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Promoting High-quality Development of Grain and Oil in Ethnic Areas of the Yangtze River Economic Belt from the Perspective of Agricultural Power
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作者 Li GAO Jianjun ZHANG +2 位作者 Yuanpeng SUN Zhiyang LIU Zhiguo SUN 《Asian Agricultural Research》 2024年第2期1-7,11,共8页
Accelerating the construction of agricultural power,further promoting the high-quality development of the Yangtze River Economic Belt,and better supporting and serving Chinese-style modernization are the key issues at... Accelerating the construction of agricultural power,further promoting the high-quality development of the Yangtze River Economic Belt,and better supporting and serving Chinese-style modernization are the key issues at present.This paper first introduces the Yangtze River Economic Belt and its ethnic areas,and studies the characteristics of the grain and oil industry in the ethnic autonomous areas of the economic belt,as well as the current situation of various types of intellectual property resources,such as industrial cultural heritage,scientific and tech-nological innovation,and brand marking intellectual property.Besides,it analyzes the main problems in the high-quality development of grain and oil in the Yangtze River Economic Belt ethnic areas.Finally,it comes up with recommendations,including protecting the intellectual prop-erty rights of cultural heritage in the field of grain and oil,leading the inheritance and development of excellent traditional Chinese culture,use scientific and technological innovation intellectual property rights to promote the innovation-driven development strategy of the grain and oil in-dustry,and providing counterpart assistance to ethnic autonomous areas in the Yangtze River Economic Belt to further promote the high-quality development of the Yangtze River Economic Belt. 展开更多
关键词 the yangtze River Economic Belt Ethnic areas Grain and oil Intellectual property Agricultural power
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Organic Phosphorus in Shallow Lake Sediments in Middle and Lower Reaches of the Yangtze River Area in China 被引量:24
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作者 JIN Xiang-Can WANG Sheng-Rui +1 位作者 CHU Jian-Zhou WU Feng-Chang 《Pedosphere》 SCIE CAS CSCD 2008年第3期394-400,共7页
Thirteen sediment core samples(0-10 cm) were taken from the seven lakes in the middle and lower reaches of the Yangtze River to determine the contents and distributions of organic phosphorus(P) fractions in the sedime... Thirteen sediment core samples(0-10 cm) were taken from the seven lakes in the middle and lower reaches of the Yangtze River to determine the contents and distributions of organic phosphorus(P) fractions in the sediments of the shallow lakes in the area.The organic P fractions in the sediments were in the order of moderately labile organic P(MLOP) > moderately resistant organic P(MROP) > highly resistant organic P(HROP) > labile organic P(LOP),with average proportional ratios of 13.2:2.8:1.3:1.0.LOP,MLOP,and MROP were significantly related to the contents of total organic carbon(TOC),water-soluble P(WSP),algal-available P(AAP),NaHCO3-extractable P(Olsen-P),total P(TP),organic P(OP),and inorganic P(IP).However,HROP was significantly related to OP and weakly correlated with TOC,WSP,AAP,Olsen-P,TP or IP.This suggested that organic P,especially LOP and MLOP in sediments,deserved even greater attention than IP in regards to lake eutrophication.In terms of organic P,sediments were more hazardous than soils in lake eutrophication.Although OP concentrations were higher in moderately polluted sediment than those in heavily polluted sediment,LOP and MLOP were higher in the heavily polluted sediment,which indicated that heavily polluted sediment was more hazardous than moderately polluted sediment in lake eutrophication. 展开更多
关键词 BIOAVAILABILITY chemical extracted phosphorus lake sediment middle and lower reaches of the yangtze River area organic phosphorus fractions
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Characteristics and Process of Land Use Changes in the Yangtze River Delta, China 被引量:17
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作者 PULIJIE YANGGUISHAN 《Pedosphere》 SCIE CAS CSCD 2001年第3期193-198,共6页
As one of the developing countries China has an arable land per capita far below the world’s average level. With a high-density population and the quick development of economy and urbanization, the Yangtze River Delt... As one of the developing countries China has an arable land per capita far below the world’s average level. With a high-density population and the quick development of economy and urbanization, the Yangtze River Delta shows the typical characteristics of land use in developed regions of China, which are: high land reclamation rate and low arable land per capita; intensive land use and high output value; and rapid increasing of construction land area and fast diminishing of arable lands. The analysis indicates that the process of the arable land changes in the Yangtze River Delta could be divided into four different change stages over the past 50 years. 展开更多
关键词 arable land use CHARACTERISTICS CHANGE PROCESS the yangtze River Delta
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The Background Features and Formation of Chemical Elements of Groundwater in the Region of the Middle and Lower Reaches of the Yangtze River 被引量:17
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作者 Zeng Zhaohua Institute of Environmental Geology,Jiangxi Bureau of Geology and Mineral Resources, Nanchang, Jiangxi Shang Ruoyun 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1997年第1期80-89,共10页
The paper deals with the background features, formation and distribution of the chemical el-ements K, Na, Ca, Mg, Si, Fe, Mn, Cr, Ni,V, Co, Ti, Mo, Cu, Pb, Zn, As, Hg, Cd, Be, Li, Sr, B,F, Cl, Br and I in the groundwa... The paper deals with the background features, formation and distribution of the chemical el-ements K, Na, Ca, Mg, Si, Fe, Mn, Cr, Ni,V, Co, Ti, Mo, Cu, Pb, Zn, As, Hg, Cd, Be, Li, Sr, B,F, Cl, Br and I in the groundwater in the region of the middle and lower reaches of the YangtzeRiver and their relations to the composition of the water-bearing media, properties of the overly-ing rocks and soils, redox environment, and groundwater flow condition, mineralization and pHof groundwater. 展开更多
关键词 lower-middle reaches of the yangtze River GROUNDWATER chemical element background feature
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Biogenic silica in intertidal marsh plants and associated sediments of the Yangtze Estuary 被引量:11
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作者 Lijun Hou Min Liu +3 位作者 Yi Yang Dongni Ou Xiao Lin Hui Chen 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2010年第3期374-380,共7页
Biogenic silica (BSi) contents in the marsh plants (Phragmites australis, Scirpus mariqueter and Spartina alterniflora) and associated sediments in Chongming Island eastern intertidal flat of the Yangtze Estuary w... Biogenic silica (BSi) contents in the marsh plants (Phragmites australis, Scirpus mariqueter and Spartina alterniflora) and associated sediments in Chongming Island eastern intertidal flat of the Yangtze Estuary were determined. The BSi contents in P. australis, S. mariqueter and S. alterniflora varied from 25.78–42.74 mg/g, 5.71–19.53 mg/g and 6.71–8.92 mg/g, respectively. Over the entire growth season, P. australis and S. mariqueter were characterized by linear accumulation patterns of BSi. The aboveground biomass (leaves and culms) of the marsh plants generally contained more BSi than underground biomass (roots). BSi contents were relatively higher in dead plant tissues than in live tissues which was probably due to the decomposition and the leaching of labile components of plant tissues such as organic carbon and nitrogen. Comparing with the habitats of S. mariqueter and S. alterniflora, the highest BSi content was recorded in sediments inhabited by P. australis, with an annual average of 15.69 mg/g. Overall, the intertidal marshes in the Yangtze Estuary may act as a net sink of BSi via plant uptake and sedimentary burial. 展开更多
关键词 biogenic silica marsh plants intertidal flat the yangtze Estuary
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Surface Water Pollution in the Yangtze River Delta:Patterns and Countermeasures 被引量:11
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作者 CHENZHENLOU XUSHIYUAN 《Pedosphere》 SCIE CAS CSCD 2002年第2期111-120,共10页
On the basis of field investigations, observations andexperimental data combined with environmental monitoring information,the status and the spatial and temporal patterns of surface waterpollution over the past ten y... On the basis of field investigations, observations andexperimental data combined with environmental monitoring information,the status and the spatial and temporal patterns of surface waterpollution over the past ten years in the Yangtze River Delta havebeen assessed. The water quality of large rivers is still very goodbut most of the medium-sized and small rivers have been veryseriously polluted. The appearance of black and odorous conditions inrivers in the urban areas has increased due to serious pollution byorganic matter with consequent high oxygen demand. Annual increasesin N and P concentrations in lakes have accelerated eutrophication.The water quality of river sin small towns is rapidly deteriorating.The main sources of surface water pollution include industrial anddomestic sewage, animal manures, chemical fertilizers in farmland,and polluted sediments in rivers and lakes. 展开更多
关键词 COUNTERMEASURES pollution patterns surface water the yangtze RiverDelta
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Changes of Frequency of Summer Precipitation Extremes over the Yangtze River in Association with Large-scale Oceanic-atmospheric Conditions 被引量:11
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作者 王毅 严中伟 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2011年第5期1118-1128,共11页
Changes of the frequency of precipitation extremes (the number of days with daily precipitation exceeding the 90th percentile of a daily climatology,referred to as R90N) in summer (June-August) over the mid-lower ... Changes of the frequency of precipitation extremes (the number of days with daily precipitation exceeding the 90th percentile of a daily climatology,referred to as R90N) in summer (June-August) over the mid-lower reaches of the Yangtze River are analyzed based on daily observations during 1961-2007.The first singular value decomposition (SVD) mode of R90N is linked to an ENSO-like mode of the sea surface temperature anomalies (SSTA) in the previous winter.Responses of different grades of precipitation events to the climatic mode are compared.It is notable that the frequency of summer precipitation extremes is significantly related with the SSTA in the Pacific,while those of light and moderate precipitation are not.It is suggested that the previously well-recognized impact of ENSO on summer rainfall along the Yangtze River is essentially due to a response in summer precipitation extremes in the region,in association with the East Asia-Pacific (EAP) teleconnection pattern.A negative relationship is found between the East Asian Summer Monsoon (EASM) and precipitation extremes over the mid-lower reaches of the Yangtze River.In contrast,light rainfall processes are independent from the SST and EASM variations. 展开更多
关键词 precipitation extremes ENSO East Asian Summer Monsoon the yangtze River
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The SIA method for spatial analysis of precipitation in the upper-middle reaches of the Yangtze River 被引量:14
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作者 ZHOUSuoquan XUEGenyuan +6 位作者 GONGPeng CHENJingming ZHANGHongping ZHOUZhijiang FANXiong DENGXiaochun WUZhanping 《Journal of Geographical Sciences》 SCIE CSCD 2005年第2期223-238,共16页
Using geographic information system (GIS) techniques and the newest seasonal and annual average precipitation data of 679 meteorological stations from 1971 to 2000, the multiple regressions equations of the precipitat... Using geographic information system (GIS) techniques and the newest seasonal and annual average precipitation data of 679 meteorological stations from 1971 to 2000, the multiple regressions equations of the precipitation and topographical variables are established to extract the effect of topography on the annual and seasonal precipitation in the upper-middle reaches of the Yangtze River. Then, this paper uses a successive interpolation approach (SIA), which combines GIS techniques with the multiple regressions, to improve the accuracy of the spatial interpolation of annual and seasonal rainfall. The results are very satisfactory in the case of seasonal rainfall, with the relative error of 6.86%, the absolute error of 13.07 mm, the average coefficient of variation of 0.070, and the correlation coefficient of 0.9675; in the case of annual precipitation, with the relative error of 7.34%, the absolute error of 72.1 mm, the average coefficient of variation of 0.092, and the correlation coefficient of 0.9605. The analyses of annual mean precipitation show that the SIA calculation of 3-5 steps considerably improves the interpolation accuracy, decreasing the absolute error from 211.0 mm to 62.4 mm, the relative error from 20.74% to 5.97%, the coefficient of variation from 0.2312 to 0.0761, and increasing the correlation coefficient from 0.5467 to 0.9619. The SIA iterative results after 50 steps identically converge to the observed precipitation. 展开更多
关键词 the upper-middle reaches of the yangtze River precipitation resource spatial analysis successive interpolation approach (SIA)
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Functional Rehabilitation of the "Soil Reservoir"in Degraded Soils to Control Floods in the Yangtze River Watershed 被引量:9
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作者 SHIXue-Zheng LIANGYin +3 位作者 YUDong-Sheng PANXian-Zhang E.D.WARNER WANGHong-Jie 《Pedosphere》 SCIE CAS CSCD 2004年第1期1-8,共8页
The reasons for the Yangtze River flood calamity in 1998 are briefly introduced. The authors believe that using a 'soil reservoir' concept is an important means to help control flooding of the Yangtze River.A ... The reasons for the Yangtze River flood calamity in 1998 are briefly introduced. The authors believe that using a 'soil reservoir' concept is an important means to help control flooding of the Yangtze River.A 'soil reservoir' has a large potential storage capacity and its water can be rapidly 'discharged' into the underground water in a timely fashion. The eroded, infertile soils of the Yangtze River Watershed are currently an obstacle to efficient operation of the 'soil reservoir'. The storage capacity of this 'soil reservoir'has been severely hampered due to intensive soil erosion and the formation of soil crusts. Therefore, possible measures to control floods in the Yangtze River Watershed include: rehabilitating the vegetation to preserve soil and water on the eroded infertile soils, enhancing infiltration of the different soil types, and utilizing the large 'soil reservoir' of the upper reaches of the Yangtze River. 展开更多
关键词 flood calamity soil erosion 'soil reservoir' the yangtze river watershed
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Seasonal bioconcentration of heavy metals in Onchidium struma(Gastropoda:Pulmonata)from Chongming Island,the Yangtze Estuary,China 被引量:8
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作者 LI Xiaobo JIA Linzhi +2 位作者 ZHAO Yunlong WANG Qun CHENG Yongxu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2009年第2期255-262,共8页
The seasonal concentration changes of selected heavy metal Cd, Cr, Cu, Fe, Mn, Pb, and Zn in five tissues of marine gastropod Onchidium struma were studied in the Chongming Island, the Yangtze Estuary in April 2007, J... The seasonal concentration changes of selected heavy metal Cd, Cr, Cu, Fe, Mn, Pb, and Zn in five tissues of marine gastropod Onchidium struma were studied in the Chongming Island, the Yangtze Estuary in April 2007, July 2006, September 2006, and November 2006, respectively. The results demonstrated that the bioconcentration factor of Cu (biomass/water) in all selected tissues was about 104 magnitudes, Fe and Cd were 103, Zn was 102, and Mn, Pb, and Cr were 101. Hepatopancreas was proven to be the dominant storage tissue of Cr, Cu, Mn, and Zn, whereas Fe and Pb were mainly stored in muscle and digenetic gland, and Cd was stored in vitelline gland and albumen gland. Additionally, it was found that Cu, Fe, Mn, and Zn were concentrated significantly by O. struma (whole-body) in summer or autumn, and Cd, Cr, and Pb increased slightly in spring and winter. Furthermore, the bioconcentration of Cr was nearly 2-fold higher and Zn was 1.6-fold higher in the water compared with the Water Quality Standard for Fisheries. With view of excessive amount of Pb, Cd, and Cu according to seafood standard, the consumption of O. struma might have the risk of health hazard. 展开更多
关键词 Onchidium struma heavy metal BIOCONCENTRATION the yangtze Estuary
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Distribution and accumulation of biogenic silica in the intertidal sediments of the Yangtze Estuary 被引量:7
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作者 HOU Lijun LIU Min +4 位作者 XU Shiyuana YAN Huimin OU Dongni CHENG Shubo LIN Xiao 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2008年第5期543-550,共8页
Sedimentary biogenic silica is known to be an important parameter to understand biogeochemical processes and paleoenviromental records in estuarine and coastal ecosystems. Consequently, it is of great significance to ... Sedimentary biogenic silica is known to be an important parameter to understand biogeochemical processes and paleoenviromental records in estuarine and coastal ecosystems. Consequently, it is of great significance to investigate accumulation and distribution of biogenic silica in sediments. The two-step mild acid-mild alkaline extraction procedure was used to leach biogenic silica and its early diagenetic products in intertidal sediments of the Yangtze Estuary. The results showed that total biogenic silica (t-BSi) in the intertidal sediments varied from 237.7-419.4 μmol Si/g, while the mild acid leachable silica (Si-HCl) and the mild alkaline leachable silica (Si- Alk) were in the range of 25.1-72.9 μmol Si/g and 208.1-350.4 μmol Si/g, respectively. Significant correlations were observed for the grain size distributions of sediments and different biogenic silica pools in intertidal sediments. This confirms that grain size distribution can significantly affect biogenic silica contents in sediments. Close relationships of biogenic silica with organic carbon and nitrogen were also found, reflecting that there is a strong coupling between biogenic silica and organic matter biogeochemical cycles in the intertidal system of the Yangtze Estuary. Additionally, the early diagenetic changes of biogenic silica in sediments are discussed in the present study. 展开更多
关键词 biogenic silica early diagenesis intertidal flats the yangtze Estuary
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Trends of soil organic matter turnover in the salt marsh of the Yangtze River estuary 被引量:6
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作者 CHEN Qingqiang GU Hequan ZHOU Juzhen MENG Yi HU Kelin 《Journal of Geographical Sciences》 SCIE CSCD 2007年第1期101-113,共13页
Characteristics and tidal flat trends of soil organic matter (SOM) turnover were studied for the Chongmingdongtan Salt Marsh in the Yangtze River estuary, based on analyses of stable carbon isotope composition (δ^... Characteristics and tidal flat trends of soil organic matter (SOM) turnover were studied for the Chongmingdongtan Salt Marsh in the Yangtze River estuary, based on analyses of stable carbon isotope composition (δ^13C), grain sizes and contents of particulate organic carbon (POC), total nitrogen (TN) and inorganic carbon (TIC) for three cores excavated from high tidal flat, middle tidal flat and bare flat. Results demonstrate that correlations between soil POC contents and δ^13C values of the salt marsh cores were similar to those between soil organic carbon (SOC) contents and δ^13C values of the upper soil layers of mountainous soil profiles with different altitudes. SOM of salt marsh was generally younger than 100 years, and originated mainly from topsoil erosions in catchments of the Yangtze River. Correlations of TN content with C/N ratio, POC content with TIC content and POC content with δ^13C values for the cores suggest that turnover degrees of SOM from the salt marsh are overall low, and trends of SOM turnover are clear from the bare flat to the high tidal flat. Bare flat samples show characteristics of original sediments, with minor SOM turnover. Turnover processes of SOM have occurred and are discernable in the high and middle tidal flats, and the mixing degrees of SOM compartments with different turnover rates increase with evolution of the muddy tidal flat. The exclusive strata structure of alternate muddy laminae and silty laminae originated from dynamic depositional processes on muddy tidal flat was a great obstacle to vertical migration of dissolved materials, and SOM turnover was then constrained. The muddy tidal flat processes exerted direct influences on sequestration and turnover of SOM in the salt marsh, and had great constraints on the spatial and temporal characteristics of SOM turnover of the Chongmingdongtan Salt Marsh in the Yangtze River estuary. 展开更多
关键词 salt marsh soil organic carbon carbon cycling soil organic matter turnover the yangtze River estuary
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Eco-environment range in the source regions of the Yangtze and Yellow rivers 被引量:18
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作者 DING Yongjian,YANG Jianping,LIU Shiyin,CHEN Rensheng,WANG Genxu,SHEN Yongping,WANG Jian,XIE Changwei,ZHANG Shiqing(Cold and Arid Regions Environmental and Engineering Research Institute, CAS, Lanzhou 730000, China) 《Journal of Geographical Sciences》 SCIE CSCD 2003年第2期172-180,共9页
Based on geographical and hydrological extents delimited, four principles are identified, as the bases for delineating the ranges of the source regions of the Yangtze and Yellow rivers in the paper.... Based on geographical and hydrological extents delimited, four principles are identified, as the bases for delineating the ranges of the source regions of the Yangtze and Yellow rivers in the paper. According to the comprehensive analysis of topographical characteristics, climate conditions, vegetation distribution and hydrological features, the source region ranges for eco-environmental study are defined. The eastern boundary point is Dari hydrological station in the upper reach of the Yellow River. The watershed above Dari hydrological station is the source region of the Yellow River which drains an area of 4.49×10 4 km 2 . Natural environment is characterized by the major topographical types of plateau lakes and marshland, gentle landforms, alpine cold semi-arid climate, and steppe and meadow vegetation in the source region of the Yellow River. The eastern boundary point is the convergent site of the Nieqiaqu and the Tongtian River in the upstream of the Yangtze River. The watershed above the convergent site is the source region of the Yangtze River, with a watershed area of 12.24×10 4 km 2 . Hills and alpine plain topography, gentle terrain, alpine cold arid and semi-arid climate, and alpine cold grassland and meadow are natural conditions in the source region of the Yangtze River. 展开更多
关键词 the source regions of the yangtze and Yellow rivers eco-environmental range CLC number:X171.1
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Correlation Analysis of Persistent Heavy Rainfall Events in the Vicinity of the Yangtze River Valley and Global Outgoing Longwave Radiation in the Preceding Month 被引量:6
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作者 汤燕冰 赵璐 高坤 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2009年第6期1169-1180,共12页
Based on the National Oceanic and Atmospheric Administration (NOAA) daily satellite dataset of global outgoing longwave radiation (OLR) for the period of 1974-2004 and the NCEP-NCAR reanalysis for 1971- 2004, the ... Based on the National Oceanic and Atmospheric Administration (NOAA) daily satellite dataset of global outgoing longwave radiation (OLR) for the period of 1974-2004 and the NCEP-NCAR reanalysis for 1971- 2004, the linkage between persistent heavy rainfall (PHR) events in the vicinity of the Yangtze River valley and global OLR leading up to those events (with 1- to 3O-day lag) was investigated. The results reveal that there is a significant connection between the initiation of PHR events over the study area and anomalous convective activity over the tropical Indian Ocean, maritime continent, and tropical western Pacific Ocean. During the 30-day period prior to the onset of PHR events, the major significantly anomalous convective centers have an apparent dipole structure, always with enhanced convection in the west and suppressed convection in the east. This dipole structure continuously shifts eastward with time during the 30-day lead period. The influence of the anomalous convective activity over the tropical oceans on the initiation of PHR events over the study area is achieved via an interaction between tropical and extratropical latitudes. More specifically, anomalous convective activity weakens the Walker circulation cell over the tropical Indian Ocean first. This is followed by a weakening of the Indian summer monsoon background state and the excitation and dispersion of Rossby wave activity over Eurasia. Finally, a major modulation of the large scale background circulation occurs. As a result, the condition of a phase-lock among major large scale circulation features favoring PHR events is established over the study area. 展开更多
关键词 persistent heavy rainfall events global outgoing longwave radiation the yangtze River valley
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Basement Characteristics and Crustal Evolution of the Copper-Gold Metallogenic Belt in the Middle and Lower Reaches of the Yangtze River:Some Isotope Constraints 被引量:5
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作者 ZHOU Taofa YUE Shucang 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2000年第2期207-212,共6页
Studies of the Pb, Sr and Nd isotopic composition of Mesozoic intrusive rocks indicate that the basement of the copper-gold metallogenic belt of the middle and lower reaches of the Yangtze River has “two-layer struct... Studies of the Pb, Sr and Nd isotopic composition of Mesozoic intrusive rocks indicate that the basement of the copper-gold metallogenic belt of the middle and lower reaches of the Yangtze River has “two-layer structure” and partly has “multi-layered structure”, and is inhomogeneous and shows the distinct feature of E-W provincialism. The calculated model lead ages (t1) are mostly greater than 2600 Ma, and the model neodymium ages (TDM) vary from 953 to 2276 Ma and concentrate in two time intervals: 1800–2000 Ma and 1200–1600 Ma. It is concluded that the basement of the MBYR is composed of the Late Archaeozoic to Middle Proterozoic metamorphic series and that the crust was initiated in the Archaean and continued to grow in the Early and Middle Proterozoic, and the proportion of new crust formed by mantle differentiation during the Late Proterozoic is low. 展开更多
关键词 BASEMENT crustal age Pb Sr and Nd isotopes metallogenic belt of the middle and lower reaches of the yangtze River
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Characteristics and runoff volume of the Yangtze River paleo-valley at Nanjing reach in the Last Glacial Maximum 被引量:4
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作者 CAO Guangjie WANG Jian +1 位作者 WANG Lingjun LI Yanyan 《Journal of Geographical Sciences》 SCIE CSCD 2010年第3期431-440,共10页
The stratigraphical cross-sections of the Yangtze River incised-valley near the No.l, No.3 and No.4 Nanjing Yangtze River bridges were established with respective bore date and documents. By ^14C age analysis of the s... The stratigraphical cross-sections of the Yangtze River incised-valley near the No.l, No.3 and No.4 Nanjing Yangtze River bridges were established with respective bore date and documents. By ^14C age analysis of the samples of four drilling cores near the No.4 Bridge (to be built), we can find that the time range of paleo-valley is dated in the LGM at a depth of-60 m to -90 m near Nanjing. It is also indicated that the deep incised-valley channel was narrow and the river flowed swiftly. The ancient Yangtze River deep channel presented partially and deeply incised features near the No.1 Bridge. According to previous publications, much research has been done on the main paleo-channel of the Yangtze River, but few results have been achieved on discharge estimation. In this paper, the incipient velocity and average veIocity of the LGM was calculated with Vc=4.60d^1/3h^1/6, Vc=1.281g( 13.15. h /d95) √gd, V≈6.5u*|h/d90|^1/6 etc., in terms of the river shape, sedimentary grain size and sequences near the No.3 and No.1 bridges. Moreover, the discharge in Nanjing reach of the Yangtze River during the LGM has been estimated to be around 12,000-16,000 m^3/s according to the relationship of discharge, velocity of flow and cross-section. 展开更多
关键词 the Last Glacial Maximum Nanjing reach of the yangtze River paleo-valley velocity of flow runoff volume
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Anomalous Atmospheric Circulation, Heat Sources and Moisture Sinks in Relation to Great Precipitation Anomalies in the Yangtze River Valley 被引量:5
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作者 杨辉 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2001年第5期972-983,共12页
Using the summer (June to August) monthly mean data of the National Centers for Environmental Predictions (NCEP) - National Center for Atmospheric Research (NCAR) reanalysis from 1980 to 1997, atmospheric heat sources... Using the summer (June to August) monthly mean data of the National Centers for Environmental Predictions (NCEP) - National Center for Atmospheric Research (NCAR) reanalysis from 1980 to 1997, atmospheric heat sources and moisture sinks are calculated. Anomalous circulation and the vertically integrated heat source with the vertical integrated moisture sink and outgoing longwave radiation (OLR) flux are examined based upon monthly composites for 16 great wet-spells and 8 great dry-spells over the middle-lower reaches of the Yangtze River. The wind anomaly exhibits prominent differences between the great wet-spell and the great dry-spell over the Yangtze River Valley. For the great wet-spell, the anomalous southerly from the Bay of Bengal and the South China Sea and the anomalous northerly over North China enhanced low-level convergence toward a narrow latitudinal belt area (the middle-lower reaches of the Yangtze River). The southerly anomaly is connected with an anticyclonic anomalous circulation system centered at 22 degreesN, 140 degreesE and the northerly anomaly is associated with a cyclonic anomalous circulation system centered at the Japan Sea. In the upper level, the anomalous northwesterly between an anticyclonic anomalous system with the center at 23 degreesN, 105 degreesE and a cyclonic anomalous system with the center at Korea diverged over the middle-lower reaches of the Yangtze River. On the contrary, for the great dry-spell, the anomalous northerly over South China and the anomalous southerly over North China diverged from the Yangtze River Valley in the low level. The former formed in the western part of a cyclonic anomalous system centered at 23 degreesN, 135 degreesE. The latter was located in the western ridge of an anticyclonic anomalous system in the northwestern Pacific. The upper troposphere showed easterly anomaly that converged over the middle-lower reaches of the Yangtze River. A cyclonic anomalous system in South China and an anticyclonic system centered in the Japan Sea enhanced the easterly. Large atmospheric heat source anomalies of opposite signs existed over the western Pacific - the South China Sea, with negative in the great wet-spell and positive in the great dry-spell. The analysis of heat source also revealed positive anomalous heat sources during the great wet-spell and negative anomalous heat sources during the great dry-spell over the Yangtze River valley. The changes of the moisture sink and OLR were correspondingly altered, implying the change of heat source anomaly is due to the latent heat releasing of convective activity. Over the southeastern Tibetan Plateau- the Bay of Bengal, the analysis of heat source shows positive anomalous heat sources during the great wet-spell and negative anomalous heat sources during the great dry-spell because of latent heating change. The change of divergent wind coexisted with the change of heat source. In the great wet-spell, southerly divergent wind anomaly in the low level and northerly divergent wind anomaly in high-level are seen over South China. These divergent wind anomalies are helpful to the low-level convergence anomaly and high-level divergence anomaly over the Yangtze River valley. The low-level northerly divergent wind anomaly and high-level southerly divergent wind anomaly over South China reduced the low-level convergence and high-level divergence over the Yangtze River valley during the great dry-spell. 展开更多
关键词 anomalous atmospheric circulation heat sources and moisture sinks anomalies great precipitation anomalies in the yangtze River valley
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Sediment Deposition and Resuspension in Mouth Bar Area of the Yangtze Estuary 被引量:3
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作者 李九发 何青 +1 位作者 莉莉 沈焕庭 《China Ocean Engineering》 SCIE EI 2000年第3期339-348,共10页
A comprehensive analysis is conducted based on observations on topography, tidal current, salinity, suspended sediment and bed load during the years of 1982, 1983, 1988, 1989. 1996, and 1997 in the Yangtze Estuary. Re... A comprehensive analysis is conducted based on observations on topography, tidal current, salinity, suspended sediment and bed load during the years of 1982, 1983, 1988, 1989. 1996, and 1997 in the Yangtze Estuary. Results show that the deformation of tidal waves is distinct and the sand carrying capacity is large within the mouth bar due to strong tidal currents and large volume of incoming water and sediments. Owing to both temporal and spatial variation of tidal current, deposition and erosion ore extremely active. In general a change of up to 0.1 m of bottom sediments takes place during a tidal period. The maximum siltation and erosion are around 0.2 m in a spring to neap tides cycle. The riverbed is silted during flood when there is heavy sediment load, eroded during dry season when sediment lo:ld is low. The annual average depth of erosion anti siltation on the riverbed is around 0.6 m. In particular cases, it may increase to 1.4 m to 2.4 m at some locations. 展开更多
关键词 the yangtze Estuary sediment movement DEPOSITION sediment resuspension mouth bar
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Numrical Model of Total Sediment Transport in the Yangtze Estuary 被引量:3
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作者 窦希萍 李禔来 窦国仁 《China Ocean Engineering》 SCIE EI 1999年第3期277-286,共10页
Based on the non-equilibrium suspended load transport equation, bed load transport equation and sediment transport capacity formulas derived by Don et al. , a 2-D numerical model of total sediment transport in the Yan... Based on the non-equilibrium suspended load transport equation, bed load transport equation and sediment transport capacity formulas derived by Don et al. , a 2-D numerical model of total sediment transport in the Yangtze Estuary is presented. In the model, the actions of tidal currents and wind waves and the effect of salinity on sediment transport are considered. An automatically generated boundary-fitted grid is used to fit the boundaries of the estuary and the boundaries of engineering projects. The verification of calculations shows that the sediment concentration, the deformation of riverbed and siltation in the channels caused by typhoons can be successfully simulated. 展开更多
关键词 the yangtze Estuary tidal currents suspended load bed load numerical model
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Land Use Change During 1960~2000 Period and itsEco-environmental Effects in the Middle and UpperReaches of the Yangtze River:a Case Study in YiliangCounty,Yunnan,China 被引量:4
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作者 YANGZisheng LIANGLuohui +1 位作者 LIUYansui HEYimei 《Journal of Mountain Science》 SCIE CSCD 2004年第3期250-263,共14页
Land use/land cover change (LUCC) is a focus of the research of global environmental changes. The middle and upper reaches of the Yangtze River, which are the most ecologically fragile mountainous area in China as wel... Land use/land cover change (LUCC) is a focus of the research of global environmental changes. The middle and upper reaches of the Yangtze River, which are the most ecologically fragile mountainous area in China as well as one of the areas in China with most notable LUCC, have been on the Chinese Government's list of priority areas for ecological restoration. This paper is to reveal the trend of LUCC and the ecological degradation arising from it, and to provide a basis for the future sustainable use of land resources in the region based on a detailed analysis of Yiliang County. Based on the county's land use/cover maps in 1960, 1980 and 2000 drawn with the aid of aerial photograph interpretation, field investigation and GIS based spatial-temporal data analysis, LUCC during 1960~2000 period and the ecological degradation arising from it were analyzed. Using the Markv model, the paper brings out a forecast of what the county's LUCC would be like if the county's current land use continues, as well as the reasons and countermeasures for restoring degraded ecosystems. 展开更多
关键词 Land use/cover change (LUCC) drivingforce eco-environmental effect ecological security sustainable use upper reaches of the yangtze River
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