struvite-removed real wastewater) over time on runoff-water-quality parameters from laboratory-conducted, rainfall-runoff simulations. Mesh tea bags containing each soil-fertilizer treatment combination were rained on with each water source (Trial 1), incubated for 6 months, and rained on again (Trial 2) to evaluate runoff-water quality. Struvite fertilizers had similar runoff-water-quality properties to those from MAP. In Trial 1, runoff total P (TP) concentration differences (i.e., soil-fertilizer-water-type response minus control response minus blank response) from ECSTsyn or ECSTreal were 1 to 5 times larger than MAP and CPST for all water-soil-fertilizer-P source treatment combinations, except for the Creldon-groundwater and Roxana-wastewater combinations. In both trials, runoff TP decreased over time in all water-soil and soil-fertilizer-P source treatment combinations, except for the Roxana-CPST combination where TP increased over time by 46%. The similar water-quality responses from the struvite fertilizers among the various soils and water types compared to MAP suggest that struvite has similar runoff-water-quality implications as at least one widely used, commercially available fertilizer-P source.
文摘Instream aeration has been used as a supplement to secondary treatment or a substitute for tertiary treatment for meeting dissolved oxygen (DO) standards in rivers. Many studies have used water quality models to determine the number, location, and capacity of instream aeration stations (IASs) needed to meet DO standards in combination with other pollution control measures. DO concentrations have been improved in the North Shore Channel and North Branch Chicago River by the Devon Avenue IAS for more than 35 years. A study was initiated to determine whether it was better to rehabilitate or relocate this station and to determine appropriate operational guidance for the IAS at the selected location. A water quality model capable of simulating DO concentrations during unsteady flow was used to evaluate the proper location for an IAS and operational guidance for this IAS. Three test years, a dry year, a wet year, and an extreme year, were considered in the evaluation. The study found that the Devon Avenue IAS should be rehabilitated as this location performed as well as or better than any of 10 alternative locations. According to the new operational guidance for this IAS, the amount of time with blowers operating could be substantially reduced compared to traditional operations while at the same time the attainment of the DO standards could be increased. This study shows that a carefully designed modeling study is key to effective selection, location, and operation of IASs such that attainment of DO standards can be maximized while operation hours of blowers can be minimized.
基金Major consultation programs of Chinese Academy of EngineeringKey Scientific and Technological Pro-grams of the Ministry of Education, No.105042"973" Project,No.G1999043601
文摘In this article the meaning of the quantity and quality of environmental flows of river in dualistic water cycle is discussed, and compared with the meaning of unitary water cycle. Based on the analysis of the relationship between environmental flows of river requirements, the efficiency of water resource usage, the consumption coefficient, and the concentration of waste water elimination, the water quantity and water quality calculation method of the environmental flows of river requirements in dualistic water cycle is developed, and the criteria for environmental flows of river requirements are established, and therefore the water quantity-quality combined evaluation of natural river flows requirements are realized Taking the Liaohe River as a model, the environmental flows of river requirements for Xiliao River, Dongliao River, mainstream Liaohe River, Huntai River and northeast rivers along the coasts of the Yellow and Bohai seas in unitary water cycle are calculated, each taking up 39.3%, 63.0%, 43.9%, 43.3% and 43.5% of runoff respectively. Evaluated according to Tennant recommended flow, the results show that: except Xiliao River is "median", the rest are all upon "good", the Dongliao River is even "very good". The corresponding results in dualistic water cycle are that, the proportion of natural flows for each river is 57.5%, 74.1%, 60.8%, 60.3% and 60.4%; while the combined evaluation results show that: considering "quantity", except Xiliao River, the rest rivers can all achieve the "quantity" criteria of the en- vironmental flows of river requirements, but if considering the aspect of "quality", only Dongliao River can reach the "quality" standard. By water quantity-quality combined evaluation method, only Dongliao River can achieve the criteria. So the water quality is the main factor that determines whether the environmental flows can meet the river ecosystem demands.
文摘With respect to groundwater deterioration from human activities a unique situation of co-disposal of non-engineered Municipal Solid Waste (MSW) dumping and Secondary Wastewater (SWW) disposal on land prevails simultaneously within the same campus at Puducherry in India. Broadly the objective of the study is to apply and compare Artificial Neural Network (ANN) and Multi Linear Regression (MLR) models on groundwater quality applying Canadian Water Quality Index (CWQI). Totally, 1065 water samples from 68 bore wells were collected for two years on monthly basis and tested for 17 physio-chemical and bacteriological parameters. However the study was restricted to the pollution aspects of 10 physio-chemical parameters such as EC, TDS, TH, , Cl-, , Na+, Ca2+, Mg2+ and K+. As there is wide spatial variation (2 to 3 km radius) with ground elevation (more than 45 m) among the bore wells it is appropriate to study the groundwater quality using Multivariate Statistical Analysis and ANN. The selected ten parameters were subjected to Hierarchical Cluster Analysis (HCA) and the clustering procedure generated three well defined clusters. Cluster wise important physio-chemical attributes which were altered by MSW and SWW operations, are statistically assessed. The CWQI was evolved with the objective to deliver a mechanism for interpreting the water quality data for all three clusters. The ANOVA test results viz., F-statistic (F = 134.55) and p-value (p = 0.000 2, low RMSE and MAE values but in Cluster 3 only ANN model fared well. Thus this study will be very useful to decision makers in solving water quality problems.
文摘Using the RMA4 water quality model to simulate the water quality of Neijiang river in Zhenjiang, the result showed that: in the dry season the ranges of the concentration of various pollutants simulation of Neijiang were BOD5 3.2-5.2 mg/L, CODMn 4.7-6.8 mg/L, NH3-N 0.46-1.8 mg/L, TP 0.23-0.48 mg/L, and in the rainy period, the ranges of the concentration of various pollutants simulation of Neijiang were BOD5 0.69-0.73 mg/L, CODM, 1.9-2.3 mg/L, NH3-N 0.25-0.38 mg/L, TP 0.14-0.17 mg/L.These simulated values were closed to the monitoring values of pollution concentrations of Neijiang, which indicated that RMA4 was certain practical in the river water quality simulation, and simulation results have a certain degree of reliability, and it provides a scientific planning and management method for the river pollution control.
文摘With the progress of computer technology, water pollution control and planning has been a hot topic in the scientific community. This paper discusses corresponding research on the applications of cyclic water quality model and simulated annealing algorithm for water pollution control and planning. Environmental engineering education has been the focus of much attention in recent years. Teaching methods of water pollution control and sustainable teaching innovation and creation was explored by many scholars, and the majority of workers engaged in teaching the course. The simulation result proves the effectiveness of the method. We plan to conduct more research in the future research to obtain better research result.
基金Supported by National Science and Technology Project of China(2007BAD30B04)~~
文摘[Objective] The aim was to study the coupling effect of water and phosphate on economic traits of sugarcane. [Method] Taking sugarcane variety ROC22 as tested material,coupling effects of different levels of water supply quantity and different levels of phosphorus fertilizer on the yield and quality of sugarcane were studied. Among them,water supply quantity had 3 levels,that was,the water supply quantity per 10 days from the early tillering stage of sugarcane to the end of elongation was 199.5 m3/hm2 (A1),400.5 m3/hm2 (A2) and 600.0 m3/hm2 (A3),respectively; Phosphorus fertilizer as basic fertilizer had 4 levels:P2O5 0 kg/hm2 (B1),120 kg/hm2 (B2),240 kg/hm2 (B3) and 360 kg/hm2 (B4). [Result] Treatment A3B2 in water-fertilizer coupling was more suitable to improve economic traits of sugarcane. [Conclusion] The research results provide theoretical basis for the efficient utilization of water and phosphorus fertilizer in production of Guangxi sugarcane and the cultivation of high-yield and high-glucose sugarcane.
文摘The underwater topography in the offshore sea area of north Jiangsu is complicated, including the middle radial sand ridges and northern Haizhou bay underwater shoal. Therefore, it forms special marine dynamic conditions and typical shoal wetland ecosystem. Previous researches of these sea areas were mainly focused on the forms of morphogenesis and the characteristic of conformation of sand ridges. Few studies have done on three dimensional hydrodynamic and water quality simulation. This paper introduced EFDC (Environ-mental Fluid Dynamics Code) to study the tidal current fields, dilution and diffusion of the sewage outlet near Yangkou Port. Comparison between computation results and the observed data indicates that this model could reasonably simulate hydrodynamic fields. Based on the computed tidal current field, the distributions of COD concentration were simulated. The range of contamination diffusion derived from sewage outlet was very limited, and the influence range of sewage came to the maximum when ebb slacks in neap tide period.
文摘A three-dimensional coupled physical and water quality model was developed and applied to the Jiaozhou Bay to study water quality involving nutrients, biochemical oxygen demand, dissolved oxygen, and phytoplankton that are closely related to eutrophication process. The physical model is a modified ECOM-si version with inclusion of flooding/draining processes over the intertidal zone. The water quality model is based on WASP5 which quantifies processes governing internal nutrients cycling, dissolved oxygen balance and phytoplankton growth. The model was used to simulate the spatial distribution and the temporal variation of water quality in the Jiaozhou Bay for the period of May 2005 to May 2006. In addition, the effect of reduction of riverine nutrients load was simulated and evaluated. The simulated results show that under the influence of nutrients discharged from river, the concentrations of nutrients and phytoplankton were higher in the northwest and northeast of the bay, and decreased from the inner bay to the outer. Affected by strong tidal mixing, the concentrations of all state variables were vertically homogeneous except in the deeper regions where a small gradient was found. Obvious seasonal variation of phytoplankton biomass was found, which exhibited two peaks in March and July, respectively. The variation of riverine waste loads had remarkable impact on nutrients concentration in coastal areas, but slightly altered the distribution in the center of the bay.
基金supported by National Natural Science Foundation of China(grant nos.31971629,42007335)Natural Science Foundation of Guangdong Province(2021A1515012157)。
文摘`The application of sewage sludge(SS)to forested lands may lead to the downward migration of potentially toxic elements(PTEs)through rainfall and thus pose risk to the subsoil and groundwater.Batch column experiments were conducted using leaching water equivalent to the rainfall amount in the study area over 3 years to investigate changes in concentrations of PTEs,including copper(Cu),zinc(Zn),lead(Pb),cadmium(Cd),and nickel(Ni)in the leachate from the acidic forest soil.Water quality index of leachate,potential ecological risk and human health risk in soil at different leaching stages were compared.Sewage sludge was applied at SS/soil mass ratios of 0:100(controls),15:85(T1),30:70(T2),45:55(T3),60:40(T4),and 75:25(T5).All treatments resulted in increased PTEs concentration in the upper 20 cm soil,T3-T5 increased potential ecological risk from"low"(control)to"moderate"or"considerable".During first year leaching,PTEs concentration increased with increasing SS/soil ratios,but the water quality index of T1-T3 was"excellent"or"good".Pb,Cu,Cd,and Ni in the 20-40 cm soil depth,and Zn in the 60-80 cm soil depth were also enriched,but potential ecological risk was"low".In subsequent leaching,PTEs concentration of leachate gradually returned to the background value and water quality index was"excellent".There were no significant changes in PTEs and ecological risk observed.During the monitoring process,the health risk caused by the migration of PTEs to the human body was always within the acceptable range.Overall,this study provides a reference for the management of risks from the application of SS on forestlands,i.e.,SS/soil ratios<45:55 is recommended on forestlands,and special attention should be given to early leaching risk.In addition,it also provides an important assessment method for the risk of PTEs leaching and migration in forested land application.
文摘Taking Liyang City of Jiangsu Province as the research object, a water pollution accident diffusion simulation and analysis system, taking WebGIS as the core, was established by taking finite difference method to do the system dynamics water quality model solution. This paper introduces the construction process of the model, the integration of the model with GIS, the interactive application of the system and users and the visual dynamic expression of water pollution accidents. By combining the statistical analysis of the spatial and environmental database in the system, the scientific simulation of the temporal and spatial relationship of the development of water pollution accidents on the client side is realized and providing precise decision support for early warning and control of water pollution diffusion.
文摘The purpose of the study is to enhance the watershed management for St. Tammany parish, LA through development of a model that will account for water quality impacts. Bayou Chinchuba in St. Tammany parish Louisiana is selected for this water quality model. Developed with HSPF (Hydrologic Simulation Program in Fortran), the model is used to calculate NO3, PO4, and BOD loading rates for varying scenarios of land use development. GIS tools are used to determine, visualize, and compare the total loads generated within sub-basins of the watershed based on the model simulation results. With the GIS calculation of NO3, PO4, and BOD total load and visualization enhancement, this tool simulates existing conditions and compares the water quality impact to 2020 expectation values.
文摘In order to establish economic development region at Mawei districtwhich is nearby downstream of Minjiang river and to answer the question of impact of economic development on water quality of Minjiang estuary, the analyses of hydrologic and hydraulic characteristics of Mawei reach of Minjiang tidal river, a two-dimensional mathematical model has been established and simulation of water quality was studied. The results show that the flushing time of a conservative pollutant during dry and raining period are 12 and 7 days respectively from Mawei to Minjiang mouth, the decay rate constants of BOD and NH3-N are 0.1 to 0.4 and 0.18 to 0.45 d-1 respectively. The capacity of dilution and assimilation for pollutants is larger.
基金Funded by the National Natural Science Foundation of China (No.59838300 No.59778021)
文摘A one-dimensional BOD-DO coupling model for water quality simulation is presented, which adopts Streeter-Phelps equations and the theory of back-propagation artificial neural network. The water quality data of Yangtze River in the Chongqing region in the year of 1989 are divided into 5 groups and used in the learning and testing courses of this model. The result shows that such model is feasible for water quality simulation and is more accurate than traditional models.
文摘Monitoring of environmental parameters is one of the highest priorities in the evaluation of environmental status of water resources and in environmental protection policy. The main objectives are to understand and evaluate the water quantity and quality in order to provide water of appropriate quality to various water users. The water quantity was assessed by the measurement of runoff or discharge at specific river cross sections using floating method for surface water and bucket and stopwatch method for springs and boreholes. The quality of river water and spring was identified in terms of its physical, chemical, and biological parameters. The analyzed data were compared with standard values recommended by WHO. Macroinvertebrates were collected in the rivers using a plankton nets and 10 minutes of sampling. Identification was made at the laboratory of Malacology. Results revealed that the quality of water obtained from sampling points is generally good to use for different domestic purposes except the Idanta River and Rwembwe borehole, which need an appropriate treatment before use. All sampling points are located far from houses and latrines, which can contribute to fecal contamination. On the different sampling points, bathing and washing clothes were observed and could constitute the source of pollution of drinking water. In Idanta and Kamira Rivers animals used water for drinking while also people use this water for domestic and drinking. In the two sampling points high values of Escherichia coli were found. No pollutant-taxa tolerant were found in the two monitored rivers for macroinvertebrates. Since water quality and quantity remain a major challenge in rural areas, the government should provide safe water to the population around Mikeno sector after treatment using suitable techniques.
文摘The Inohana Lake is a branch lake of the Hamana Lake. The Inohana Lake is an estuary rather than a brackish lake, and has suffered environmental problems such as eutrophication and bottom hypoxic water. In this study, the coupled hydrodynamic and ecological models (eco-hydrodynamic model) were used to construct the strategy for preventing the bottom hypoxic water and improving or recovering the water quality in the lake. Using the model input obtained from the summertime data over 1998-2002, the summer-average flow field and oxygen concentration and budget of the standard run were calculated. Remedial measures used in this study are divided into two parts: the biogeochemical and physical changes in the present situation. For the remedial measures including the biogeochemical changes in the present situation, the simulations considering the reductions of the nutrient inputs from the river, main lake (land) and bottom sediment, and the sediment oxygen demand (SOD) were carried out. For the remedial measures including the physical changes, the 50 and 100 m extensions of the inlet width were considered in the model runs. These simulated results were compared in terms of changes in the dissolved oxygen (DO) concentration and oxygen budget in the bottom layer in the Inohana Lake. There was no significant change in the DO concentration and oxygen stock in the simulations for the reduction of the nutrient inputs from the land and bottom sediment, however increases in those in the simulations for the reduction of SOD. When SOD was reduced by 50%, the bottom DO concentration increased by approximately 2 mg/L and the oxygen stock in the bottom layer increased by 47% comparing the present situation (the standard run) of the lake. The simulation results for inlet width extension showed that the extension of width makes the DO concentration and oxygen stock lower. The remedial measures for the sediment control were proposed to prevent the bottom hypoxia and manage the water quality.