Many hydropower projects have been constructed in Southwest China with the strategic goal of achieving carbon neutrality.Most of these hydropower projects utilize concrete face rockfilldams(CFRDs)built on a deep overb...Many hydropower projects have been constructed in Southwest China with the strategic goal of achieving carbon neutrality.Most of these hydropower projects utilize concrete face rockfilldams(CFRDs)built on a deep overburden layer.The deep overburden layer causes uneven settlement between the overburden layer and the dam,which poses a serious threat to the safety of both the construction and operation of the dam.In this study,microseismic(MS)monitoring technology was employed for the firsttime in the fieldof dam fillingengineering,allowing for the real-time monitoring of microfracture in the bedrock during dam construction.The time-frequency analysis method was used to summarize the MS waveform characteristics induced by dam filling.The fracture mechanism of bedrock was revealed,and the relationships among slope deformation,dam settlement,and MS activity were analyzed.The following research results have been obtained.The MS signal induced by dam fillinghas low energy and amplitude,short duration,and high frequency.The fracture of the bedrock was mainly shear failure.MS monitoring can predict deformation during blasting excavation and capture the large settlement that may occur during dam fillingin advance.Research findingshave demonstrated the significantapplication value of MS monitoring technology in predicting the risk of dam settlement and provide a reference for similar projects.展开更多
Deformation prediction for extra-high arch dams is highly important for ensuring their safe operation.To address the challenges of complex monitoring data,the uneven spatial distribution of deformation,and the constru...Deformation prediction for extra-high arch dams is highly important for ensuring their safe operation.To address the challenges of complex monitoring data,the uneven spatial distribution of deformation,and the construction and optimization of a prediction model for deformation prediction,a multipoint ultrahigh arch dam deformation prediction model,namely,the CEEMDAN-KPCA-GSWOA-KELM,which is based on a clustering partition,is pro-posed.First,the monitoring data are preprocessed via variational mode decomposition(VMD)and wavelet denoising(WT),which effectively filters out noise and improves the signal-to-noise ratio of the data,providing high-quality input data for subsequent prediction models.Second,scientific cluster partitioning is performed via the K-means++algorithm to precisely capture the spatial distribution characteristics of extra-high arch dams and ensure the consistency of deformation trends at measurement points within each partition.Finally,CEEMDAN is used to separate monitoring data,predict and analyze each component,combine the KPCA(Kernel Principal Component Analysis)and the KELM(Kernel Extreme Learning Machine)optimized by the GSWOA(Global Search Whale Optimization Algorithm),integrate the predictions of each component via reconstruction methods,and precisely predict the overall trend of ultrahigh arch dam deformation.An extra high arch dam project is taken as an example and validated via a comparative analysis of multiple models.The results show that the multipoint deformation prediction model in this paper can combine data from different measurement points,achieve a comprehensive,precise prediction of the deformation situation of extra high arch dams,and provide strong technical support for safe operation.展开更多
The integration of digital twin(DT)technology with microseismic(MS)monitoring for evaluating the dynamic response of high-arch dams remains under-explored.This paper investigates the application of MS monitoring on th...The integration of digital twin(DT)technology with microseismic(MS)monitoring for evaluating the dynamic response of high-arch dams remains under-explored.This paper investigates the application of MS monitoring on the Dagangshan high-arch dam during its normal water storage operating period to assess potential damage.The study analyzes the MS characteristics of the dam during the Luding earthquake(Ms=6.8).A framework for constructing a damage driven DT model of a high-arch dam is proposed.The DT model is capable of self-updating its mechanical parameters based on MS data.Seismic response calculations are conducted utilizing cloud computing,allowing for the direct presentation of results within the DT model.The results indicate a high-risk area of the Dagangshan arch dam,characterized by significantMS deformation,primarily centered on the arch crown beam.This zone encompasses dam sections Nos.5-6,10-11,13-16,and 19-20,all located above 1030 m elevation.Under seismic loading,the arch dam exhibits a back-and-forth movement along the river,ultimately reaching a stable state.Following the earthquake,the stress state of the dam does not experience substantial changes.The average relative error between numerical results and measured peak ground acceleration values is 17%when considering the cumulative effect of damage,compared to 36%when neglecting this effect.This study presents a more reliable approach for assessing the state of dams.展开更多
The first author proposed the concept of the cemented material dam （CMD） in 2009. This concept was aimed at building an environmentally friendly dam in a safer and more economical way for both the dam and the area d...The first author proposed the concept of the cemented material dam （CMD） in 2009. This concept was aimed at building an environmentally friendly dam in a safer and more economical way for both the dam and the area downstream. The concept covers the cemented sand, gravel, and rock dam （CSGRD）, the rockfill concrete （RFC） dam （or the cemented rockfill dam, CRD）, and the cemented soil dam （CSD）. This paper summarizes the concept and principles of the CMD based on studies and practices in projects around the world. It also introduces new developments in the CSGRD, CRD, and CSD.展开更多
Composite dams,due to their combination of advantages from multiple dam types,are widely used under complex topographic and geological conditions.The static and dynamic stability of their spillway sections is crucial ...Composite dams,due to their combination of advantages from multiple dam types,are widely used under complex topographic and geological conditions.The static and dynamic stability of their spillway sections is crucial for project safety.This paper takes a composite dam as the research object and uses finite difference software FLAC^(3D) to perform static and dynamic calculation analysis on its No.12 and No.13 spillway sections.The static conditions consider normal water level and dead water level,while the dynamic conditions are based on free-field boundary conditions and Rayleigh damping,with an input peak acceleration of 0.15g artificial synthetic seismic wave(duration 10s),analyzing dam displacement and stress distribution.Based on relevant national standards and specifications,the analysis results show:Under static conditions,the dam displacement and stress distribution conform to conventional patterns,with the maximum horizontal displacement at the dam crest being 3.43mm,meeting safety requirements;The tensile stress near the hinged beam area is relatively large,suggesting strengthened reinforcement,with no other hazardous areas.Under dynamic conditions,the maximum relative dynamic displacement at the dam crest is 5.51mm,which is safe and controllable;The tensile stress at the junction of the weir crest and gate pier exceeds the dynamic tensile strength of concrete,and the tensile stress near the hinged beam is relatively high,requiring strengthened reinforcement,with no other hazardous areas.The study indicates that the dam structure design generally meets safety requirements,but local high tensile stress areas need optimized reinforcement design.展开更多
Underpinned by the ultrahigh-core rockfill dam at the Nuozhadu Hydropower Station,comprehensive studies and engineering practices have been conducted to address several critical challenges:coordination of seepage defo...Underpinned by the ultrahigh-core rockfill dam at the Nuozhadu Hydropower Station,comprehensive studies and engineering practices have been conducted to address several critical challenges:coordination of seepage deformation in dam materials,prevention and control of high-water-pressure seepage failure,static and dynamic deformation control,and construction quality monitoring.Advanced technologies have been developed for modifying impermeable soil materials and utilizing soft rocks.Constitutive models and high-performance fine computational methods for dam materials have been improved,along with innovative seismic safety measures.Additionally,a“Digital Dam”and an information system for monitoring the construction quality were implemented.These efforts ensured the successful construction of the Nuozhadu Dam,making it the tallest dam in China and the third tallest dam in the world upon completion.This achievement increased the height of core dams in China by 100 m and established a design and safety evaluation framework for ultrahigh-core rockfill dams exceeding 300 m in height.Furthermore,the current safety monitoring results indicate that the Nuozhadu Dam is safe and controllable.展开更多
Based on raw data from dams damaged in the Wenchuan earthquake, including many that were severely damaged, characteristics and factors that influenced the damage are discussed in this paper. Findings from this study i...Based on raw data from dams damaged in the Wenchuan earthquake, including many that were severely damaged, characteristics and factors that influenced the damage are discussed in this paper. Findings from this study include： severely damaged dams were densely distributed along the seismologic fault; small dams, especially small earth-rock dams, had the most serious damage that was caused by a variety of factors; the most serious damage was caused by seismic waves; damage was aggregated by aftershocks; and the extent of the damage patterns increased with the seismic intensity. Damage patterns varied in different intensity zones and cracking was the most common type of damage. Most of the dams had a good base with relatively high bearing capacity, and the walls of the earth-rock dams were mostly of clay soil. This type of base and body material mitigated some of the damage to dams. Reservoir maintenance and other factors also have a significant impact on the seismic safety of the dam. Finally, some recommendations to reduce seismic damage to dams are proposed.展开更多
Check dams are widely constructed on China's Loess Plateau,which had a total number of 58,776 by the end of 2019.Great achievements in check dam construction have been gained regarding the economic and environment...Check dams are widely constructed on China's Loess Plateau,which had a total number of 58,776 by the end of 2019.Great achievements in check dam construction have been gained regarding the economic and environmental impacts.This study reviews the remarkable benefits of check dams on the land reclamation and environmental improvement on the Loess Plateau,and sediment reduction entering the Yellow River.However,the flood incidents on check dams have been frequently reported for the past decades,which has attracted more attention in the context of climate change and extreme rainfall events recently.Advances in the flood migration techniques achieved by the research group led by the first author have been highlighted to migrate the breach risk of check dams due to floods.The“family tree method”has been proposed to determine the survival status and critical rainfall threshold of each check dam in the complicated dam system.An updated dam breach flood evaluation framework and the corresponding numerical algorithm(i.e.,DB-IWHR)have been developed.Moreover,innovative types of water-release facilities for check dams,including geobag stepped spillway and prestressed concrete cylinder pipe in the underlying conduit,have been proposed and developed.Finally,the perspectives concerning the check dam construction on the Loess Plateau have been put forward.展开更多
In the application of regression analysis method to model dam deformation, the ill-condition problem occurred in coefficient matrix always prevents an accurate modeling mainly due to the multicollinearity of the varia...In the application of regression analysis method to model dam deformation, the ill-condition problem occurred in coefficient matrix always prevents an accurate modeling mainly due to the multicollinearity of the variables. Independent component regression （ICR） was proposed to model the dam deformation and identify the physical origins of the deformation. Simulation experiment shows that ICR can successfully resolve the problem of ill-condition and produce a reliable deformation model. After that, the method is applied to model the deformation of the Wuqiangxi Dam in Hunan province, China. The result shows that ICR can not only accurately model the deformation of the dam, but also help to identify the physical factors that affect the deformation through the extracted independent components.展开更多
Hydroelectric power production from Garafiri dam and rainfall are essential elements with the observation of hydroelectric power production in West African power system,particularly in Guinea.This article focuses on t...Hydroelectric power production from Garafiri dam and rainfall are essential elements with the observation of hydroelectric power production in West African power system,particularly in Guinea.This article focuses on the study and the influence of climate variability on hydroelectric power production at Garafiri dam over 16-year period(2008-2023).The aim of this work is to show the correlation between rainfall anomalies and hydroelectric power production at Garafiri dam.The method used consists of calculating precipitation anomalies at Garafiri site and those for the production of hydroelectric power from Garafiri dam over the study period.This approach led us to calculate the anomalies,leading to the study on climatic variability,in order to establish correlation between rainfall and hydroelectric power dam’s production.The trend with the correlation found made it possible to carry out a significance test between these two variables.These results clearly show that rainfall in Garafiri site increases hydroelectric power production and vice versa,which explains the interdependence between these two parameters,i.e.climatic variability and hydroelectric power production.展开更多
This study addresses the pressing need to evaluate the quality of water resources in the Oued Guir watershed,highlighting the importance of monitoring both surface water and groundwater in the context of environmental...This study addresses the pressing need to evaluate the quality of water resources in the Oued Guir watershed,highlighting the importance of monitoring both surface water and groundwater in the context of environmental and public health.It focuses on the evaluation of physicochemical and bacteriological water quality downstream of the Kaddoussa Dam,as well as the characterization of wastewater from the Boudnib treatment plant discharged into Oued Guir.The goal is to assess the health of aquatic ecosystems and understand the impact of anthropogenic activities on these sensitive environments.A comprehensive analysis was conducted at 15 selected stations during a sampling campaign in November 2023.Groundwater and surface water were assessed using 10 physicochemical parameters,while bacteriological quality was evaluated based on fecal coliforms and Escherichia coli.In addition,38 parameters were studied to characterize the wastewater discharge.All analyses followed standard procedures and the results were compared to Moroccan and World Health Organization(WHO)standards.The study revealed that surface water and groundwater in the study area exhibited strong mineralization,with Electrical Conductivity(EC)exceeding 1400µS/cm at all stations.Nitrogen quality,in terms of Nitrates(NO₃⁻),was moderate across stations,while Ammonium(NH₄⁺)quality was consistently excellent.Physicochemical parameters of surface waters indicated overall excellent quality.Bacteriological analysis showed minimal contamination by fecal coliforms and Escherichia coli,with levels deemed negligible.However,wastewater from the Boudnib treatment plant exceeded Moroccan standards for organic load,presenting a potential environmental risk.展开更多
基金support from the Joint Funds of the National Natural Science Foundation of China(Grant No.42177143)the National Natural Science Foundation of China(Grant No.U23A2060).
文摘Many hydropower projects have been constructed in Southwest China with the strategic goal of achieving carbon neutrality.Most of these hydropower projects utilize concrete face rockfilldams(CFRDs)built on a deep overburden layer.The deep overburden layer causes uneven settlement between the overburden layer and the dam,which poses a serious threat to the safety of both the construction and operation of the dam.In this study,microseismic(MS)monitoring technology was employed for the firsttime in the fieldof dam fillingengineering,allowing for the real-time monitoring of microfracture in the bedrock during dam construction.The time-frequency analysis method was used to summarize the MS waveform characteristics induced by dam filling.The fracture mechanism of bedrock was revealed,and the relationships among slope deformation,dam settlement,and MS activity were analyzed.The following research results have been obtained.The MS signal induced by dam fillinghas low energy and amplitude,short duration,and high frequency.The fracture of the bedrock was mainly shear failure.MS monitoring can predict deformation during blasting excavation and capture the large settlement that may occur during dam fillingin advance.Research findingshave demonstrated the significantapplication value of MS monitoring technology in predicting the risk of dam settlement and provide a reference for similar projects.
基金supported by the National Natural Science Foundation of China(Grant Nos.52069029,52369026)the Belt and Road Special Foundation of National Key Laboratory of Water Disaster Preven-tion(Grant No.2023490411)+2 种基金the Yunnan Agricultural Basic Research Joint Special General Project(Grant Nos.202501BD070001-060,202401BD070001-071)Construction Project of the Yunnan Key Laboratory of Water Security(No.20254916CE340051)the Youth Talent Project of“Xingdian Talent Support Plan”in Yunnan Province(Grant No.XDYC-QNRC-2023-0412).
文摘Deformation prediction for extra-high arch dams is highly important for ensuring their safe operation.To address the challenges of complex monitoring data,the uneven spatial distribution of deformation,and the construction and optimization of a prediction model for deformation prediction,a multipoint ultrahigh arch dam deformation prediction model,namely,the CEEMDAN-KPCA-GSWOA-KELM,which is based on a clustering partition,is pro-posed.First,the monitoring data are preprocessed via variational mode decomposition(VMD)and wavelet denoising(WT),which effectively filters out noise and improves the signal-to-noise ratio of the data,providing high-quality input data for subsequent prediction models.Second,scientific cluster partitioning is performed via the K-means++algorithm to precisely capture the spatial distribution characteristics of extra-high arch dams and ensure the consistency of deformation trends at measurement points within each partition.Finally,CEEMDAN is used to separate monitoring data,predict and analyze each component,combine the KPCA(Kernel Principal Component Analysis)and the KELM(Kernel Extreme Learning Machine)optimized by the GSWOA(Global Search Whale Optimization Algorithm),integrate the predictions of each component via reconstruction methods,and precisely predict the overall trend of ultrahigh arch dam deformation.An extra high arch dam project is taken as an example and validated via a comparative analysis of multiple models.The results show that the multipoint deformation prediction model in this paper can combine data from different measurement points,achieve a comprehensive,precise prediction of the deformation situation of extra high arch dams,and provide strong technical support for safe operation.
基金supported by the National Natural Science Foundation of China(Grant Nos.52379098 and 42122052)the Liaoning XingLiao Talent Program(Grant No.XLYC2203008).
文摘The integration of digital twin(DT)technology with microseismic(MS)monitoring for evaluating the dynamic response of high-arch dams remains under-explored.This paper investigates the application of MS monitoring on the Dagangshan high-arch dam during its normal water storage operating period to assess potential damage.The study analyzes the MS characteristics of the dam during the Luding earthquake(Ms=6.8).A framework for constructing a damage driven DT model of a high-arch dam is proposed.The DT model is capable of self-updating its mechanical parameters based on MS data.Seismic response calculations are conducted utilizing cloud computing,allowing for the direct presentation of results within the DT model.The results indicate a high-risk area of the Dagangshan arch dam,characterized by significantMS deformation,primarily centered on the arch crown beam.This zone encompasses dam sections Nos.5-6,10-11,13-16,and 19-20,all located above 1030 m elevation.Under seismic loading,the arch dam exhibits a back-and-forth movement along the river,ultimately reaching a stable state.Following the earthquake,the stress state of the dam does not experience substantial changes.The average relative error between numerical results and measured peak ground acceleration values is 17%when considering the cumulative effect of damage,compared to 36%when neglecting this effect.This study presents a more reliable approach for assessing the state of dams.
文摘The first author proposed the concept of the cemented material dam （CMD） in 2009. This concept was aimed at building an environmentally friendly dam in a safer and more economical way for both the dam and the area downstream. The concept covers the cemented sand, gravel, and rock dam （CSGRD）, the rockfill concrete （RFC） dam （or the cemented rockfill dam, CRD）, and the cemented soil dam （CSD）. This paper summarizes the concept and principles of the CMD based on studies and practices in projects around the world. It also introduces new developments in the CSGRD, CRD, and CSD.
文摘Composite dams,due to their combination of advantages from multiple dam types,are widely used under complex topographic and geological conditions.The static and dynamic stability of their spillway sections is crucial for project safety.This paper takes a composite dam as the research object and uses finite difference software FLAC^(3D) to perform static and dynamic calculation analysis on its No.12 and No.13 spillway sections.The static conditions consider normal water level and dead water level,while the dynamic conditions are based on free-field boundary conditions and Rayleigh damping,with an input peak acceleration of 0.15g artificial synthetic seismic wave(duration 10s),analyzing dam displacement and stress distribution.Based on relevant national standards and specifications,the analysis results show:Under static conditions,the dam displacement and stress distribution conform to conventional patterns,with the maximum horizontal displacement at the dam crest being 3.43mm,meeting safety requirements;The tensile stress near the hinged beam area is relatively large,suggesting strengthened reinforcement,with no other hazardous areas.Under dynamic conditions,the maximum relative dynamic displacement at the dam crest is 5.51mm,which is safe and controllable;The tensile stress at the junction of the weir crest and gate pier exceeds the dynamic tensile strength of concrete,and the tensile stress near the hinged beam is relatively high,requiring strengthened reinforcement,with no other hazardous areas.The study indicates that the dam structure design generally meets safety requirements,but local high tensile stress areas need optimized reinforcement design.
基金National Natural Science Foundation of China,Grant/Award Number:52309153Key Science and Technology Projects of China Power Construction Group,Grant/Award Numbers:DJ-ZDXM-2022-01,DJ-ZDXM-12025-45。
文摘Underpinned by the ultrahigh-core rockfill dam at the Nuozhadu Hydropower Station,comprehensive studies and engineering practices have been conducted to address several critical challenges:coordination of seepage deformation in dam materials,prevention and control of high-water-pressure seepage failure,static and dynamic deformation control,and construction quality monitoring.Advanced technologies have been developed for modifying impermeable soil materials and utilizing soft rocks.Constitutive models and high-performance fine computational methods for dam materials have been improved,along with innovative seismic safety measures.Additionally,a“Digital Dam”and an information system for monitoring the construction quality were implemented.These efforts ensured the successful construction of the Nuozhadu Dam,making it the tallest dam in China and the third tallest dam in the world upon completion.This achievement increased the height of core dams in China by 100 m and established a design and safety evaluation framework for ultrahigh-core rockfill dams exceeding 300 m in height.Furthermore,the current safety monitoring results indicate that the Nuozhadu Dam is safe and controllable.
基金Special Scientific Found for Seismic Industry Under Grant No.201008005
文摘Based on raw data from dams damaged in the Wenchuan earthquake, including many that were severely damaged, characteristics and factors that influenced the damage are discussed in this paper. Findings from this study include： severely damaged dams were densely distributed along the seismologic fault; small dams, especially small earth-rock dams, had the most serious damage that was caused by a variety of factors; the most serious damage was caused by seismic waves; damage was aggregated by aftershocks; and the extent of the damage patterns increased with the seismic intensity. Damage patterns varied in different intensity zones and cracking was the most common type of damage. Most of the dams had a good base with relatively high bearing capacity, and the walls of the earth-rock dams were mostly of clay soil. This type of base and body material mitigated some of the damage to dams. Reservoir maintenance and other factors also have a significant impact on the seismic safety of the dam. Finally, some recommendations to reduce seismic damage to dams are proposed.
基金National Natural Science Foundation of China,Grant/Award Number:42330719National Natural Science Foundation of China,Grant/Award Number:U2443228+1 种基金Power Construction Corporation of China,Grant/Award Number:DJ-ZDXM-2021-51China Institute of Water Resources and Hydropower Research,Grant/Award Number:GE121003A0042022。
文摘Check dams are widely constructed on China's Loess Plateau,which had a total number of 58,776 by the end of 2019.Great achievements in check dam construction have been gained regarding the economic and environmental impacts.This study reviews the remarkable benefits of check dams on the land reclamation and environmental improvement on the Loess Plateau,and sediment reduction entering the Yellow River.However,the flood incidents on check dams have been frequently reported for the past decades,which has attracted more attention in the context of climate change and extreme rainfall events recently.Advances in the flood migration techniques achieved by the research group led by the first author have been highlighted to migrate the breach risk of check dams due to floods.The“family tree method”has been proposed to determine the survival status and critical rainfall threshold of each check dam in the complicated dam system.An updated dam breach flood evaluation framework and the corresponding numerical algorithm(i.e.,DB-IWHR)have been developed.Moreover,innovative types of water-release facilities for check dams,including geobag stepped spillway and prestressed concrete cylinder pipe in the underlying conduit,have been proposed and developed.Finally,the perspectives concerning the check dam construction on the Loess Plateau have been put forward.
基金Project(41074004)supported by the National Natural Science Foundation of ChinaProject(2013CB733303)supported by the National Basic Research Program of China
文摘In the application of regression analysis method to model dam deformation, the ill-condition problem occurred in coefficient matrix always prevents an accurate modeling mainly due to the multicollinearity of the variables. Independent component regression （ICR） was proposed to model the dam deformation and identify the physical origins of the deformation. Simulation experiment shows that ICR can successfully resolve the problem of ill-condition and produce a reliable deformation model. After that, the method is applied to model the deformation of the Wuqiangxi Dam in Hunan province, China. The result shows that ICR can not only accurately model the deformation of the dam, but also help to identify the physical factors that affect the deformation through the extracted independent components.
文摘Hydroelectric power production from Garafiri dam and rainfall are essential elements with the observation of hydroelectric power production in West African power system,particularly in Guinea.This article focuses on the study and the influence of climate variability on hydroelectric power production at Garafiri dam over 16-year period(2008-2023).The aim of this work is to show the correlation between rainfall anomalies and hydroelectric power production at Garafiri dam.The method used consists of calculating precipitation anomalies at Garafiri site and those for the production of hydroelectric power from Garafiri dam over the study period.This approach led us to calculate the anomalies,leading to the study on climatic variability,in order to establish correlation between rainfall and hydroelectric power dam’s production.The trend with the correlation found made it possible to carry out a significance test between these two variables.These results clearly show that rainfall in Garafiri site increases hydroelectric power production and vice versa,which explains the interdependence between these two parameters,i.e.climatic variability and hydroelectric power production.
文摘This study addresses the pressing need to evaluate the quality of water resources in the Oued Guir watershed,highlighting the importance of monitoring both surface water and groundwater in the context of environmental and public health.It focuses on the evaluation of physicochemical and bacteriological water quality downstream of the Kaddoussa Dam,as well as the characterization of wastewater from the Boudnib treatment plant discharged into Oued Guir.The goal is to assess the health of aquatic ecosystems and understand the impact of anthropogenic activities on these sensitive environments.A comprehensive analysis was conducted at 15 selected stations during a sampling campaign in November 2023.Groundwater and surface water were assessed using 10 physicochemical parameters,while bacteriological quality was evaluated based on fecal coliforms and Escherichia coli.In addition,38 parameters were studied to characterize the wastewater discharge.All analyses followed standard procedures and the results were compared to Moroccan and World Health Organization(WHO)standards.The study revealed that surface water and groundwater in the study area exhibited strong mineralization,with Electrical Conductivity(EC)exceeding 1400µS/cm at all stations.Nitrogen quality,in terms of Nitrates(NO₃⁻),was moderate across stations,while Ammonium(NH₄⁺)quality was consistently excellent.Physicochemical parameters of surface waters indicated overall excellent quality.Bacteriological analysis showed minimal contamination by fecal coliforms and Escherichia coli,with levels deemed negligible.However,wastewater from the Boudnib treatment plant exceeded Moroccan standards for organic load,presenting a potential environmental risk.
