The variation laws of runoff and sediment load under different climate,vegetation,and human activity scenarios are significantly different.Exploring the impacts of climate change and human activities on runoff and sed...The variation laws of runoff and sediment load under different climate,vegetation,and human activity scenarios are significantly different.Exploring the impacts of climate change and human activities on runoff and sediment load dynamics can provide a profound understanding of the mechanism of runoff and sediment load variability in basins,which is crucial for the sustainable development of regional ecosystems.This study investigates the Tao River Basin(TRB)on the Tibetan Plateau,as well as the Zuli River Basin(ZRB)and Jing River Basin(JRB)on the Loess Plateau,to differentiate the impacts of climate change and human activities on runoff and sediment load dynamics.The runoff and sediment load of the three watersheds have shown a decreasing trend over the past 40 years,and combined with the DMC(Dual mass curve)method,it was found that the slope of the runoff sediment gradually tends to flatten out.After the time period was divided,the CA(Cumulative anomaly)method was used for verification,which revealed good correspondence between the two before 2000 and then gradual deviations.The power function best represents the relationship between runoff and sediment load.During the initial period,climate had a significant impact on runoff variation in the TRB and JRB,with contribution rates of-54.93%and-63.02%,respectively.In the later period,human activities became the dominant influence,contributing more than-60%of the runoff variation.In the ZRB,human activities consistently dominated runoff variation,with contribution rates of-72.72%and-55.66%during both periods.In the early stages of research,the impact of climate change on sediment load was more severe in the TRB and JRB,and human activities played a significant role in the later stages.However,in the ZRB,human activities have always been the main contributor.Based on the actual local situation,runoff and sediment load in the TRB are influenced primarily by engineering measures,and vegetation and check dams exert greater impacts on the ZRB and JRB.This study explores the attribution of water and sediment load changes in different ecological geographic regions from a comparative perspective,providing a valuable theoretical basis and reference for understanding global runoff and sediment transport changes in similar areas.展开更多
Urban rainwater runoff is an important source of nonpoint source pollution due to its transport of diverse contaminants,including polycyclic aromatic hydrocarbons(PAHs)and chlorinated derivatives.Importantly,these chl...Urban rainwater runoff is an important source of nonpoint source pollution due to its transport of diverse contaminants,including polycyclic aromatic hydrocarbons(PAHs)and chlorinated derivatives.Importantly,these chlorinated polycyclic aromatic hydrocarbons(Cl-PAHs)exhibit elevated toxicological potential compared to their non-halogenated parent compounds.In this study,we proposed an approach that combined multivariate receptor model with integration of SHapley Additive exPlanations and Random Forest model.This method identifies the possible sources and reveals the impact of source apportionment results and environmental driving factors(such as geographical and meteorological data)on pollutant concentrations.Sixteen PAHs and nine ClPAHs were detected in 79 runoff samples from all three sites.TheΣ_(16)PAHs average concentration(2923.93 to 6071.83 ng/L)was significantly higher than theΣ_(9)Cl-PAHs(384.34 to 1314.73 ng/L).The source apportionment was conducted by positive matrix factorization(PMF),and six potential pollution sources for PAHs and three for Cl-PAHs were quantified.PAHs primarily originate from the combustion of fossil fuels such as traffic,industrial emissions and coal tar,while Cl-PAHs are mainly derived from atmospheric deposition and industrial emissions.Meanwhile,the self‑organizing map classified PAHs and Cl-PAHs into 2 and 3 groups,respectively.The k-means algorithm yielded 4 clusters for runoff samples.Among machine learning models,Random Forest(RF)demonstrated optimal predictive performance and integrated with SHapley Additive exPlanations(RF-SHAP)revealed the effects of driving factors on the predicted concentration of PAHs and Cl-PAHs in urban runoff samples.展开更多
Based on monthly runoff and climate datasets spanning 2000–2024,this study employed the Theil–Sen’s slope estimation,Mann–Kendall(M–K)trend test,as well as Pearson correlation and Spearman rank correlation analys...Based on monthly runoff and climate datasets spanning 2000–2024,this study employed the Theil–Sen’s slope estimation,Mann–Kendall(M–K)trend test,as well as Pearson correlation and Spearman rank correlation analyses to systematically examine the spatiotemporal patterns of runoff and its climatic driving mechanisms across Tajikistan,providing a scientific basis for sustainable water resource utilization and management in the study area.Results indicated that during 2000–2024,the annual runoff in Tajikistan exhibited statistically non-significant long-term trend(P=0.76),while displaying pronounced seasonal variability and strong spatial heterogeneity.Spring and summer average runoff primarily exhibited slight declining tendencies,while winter average runoff exhibited pronounced reduction in localized regions,such as the Syr Darya Basin,the Vakhsh River Basin,and the lower reaches of the Zeravshan River Basin.Precipitation emerged as the dominant positive driver of runoff,exhibiting moderate to strong positive correlations across over 78.00%of the country,whereas potential evapotranspiration consistently functioned as a negative driver.Rising temperatures exerted a dual competitive effect on runoff:in high-elevation,glacier-covered regions,rising temperatures temporarily increased runoff by accelerating glacier melt;however,at the national scale,the negative impact of rising temperature on runoff has played a slightly dominant role to a certain extent by enhancing evapotranspiration.Collectively,these results indicated that the present stability of runoff in Tajikistan is strongly dependent on the short-term compensatory effects of glacier melt and the risk of future runoff decline is likely to intensify as glacier reserves continue to diminish.This study provides a critical scientific evidence to inform sustainable water resource management in Tajikistan and underscores the need for glacier conservation and integrated water resource management strategies.展开更多
Microplastics(MPs),as a new category of environmental pollutant,have been the hotspot of eco-friendly issues nowadays.Studies based on the aging process,the migration pattern of MPs in runoff rainwater,and the use of ...Microplastics(MPs),as a new category of environmental pollutant,have been the hotspot of eco-friendly issues nowadays.Studies based on the aging process,the migration pattern of MPs in runoff rainwater,and the use of bioretention cells to remove MPs from runoff rainwater are beginning to attract widespread attention.This review analyses the migration patterns of MPs in rainwater runoff through their sources,structure and characteristics.The mechanism of removing MPs from runoff stormwater,the purification efficiency of different fillers and their influencing factors,and the accumulation,fate,and aging of MPs in bioretention cells are described.Furthermore,the hazards of MP accumulation on the performance of bioretention cells are summarised.Future directions for removing MPs in bioretention cells are proposed:(1)research on MPs smaller than 100μm;(2)influence of MPs aging process on bioretention cells;(3)exploration of more effective fillers to enhance their removal efficiency;(4)research on synergistic removal mechanism of MPs and other pollution.展开更多
Previous works were mainly concentrated on long-term average runoff alterations,and extreme temperatures and watershed conditions are little analyzed.In this study,we collected gauged river flow and meteorological dat...Previous works were mainly concentrated on long-term average runoff alterations,and extreme temperatures and watershed conditions are little analyzed.In this study,we collected gauged river flow and meteorological data time series from 1916 to 2015 and 1941 to 2015 across the contiguous United States(CONUS)for 188 catchments to investigate the temporal trends and spatial features of runoff changes at multi-time scales.We also analyzed the relationships between runoff changes and climatic factors.Median descriptive statistics and Budyko coupled climate elasticity methods were used to calculate runoff elasticity in each time scale.The original Mann-Kendall trend test was used to test their trend significance in four time-scale(11,20,40,and 60 a),respectively.The results show that the trend of runoff changes is more significant in high time scales;total changes are heterogeneous over CONUS.After the 1970s,increases of up to 27%decade-1 were mainly concentrated in the mid-northern regions.Maximum temperature and catchment characteristics are vital factors for runoff alteration;runoff changes are independent of rainfall,and wet regions tend to have lower changes.These findings could help develop better regional water resource planning and management.展开更多
Land use and precipitation are two major factors affecting phosphorus(P)pollution of watershed runoff.However,molecular characterization of dissolved organic phosphorus(DOP)in runoff under the joint influences of land...Land use and precipitation are two major factors affecting phosphorus(P)pollution of watershed runoff.However,molecular characterization of dissolved organic phosphorus(DOP)in runoff under the joint influences of land use and precipitation remains limited.This study used Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR-MS)to study the molecular characteristics of DOP in a typical P-polluted watershed with spatially variable land use and precipitation.The results showed that low precipitation and intense human activity,including phosphate mining and associated industries,resulted in the accumulation of aliphatic DOP compounds in the upper reaches,characterized by low aromaticity and low biological stability.Higher precipitation and widespread agriculture in the middle and lower reaches resulted in highly unsaturated DOP compounds with high biological stability constituting a higher proportion,compared to in the upper reaches.While,under similar precipitation,more aliphatic DOP compounds characterized by lower aromaticity and higher saturation were enriched in the lower reaches due to more influence from urban runoff relative to the middle reaches.Photochemical and/or microbial processes did result in changes in the characteristics of DOP compounds during runoff processes due to the prevalence of low molecular weight and low O/C bioavailable aliphatic DOP molecules in the upper reaches,which were increasingly transformed into refractory compounds from the upper tomiddle reaches.The results of this study can increase the understanding of the joint impacts of land use and precipitation on DOP compounds in watershed runoff.展开更多
This study employs the Long Short-Term Memory(LSTM)rainfall-runoff model to simulate and predict runoff in typical basins of the Jiziwan Region of the Yellow River,aiming to overcome the shortcomings of traditional hy...This study employs the Long Short-Term Memory(LSTM)rainfall-runoff model to simulate and predict runoff in typical basins of the Jiziwan Region of the Yellow River,aiming to overcome the shortcomings of traditional hydrological models in complex nonlinear environments.The Jiziwan Region of the Yellow River is affected by human activities such as urbanization,agricultural development,and water resource management,leading to increasingly complex hydrological processes.Traditional hydrological models struggle to effectively capture the relationship between rainfall and runoff.The LSTM rainfall-runoff model,using deep learning techniques,automatically extracts features from data,identifies complex patterns and long-term dependency in time series,and provides more accurate and reliable runoff predictions.The results demonstrate that the LSTM rainfall-runoff model adapts well to the complex hydrological characteristics of the Jiziwan Region,showing superior performance over traditional hydrological models,especially in addressing the changing trends under the influence of climate change and human activities.By analyzing the interannual and within-year variations of runoff under different climate change scenarios,the model can predict the evolution trends of runoff under future climate conditions,providing a scientific basis for water resource management and decision-making.The results indicate that under different climate change scenarios,the runoff in several typical basins of the Jiziwan Region exhibits different variation trends.Under SSP1-2.6 and SSP2-4.5,some basins,such as the Wuding River Basin,Tuwei River Basin,and Gushanchuan Basin,show a decreasing trend in annual runoff.For example,in the Wuding River Basin,the average runoff from 2025 to 2040 is 12.48 m^(3)/s(SSP1-2.6),with an annual decrease of 0.10 m^(3)/s;in the Tuwei River Basin,the runoff from 2025 to 2040 is 12.96 m^(3)/s(SSP1-2.6),with an annual decrease of 0.10 m^(3)/s.In contrast,under SSP3-7.0 and SSP5-8.5,with climate warming and changes in precipitation patterns,runoff in some basins shows an increasing trend,particularly during the snowmelt period and with increased summer precipitation,leading to a significant rise in runoff.展开更多
This study aims to construct a large-scale hydrological Variable Infiltration Capacity(VIC)model based on temperature and precipitation at high altitudes,while elucidating the applicability of the model for hydrologic...This study aims to construct a large-scale hydrological Variable Infiltration Capacity(VIC)model based on temperature and precipitation at high altitudes,while elucidating the applicability of the model for hydrological simulation and analyzing the factors affecting runoff volume.Runoff volume and runoff depth were simulated using the VIC model and its performance was evaluated.Meanwhile,the factors affecting runoff volume were analyzed using Spearman correlation.The following model sensitivity parameters were obtained based on the China Natural Runoff Grid Point Dataset(CNRD v1.0):The variable infiltration curve parameter was 0.3,the Dsmax fraction where non-linear baseflow begins was 0.02,the maximum baseflow velocity was 15 mm/d,the maximum soil moisture where non-linear baseflow occurred was 0.7,the second soil moisture layer thickness was 0.3,and the thickness of the third soil moisture layer was 1.5.The surface runoff values in the Nyang River basin were similar in the first and fourth quarters(1.05–2.27 mm and 2.38–4.77 mm,respectively),and the surface runoff values were similar in the second and third quarters when the surface runoff was greater(23.46–52.20 mm and 60.59–85.63 mm,respectively).Watershed area,temperature,and precipitation significantly influenced the amount of runoff from the Nyang River.The applicability of the model to the Nyang River basin was confirmed using two different rate models.In some areas,precipitation and temperature did not have a dominating influence on runoff.Although the VIC model has significant advantages in runoff simulation,it requires a wealth of meteorological,soil,and hydrological data that may be difficult to obtain in some areas.展开更多
This study investigated the impacts of spring runoff on the formation of halobenzoquinones(HBQs)and their correlation with common water quality parameters(WQPs)and aromatic amino acids(AAs)in source water.Source water...This study investigated the impacts of spring runoff on the formation of halobenzoquinones(HBQs)and their correlation with common water quality parameters(WQPs)and aromatic amino acids(AAs)in source water.Source water and treated water samples were collected at two drinking water treatment plants in 2021,2022,and 2023.HBQs and aromatic AAs were analyzed using solid phase extraction with high performance liquid chromatography–tandem mass spectrometry methods.The only HBQs detected in treated water were 2,6-dichloro-1,4-benzoquinone(DCBQ)and hydroxy–DCBQ(OH-DCBQ).The concentration of DCBQ was 3-4 times higher during spring runoff events than during non-spring-runoff periods,suggesting the impact of spring runoff on the formation of DCBQ.The DCBQ concentrations in finished water positively correlated with the color,dissolved organic carbon,total organic nitrogen,and specific ultraviolet absorbance WQPs of source water in 2021 and 2022.The temporal trend of the total aromatic AAs determined in source water was strongly and positively correlated to DCBQ in finished water.Finally,there was a significant positive correlation between the concentration of DCBQ determined immediately following the addition of chlorine and the presence of its transformation product,OH-DCBQ,in finished water.The results also showed that powdered activated carbon can remove some of the HBQ precursors in the sourcewater to reduce DCBQ formation.This study demonstrated that WQPs and aromatic AAs are useful indicators for the removal of precursors to reduce HBQ formation during drinking water treatment.展开更多
The South-to-North Water Diversion Project in China aims to address the imbalanced distribution of water resources between the northern and southern regions,a critical safeguard for sustainable socio-economic and ecol...The South-to-North Water Diversion Project in China aims to address the imbalanced distribution of water resources between the northern and southern regions,a critical safeguard for sustainable socio-economic and ecological development.In this study,we investigated the hydroclimatic evolution of the water source area and its driving mechanisms using the inflow runoff data at Danjiangkou Reservoir from 1954 to 2013,along with multiple gridded hydroclimatic datasets.Based on the correlations between instrumental runoff data and gridded hydroclimatic variables,we used linear regression to extend the long-term runoff record to the period of 1902-2019.Our results indicate that climate changes,dominated by regional wet-dry cycles,have significant impacts on runoff variations,while the influence of human activities remains comparatively limited.Danjiangkou Reservoir can maintain a balanced base flow,even during the operation of the water diversion project.Preliminary synoptic climatology analyses reveal that runoff variations are mainly driven by the El Niño-Southern Oscillation(ENSO)and the Pacific Walker Circulation(PWC),which affect runoff by altering large-scale ocean-to-continent water vapor processes.This study advances the field by integrating multi-source data with analytical techniques,which enhances understanding of long-term runoff changes in the Danjiangkou Reservoir and their climatic drivers,ultimately supporting sustainable water resource management.展开更多
Climate change and human activities are primary drivers of runoff variations,significantly impacting the hydrological balance of river basins.In recent decades,the Yellow River Basin,China has experienced a marked dec...Climate change and human activities are primary drivers of runoff variations,significantly impacting the hydrological balance of river basins.In recent decades,the Yellow River Basin,China has experienced a marked decline in runoff,posing challenges to the sustainable development of regional water resources and ecosystem stability.To enhance the understanding of runoff dynamics in the basin,we selected the Dahei River Basin,a representative tributary in the upper reaches of the Yellow River Basin as the study area.A comprehensive analysis of runoff trends and contributing factors was conducted using the data on hydrology,meteorology,and water resource development and utilization.Abrupt change years of runoff series in the Dahei River Basin was identified by the Mann-Kendall and Pettitt tests:1999 at Dianshang,Qixiaying,and Meidai hydrological stations and 1995 at Sanliang hydrological station.Through hydrological simulations based on the Variable Infiltration Capacity(VIC)model,we quantified the factors driving runoff evolution in the Dahei River Basin,with climate change contributing 9.92%–22.91%and human activities contributing 77.09%–90.08%.The Budyko hypothesis method provided similar results,with climate change contributing 13.06%–20.89%and human activities contributing 79.11%–86.94%.Both methods indicated that human activities,particularly water consumption,were dominant factors in the runoff variations of the Dahei River Basin.The integration of hydrological modeling with attribution analysis offers valuable insights into runoff evolution,facilitating adaptive strategies to mitigate water scarcity in arid and semi-arid areas.展开更多
Over the period of rainfall, urban green infrastructures(UGI) function like a sponge by absorbing surface runoff as sinks;however, they will shift to sources once their runoff reduction capacities are exceeded. This d...Over the period of rainfall, urban green infrastructures(UGI) function like a sponge by absorbing surface runoff as sinks;however, they will shift to sources once their runoff reduction capacities are exceeded. This dynamic of sink-source shifts, and its dependence on the vegetation structure, remain poorly understood, limiting the action of flood-resilient UGI strategies. This study employs MIKE SHE/11 model coupled with statistical analysis for such resolution. Across four scenarios ranging from light to heavy rainfall, we identified regime shifts in UGI system through the decreasing to increasing trends of sink fractions, typically occurring around 13–18 h after rainfall starts. Based on these regime shifts, we categorized the UGI system into vulnerable, reliable, and recoverable components, highlighting its heterogeneous performance. In addition, by examining the influence of vegetation structure on sink–source dynamics, we found that a higher probability of sinks under light rainfalls was associated with a greater leaf area index(LAI) and vegetation height standard deviation(VHSTD), while green volume(GV) and canopy height(CH) played a more prominent role under heavier rainfalls. Threshold effect analysis further revealed that, a high proportion of the recoverable parts met the thresholds of CH(82 %)and GV(85 %), whereas fewer reached the thresholds of LAI(15 %–19 %) and VHSTD(3 %–6 %). These findings underscore the importance of enhancing 3D vegetation configuration for UGI to adapt to flood impacts. Our study expects to provide actionable knowledge for understanding, quantification, and management of the runoff sink-source dynamics, informing UGI design and planning to achieve urban flood resilience.展开更多
The Songhua River Basin(SRB),ranking third largest in China in terms of both runoff volume and basin area,has experi-enced frequent disasters and drastic changes in runoff since the early 20th century.Many studies hav...The Songhua River Basin(SRB),ranking third largest in China in terms of both runoff volume and basin area,has experi-enced frequent disasters and drastic changes in runoff since the early 20th century.Many studies have analyzed the causes of runoff re-duction;however,the spatiotemporal differences in runoff contributions and their underlying mechanisms remain poorly understood,which are crucial for regional water resources management and effective utilization.This study used the Mann-Kendall rank correlation trend test,continuous wavelet analysis,cumulative anomaly,and the slope change ratio of cumulative quantities(SCRCQ)method to explore the runoff changes characteristics and spatiotemporal differences of the contributions of climate change and human activities to runoff changes across three sub-basins of the SRB.The results show that:1)runoff from 1955 to 2022 in all the three sub-basins exhibit a statistically significant decreasing trend at 0.05 significant level.2)Four abrupt change points in runoff were detected in Nenjiang River Basin(NRB)and the mainstream of the SRB(MSRB),whereas only two change points in the Second Songhua River(SSRB).3)Runoff and precipitation series of the NRB and MSRB exhibit similar multi-timescale cycle characteristics with the most dominated cycles of 45-58 yr.In contrast,it is 12-18 yr for SSRB.4)Anthropogenic activities are the primary factor leading to in the reduction of runoff in NRB(74.33%-91.67%)and MSRB(50.11%-102.12%),whereas it is only 5.38%-33.12%in SSRB.This is attributed to the uneven distribution of regional climate and human activities in the entire SRB.5)With the growing demand for water diversion for agri-cultural irrigation,anthropogenic activities in the NRB and MSRB have increased.However,the opposite is found in SSR,where the in-creased influence of precipitation on runoff and water conservation policies are identified.展开更多
The Tianshan Mountains of Central Asia,highly sensitive to climate change,has been comprehensively assessed for its ecosystem vulnerability across multiple aspects.However,studies on the region's main river system...The Tianshan Mountains of Central Asia,highly sensitive to climate change,has been comprehensively assessed for its ecosystem vulnerability across multiple aspects.However,studies on the region's main river systems and hydropower resources remain limited.Thus,examining the impact of climate change on the runoff and gross hydropower potential(GHP)of this region is essential for promoting sustainable development and effective management of water and hydropower resources.This study focused on the Kaidu River Basin that is situated above the Dashankou Hydropower Station on the southern slope of the Tianshan Mountains,China.By utilizing an ensemble of bias-corrected global climate models(GCMs)from Coupled Model Intercomparison Project Phase 6(CMIP6)and the Variable Infiltration Capacity(VIC)model coupled with a glacier module(VIC-Glacier),we examined the variations in future runoff and GHP during 2017-2070 under four shared socio-economic pathway(SSP)scenarios(SSP1-2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5)compared to the baseline period(1985-2016).The findings indicated that precipitation and temperature in the Kaidu River Basin exhibit a general upward trend under the four SSP scenarios,with the fastest rate of increase in precipitation under the SSP2-4.5 scenario and the most significant changes in mean,maximum,and minimum temperatures under the SSP5-8.5 scenario,compared to the baseline period(1980-2016).Future runoff in the basin is projected to decrease,with rates of decline under the SSP1-2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5 scenarios being 3.09,3.42,7.04,and 7.20 m^(3)/s per decade,respectively.The trends in GHP are consistent with runoff,with rates of decline in GHP under the SSP1-2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5 scenarios at 507.74,563.33,1158.44,and 1184.52 MW/10a,respectively.Compared to the baseline period(1985-2016),the rates of change in GHP under the SSP1-2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5 scenarios are-20.66%,-20.93%,-18.91%,and-17.49%,respectively.The Kaidu River Basin will face significant challenges in water and hydropower resources in the future,underscoring the need to adjust water resource management and hydropower planning within the basin.展开更多
基金funding from the Natural Science Foundation of Shanxi Province(202403021222245,20240302121217)。
文摘The variation laws of runoff and sediment load under different climate,vegetation,and human activity scenarios are significantly different.Exploring the impacts of climate change and human activities on runoff and sediment load dynamics can provide a profound understanding of the mechanism of runoff and sediment load variability in basins,which is crucial for the sustainable development of regional ecosystems.This study investigates the Tao River Basin(TRB)on the Tibetan Plateau,as well as the Zuli River Basin(ZRB)and Jing River Basin(JRB)on the Loess Plateau,to differentiate the impacts of climate change and human activities on runoff and sediment load dynamics.The runoff and sediment load of the three watersheds have shown a decreasing trend over the past 40 years,and combined with the DMC(Dual mass curve)method,it was found that the slope of the runoff sediment gradually tends to flatten out.After the time period was divided,the CA(Cumulative anomaly)method was used for verification,which revealed good correspondence between the two before 2000 and then gradual deviations.The power function best represents the relationship between runoff and sediment load.During the initial period,climate had a significant impact on runoff variation in the TRB and JRB,with contribution rates of-54.93%and-63.02%,respectively.In the later period,human activities became the dominant influence,contributing more than-60%of the runoff variation.In the ZRB,human activities consistently dominated runoff variation,with contribution rates of-72.72%and-55.66%during both periods.In the early stages of research,the impact of climate change on sediment load was more severe in the TRB and JRB,and human activities played a significant role in the later stages.However,in the ZRB,human activities have always been the main contributor.Based on the actual local situation,runoff and sediment load in the TRB are influenced primarily by engineering measures,and vegetation and check dams exert greater impacts on the ZRB and JRB.This study explores the attribution of water and sediment load changes in different ecological geographic regions from a comparative perspective,providing a valuable theoretical basis and reference for understanding global runoff and sediment transport changes in similar areas.
基金supported by Guangdong Basic and Applied Basic Research Foundation(Nos.2021B1515120055 and 2022A1515010499).
文摘Urban rainwater runoff is an important source of nonpoint source pollution due to its transport of diverse contaminants,including polycyclic aromatic hydrocarbons(PAHs)and chlorinated derivatives.Importantly,these chlorinated polycyclic aromatic hydrocarbons(Cl-PAHs)exhibit elevated toxicological potential compared to their non-halogenated parent compounds.In this study,we proposed an approach that combined multivariate receptor model with integration of SHapley Additive exPlanations and Random Forest model.This method identifies the possible sources and reveals the impact of source apportionment results and environmental driving factors(such as geographical and meteorological data)on pollutant concentrations.Sixteen PAHs and nine ClPAHs were detected in 79 runoff samples from all three sites.TheΣ_(16)PAHs average concentration(2923.93 to 6071.83 ng/L)was significantly higher than theΣ_(9)Cl-PAHs(384.34 to 1314.73 ng/L).The source apportionment was conducted by positive matrix factorization(PMF),and six potential pollution sources for PAHs and three for Cl-PAHs were quantified.PAHs primarily originate from the combustion of fossil fuels such as traffic,industrial emissions and coal tar,while Cl-PAHs are mainly derived from atmospheric deposition and industrial emissions.Meanwhile,the self‑organizing map classified PAHs and Cl-PAHs into 2 and 3 groups,respectively.The k-means algorithm yielded 4 clusters for runoff samples.Among machine learning models,Random Forest(RF)demonstrated optimal predictive performance and integrated with SHapley Additive exPlanations(RF-SHAP)revealed the effects of driving factors on the predicted concentration of PAHs and Cl-PAHs in urban runoff samples.
基金funded by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0720203)the National Key Research and Development Program of China(2023YFF0805603).
文摘Based on monthly runoff and climate datasets spanning 2000–2024,this study employed the Theil–Sen’s slope estimation,Mann–Kendall(M–K)trend test,as well as Pearson correlation and Spearman rank correlation analyses to systematically examine the spatiotemporal patterns of runoff and its climatic driving mechanisms across Tajikistan,providing a scientific basis for sustainable water resource utilization and management in the study area.Results indicated that during 2000–2024,the annual runoff in Tajikistan exhibited statistically non-significant long-term trend(P=0.76),while displaying pronounced seasonal variability and strong spatial heterogeneity.Spring and summer average runoff primarily exhibited slight declining tendencies,while winter average runoff exhibited pronounced reduction in localized regions,such as the Syr Darya Basin,the Vakhsh River Basin,and the lower reaches of the Zeravshan River Basin.Precipitation emerged as the dominant positive driver of runoff,exhibiting moderate to strong positive correlations across over 78.00%of the country,whereas potential evapotranspiration consistently functioned as a negative driver.Rising temperatures exerted a dual competitive effect on runoff:in high-elevation,glacier-covered regions,rising temperatures temporarily increased runoff by accelerating glacier melt;however,at the national scale,the negative impact of rising temperature on runoff has played a slightly dominant role to a certain extent by enhancing evapotranspiration.Collectively,these results indicated that the present stability of runoff in Tajikistan is strongly dependent on the short-term compensatory effects of glacier melt and the risk of future runoff decline is likely to intensify as glacier reserves continue to diminish.This study provides a critical scientific evidence to inform sustainable water resource management in Tajikistan and underscores the need for glacier conservation and integrated water resource management strategies.
基金supported by the National Natural Science Foundation of China(No.52070152).
文摘Microplastics(MPs),as a new category of environmental pollutant,have been the hotspot of eco-friendly issues nowadays.Studies based on the aging process,the migration pattern of MPs in runoff rainwater,and the use of bioretention cells to remove MPs from runoff rainwater are beginning to attract widespread attention.This review analyses the migration patterns of MPs in rainwater runoff through their sources,structure and characteristics.The mechanism of removing MPs from runoff stormwater,the purification efficiency of different fillers and their influencing factors,and the accumulation,fate,and aging of MPs in bioretention cells are described.Furthermore,the hazards of MP accumulation on the performance of bioretention cells are summarised.Future directions for removing MPs in bioretention cells are proposed:(1)research on MPs smaller than 100μm;(2)influence of MPs aging process on bioretention cells;(3)exploration of more effective fillers to enhance their removal efficiency;(4)research on synergistic removal mechanism of MPs and other pollution.
基金supported by National Key R&D Program of China(No.2018YFC0407303)“Young Talents”Project of Northeast Agricultural University(No.20QC13)the Natural Science Foundation of Heilongjiang Province of China(No.E2017009)。
文摘Previous works were mainly concentrated on long-term average runoff alterations,and extreme temperatures and watershed conditions are little analyzed.In this study,we collected gauged river flow and meteorological data time series from 1916 to 2015 and 1941 to 2015 across the contiguous United States(CONUS)for 188 catchments to investigate the temporal trends and spatial features of runoff changes at multi-time scales.We also analyzed the relationships between runoff changes and climatic factors.Median descriptive statistics and Budyko coupled climate elasticity methods were used to calculate runoff elasticity in each time scale.The original Mann-Kendall trend test was used to test their trend significance in four time-scale(11,20,40,and 60 a),respectively.The results show that the trend of runoff changes is more significant in high time scales;total changes are heterogeneous over CONUS.After the 1970s,increases of up to 27%decade-1 were mainly concentrated in the mid-northern regions.Maximum temperature and catchment characteristics are vital factors for runoff alteration;runoff changes are independent of rainfall,and wet regions tend to have lower changes.These findings could help develop better regional water resource planning and management.
基金supported by the Three Gorges Corporation (No.HBHB2023018)the Project of Hubei Provincial Key Research and Development (No.2022BCA074)the National Key Research and Development Program of China (No.2022YFC3705002).
文摘Land use and precipitation are two major factors affecting phosphorus(P)pollution of watershed runoff.However,molecular characterization of dissolved organic phosphorus(DOP)in runoff under the joint influences of land use and precipitation remains limited.This study used Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR-MS)to study the molecular characteristics of DOP in a typical P-polluted watershed with spatially variable land use and precipitation.The results showed that low precipitation and intense human activity,including phosphate mining and associated industries,resulted in the accumulation of aliphatic DOP compounds in the upper reaches,characterized by low aromaticity and low biological stability.Higher precipitation and widespread agriculture in the middle and lower reaches resulted in highly unsaturated DOP compounds with high biological stability constituting a higher proportion,compared to in the upper reaches.While,under similar precipitation,more aliphatic DOP compounds characterized by lower aromaticity and higher saturation were enriched in the lower reaches due to more influence from urban runoff relative to the middle reaches.Photochemical and/or microbial processes did result in changes in the characteristics of DOP compounds during runoff processes due to the prevalence of low molecular weight and low O/C bioavailable aliphatic DOP molecules in the upper reaches,which were increasingly transformed into refractory compounds from the upper tomiddle reaches.The results of this study can increase the understanding of the joint impacts of land use and precipitation on DOP compounds in watershed runoff.
基金the National Key R&D Program of China(No.2023YFC3206504)National Natural Science Foundation of China(Nos.52121006,41961124006,51911540477)+1 种基金Young Top-Notch Talent Support Program of National High-level Talents Special Support PlanResearch Project of Ministry of Natural Resources(No.20210103)for providing financial support for this research。
文摘This study employs the Long Short-Term Memory(LSTM)rainfall-runoff model to simulate and predict runoff in typical basins of the Jiziwan Region of the Yellow River,aiming to overcome the shortcomings of traditional hydrological models in complex nonlinear environments.The Jiziwan Region of the Yellow River is affected by human activities such as urbanization,agricultural development,and water resource management,leading to increasingly complex hydrological processes.Traditional hydrological models struggle to effectively capture the relationship between rainfall and runoff.The LSTM rainfall-runoff model,using deep learning techniques,automatically extracts features from data,identifies complex patterns and long-term dependency in time series,and provides more accurate and reliable runoff predictions.The results demonstrate that the LSTM rainfall-runoff model adapts well to the complex hydrological characteristics of the Jiziwan Region,showing superior performance over traditional hydrological models,especially in addressing the changing trends under the influence of climate change and human activities.By analyzing the interannual and within-year variations of runoff under different climate change scenarios,the model can predict the evolution trends of runoff under future climate conditions,providing a scientific basis for water resource management and decision-making.The results indicate that under different climate change scenarios,the runoff in several typical basins of the Jiziwan Region exhibits different variation trends.Under SSP1-2.6 and SSP2-4.5,some basins,such as the Wuding River Basin,Tuwei River Basin,and Gushanchuan Basin,show a decreasing trend in annual runoff.For example,in the Wuding River Basin,the average runoff from 2025 to 2040 is 12.48 m^(3)/s(SSP1-2.6),with an annual decrease of 0.10 m^(3)/s;in the Tuwei River Basin,the runoff from 2025 to 2040 is 12.96 m^(3)/s(SSP1-2.6),with an annual decrease of 0.10 m^(3)/s.In contrast,under SSP3-7.0 and SSP5-8.5,with climate warming and changes in precipitation patterns,runoff in some basins shows an increasing trend,particularly during the snowmelt period and with increased summer precipitation,leading to a significant rise in runoff.
基金supported by the Key R&D Project of Science and Technology Program of Tibet Autonomous Region(XZ202301ZY0006G)the Graduate High-level Talent Training Program of Xizang University(2022-GSP-B007)+1 种基金Nagqu City Science and Technology Program Key R&D Projects(NQKJ-2023-15)Central Financial Support for Local Universities to Construct Wetland Station in Mitika and Collaborative Innovation Center for Ecological Civilization of the Qinghai-Tibetan Plateau([2024]NO.01).
文摘This study aims to construct a large-scale hydrological Variable Infiltration Capacity(VIC)model based on temperature and precipitation at high altitudes,while elucidating the applicability of the model for hydrological simulation and analyzing the factors affecting runoff volume.Runoff volume and runoff depth were simulated using the VIC model and its performance was evaluated.Meanwhile,the factors affecting runoff volume were analyzed using Spearman correlation.The following model sensitivity parameters were obtained based on the China Natural Runoff Grid Point Dataset(CNRD v1.0):The variable infiltration curve parameter was 0.3,the Dsmax fraction where non-linear baseflow begins was 0.02,the maximum baseflow velocity was 15 mm/d,the maximum soil moisture where non-linear baseflow occurred was 0.7,the second soil moisture layer thickness was 0.3,and the thickness of the third soil moisture layer was 1.5.The surface runoff values in the Nyang River basin were similar in the first and fourth quarters(1.05–2.27 mm and 2.38–4.77 mm,respectively),and the surface runoff values were similar in the second and third quarters when the surface runoff was greater(23.46–52.20 mm and 60.59–85.63 mm,respectively).Watershed area,temperature,and precipitation significantly influenced the amount of runoff from the Nyang River.The applicability of the model to the Nyang River basin was confirmed using two different rate models.In some areas,precipitation and temperature did not have a dominating influence on runoff.Although the VIC model has significant advantages in runoff simulation,it requires a wealth of meteorological,soil,and hydrological data that may be difficult to obtain in some areas.
基金supported by grants from the Natural Sciences and Engineering Research Council of Canada(NSERC)Alberta Innovates,and the Canada Research Chairs Program.The authors acknowledge the support of the NSERC Postgraduate Doctoral Scholarship(NJPW),the Alberta Innovates Graduate Student Scholarship(KC),and the 75th Anniversary Graduate Student Award and the Graduate Student Recruitment Scholarship of the Faculty of Medicine and Dentistry at the University of Alberta(KNMC).
文摘This study investigated the impacts of spring runoff on the formation of halobenzoquinones(HBQs)and their correlation with common water quality parameters(WQPs)and aromatic amino acids(AAs)in source water.Source water and treated water samples were collected at two drinking water treatment plants in 2021,2022,and 2023.HBQs and aromatic AAs were analyzed using solid phase extraction with high performance liquid chromatography–tandem mass spectrometry methods.The only HBQs detected in treated water were 2,6-dichloro-1,4-benzoquinone(DCBQ)and hydroxy–DCBQ(OH-DCBQ).The concentration of DCBQ was 3-4 times higher during spring runoff events than during non-spring-runoff periods,suggesting the impact of spring runoff on the formation of DCBQ.The DCBQ concentrations in finished water positively correlated with the color,dissolved organic carbon,total organic nitrogen,and specific ultraviolet absorbance WQPs of source water in 2021 and 2022.The temporal trend of the total aromatic AAs determined in source water was strongly and positively correlated to DCBQ in finished water.Finally,there was a significant positive correlation between the concentration of DCBQ determined immediately following the addition of chlorine and the presence of its transformation product,OH-DCBQ,in finished water.The results also showed that powdered activated carbon can remove some of the HBQ precursors in the sourcewater to reduce DCBQ formation.This study demonstrated that WQPs and aromatic AAs are useful indicators for the removal of precursors to reduce HBQ formation during drinking water treatment.
基金supported by the National Natural Science Foundation of China(NSFC Project No.32061123008)the Innovation Training Programme for Undergraduate Students of Yunnan University(Project No.202301051).
文摘The South-to-North Water Diversion Project in China aims to address the imbalanced distribution of water resources between the northern and southern regions,a critical safeguard for sustainable socio-economic and ecological development.In this study,we investigated the hydroclimatic evolution of the water source area and its driving mechanisms using the inflow runoff data at Danjiangkou Reservoir from 1954 to 2013,along with multiple gridded hydroclimatic datasets.Based on the correlations between instrumental runoff data and gridded hydroclimatic variables,we used linear regression to extend the long-term runoff record to the period of 1902-2019.Our results indicate that climate changes,dominated by regional wet-dry cycles,have significant impacts on runoff variations,while the influence of human activities remains comparatively limited.Danjiangkou Reservoir can maintain a balanced base flow,even during the operation of the water diversion project.Preliminary synoptic climatology analyses reveal that runoff variations are mainly driven by the El Niño-Southern Oscillation(ENSO)and the Pacific Walker Circulation(PWC),which affect runoff by altering large-scale ocean-to-continent water vapor processes.This study advances the field by integrating multi-source data with analytical techniques,which enhances understanding of long-term runoff changes in the Danjiangkou Reservoir and their climatic drivers,ultimately supporting sustainable water resource management.
基金supported by the National Key Research and Development Program of China(2022YFC3204401)the National Natural Science Foundation of China(U23A2001,U2243234)+2 种基金the Major Science and Technology Projects of Inner Mongolia Autonomous Region(KCX2024013-1,2022EEDSKJXM005)the Inner Mongolia Autonomous Region Science and Technology Leading Talent Team(2022LJRC0007)the Inner Mongolia Agricultural University Basic Research Business Expenses Project(BR221012,BR221204).
文摘Climate change and human activities are primary drivers of runoff variations,significantly impacting the hydrological balance of river basins.In recent decades,the Yellow River Basin,China has experienced a marked decline in runoff,posing challenges to the sustainable development of regional water resources and ecosystem stability.To enhance the understanding of runoff dynamics in the basin,we selected the Dahei River Basin,a representative tributary in the upper reaches of the Yellow River Basin as the study area.A comprehensive analysis of runoff trends and contributing factors was conducted using the data on hydrology,meteorology,and water resource development and utilization.Abrupt change years of runoff series in the Dahei River Basin was identified by the Mann-Kendall and Pettitt tests:1999 at Dianshang,Qixiaying,and Meidai hydrological stations and 1995 at Sanliang hydrological station.Through hydrological simulations based on the Variable Infiltration Capacity(VIC)model,we quantified the factors driving runoff evolution in the Dahei River Basin,with climate change contributing 9.92%–22.91%and human activities contributing 77.09%–90.08%.The Budyko hypothesis method provided similar results,with climate change contributing 13.06%–20.89%and human activities contributing 79.11%–86.94%.Both methods indicated that human activities,particularly water consumption,were dominant factors in the runoff variations of the Dahei River Basin.The integration of hydrological modeling with attribution analysis offers valuable insights into runoff evolution,facilitating adaptive strategies to mitigate water scarcity in arid and semi-arid areas.
基金supported by the National Key R&D Program of China(Grant No.2022YFF1303102)the Global Engagement for Strategic Partnership project of Nanjing University,the China Scholarship Council(Grant No.202406190182)+1 种基金the Swedish Research Council(VR,Grant No.2022–04672)the Kunshan Water Bureau for supporting this study through the project cooperation.
文摘Over the period of rainfall, urban green infrastructures(UGI) function like a sponge by absorbing surface runoff as sinks;however, they will shift to sources once their runoff reduction capacities are exceeded. This dynamic of sink-source shifts, and its dependence on the vegetation structure, remain poorly understood, limiting the action of flood-resilient UGI strategies. This study employs MIKE SHE/11 model coupled with statistical analysis for such resolution. Across four scenarios ranging from light to heavy rainfall, we identified regime shifts in UGI system through the decreasing to increasing trends of sink fractions, typically occurring around 13–18 h after rainfall starts. Based on these regime shifts, we categorized the UGI system into vulnerable, reliable, and recoverable components, highlighting its heterogeneous performance. In addition, by examining the influence of vegetation structure on sink–source dynamics, we found that a higher probability of sinks under light rainfalls was associated with a greater leaf area index(LAI) and vegetation height standard deviation(VHSTD), while green volume(GV) and canopy height(CH) played a more prominent role under heavier rainfalls. Threshold effect analysis further revealed that, a high proportion of the recoverable parts met the thresholds of CH(82 %)and GV(85 %), whereas fewer reached the thresholds of LAI(15 %–19 %) and VHSTD(3 %–6 %). These findings underscore the importance of enhancing 3D vegetation configuration for UGI to adapt to flood impacts. Our study expects to provide actionable knowledge for understanding, quantification, and management of the runoff sink-source dynamics, informing UGI design and planning to achieve urban flood resilience.
基金Under the auspices of National Natural Science Foundation of China(No.42271125)Jilin Province Foreign Expert Project(No.L202322)Doctoral Research Initiation Project of Jilin Normal University(No.0420237)。
文摘The Songhua River Basin(SRB),ranking third largest in China in terms of both runoff volume and basin area,has experi-enced frequent disasters and drastic changes in runoff since the early 20th century.Many studies have analyzed the causes of runoff re-duction;however,the spatiotemporal differences in runoff contributions and their underlying mechanisms remain poorly understood,which are crucial for regional water resources management and effective utilization.This study used the Mann-Kendall rank correlation trend test,continuous wavelet analysis,cumulative anomaly,and the slope change ratio of cumulative quantities(SCRCQ)method to explore the runoff changes characteristics and spatiotemporal differences of the contributions of climate change and human activities to runoff changes across three sub-basins of the SRB.The results show that:1)runoff from 1955 to 2022 in all the three sub-basins exhibit a statistically significant decreasing trend at 0.05 significant level.2)Four abrupt change points in runoff were detected in Nenjiang River Basin(NRB)and the mainstream of the SRB(MSRB),whereas only two change points in the Second Songhua River(SSRB).3)Runoff and precipitation series of the NRB and MSRB exhibit similar multi-timescale cycle characteristics with the most dominated cycles of 45-58 yr.In contrast,it is 12-18 yr for SSRB.4)Anthropogenic activities are the primary factor leading to in the reduction of runoff in NRB(74.33%-91.67%)and MSRB(50.11%-102.12%),whereas it is only 5.38%-33.12%in SSRB.This is attributed to the uneven distribution of regional climate and human activities in the entire SRB.5)With the growing demand for water diversion for agri-cultural irrigation,anthropogenic activities in the NRB and MSRB have increased.However,the opposite is found in SSR,where the in-creased influence of precipitation on runoff and water conservation policies are identified.
基金funded by the National Natural Science Foundation of China(42067062).
文摘The Tianshan Mountains of Central Asia,highly sensitive to climate change,has been comprehensively assessed for its ecosystem vulnerability across multiple aspects.However,studies on the region's main river systems and hydropower resources remain limited.Thus,examining the impact of climate change on the runoff and gross hydropower potential(GHP)of this region is essential for promoting sustainable development and effective management of water and hydropower resources.This study focused on the Kaidu River Basin that is situated above the Dashankou Hydropower Station on the southern slope of the Tianshan Mountains,China.By utilizing an ensemble of bias-corrected global climate models(GCMs)from Coupled Model Intercomparison Project Phase 6(CMIP6)and the Variable Infiltration Capacity(VIC)model coupled with a glacier module(VIC-Glacier),we examined the variations in future runoff and GHP during 2017-2070 under four shared socio-economic pathway(SSP)scenarios(SSP1-2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5)compared to the baseline period(1985-2016).The findings indicated that precipitation and temperature in the Kaidu River Basin exhibit a general upward trend under the four SSP scenarios,with the fastest rate of increase in precipitation under the SSP2-4.5 scenario and the most significant changes in mean,maximum,and minimum temperatures under the SSP5-8.5 scenario,compared to the baseline period(1980-2016).Future runoff in the basin is projected to decrease,with rates of decline under the SSP1-2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5 scenarios being 3.09,3.42,7.04,and 7.20 m^(3)/s per decade,respectively.The trends in GHP are consistent with runoff,with rates of decline in GHP under the SSP1-2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5 scenarios at 507.74,563.33,1158.44,and 1184.52 MW/10a,respectively.Compared to the baseline period(1985-2016),the rates of change in GHP under the SSP1-2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5 scenarios are-20.66%,-20.93%,-18.91%,and-17.49%,respectively.The Kaidu River Basin will face significant challenges in water and hydropower resources in the future,underscoring the need to adjust water resource management and hydropower planning within the basin.
