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Organic Matter Accumulation in the Upper Permian Dalong Formation from the Lower Yangtze Region,South China

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Acta Geologica Sinica(English Edition) 2024年第1期98卷 150-167页

作者： FANG Chaogang ZHANG Chengcheng MENG Guixi XU Jinlong XU Naicen LI Hualing LIU Mu LIU Bo Institute of international Rivers and Eco-Security Yunnan UniversityKunming 650500China Nanjing Center China Geological SurveyNanjing 210016China Exploration Research Institute Anhui Provincial Bureau of Coal GeologyHefei 230088China China United Coalbed Methane Corporation Ltd. Beijing 100015China Geological Survey of Anhui Province Hefei 230001China Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China

The Late Permian was marked by a series of important geological events and widespread organic-rich black shale depositions,acting as important unconventional hydrocarbon source ***,the mechanism of organic matter(OM)enrichment throughout this period is still *** on geochemical data,the marine redox conditions,paleogeographic and hydrographic environment,primary productivity,volcanism,and terrigenous input during the Late Permian in the Lower Yangtze region have been studied from the Putaoling section,Chaohu,to provide new insights into OM *** Phases are distinguished based on the TOC and environmental *** Phase I,anoxic conditions driven by water restriction enhanced OM *** Phase II,euxinic and cycling hydrological environments were the two most substantial controlling factors for the massive OM *** Phase III,intensified terrestrial input potentially diluted the OM in sediment and the presence of oxygen in bottom water weakened the preservation *** IV was characterized by a relatively higher abundance of mercury(Hg)and TOC(peak at 16.98 wt%),indicating that enhanced volcanism potentially stimulated higher productivity and a euxinic *** Phase V,extremely lean OM was preserved as a result of terrestrial dilutions and decreasing primary *** I,II and IV are characterized as the most prominent OM-rich zones due to the effective interactions of the controlling factors,namely paleogeographic,hydrographic environment,volcanism,and redox conditions.

关键词： geochemistry redox condition primary productivity OM accumulation Lopingian/Changhsingian Lower Yangtze region

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Weathering Processes on Martian Craters: Implications on Recurring Slope Lineae and the Location of Liquid Water

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Open Journal of Modern Hydrology 2017年第4期7卷 245-256页

作者： Pablo Garcia-Chevesich Eduardo Bendek Roberto Pizarro Rodrigo Valdes-Pineda David Gonzalez Horacio Bown Eduardo Martínez Luis Gonzalez Department of Hydrology and Atmospheric Sciences & Department of Agricultural and Biosystems Engineering University of Arizona Tucson USA Faculty of Forest Sciences and Nature Conservation International Hydrology Research Group University of Chile Santiago Chile international sediment initiative and international hydrological programme UNESCO Paris France Ames Research Center NASA Washington DC USA Technological Center for Environmental Hydrology University of Talca Talca Chile Faculty of Forest Sciences University of Concepción Concepción Chile

Recent attention has been put into recurring slope lineae (RSL), after the discovery that water is present in them. It is assumed that RSL are due to flowing water. However, even though that might be the case, the general characteristics of RSL as well as their seasonal and spatial distribution in Mars, and their occurrence within craters, suggest that RSL correspond to the weathering of frozen aquifers, which coincides with slope stability processes occurring in impact craters and scree slopes from Earth. In this study, we associated RSL with similar weathering processes occurring on impact craters and hydrogeological processes occurring on Earth (including ice, water, and wind erosion and natural aquifer recharge processes). We were able to create a conceptual model on how RSL develop, why are they found mostly in mid latitudes around craters, why are they present in more frequency in one side of crates in high latitudes, and why are there more RSL in the Martian southern hemisphere. Considering the whole hydrogeological processes occurring in craters that experience RSL, we were able to predict where large quantities of liquid water are most likely to be present in the red planet.

关键词： Mars Recurring Slope Lineae (RSL) Weathering Processes Craters Groundwater

Water use efficiency in an arid watershed: a case study

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Research in Cold and Arid Regions 2013年第1期5卷 16-26页

作者： Damaris Orphanopoulos Koen Verbist Alvaro Chavez Guido Soto Rodhos Consulting Vaticano 4026 B Santiago Chile UNESCO-international hydrological programme 1 Rue Miolis Paris France Centro del Agua para Zonas áridas y Semiáridas de América Latina y el Caribe (CAZALAC) Benavente 980 La Serena Chile

Integrated Water Resource Management （IWRM） becomes increasingly important in arid watersheds, where water resources are scarce and demands are rising under increased population pressure. In this case study, we present the results from the Elqui Valley in Chile, where water resources are shared between agriculture, mining operations, hydropower generation and drinking water for nearby cities. An IWRM model was applied to visualize water resources distribution in the catchment and determine irrigation and water use efficiencies. After calibration with observed surface and groundwater measurements, the model showed large differ- ences in efficiencies between different irrigation sectors. Most notably, irrigation sectors with the highest irrigation security, i.e., higher water rights per hectare, were characterized with lower water use efficiencies. Frequent water deficits were present in sec- tors downstream of the main reservoir, which was related to limited water rights per hectare, lower irrigation efficiencies and higher water demands due to larger agricultural areas. In subsequent scenario analyses, the model was used to evaluate the impact of improved irrigation and water use efficiencies in these downstream sectors, to confirm an important reduction in water deficits, except for drought years when surface water resources are insufficient. In a third scenario, groundwater resources were allowed to compensate for water deficits, effectively reducing these in most irrigation sectors, especially during droughts. Expansion of the current agricultural area by 37% was evaluated, as a future scenario, and was found to be unsustainable, as aquifer levels are low- ered to such levels that make annual recharge insufficient.

关键词： integrated water resources management drought arid zones Chile

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Establishment and development of the World Association for sedimentation and Erosion Research

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international Journal of sediment Research 2023年第6期38卷 901-909页

作者： Cheng Liu Zhaoyin Wang Des E.Walling international Research and Training Center on Erosion and sedimentation Department of Hydraulic Engineering Tsinghua University Geography Faculty of EnvironmentScience and EconomyUniversity of Exeter

Problems of soil erosion and sedimentation are issues of global *** the intensification of global change and the impacts of human activities,many countries are facing severe challenges from wideranging sediment-related *** prevention and control of sediment disasters and the rational use of soil and sediment resources are important requirements for the sustainable development strategies of all *** sediment problems are closely related to social,economic,and other human activities,the effective solution of sediment problems requires the concerted efforts of experts in different fields and thus an interdisciplinary approach is *** view of the increasing recognition of sediment as a topic of global significance and the need to promote interdisciplinary research in this field,the World Association for sedimentation and Erosion Research(WASER) was inaugurated in *** this paper the history of the establishment of WASER is reviewed and its main activities are briefly *** series of international Symposia on River sedimentation(ISRS) has served as the official symposium of WASER since *** triennial technical events have been held in China,Russia,Japan,South Africa,and Germany with about 2,000 *** addition to sponsoring the ISRS,WASER has to date also sponsored/organized or co-sponsored/co-organized over 30 other international conferences,workshops,training courses,and study tours besides sponsoring the *** adoption of the international Journal of sediment Research(IJSR) as the official journal of WASER in 2004has also played an important role in increasing the exposure of the *** activities have served to raise WASER’s profile as well as promoting collaboration with agencies and other organizations working in the field of erosion and *** types of prizes and honors are awarded by *** include the international Qian Ning Prize for Erosion and sedimentation Technolog

关键词： Erosion and sedimentation Association Symposia Journal

Upstream-downstream linkages of hydrological processes in the Himalayan region

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Ecological Processes 2014年第1期3卷 51-66页

作者： Santosh Nepal Wolfgang-Albert Flugel Arun Bhakta Shrestha international Centre for Integrated Mountain Development(ICIMOD) KathmanduNepal Department of Geoinformatics Hydrology and ModellingFriedrich Schiller UniversityJena(FSU-Jena)Germany

Understanding the upstream-downstream linkages in hydrological processes is essential for water resources planning in river *** there are many studies of individual aspects of these processes in the Himalayan region,studies along the length of the basins are *** study summarizes the present state of knowledge about linkages in hydrological processes between upstream and downstream areas of river basins in the Himalayan region based on a literature *** paper studies the linkages between the changes in the physical environment of upstream areas(land use,snow storage,and soil erosion)and of climate change on the downstream water availability,flood and dry season flow,and erosion and *** is argued that these linkages are complex due to the extreme altitudinal range associated with the young and fragile geology,extreme seasonal and spatial variation in rainfall,and diversity of anthropogenic *** on the findings,the paper concludes that integrated systems analysis is required to understand the holistic complexity of upstream-downstream linkages of hydrological processes in the river basin *** integrated land and water resources management(ILWRM)approach can be instrumental in developing adaptive solutions to problems and can also enable stakeholders of upstream and downstream areas with various interests and needs to work together for the better utilization and management of land and water *** a part of this,the specific circumstances of the upstream communities,who live in fragile and inaccessible mountain areas with limited resource opportunities,should be taken into account so that incentive mechanisms can be established to encourage and acknowledge their contribution.

关键词： Integrated land and water resources management Himalayan region Integrated systems analysis Geoinformatics Physical linkages Value of environmental services

Review:The international sediment initiative case studies of sediment problems in river basins and their management

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international Journal of sediment Research 2018年第2期33卷 216-219页

作者： Cheng Liu Desmond E.Walling Yun He international Research and Training Center on Erosion and sedimentation College of Life and Environmental Sciences University of Exeter Information Center China Institute of Water Resources and Hydropower Research

Management of sediment in river basins and waterways has been an important issue for water managers throughout history. The changing nature of sediment issues has meant that water managers today face many complex technical and environmental challenges in relation to sediment management. UNESCO’s international hydrological programme(IHP) launched the international sediment initiative(ISI) in *** aims to further advance sustainable sediment management on a global scale. This is achieved through the delivery of a decision support framework for sediment management that provides guidance on legislative and institutional solutions, applicable across a range of socio-economic and physiographic settings in the context of global change. ISI mobilizes international experience on sediment problems and their management through the compilation of a series of case studies representative of a broad range of physiographic and socio-economic conditions, which are made available as guidance for policy makers dealing with water and river basin management. Case studies prepared to date include the basins of the Nile, Mississippi, Rhine, Volga, Yellow, and Haihe and Liaohe rivers. Available in full from the ISI website,these detailed case studies are briefly introduced in this review articles.

关键词： sediment River basin international sediment initiative(ISI) sediment management

Pollution assessment of heavy metals along the Mekong River and dam effects

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Journal of Geographical Sciences 2012年第5期22卷 874-884页

作者： FU Kaidao SU Bin HE Daming LU Xixi SONG Jingyi HUANG Jiangcheng Asian international Rivers Center Yunnan University Kunming 650091 China Yunnan Key Laboratory for international Rivers and Transboundary Ecology Security Kunming 650091 China Department of Geography National University of Singapore 119260 Singapore

The resource development and changes of hydrological regime, sediment and water quality in the Mekong River basin have attracted great attentions. This research aimed to enhance the study on transboundary pollution of heavy metals in this international river. In this study, eight sampling sites were selected to collect the bed sand samples along the mainstream of the Mekong River. In addition, the contents of 5 heavy metal elements and their spatial variability along the mainstream of the river were analyzed. The geoaccumulation index （l^eo） and potential ecological risk analysis were employed to assess heavy metal pol- lution status in the mainstream of the Mekong River. The results show that the average con- tent of the heavy metal elements Zn is 91.43 mg/kg, Pb is 41.85 mg/kg, and As is 21.84 mg/kg in the bed sands of the Upper Mekong River, which are higher than those （Zn 68.17 mg/kg, Pb 28.22 mg/kg, As 14.97 mg/kg） in the Lower Mekong. The average content of Cr in the Lower Mekong is 418.86 mg/kg, higher than that in the Upper Mekong （42.19 mg/kg）. Luang Prabang has a very high Cr concentration with 762.93 mg/kg and Pakse with 422.90 mg/kg. The concentration of Cu in all of the 8 sampling sites is similar, except for in Jiajiu with 11.70 mg/kg and Jiebei with 7.00 mg/kg. The results of the geoaccumulation index reveal that contaminations caused by Zn and Pb while Pb and As are more than those by Zn in Upper Mekong. Cr is the primary pollutant in the Lower Mekong, especially at Luang Prabang and Pakse. Slight pollution with As also occurs in Pakse. The potential ecological risk index indi- cates that the potential ecological risk of heavy metals in the mainstream of the Mekong River is low. We argue that the pollution of water quality and contamination of heavy metals in bed sediment caused by mining of mineral resources or geochemical background values in the Mekong is not transmitted from the Upper to the Lower Mekong because of the reservoir sedimentation and

关键词： Mekong River basin heavy metal pollution geoaccumulation index potential ecological risk index

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Influence of anthropic and eco-hydrological factors on the floristic diversity of the herbaceous vegetation around the temporary ponds in Ferlo,northern Senegal

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Journal of Plant Ecology 2022年第1期15卷 26-38页

作者： Ndiabou Faye Aly Diallo Moustapha BassimbéSagna Jean Luc Peiry Papa Saliou Sarr Aliou Guisse Département de Biologie Végétale UniversitéCheikh Anta DiopDakarSenegal IRL3189 Environment SantéSociétésCentre National de la Recherche Scientifiques(CNRS)ParisFrance IRL3189 Environnement SantéSociétésUniversitéCheikh Anta DiopDakarSenegal Observatoire international Hommes Milieux-OHMi Tessekere UniversitéCheikh Anta DiopDakarSenegal Observatoire international Hommes Milieux-OHMi Tessekere Centre National de la Recherche Scientifique(CNRS)ParisFrance Departement d’Agroforesterie UniversitéAssane Seck de ZiguinchorZinguinchorSenegal Département de Géographie Universitéde Clermont FerrandClermont-FerrandFrance Japan international Research Center for Agricultural Sciences(JIRCAS) TsukubaIbarakiJapan

Temporary ponds play substantial roles in preserving biodiversity in the *** study investigated the influence of anthropic and eco-hydrological factors on the plant diversity around two grazed ponds and one ungrazed pond in Ferlo,northern *** phytoecological transects were established per *** each transect,homogenous herbaceous vegetation units were identified and characterized(herbaceous cover,exposure,soil texture,soil moisture and pH,average height and slope).The herbaceous flora comprised 55 species,41 genera and 22 families across the three *** of the Poaceae,particularly Eragrostis tremula and Enteropogon prieurii,mostly colonized the grazed ponds,while the ungrazed pond favored other families’species such as Achyranthes sp.,Commelina forsskaolii,Corchorus *** Shannon’s diversity index(H′)of Wendu Marodi(ungrazed pond)was slightly higher(4.9 bits)than that of Belel Lougal and Belel Sow(grazed ponds)with 4.8 and 4.5 bits,*** equitability indices were relatively high in the three ponds(0.85,0.83 and 0.78).Eco-ecological factors distinguished four species’groupings:a Tribulus terrestris grouping colonizing the constraining and over-grazed zones,a Digitaria horizontalis grouping,and Chloris barbata grouping found in the transition zones,and an Achyranthes aspera grouping in the wetlands,where woody plants were strongly present and the anthropic action *** study highlighted the importance of maintaining a landscape mosaic of ungrazed or semi-protected ponds and grazed ponds to preserve the herbaceous floristic diversity in the center of Ferlo(Senegal)and the Sahel in general.

关键词： ponds Ferlo grazing herbaceous vegetation transect

Revisiting functional no-flow events in the Lower Yellow River

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international Journal of sediment Research 2016年第4期31卷 351-359页

作者： Rong Huang Tianhong Li Lianjun Zhao School of Environment and Energy Peking University Shenzhen Graduate School Department of Environmental Engineering Peking University The Key Laboratory of Water and sediment Sciences Ministry of Education Yellow River Institute of Hydraulic Research

Functional no-flow is a topic of considerable interest in the research and management of the Yellow *** operation of the Xiaolangdi Reservoir has been a source of concern regarding hydraulic characteristics and hydro-environmental ***,the impacts of the reservoir on functional no-flow events have not been reported to *** a complete set of daily hydrological data from four key hydrological stations for the past six decades and at three different temporal scales(year,wet season and dry season),the differences in incoming water and functional no-flow events have been compared before and after the Xiaolangdi Reservoir began operation,using two sets of critical runoff values that were summarized from previous *** results indicate that the frequency of functional no-flow events has decreased since the Xiaolangdi Reservoir began to operate,based on critical runoff or discharge values defined by long term hydrological records,and the frequency decreased more when the critical values defining the new situation were ***,functional no-flow events still occurred in the Lower Yellow River,especially in the lower reach during the wet *** degree of severity of the functional no-flow events and the magnitude and variation of daily discharge are strongly linearly related before and after the reservoir began operation,regardless of which set of critical values were used to identify the functional no-flow events.

关键词： Lower Yellow River Incoming water Critical discharge Functional no-flow events Severity level Linear regression