Distribution Characteristics and Environmental Response of Diatoms Deposited in Reservoirs in the Source Region of Le'an River by YIN Hongwei, ZHANG Jie, YAN Ruyu, JI Yong, XIAO Weiqi, CAI Gaotang

“…At present, the study of heavy metal pollution in the Le'an River Basin should be explored.To fully elucidate the environmental characteristics and change-driven processes of reservoirs in the source region of the Le'an River, this paper employs Qinghua and Shijing reservoirs with different ecological environments and development backgrounds as research objects.Experimental records of diatom species and physicochemical indicators in sedimentary column cores are conducted, and meanwhile combined with modern monitoring data and multivariate statistical methods, environmental characteristics driving factors affecting changes in sedimentary diatom assemblages and sedimentary environment in reservoirs are analyzed.The results show that nutrient levels in the reservoirs gradually increase with the depth to the surface, and the sediment pollution evaluation also reveals the collection process of nutrients.Universal and cleaning indicator species have been replaced by fouling-tolerant and eutrophication indicator species of sedimentary diatoms, with representative species being Achnanthidium minutissima and Navicula minima.The multivariate statistical analysis results show that TP, TN, TP, and TOC are the main driving factors of diatom community structure distribution in Qinghua and Shijing reservoirs respectively (p<0.05).Box plot analysis results of 18 diatom indices reveal that CEE and LOBO indices are screened and show sound evaluation suitability and correlation.The input of exogenous materials into the reservoirs is affected by different anthropogenic practices to drive the succession of the diatom community, with a trend towards eutrophication in both reservoirs.…”
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Research on Runoff Simulation of Arid Oasis Irrigation Area Based on SWAT Model by JIANG Mengyao, WANG Shuixian, ZHAO Zhigang

“…In order to study the runoff changes in the arid oasis irrigation area,this paper constructs a distributed hydrological model of Yanqi Basin based on SWAT model with the Chinese meteorological assimilation driving datasets (CMADS) from 1955 to 2017,traditional hydrometeorological station data,land use data,soil data,digital elevation data,analyzes the sensitivity of parameters by SUFI-2 (Sequential Uncertainty Fitting) algorithm,calibrates several important parameters influencing runoff simulation results through SWAT-CUP (SWAT Calibration Uncertainty Procedures) software,and verifies the model by the measured runoff from 1991 to 2017.The results show that:the simulated runoff of Yanqi Basin in Xinjiang for a long time scales coincides with the measured runoff.During the calibration period and verification period,the Nash coefficient (NES) is above 0.82,the Pearson correlation coefficient (R²) is 0.86 and 0.90 respectively,and the relative error (R_e) is less than 10.Therefore,SWAT model is well applicable to the runoff simulation of Yanqi Basin.Based on this,runoff changes from 2016 to 2100 in Yanqi Basin under the scenarios of RCP4.5 and RCP8.5 are simulated.It can be found that precipitation changes in Kaidu River basin have a significant impact on runoff in Yanqi Basin,that is,when precipitation increases by 20% and temperature increases by 2°C,the runoff increases by 26.53% compared with the current year.…”
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Application of MIKE11 Model in River Network Area of Pearl River Delta for Water Quality Improvement by LI Qingfeng, GUO Shan, ZHANG Ruyu, YAN Xiaoman, ZHANG Xuelin

“…The water quality improvement in the river network area of the Pearl River Delta is an important part of the comprehensive management of the river basin,and it is necessary to study the compliance of water quality improvement measures.Taking the Beicun river system of Nanhai district,Foshan city in the Pearl River Delta as an example,this paper chooses COD,NH₃-N and TP as the characteristic indexes based on the MIKE11 one-dimensional hydrodynamic water quality model to study the hydrodynamic force of rivers and water quality improvement effect under different engineering schemes.The results show that measures such as pollution interception,silt removal,and water diversion can improve the overall water quality of the studied river reach in varying degrees,and thus the water quality improvement is achieved.As the projects of pollution interception and fresh water are implemented,the water quality in typical cross sections of main rivers in the Beicun river system can meet the requirement of class Ⅴ.After the implementation of water diversion and transfer,as well as CSO storage pool,the pollutant concentration in the observed cross section of seriously polluted rivers decreases by more than 70%.As a result,this paper can provide a basis for improving water quality in the river network area of the Pearl River Delta.…”
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Study on River System Flood Forecasting Scheme for Longtan Hydropower Station Interval in Hongshui River by DU Yong, FU Yupeng, WEI Yongjiang, LI Zongtai

“…Longtan Hydropower Station is a flood control project in the Pearl River Basin,but there is currently a lack of a comprehensive river system flood forecasting scheme.In order to give full play to the flood control and storage function of Longtan Hydropower Station,tributary control stations such as Leigongtan,Moyang,Pinglihe,Pinghu,and Xianrenqiao are selected,and the key areas of concern are determined through the analysis of important sub-intervals.The river system flood forecasting scheme for the Longtan Hydropower Station interval is constructed by using the Xin'an River three-source runoff generation model,three-source lag routing convergence model,and Maskingen convergence algorithm.The research results show that the proportion of the maximum inflow flood volume of Longtan Hydropower Station is usually in uncontrolled intervals,followed by the tributaries in Guizhou Province (Mengjiang River,Bawang River,Caodu River,and Liudong River),which are the focus of flood forecasting.The total average relative peak flow error and the average relative flood volume error in the river system flood forecasting scheme are both 10%,and the average deterministic coefficients are above 0.75.The overall results are relatively accurate.Therefore,the river system flood forecasting scheme for the Longtan Hydropower Station interval can be applied to real-time flood operation forecasting,and it lays a solid foundation for further improving the “forecast,early warning,rehearsal,and contingency plan” capability.…”
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Spatiotemporally Combined Dimensionality Reduction Algorithm for Optimizing Long-term Operation of Multi-reservoir Systems by CHEN Jia, ZHANG Hanjun, XU Nan

“…To alleviate the “curse of dimensionality” and improve the solution efficiency while ensuring the quality of solutions in optimizing the operation of multi-reservoir systems,this paper proposes a spatiotemporally combined dimensionality reduction algorithm which integrates and improves the dynamic programming with successive approximation (DPSA) and the progressive optimality algorithm (POA).First,a chain-based successive approximation strategy is proposed to expand the DPSA's optimization mode from “single reservoir alternation” to “cascade reservoir chain alternation”,which makes up for the DPSA's shortcomings in dealing with the hydraulic coupling relationships among cascade reservoirs.Then,a dynamic variable decoupling strategy and perturbation mechanism are proposed to deal with the POA's blind search problem and dimensionality problem.Finally,the two improved algorithms are combined,in which the improved POA is applied to solving the optimization problems of cascade reservoir chains under the framework of the improved DPSA.The power generation operation problem of the cascade reservoirs in the Yuan River Basin of Hunan Province and the classical ten-reservoir problem are utilized to test the performance of the proposed algorithm.The proposed algorithm outperforms seven existing alternatives in terms of solution quality and efficiency.The results indicate that the proposed algorithm can effectively alleviate the “curse of dimensionality” in optimizing the operation of multi-reservoir systems,improve the efficiency while ensuring the quality of solutions and has potential to be applied to optimizing the operation of complex large-scale multi-reservoir systems.…”
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Effect of Fast Freeze-Thaw Cycles on Mechanical Properties of Ordinary-Air-Entrained Concrete by Huai-shuai Shang, Wei-qun Cao, Bin Wang

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Research on Impacts of Climate Change and Human Activitieson Runoff in the Yiluo River Based on SWAT Model by LIU Lyuliu, WANG Xiujie, ZHANG Pengfei

“…Taking Yiluo River in the Yellow River Basin as the research object, this paper analyzes the impacts of numbers of HRUs (Hydrological Response Units) on SWAT model parameters and simulation performance and applies it on the attribution analysis of the change on annual runoff in Yiluo River by comparing among six HRUs division schemes. …”
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Improving the Stability of Mining Slopes in Tarcha Coal Mine, Southwestern Ethiopian Deposit Through Geometric Adjustments by Getaneh Abebay, Endalu Tadele Chala, Nagessa Zerihun Jilo, Tiyasha Tiyasha

“…The Tarcha coal deposit, located beneath the Omo trachyte flows in the Omo-Gibe River basin of southern Ethiopia, is actively mined using open-pit methods for energy resources. …”
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Health Evaluation of Fenghe River Based on AHP-Fuzzy Mathematical Model and Item-by-Item Evaluation Method by ZHANG Zeyang, LIU Qiang, WANG Gang, XU Ziwei

“…This paper takes Fenghe River in Langfang City as the research object to conduct river health evaluation,which is expected to provide a direction for the future health management of Fenghe River and achieve the goal of healthy development of the water ecology of local rivers.On the basis of the relatively perfect evaluation standard,the scientific and reasonable health evaluation of Fenghe River is carried out by the item-by-item evaluation method and the AHP-fuzzy mathematical model,which is suitable for the local actual situation.An evaluation system is constructed,which consists of four criterion layers covering “basin”,“water”,“biology”,and social service functions and 12 subordinate index layers.The evaluation results show that Fenghe River is healthy according to the item-by-item evaluation method.In the evaluation of the AHP-fuzzy mathematical model,Fenghe River is “very healthy”,with a grade of 0.411 0.By this method,the grade of “healthy” is 0.343 8,and the grades of 0.223 9,0.021 3,and 0 denote the health status of “sub-healthy”,“unhealthy”,and “bad”,respectively.The Fenghe River Basin in Langfang Economic and Technological Development Zone has poor performance in terms of riparian bandwidth,sediment pollutants,and water quality.The proposed evaluation method can provide a reference for the health evaluation of rivers heavily influenced by cities and artificial interventions.…”
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Hydrological Modeling of the Jiaoyi Watershed (China) Using HSPF Model by Chang-An Yan, Wanchang Zhang, Zhijie Zhang

“…A watershed hydrological model, hydrological simulation program-Fortran (HSPF), was applied to simulate the spatial and temporal variation of hydrological processes in the Jiaoyi watershed of Huaihe River Basin, the heaviest shortage of water resources and polluted area in China. …”
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Identifying and Evaluating Chaotic Behavior in Hydro-Meteorological Processes by Soojun Kim, Yonsoo Kim, Jongso Lee, Hung Soo Kim

“…For solving this issue, hydro-meteorological time series such as precipitation, air temperature, discharge, and storage volume were collected in the Great Salt Lake and Bear River Basin, USA. The time series in the period of approximately one year were extracted from the original series using the wavelet transform. …”
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Under the bridge: marking sites prove the presence of Eurasian otter Lutra lutra in the Poljanska Sora River valley, Slovenia by Rudi Kraševec, Aleksander Trajbarič, Urša Fležar

“…Since this area could act as a corridor for the otter’s recovery in the Adriatic River basin, it is crucial to continue to monitor its presence and the potential expansion to the west of the country. …”
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Numerical Simulation of Flow and Suspended Sediment Transport in the Distributary Channel Networks by Wei Zhang, Qiong Jia, Xiaowen Chen

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Changes in Sediment Flux from Hanjiang River into the Sea and Its Influence on Adjacent Sea Areas over the Last 60 Years by WANG Yufei, LIU Xiujuan, WANG Yang, WANG Wanhu, WANG Hongbing, YI Jiaji

“…In order to study the changes in sediment flux from the Hanjiang River into the sea and its environmental effects over the last 60 years,this paper uses the Mann-Kendall method to test the runoff discharge and sediment flux measured by the Chao'an hydrological station from 1958 to 2019,analyzes the main driving factors affecting the changes of sediment flux,and investigates the impact of sediment flux changes on adjacent sea areas.The results show that there is no significant change in runoff discharge for the Hanjiang River.The sediment flux into the sea has significantly decreased since 1998,and it has dropped more sharply since 2001.The large hydropower stations (Qingxi and Mianhuatan hydropower stations) in the Hanjiang River Basin are the main factors that lead to the significant decrease in the sediment flux into the sea.Since the sediments into the sea decreases greatly at the end of the 1990s,adjacent sea areas near the Hanjiang estuary have witnessed a transformation from slight sedimentation during 1971—2010 to slight erosion during 2010—2016 and a change of the delta shoreline from progradation (2.40~5.38 m/a) during 1830s—1964 to relative stability in 1980s.These findings indicate that the remarkable decrease in sediments from the Hanjiang River into the sea has greatly affected adjacent sea areas near the estuary.…”
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Study on Spatio-temporal Variation Characteristics of Hydro-meteorological Factors in the Source Region of Yellow River by WANG Dong, WU Dongdong, JIE Xiaobai, LI Xuehui

“…The researchis helpful for understanding the evolution characteristics of water resources in river basin, which canserve as a technical reference for the water resource management.…”
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Hyper-resolution naturalized streamflow data for Geum River in South Korea (1951–2020) by Byeong-Hee Kim, Young-Oh Kim, Jonghun Kam

“…Abstract Long-term streamflow data at a hyper-resolution (less than 1 km) is essential for hydroclimatic extreme and ecological assessment, which is not available over a river basin where rapid socioeconomic growth have been experienced. …”
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ASSESSMENT OF WATER RESOURCES OF THE BOLSHOY KINEL RIVER FOR SUSTAINABLE WATER SUPPLY by Aleksandra V. Selezneva, Ksenia V. Bespalova

“…The article presents the results of analysis of the water flow data for main rivers in the Bolshoy Kinel River basin from the moment of the instrumental observation start in 1993. …”

Composition and Water Ecology Indication of Functional Feeding Groups of Zoobenthos in Liuxi River by CHEN Ci, ZHU Kunpeng, LIU Yue, LI Jiaxu, TAN Ying, WANG Lu

“…The Liuxi River is the most important river system in Guangzhou,and systematic monitoring and assessment provide basic information for the health management of the Liuxi River ecosystem.Field in-situ sampling of zoobenthos in the Liuxi River was conducted during the dry (March) and wet (September) seasons in 2019 to explore the spatio-temporal distribution characteristics of functional feeding groups (FFGs) of zoobenthos,and the habitat conditions of the Liuxi River were assessed by the composition of the zoobenthos FFGs.The results show that the main group of zoobenthos in the Liuxi River Basin is collectors,followed by scrapers and predators,whereas filterers and shredders are rarely observed.The dominant groups at the sampling sites in the upper and middle reaches are moderate pollution tolerant collectors (Baetidae and Corbiculidae) and pollution tolerant collectors (Chironomidae),while the sampling sites in the lower reaches are overwhelmingly dominated by pollution tolerant collectors (Chironomidae).Environmental factors significantly affect the distribution of zoobenthos FFGs.Specifically,the key environmental factors in the dry season are velocity and NO₃,while those in the wet season are SiO₂ and velocity.The attributes of the Liuxi River ecosystem were analyzed on the basis of the composition of the zoobenthos FFGs.The results indicate that the ecosystems at most of the sampling sites in the Liuxi River are heterotrophic ones,and the riparian zone of this basin is not healthy.The longitudinal transport ability of the river is mostly in an unhealthy state.Predators' control effect is normal except at some sampling sites in the upper reaches.The basin maintains favorable habitat stability except at the sampling sites affected by sand dredging.…”
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Flocculation Settling Characteristics of Ultra-Fine Iron Tailings with Rich Gypsum by Daiqiang Deng, Guodong Cao

“…This study can provide technological support for goaf management and environment-friendly treatment of solid waste in the Yangtze River basin, which plays important roles in ecological protection.…”
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A Coupled Model of the 1D River Network and 3D Estuary Based on Hydrodynamics and Suspended Sediment Simulation by Wei Zhang, Shujie Lyu, Yuliang Zhu, Xiaowen Chen

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