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Export of dissolved carbonaceous and nitrogenous substances in rivers of the “Water Tower of Asia”

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Journal of Environmental Sciences 2018年第3期30卷 53-61页

作者： Bin Qu Mika Sillanpaa Shichang Kang Fangping Yan Zhiguo Li Hongbo Zhang Chaoliu Li Laboratory of Green Chemistry Lappeenranta University of Technology Mikkeli 50130 Finland Key Laboratory of Tibetan Enuironment Changes and Land Surface Processes Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100101 China State Key Laboratory of Cryospheric Sciences Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou Gansu 730000 China Shangqiu Normal University Shangqiu He'nan 476000 China CAS Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of Sciences Beijing 100085 China

rivers are critical links in the carbon and nitrogen cycle in aquatic,terrestrial,and atmospheric environments.Here riverine carbon and nitrogen exports in nine large rivers on the Tibetan Plateau—the＂Water Tower of Asia＂—were investigated in the monsoon season from 2013 to 2015.Compared with the world average,concentrations of dissolved inorganic carbon（DIC,30.7 mg/L）were high in river basins of the plateau due to extensive topographic relief and intensive water erosion.Low concentrations of dissolved organic carbon（DOC,1.16 mg/L）were likely due to the low temperature and unproductive land vegetation environments.Average concentrations of riverine DIN（0.32 mg/L）and DON（0.35 mg/L）on the Tibetan Plateau were close to the world average.However,despite its predominantly pristine environment,discharge from agricultural activities and urban areas of the plateau has raised riverine N export.In addition,DOC/DON ratio（C/N,~6.5）in rivers of the Tibetan Plateau was much lower than the global average,indicating that dissolved organic carbon in the rivers of this region might be more bioavailable.Therefore,along with global warming and anthropogenic activities,increasing export of bioavailable riverine carbon and nitrogen from rivers of the Tibetan Plateau can be expected in the future,which will possibly influence the regional carbon and nitrogen cycle.

关键词： Dissolved carbon Dissolved nitrogen rivers The Tibetan Plateau

Watershed characteristics and climate factors effect on the temporal variability of mercury in the southern Baltic Sea rivers

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Journal of Environmental Sciences 2018年第6期30卷 55-64页

作者： Karolina Gebka Magdalena Beldowska Dominika Saniewska Karol Kuliński Jacek Beldowski The Institute of Oceanography University of Gdansk Marszalka Pilsudskiego Alley 46 81-378 Gdynia Poland The Institute of Oceanology of The Polish Academy of Sciences Powstaflc6w Warszawy Street 55 81-712 Sopot Poland

Mercury（Hg） is a neurotoxic metal which can enter into the human organism mainly by fish consumption, skin and transpiration. In the coastal zone of the southern Baltic Sea, rivers are the main source of Hg. The Polish region represents the largest proportion of the Baltic Sea catchment and this research included four rivers of the Baltic watershed： the Reda,Zagórska Struga, Kacza and Gizdepka. The samples were collected in the years 2011–2013.Total and particulate Hg concentration in these rivers were measured. Due to intensive rain,deposited mercury on the catchment area was washed out into the riverines water and introduced into the Baltic Sea. Consequently, the load of Hg increased three times.Additionally, the intensive dry atmospheric deposition during heating season caused the increase of the concentration of particulate Hg in the river water even by 85%. The research confirmed the role of the river flow magnitude in the load of mercury introduced into the sea by rivers. Moreover, a high variability of mercury concentration was connected to the additional sources such as the chemicals containing Hg and no municipal sewage system.The analysis of stable isotopes indicated that the SPM contained terrestrial organic matter;however, there was no clear correlation between Hgtot, Corgand Ntotconcentrations and δ13C, δ15N, C/N in particulate matter.

关键词： Hg Suspended particulate matter Stable isotopes Atmospheric deposition rivers

New methods designed to estimate the daily discharges of rivers in the Tibetan Plateau

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Science Bulletin 2019年第7期64卷 418-421页

作者： Lei Wang Arthur W.Sichangi Tian Zeng Xiuping Li Zhidan Hu Mulugeta Genanu Institute of Tibetan Plateau Research Chinese Academy of Sciences University of Chinese Academy of Sciences Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of Sciences Dedan Kimathi University of Technology Information Center Ministry of Water Resources

River discharge is a significant hydrological variable, as it represents the basin-scale integrated output of the hydrological cycle. At present, river discharge observations are usually measured at ground-based gauges across rivers worldwide. In some areas, however, measurements used in the practice of flood prediction and disaster prevention are either fully inaccessible or difficult to obtain in a timely and functional fashion (1)It has also been reported that the scarcity of global river discharge observations may have undermined the efforts to calculate a globally meaningful estimate of the adjusted biodiversity threat (2)The Tibetan Plateau(TP), also known as the ‘‘Asian Water Tower'.

关键词： New methods designed to estimate the daily discharges of rivers in the Tibetan Plateau TP

Documented changes in annual runoff and attribution since the 1950s within selected rivers in China

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Advances in Climate Change Research 2017年第1期8卷 37-47页

作者： LIU Lu-Liu DU Jian-Jun National Climate Center China Meteorological Administration Beijing 100081 China Asset Operation Center China Meteorological Administration Beijing 100081 China

To enable local water resource management and maintenance of ecosystem integrity and to protect and mitigate against flood and drought, it is necessary to determine changes in long-term series of streamflow and to distinguish the roles that climate change and human disturbance play in these changes. A review of previous research on the detection and attribution of observed changes in annual runoff in China shows a decrease in annual runoff since the 1950s in northern China in areas such as the Songhuajiang River water resources zone, the Liaohe River water resources zone, the Haihe River water resources zone, the Yellow River water resources zone, and the Huaihe River water resources Zone. Furthermore, abrupt changes in annual runoff occurred mostly in the 1970s and 1980s in all the above zones, except for some of the sub-basins in the middle Yellow River where abrupt change occurred in the 1990s. Changes in annual runoff are found to be mainly caused by climate change in the western Songhuajiang River basin, the upper mainstream of the Yangtze River, and the western Pearl River basin, which shows that studies on the impact of climate change on future water resources under different climate change scenarios are required to enable planning and management by agencies in these river basins. However, changes in annual runoff were found to be mainly caused by human activities in most of the catchments in northern China (such as the southern Songhuajiang River, Liaohe River, Haihe River, the lower reach and some of the catchments within the middle Yellow River basin) and in middle-eastern China, such as the Huaihe River and lower mainstream of the Yangtze River. This suggests that current hydro-climatic data can continue to be used in water-use planning and that policymakers need to focus on water resource management and protection.

关键词： Changes in annual runoff Climate change Human disturbance Attribution rivers in China

COMPUTATION OF DISCHARGE IN MEANDERING COMPOUND rivers

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Journal of Hydrodynamics 1999年第1期11卷 50-55页

作者： Wang, Wei Cai, Jinde Xu, Weilin Sichuan univ Chengdu China

Method of computing the discharge distribution of overbank flow in meandering rivers was presented with the concept of momentum transfer. The formulae of transverse or radial depth-average velocity on flood plains and main channel were obtained through theoretical analysis. The verification shows that the computational discharges coincide basically with the measured ones in laboratory.

关键词： Channel flow Flood control Flow of water Numerical analysis Numerical methods rivers

Equations and their physical interpretation in numerical modeling of heavy metals in fluvial rivers

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中国科学：技术科学英文版 2010年第2期53卷 548-557页

作者： HUANG SuiLiang Numerical Simulation Group for Water Environment, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Key Laboratory of Pollution Processes and Environmental Criteria of the Ministry of Education College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China Numerical Simulation Group for Water Environment Tianjin Key Laboratory of Environmental Remediation and Pollution Control Key Laboratory of Pollution Processes and Environmental Criteria of the Ministry of Education College of Environmental Science and Engineering Nankai University Tianjin China

Based on the previous work on the transport-transformation of heavy metal pollutants in fluvial rivers, this paper presented the formulation of a two-dimensional model to describe heavy metal transport-transformation in fluvial rivers by considering basic principles of environmental chemistry, hydraulics, mechanics of sediment transport and recent developments along with three very simplified test cases. The model consists of water flow governing equations, sediment transport governing equations, transport-transformation equation of heavy metal pollutants, and convection-diffusion equations of adsorption-desorption kinetics of particulate heavy metal concentrations on suspended load, bed load and bed sediment. The heavy metal transport-transformation equation is basically a mass balance equation, which demonstrates how sediment transport affects transport-transformation of heavy metals in fluvial rivers. The convection-diffusion equations of adsorption-desorption kinetics of heavy metals, being an extension of batch reactor experimental results and a major advancement of the previous work, take both physical transport, i.e. convection and diffusion and chemical reactions, i.e. adsorption-desorption into account. Effects of sediment transport on heavy metal transport-transformation were clarified through three examples. Specifically, the transport-transformation of heavy metals in a steady, uniform and equilibrium sediment-laden flow was calculated by applying this model, and results were shown to be rational. Both theoretical analysis and numerical simulation indicated that the transport-transformation of heavy metals in sediment-laden flows with clay-enriched riverbed possesses not only the generality of common tracer pollutants, but also characteristics of transport-transformation induced by sediment motion. Future work will be conducted to present validation/application of the model with available data.

关键词： heavy metals transport-transformation water-sediment-pollutants interaction fluvial rivers numerical modeling

Role of permafrost in resilience of social-ecological system and its spatio-temporal dynamics in the source regions of Yangtze and Yellow rivers

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Journal of Mountain Science 2019年第1期16卷 179-194页

作者： FANG Yi-ping ZHU Fu-biao YI Shu-hua QIU Xiao-ping DING Yong-jian Institute of Mountain Hazards and Environment Chinese Academy of Sciences College of Resource and Environment University of Chinese Academy of Sciences School of Economics Hefei University of Technology School of Geographic Sciences Nantong University College of Geography and Resources Science Sichuan Normal University State Key Laboratory of Cryospheric Sciences Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences

Permafrost is one of the key components of terrestrial ecosystem in cold regions. In the context of climate change, few studies have investigated resilience of social ecological system(SER) from the perspective of permafrost that restricts the hydrothermal condition of alpine grassland ecosystem. In this paper, based on the structural dynamics, we developed the numerical model for the SER in the permafrost regions of the source of Yangtze and Yellow rivers, analyzed the spatial-temporal characteristics and sensitivity of the SER, and estimated the effect of permafrost change on the SER. The results indicate that: 1) the SER has an increasing trend, especially after 1997, which is the joint effect of precipitation, temperature, NPP and ecological conservation projects; 2) the SER shows the spatial feature of high in southeast and low in northwest,which is consistent with the variation trends of high southeast and low northwest for the precipitation, temperature and NPP, and low southeast and high northwest for the altitude; 3) the high sensitive regions of SER to the permafrost change have gradually transited from the island distribution to zonal and planar distribution since 1980, moreover, the sensitive degree has gradually reduced; relatively, the sensitivity has high value in the north and south, and low value in the south and east; 4) the thickness of permafrost active layer shows a highly negative correlation with the SER. The contribution rate of permafrost change to the SER is-4.3%, that is, once the thickness of permafrost active layer increases 1 unit, the SER would decrease 0.04 units.

关键词： Resilience of social ecological system Permafrost Permafrost active layer thickness Structural dynamic equation Source regions of Yangtze and Yellow rivers

Water quantity-quality combined evaluation method for rivers＇ water requirements of the instream environment in dualistic water cycle： A case study of Liaohe River Basin

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Journal of Geographical Sciences 2007年第3期17卷 304-316页

作者： WANG Xiqin ZHANG Yuan LIU Changming School of Natural Resources and Environment Renmin University of China Beijing 100872 China River and Coastal Environmental Research Center Chinese Research Academy of Environmental Sciences Beijing 100012 China Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China Key Laboratory for Water and Sediment Sciences of the Ministry of Education Beijing Normal University Beijing 100875 China

In this article the meaning of the quantity and quality of environmental flows of river in dualistic water cycle is discussed, and compared with the meaning of unitary water cycle. Based on the analysis of the relationship between environmental flows of river requirements, the efficiency of water resource usage, the consumption coefficient, and the concentration of waste water elimination, the water quantity and water quality calculation method of the environmental flows of river requirements in dualistic water cycle is developed, and the criteria for environmental flows of river requirements are established, and therefore the water quantity-quality combined evaluation of natural river flows requirements are realized Taking the Liaohe River as a model, the environmental flows of river requirements for Xiliao River, Dongliao River, mainstream Liaohe River, Huntai River and northeast rivers along the coasts of the Yellow and Bohai seas in unitary water cycle are calculated, each taking up 39.3%, 63.0%, 43.9%, 43.3% and 43.5% of runoff respectively. Evaluated according to Tennant recommended flow, the results show that： except Xiliao River is ＂median＂, the rest are all upon ＂good＂, the Dongliao River is even ＂very good＂. The corresponding results in dualistic water cycle are that, the proportion of natural flows for each river is 57.5%, 74.1%, 60.8%, 60.3% and 60.4%; while the combined evaluation results show that： considering ＂quantity＂, except Xiliao River, the rest rivers can all achieve the ＂quantity＂ criteria of the en- vironmental flows of river requirements, but if considering the aspect of ＂quality＂, only Dongliao River can reach the ＂quality＂ standard. By water quantity-quality combined evaluation method, only Dongliao River can achieve the criteria. So the water quality is the main factor that determines whether the environmental flows can meet the river ecosystem demands.

关键词： dualistic water cycle rivers environmental flows of river requirements water quantity water quality evaluation Liaohe River

Studies on eco-environmental change in source regions of the Yangtze and Yellow rivers of China:present and future

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Research in Cold and Arid Regions 2019年第3期11卷 173-183页

作者： JianPing Yang State Key Laboratory of Cryospheric Sciences Northwest Institute of Eco-Environment and ResourcesChinese Academy of Sciences

The source regions of the Yangtze and Yellow rivers are important in the field of eco-environmental change research in China because of its distinct alpine ecosystem and cryosphere environment. At present, there are three different concepts on the extent of source areas of the Yangtze and Yellow rivers: hydrological, geographical, and eco-environmental. Over the past decades, annual average air temperature has warmed significantly;moreover, the temperature rise rate increases notably with increase of time of the data series. Annual precipitation has no obvious increase or decrease trend, and the climate has become warm and dry in the source regions. As a result, the cryosphere in the regions has shrunk significantly since 1960 s. A warm and dry climate and changing cryosphere together induced a substantial declination of alpine wetlands, marked decrease in river runoff, significant degradation of alpine grassland, and a reduction of engineering stability.The ecological environment, however, has a tendency for restoration in the regions because the climate has become gradually warm and wet since 2000. Thus, studies on eco-environmental change is transforming from a single element to multidisciplinary integration. Climate change-cryopshere change-physical and socioeconomic impacts/risk-adaptation constitute a chain of multidisciplinary integration research.

关键词： cryosphere change hydrological system alpine grassland the source regions of the Yangtze and Yellow rivers present and future