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| 1 | Two series of copper-gold deposits in the middle and lower reaches of the Yangtze River area (MLYRA) and the hydrogen, oxygen, sulfur and lead isotopes of their ore-forming hydrothermal systems显示文摘Based on studies on the geological characteristics of the copper-gold deposits in the middle and lower reaches of the Yangtze River area (MLYRA) and their hydrogen, oxygen, sulfur and lead isotope compositions, it is concluded that there existed two series of copper-gold deposits. They are evolutional products of two ore-forming hydrothermal systems in different geodynamic settings and geological era. Series I is stratiform or stratabound copper-gold deposits. These deposits were formed by submarine exhalation and sedimentation of hydrothermal solutions in Her-cynian tensional tectonic environment after bot brine ascending along contemporaneous faults and exhaled into the sea-floor. Series II consists of copper-gold deposits related to medium and acidic magmatic intrusions. Their mineralizations took place in Yanshanian in a tensional or a transitional period to the tensional tectonic environment from the composite of the tethys tectonic regime and the Paleo-Pacific ocean tectonic regime, as well as | 周涛发 袁峰 岳书仓 赵勇 | 2000 | Science China Earth Sciences2000,43,S1: | 40 |
| 2 | 长江中下游江湖关系演变趋势数值模拟显示文摘以长江中下游防洪系统为对象,概述了在大型复杂防洪系统洪水行为数值模拟基础上,成功地将长江中下游洪水演进数学模型转化为面向长江防洪系统防洪规划方案评估需求的长江中下游江湖水沙演变的数学模型。为适应防洪规划方案论证涉及江湖水沙相互制衡相互关联客观情况,建立了面向江湖水沙关系及其演变的数学模型。针对长江中下游江湖水沙运动特点,在水沙数值模拟的范围内侧重对下荆江河道冲刷、荆江三口分流分沙模式、洞庭湖泥沙淤积、江湖耦合等环节进行了讨论,提出了合理可行的数值处理方法。模拟结果较好反映了江湖水沙演变规律,主要成果已应用于长江中下游防洪规划和防汛调度方案中。 | 施勇 栾震宇 陈炼钢 金秋 | 2010 | 水科学进展2010,21,6: | 32 |
| 3 | Seasonal water storage change of the Yangtze River basin detected by GRACE显示文摘US-Germany co-sponsered satellite gravimetry mission GRACE (Gravity Recovery And Climate Experiment), launched in March 2002, has been producing monthly time series of Earth gravity models up to degree and order of 120. The GRACE mission consists of two identical satellites flying on an almost polar orbit with an altitude of about 300-500 km and satelite-to-satellite ranging of about 220 km. Thanks to the payloads of space-borne GPS receivers, accelerometers and high-precision K-band satelite-to-satellite ranging mesurements, GRACE gravity models are expected to achieve more than one order of magnitude of improvement over previous models at spatial scales of a few hundred kilometers or larger. Recovery of surface mass re-distribution based on GRACE’s time-varying gravity models is applied to studies in solid Earth geophysics, oceanography, climatology and geodesy. At secular time scales, GRACE is expected to provide valuable information on global ice changes, whose variations have profound influences on global climate, and in particular, on sea level changes. At seasonal time scales, GRACE is expected to reveal surface water changes with an ac- curacy of less than 1 cm, or ocean bottom pressure changes with an accuracy of less than 1 mbar (1 mbar =102 Pa). These surface mass redistribution measurements would impove our understanding of the global and regional mass and energy cycles that are critical to human life. Using 15 GRACE monthly gravity models covering the period from April 2002 to December 2003, this study compares seasonal water storage changes recovered from GRACE data and hydrology models at global and regional scales, with particular focus on the Yangtze River basin of China. Annual amplitude of 3.4 cm of equivalent water height change is found for the Yangtze River basin with maximum in Spring and Autumn, agreeing with two state-of-the-art hydrology models. The differences between GRACE re- sults and model predictions are less than 1-2 cm. We conclude that satellite gravimetry has huge potentials in monitering water storage changes in large river basins such as Yangtze. | HU Xiaogong1, CHEN Jianli1,2, ZHOU Yonghong1, HUANG Cheng1 & LIAO Xinhao1 1. Center for Astro-geodynamics Research, Shanghai Astronomical Observatory, National Astronomical Observatories, Shanghai 200030, China 2. Center for Space Research, University of Texas at Austin, 3925 W. Braker Lane, Suite 200, Austin, TX78750, USA | 2006 | Science China Earth Sciences2006,49,5: | 29 |
| 4 | Air pollution characteristics and their relationship with emissions and meteorology in the Yangtze River Delta region during 2014–2016显示文摘With rapid economic growth and urbanization, the Yangtze River Delta(YRD) region in China has experienced serious air pollution challenges. In this study, we analyzed the air pollution characteristics and their relationship with emissions and meteorology in the YRD region during 2014–2016. In recent years, the concentrations of all air pollutants, except O3,decreased. Spatially, the PM2.5, PM10, SO2, and CO concentrations were higher in the northern YRD region, and NO2 and O3 were higher in the central YRD region. Based on the number of non-attainment days(i.e., days with air quality index greater than 100), PM2.5 was the largest contributor to air pollution in the YRD region, followed by O3, PM10, and NO2.However, particulate matter pollution has declined gradually, while O3 pollution worsened.Meteorological conditions mainly influenced day-to-day variations in pollutant concentrations. PM2.5 concentration was inversely related to wind speed, while O3 concentration was positively correlated with temperature and negatively correlated with relative humidity.The air quality improvement in recent years was mainly attributed to emission reductions.During 2014–2016, PM2.5, PM10, SO2, NOx, CO, NH3, and volatile organic compound(VOC)emissions in the YRD region were reduced by 26.3%, 29.2%, 32.4%, 8.1%, 15.9%, 4.5%, and0.3%, respectively. Regional transport also contributed to the air pollution. During regional haze periods, pollutants from North China and East China aggravated the pollution in the YRD region. Our findings suggest that emission reduction and regional joint prevention and control helped to improve the air quality in the YRD region. | Tao Ma Fengkui Duan Kebin He Yu Qin Dan Tong Guannan Geng Xuyan Liu Hui Li Shuo Yang Siqi Ye Beiyao Xu Qiang Zhang Yongliang Ma | 2019 | Journal of Environmental Sciences2019,31,9: | 26 |
| 5 | Large and meso-α scale characteristics of intense rainfall in the mid- and lower reaches of the Yangtze River显示文摘Meteorological conditions associated with intense rainfall and great floods over mid- and lower reaches of Yangtze River are studied by analyzing the large-, synoptic-and meso-a-scale circulation systems for 1991, 1996 and 1998. It is found that the advance and retreat of subtropical high over the West Pacific, the monsoon moisture surge from the South China Sea, cold air outbreak over mid- and high-latitudes, and the meso-α scale systems (250-2500 km) from the Tibetan Pleateau as well, are responsible for intense rainfall over the Yangtze River Valley. The persistent and heavy rains and great floods over the Yangtze River Valley occurred when all these four systems are synergetic or in phase lock. | Shunli Zhang Shiyan Tao Qingyun Zhang Jie Wei | 2002 | Chinese Science Bulletin2002,47,9: | 22 |
| 6 | Significant relationship between spring AO and the summer rainfall along the Yangtze River显示文摘The influence of spring AO on the summer rainfall along the Yangtze River is investigated. The long-term rainfall observations are filtered to remove the low-frequency variations longer than 10 years. The inter-annual components show a high correlation to AO in the last hundred years. The strongest correlation appears for May AO and summer rainfall with a value of -0.39, significant above the 99% confidence level. Associated with one standard deviation stronger May AO index, the rainfall over the Yangtze River to the southern Japan decreases by about 3%-9%, while, at the same time increases by about 3%-6% in the northern China and far-eastern Russia. The coherent changes in rainfall are significantly related to the East Asian summer jet stream in the upper troposphere. When there is stronger AO in spring, the jet stream tends to move polarward in summer, and leads the rainfall-belt to move northward too. That gives rise to a drier condition in the Yangtze River valley, wetter anomalies in northern China. | GONG Daoyi ZHU Jinhong WANG Shaowu | 2002 | Chinese Science Bulletin2002,47,11: | 22 |
| 7 | 卫星雷达测雨在长江流域的精度分析显示文摘针对传统的雨量站点观测方法存在的缺陷,基于TRMM卫星降雨数据较高的时间和空间分辨率,通过TRMM数据与长江流域实测站点数据在时间和空间分布上的对比分析,研究了TRMM数据在长江流域的适用性。结果表明,TRMM数据在长江流域有较高的精度,为分布式水文模型提供了良好的数据支撑。 | 谷黄河 余钟波 杨传国 梁川 王维 鞠琴 | 2010 | 水电能源科学2010,28,8: | 23 |
| 8 | The Background Features and Formation of Chemical Elements of Groundwater in the Region of the Middle and Lower Reaches of the Yangtze River显示文摘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. | Zeng Zhaohua Institute of Environmental Geology,Jiangxi Bureau of Geology and Mineral Resources, Nanchang, Jiangxi Shang Ruoyun | 1997 | Acta Geologica Sinica(English Edition)1997,71,1: | 17 |
| 9 | Impact of the Three Gorges Project operation on the water exchange between Dongting Lake and the Yangtze River显示文摘The Three Gorges Project(TGP) is a world known project to utilize and manage the water resources of the Yangtze River. The reservoir stores water at the end of the flood season, and replenishes downstream reaches with water in dry seasons. In addition to such benefits, the TGP has irreversibly changed the hydrological process and the river-lake relation of the middle and lower reaches. In this paper, a hydrodynamic model was established to quantify the impact of the TGP's operation on the water exchange between Dongting Lake and the Yangtze River during 2009-2013. The results indicated that:the operation of the TGP has considerably reduced the peak discharge and the flood volume of the main stream and the Dongting Lake area. The inflow volume from the Yangtze River to Dongting Lake via three outlets decreased by 1.9-3.5 billion m^3/yr, while the outflow volume from Dongting Lake to the Yangtze River at Chenglingji increased by 0.3-1.6 billion m^3 in September and 0.4-0.6 billion m^3 in October,respectively. This research provides valuable information for flood control, irrigation, and water allocation in the middle and lower reaches of the Yangtze River, and serves as a typical case for investigating the impact of other hydropower projects around the world. | Minglong Dai Jun Wang Mingbo Zhang Xi Chen | 2017 | International Journal of Sediment Research2017,32,4: | 14 |
| 10 | Quantitatively distinguishing sediments from the Yangtze River and the Yellow River using δEu_N-ΣREEs plot显示文摘Sediment samples were collected from the lower channel of the Yangtze River and the Yellow River and the contents of rare earth elements (REEs) were measured. In addition, some historical REEs data were collected from published literatures. Based on the δEuN-ΣREEs plot, a clear boundary was found be-tween the sediments from the two rivers. The boundary can be described as an orthogonal polynomial equation by ordinary linear regression with sediments from the Yangtze River located above the curve and sediments from the Yellow River located below the curve. To validate this method, the REEs con-tents of sediments collected from the estuaries of the Yangtze River and the Yellow River were meas-ured. In addition, the REEs data of sediment Core 255 from the Yangtze River and Core YA01 from the Yellow River were collected. Results show that the samples from the Yangtze River estuary and Core 255 almost are above the curve and most samples from the Yellow River estuary and Core YA01 are below the curve in the δEuN-ΣREEs plot. The plot and the regression equation can be used to distin-guish sediments from the Yangtze River and the Yellow River intuitively and quantitatively, and to trace the sediment provenance of the eastern seas of China. The difference between the sediments from two rivers in the δEuN-ΣREEs plot is caused by different mineral compositions and regional climate patterns of the source areas. The relationship between δEuN and ΣREEs is changed little during the transport from the source area to the river, and from river to the sea. Thus the original information on mineral compositions and climate of the source area was preserved. | JIANG FuQing ZHOU XiaoJing LI AnChun LI TieGang | 2009 | Science China Earth Sciences2009,52,2: | 14 |
| 11 | High-resolution 3D crustal S-wave velocity structure of the MiddleLower Yangtze River Metallogenic Belt and implications for its deep geodynamic setting显示文摘The Middle-Lower Yangtze River Metallogenic Belt(MLYMB) is an important mineral resource region in China.High-resolution crustal models can provide crucial constraints to understand the ore-forming processes and geodynamic setting in this region. Using ambient seismic noise from 107 permanent and 82 portable stations in the MLYMB and the adjacent area,we present a new high-resolution 3D S-wave velocity model of this region. We first extract 5–50 s Rayleigh wave phase velocity dispersion data by calculating ambient noise cross-correlation functions(CFs) and then use the surface wave direct inversion method to invert the mixed path travel times for the 3D S-wave velocity structure. Checkerboard tests show that the horizontal resolution of the 3D S-wave velocity model is approximately 0.5°–1.0° and that the vertical resolution decreases with increasing noise and depth. Our high-resolution 3D S-wave velocity model reveals:(1) AV-shaped high-velocity zone(HVZ) is located in the lower crust and the uppermost mantle in the study region. The western branch of the HVZ passes through the Jianghan Basin,the Qinling-Dabie orogenic belt and the Nanxiang Basin. The eastern branch, which almost completely covers the main body of the MLYMB, is located near the Tanlu Fault. The low-velocity anomalies between the western and eastern branches are located in the area of the Qinling-Dabie orogenic belt.(2) High-velocity uplifts(HVUs) are common in the crust of the MLYMB,especially in the areas near the Tanlu Fault, the Changjiang Fault and the Yangxin-Changzhou Fault. The intensities of the HVUs gradually weaken from west to east. The V-shaped HVZ in the lower crust and uppermost mantle and the HVUs in the middle and lower crust likely represent cooled mantle intrusive rocks. During the Yanshanian period, fault systems formed in the MLYMB due to the convergence between the South China Plate and the North China Plate, the multiple-direction drifting of the PaleoPacific Plate and its subduction beneath the Eurasian Plate. The dehydration of the cold oceanic crust led to partial melting in the upper mantle. Temperature differences caused strong convection of the upper mantle material that underplated the lower crust and rose to near the surface along the deep fault systems. After mixing with the crustal materials, mineralization processes, such as assimilation and fractional crystallization, occurred in the MLYMB. | Song LUO Huajian YAO Qiusheng LI Weitao WANG Kesong WAN Yafeng MENG Bin LIU | 2019 | Science China Earth Sciences2019,62,9: | 13 |
| 12 | Teleconnection between the Indian summer monsoon onset and the Meiyu over the Yangtze River Valley显示文摘Based on the Indian and Chinese precipitation data and the NCEP-NCAR reanalysis circulation data, the relationship between the Indian summer monsoon (ISM) onset and the Meiyu over the Yangtze River Valley has been discussed by the methods of correlation analysis and composite analysis. The results show that the date of ISM onset over Kerala in the southwestern coast of the Indian Peninsula is about two weeks earlier than the beginning of the Meiyu over the Yangtze River Valley. After the outbreak of ISM, the teleconnection mode sets up from the western coast of India via the Bay of Bengal (BOB) to the Yangtze River Valley and southern Japan. It is different both in time and space from the telecon- nection mode which is from the northwest of India via the Tibetan Plateau to northern China. The for- mer mode is defined as the 'south' teleconnection of the Asian summer monsoon, forming in the pe- riod of ISM onset; while the latter mode is called the 'north' teleconnection, mainly occurring in the Asian monsoon culminant period. During the process of the 'south' teleconnection’s formation, the Asian monsoon circulation has experienced a series of important changes: ISM onset, the northward movement of the south Asia high (SAH), the onset vortex occurrence, the eastward extension of the stronger tropical westerly belt, and the northeastward jump of the western Pacific subtropical high (WPSH), etc. Consequently, since ISM sets up over Kerala, the whole Asian continent is covered by the upper SAH after about two weeks, while in the mid- and lower troposphere, a strong wind belt forms from the Arabian Sea via the southern India, BOB and the South China Sea (SCS), then along the western flank of WPSH, to the Yangtze River Valley and southern Japan. With the northward moving of the subtropical jet streams, the upper westerly jet stream and the low level jet have been coupled ver- tically over east Asia, while the Yangtze River Valley happens to locate in the ascending motion area between the upper jet stream and the low level jet, i.e. right of the entrance of the upper jet stream and left of the low level jet. Such a structure of the vertical circulation can trigger the Meiyu onset over the Yangtze River Valley. | LIU YunYun1,2,3 & DING YiHui2 1 Chinese Academy of Meteorological Sciences, Beijing 100081, China 2 National Climate Center, Beijing 100081, China 3 Graduate University of Chinese Academy of Sciences, Beijing 100049, China | 2008 | Science China Earth Sciences2008,51,7: | 13 |
| 13 | 长江中下游江湖水沙调控数值模拟显示文摘以长江中下游防洪系统为对象,在大型复杂防洪系统洪水运动数值模拟基础上,成功地将面向长江中下游防洪规划论证需求的洪水演进数学模型转化为面向长江防洪系统江湖水沙调控需求的长江中下游江湖水沙调控数学模型。为适应江湖水沙调控和评估的要求,提出了基于水动力学的闸坝调度计算模式。此外,还对河网分汊泥沙分配模式进行了深入研究。通过长江中下游防洪规划及其洞庭湖区'控支强干'方案论证模拟计算,较好地解决了防洪措施蓄泄后效评估和工程优化调控模式等关键难题,为防洪规划方案的制定提供了定量依据,主要成果已应用于长江中下游防洪规划方案。 | 施勇 栾震宇 陈炼钢 金秋 | 2010 | 水科学进展2010,21,6: | 11 |
| 14 | The 20―30-day oscillation of the global circulation and heavy precipitation over the lower reaches of the Yangtze River valley显示文摘Based on the observational data in summer, the variations of intraseasonal oscillation (ISO) of the daily rainfall over the lower reaches of the Yangtze River valley (LYRV) were studied by using the non-integer spectrum analysis. The NCEP/NCAR reanalysis data for the period of 1979―2005 were analyzed by principal oscillation pattern analysis (POP) to investigate the spatial and temporal characteristics of principal ISO patterns of the global circulation. The relationships of these ISO patterns to the rainfall ISO and the heavy precipitation process over LYRV were also discussed. It is found that the rainfall over LYRV in May―August is mainly of periodic oscillations of 10―20, 20―30 and 60―70 days, and the interannual variation of the intensity of its 20―30-day oscillation has a strongly positive correlation with the number of the heavy precipitation process. Two modes (POP1, POP2) are revealed by POP for the 20―30-day oscillation of the global 850 hPa geopotential height. One is a circumglobal telecon-nection wave train in the middle latitude of the Southern Hemisphere (SCGT) with an eastward propagation, and the other is the southward propagation pattern in the tropical western Pacific (TWP). The POP modes explain 7.72% and 7.66% of the variance, respectively. These two principal ISO patterns are closely linked to the low frequency rainfall and heavy precipitation process over LYRV, in which the probability for the heavy precipitation process over LYRV is 54.9% and 60.4% for the positive phase of the imaginary part of POP1 and real part of POP2, respectively. Furthermore, the models of the global atmospheric circulation for the 20―30-day oscillation in association with or without the heavy pre-cipitation process over LYRV during the Northern Hemisphere summer are set up by means of the composite analysis method. Most of the heavy precipitation processes over LYRV appear in Phase 4 of SCGT or Phase 6 of TWP. When the positive phases of 20―30-day oscillations for the rainfall over LYRV are associated with (without) the heavy precipitation process, a strong westerly stream appears (disappears) from the Arabian Sea via India and Bay of Bengal (BOB) to southern China and LYRV for the global 850 hPa filtered wind field during Phase 4 of SCGT. This situation is favorable (unfavorable) for the forming of the heavy precipitation process over LYRV. Similarly, a strong (weak) western wind belt forms from India through BOB to southern China and LYRV and the subtropical northwestern Pacific and central and eastern equatorial Pacific during Phase 6 of TWP for the cases with (without) the heavy precipitation process. The evolutions of these ISO patterns related to the 20―30-day oscillation are excited by either the interaction of extratropical circulation in both hemispheres or the heat source forcing in Asia monsoon domain and internal interaction of circulation in East Asia. These two global circulation models might therefore provide valuable information for the extended-range forecast of the heavy precipitation process over LYRV during the 10―30 days. | YANG QiuMing Jiangsu Meteorological Institute, Nanjing 210008, China | 2009 | Science China Earth Sciences2009,52,10: | 9 |
| 15 | Elemental composition in the sediments of the Yangtze and the Yellow Rivers and their tracing implication | 杨守业 李从先 | 2000 | Progress in Natural Science:Materials International2000,10,8: | 9 |
| 16 | Prediction and prevention of the impacts of sea level rise on the Yangtze River Delta and its adjacent areas显示文摘The Yangtze River Delta region is characterized by high density of population and rapidly developing economy. There are low lying coastal plain and deltaic plain in this region. Thus, the study area could be highly vulnerable to accelerated sea level rise caused by global warming. This paper deals with the scenarios of the relative sea level rise in the early half period of the 21st century in the study area. The authors suggested that relative sea level would rise 25-50 cm by the year 2050 in the study area, of which the magnitude of relative sea level rise in the Yangtze River Delta would double the perspective worldwide average. The impacts of sea level rise include: (i) exacerbation of coastline recession in several sections and vertical erosion of tidal flat, and increase in length of eroding coastline; (ii) decrease in area of tidal flat and coastal wetland due to erosion and inundation; (iii) increase in frequency and intensity of storm surge, which would threaten the coastal protection works; | 施雅风 朱季文 谢志仁 季子修 蒋自巽 杨桂山 | 2000 | Science China Earth Sciences2000,43,4: | 8 |
| 17 | Maintaining the connected river-lake relationship in the middle Yangtze River reaches after completion of the Three Gorges Project显示文摘After operation of the Three Gorges Project(TGP), there is a new evolution tendency for rivers and lakes in the middle reaches of the Yangtze River(i.e. the Ching River reaches). In recent years, the weakening connection relationship between the Yangtze River and Dongting Lake has resulted in a series of problems for flood regulation, water resources utilization, and aquatic ecosystem protection in the river-lake joint area. In this paper, the hydrological characteristics and fluvial processes within the river-lake joint area are studied, and possible management strategies to maintain the connected river-lake relationship are proposed. To achieve this objective, the evolution tendency, such as the zero-flow problem and river regime for three major outlets(i.e. the Songzi Outlet, Taiping Outlet, and Ouchi Outlet) to Dongting Lake from the Yangtze River, is analyzed. It is believed that the Songzi Outlet has a comparative advantage in flow diversion over the other two outlets. The Range of Variability Approach is introduced to identify hydrological characteristics at the Songzi Outlet. Several characteristic values of flow diversion from this outlet during drought periods are determined. Then, the fluvial processes in the river-lake joint area are studied by comparing topographic maps and using control gauge station data of various years. The water and sediment flux are analyzed before and after operation of the TGP. Finally, based on the results obtained, two possible management strategies are recommended and corresponding parameters are estimated to strengthen and maintain the connected river-lake relationship. This analysis takes into account operation of the TGP, mainstream shift and increasing riverbed scour in the Ching River channel.To restore the flow diversion condition to that in the 1950 s or 1960 s(i.e. 140 m^3/s of flow diversion corresponding to 5500 m^3/s of flow at the Zhicheng station), it is estimated that the river channel around the Songzi Outlet should be dredged 1.4 m under the current riverbed situation, and other corresponding improvement measures for Songzi River channels should also be implemented. | Xiuying Wang Xiang Li Baiyinbaoligao yihong wu | 2017 | International Journal of Sediment Research2017,32,4: | 8 |
| 18 | Comparison of detrital mineral compositions between stream sediments of the Yangtze River (Changjiang) and the Yellow River (Huanghe) and their provenance implication显示文摘A comparative comparative study on the detrital mineral composition of stream sediments of the Yangtze River (Changjiang) and Yellow River (Huanghe) shows that, light minerals of the Yangtze River basin were mainly quartz, feldspar, and detritus, the compositional characteristics of light minerals differed among tributaries, the main stream had a generally higher maturity index than tributaries;heavy mineral content tended to decrease progressively from the upper stream to lower stream of the Yangtze River, the primary assemblage was magnetite-hornblende-augite-garnet-epidote, and diagnostic minerals of different river basins were capable of indicating the nature and distribution of the source rock. Detrital mineral assemblages in sediments of tributaries and the main stream of the Yellow River were basically similar, Primary heavy mineral assemblage was opaque mineral-garnet-epidote-carbonate mineral and alteration mineral. Variations in the contents of garnet, opaque mineral, and hornblende mainly reflected the degree of sedimentary differentiation in suspended sediment and the hydrodynamic intensity of a drainage system. The heavy mineral differentiation index F revealed sedimentary differentiation of diagnostic detrital mineral composition due to changes in regional hydrodynamic intensity and can serve as an indicator for studying the dynamic sedimentary environment of a single-provenance river and the degree of sedimentary differentiation of its detrital minerals. Changes in detrital mineral content of the Yellow River was not completely controlled by provenance but reflected gravity sorting of the detrital mineral due to variations in the ephemeral river hydrodynamic intensity and sedimentary environment, however the index changing of Yangtze River were mainly influenced by the complex sediment sources. Therefore caution must be exercised in using the detrital mineral composition of marginal sea to determine the contribution of the Yangtze River and Yellow River. | Zhong-bo Wang Ri-hui Li Shou-ye Yang Feng-long Bai Xi Mei Jian Zhang Kai Lu | 2019 | China Geology2019,2,2: | 8 |
| 19 | Quantitative analysis of planation surfaces of the upper Yangtze River in the Sichuan-Yunnan Region, Southwest China显示文摘Identification of the planation surfaces (PSs)is key for utilizing them as a reference in studying the long- term geomorphological evolution of the Upper Yangtze River Basin in the Sichuan-Yurman region,Southwest China.Using a combined method of DEM-based fuzzy logic and topographic and fiver profiles analysis and based on a comprehensive analysis of four morphometfic parameters:slope,curvature,terrain raggedness index, and relative height,we established the relevant fuzzy membership functions,and then calculated the membership degree (MD)of the study area.Results show that patches with a MD>80% and an area>0.4 km^2 correspond well to the results of Google Earth and field investigation,representing the PS remnants.They consist of 1764 patches with an altitude,area,mean slope,and relief of mostly 2000-2500 m above sea level (asl),0-10 km^2,4°-9°,0-500 m,respectively,covering 9.2% of the study area's landscape,dipping to southeast,decreasing progressively from northwest to southeast in altitude,and with no clear relation between each patch's altitude and slope,or relief.All these results indicate that they are remnants of once regionally continuous PSs which were deformed by both the lower crust flow and the faults in upper crust,and dissected by the network of Upper Yangtze River.Additionally,topographic and river profiles analysis show that three PSs (PS1-PS3)well developed along the main valleys in the Yongren-Huili region, indicating several phases of uplift then planation during the Late Cenozoic era.Based on the incision amount deduced from projection of relict river profiles on PSs, together with erosion rates,breakup times of the PS 1,PS2,and PS3 were estimated to be 3.47 Ma,2.19 Ma,and 1.45 Ma,respectively,indicating appearance of modem Upper Yangtze River valley started between the Pliocene to early Pleistocene. | Fenliang LIU Hongshan GAO Baotian PAN Zongmeng LI Huai SU | 2019 | Frontiers of Earth Science2019,13,1: | 7 |
| 20 | Spatial-temporal Analysis of Daily Air Quality Index in the Yangtze River Delta Region of China During 2014 and 2016显示文摘Urban air pollution is a prominent problem related to the urban development in China, especially in the densely populated urban agglomerations. Therefore, scientific examination of regional variation of air quality and its dominant factors is of great importance to regional environmental management. In contrast to traditional air pollution researches which only concentrate on a single year or a single pollutant, this paper analyses spatiotemporal patterns and determinants of air quality in disparate regions based on the air quality index(AQI) of the Yangtze River Delta region(YRD) of China from 2014 to 2016. Results show that the annual average value of the AQI in the YRD region decreases from 2014 to 2016 and exhibit a basic characteristic of ‘higher in winter, lower in summer and slightly high in spring and autumn'. The attainment rate of the AQI shows an apparently spatial stratified heterogeneity, Hefei metropolitan area and Nanjing metropolitan area keeping the worst air quality. The frequency of air pollution occurring in large regions was gradually decreasing during the study period. Drawing from entropy method analysis, industrialization and urbanization represented by per capita GDP and total energy consumption were the most important factors. Furthermore, population agglomeration is a factor that cannot be ignored especially in some mega-cities. Limited to data collection, more research is needed to gain insight into the spatiotemporal pattern and influence mechanism in the future. | YE Lei OU Xiangjun | 2019 | Chinese Geographical Science2019,29,3: | 7 |