The policy of land transfer has greatly influenced the macro economy of China with the commencement of another innovation of land use system. Therefore, it is urgent to put forward some rational and feasible suggestio...The policy of land transfer has greatly influenced the macro economy of China with the commencement of another innovation of land use system. Therefore, it is urgent to put forward some rational and feasible suggestions for local government to manage the market of land transfer. Moreover, it is important in the field of study on agricultural land use change to analyze the spatial differentiation and structural specification of land transfer, which are caused by rural households’ behavior. This paper selected 11 factors covering four aspects of rural households’ family structure, family location, family income structure and the natural quality of land resources, all of which influence the behavior differentiation of rural households, to establish the index model indicating spatial differentiation of land transfer. Results show that the spatial differentiation of land transfer can be divided into four degrees and three categories through analyzing rural households’ questionnaires from Shanghai, Nanjing and Taizhou in the Changjiang (Yangtze) River Delta. Since up to 80% of rural households belong to middle degrees, it can be concluded that the rural land market develops evenly in the study areas. And it is also indicated that the natural quality of land resources and the maximum income of rural land are most important factors influencing the spatial differentiation of land transaction. Considering different factors, the countermeasures can be carried out to enhance the spatial differentiation of land transfer so as to promote economic development and social security of rural China. All in all, both micro- factors and macro-factors influencing rural households’ behavior of rural land transfer should be taken into account in order to make spatial differentiation and structural specification of rural land transfer notable.展开更多
Dating data, altitude of Neolithic sites, climatic changes from sedimentary records and previous research results were collected and analyzed to detect possible connections between climatic changes and human activitie...Dating data, altitude of Neolithic sites, climatic changes from sedimentary records and previous research results were collected and analyzed to detect possible connections between climatic changes and human activities in the Changjiang River Delta in the Neolithic Age. The results indicated that hydrological changes greatly impacted the human activities in the study region. Low-lying geomorphology made the floods and sea level changes become the important factors affecting human activities, especially the altitude change of human settlements. People usually moved to higher places during the periods characterized by high sea level and frequent floods to escape the negative influences from water body expansion, which resulted in cultural hiatus in certain profiles. However, some higher-altitude settlements were not the results of climatic changes but the results of social factors, such as religious ceremony and social status. Therefore, further research will be necessary for the degree and types of impacts of climatic changes on human activities in the study area at that time.展开更多
China is entering a critical and accelerating phase of urbanization.As one of the most urbanized regions in China,the Changjiang(Yangtze)River Delta has experienced dramatic urbanization and urban transformation.Howev...China is entering a critical and accelerating phase of urbanization.As one of the most urbanized regions in China,the Changjiang(Yangtze)River Delta has experienced dramatic urbanization and urban transformation.However,in the recent years,many changes have taken place in this region and there is limited attention to the regional urbanization path evolution,its problems and the way to solve these problems.Therefore,we should revisit the urbanization process in the Changjiang River Delta again.In this paper,we revisited urbanization paths of the Changjiang River Delta by data analysis,influence factors of urbanization by the Gray Relational Analysis,and major challenges to urbanization of the Changjiang River Delta by theoretical considerations.We found that the urbanization of the Changjiang River Delta had experienced several stages of large-scale spatial and urban system restructuring.Within the Changjiang River Delta,Shanghai,Zhejiang and Jiangshu had experienced different urbanization path with local characteristics.But with their development model gradually converging,their urbanization model is also converging.We also found that the major influence factors affecting the Changjiang River Delta urbanization were dynamic change and urbanization was driven by different key factors in different socio-economic development stages.Meanwhile,the Changjiang River Delta urbanization is facing many problems such as existing institutional arrangements,including the hukou(household registration)system and others which can not meet the needs of current socioeconomic development and urbanization.Therefore,it is imperative to promote institutional innovation and adopt a new urbanization development strategy for the sake of the orderly and sustainable urbanization development in the Changjiang River Delta.展开更多
The Changjiang River Delta is a delta of tremendous scale which is formed under the control of tide and tidal currents. The study on the role of tide and tidal currents in the process of formation and development of t...The Changjiang River Delta is a delta of tremendous scale which is formed under the control of tide and tidal currents. The study on the role of tide and tidal currents in the process of formation and development of the Changjiang River Delta can provide a typical example for the ocean-continent interaction process in the east area of our country. The tide and tidal currents in the Bohai Sea, Yellow Sea and East China Sea at the post-glacial transgression maximum are simulated, the sediment transport field in the Paleo-Changjiang River Estuary(PCRE) and its peripheral area at that time is calculated, and the seabed erosion/accretion pattern is obtained according to the divergence of sediment transport rate. The results show that a distinctive wave belly of standing tidal wave existed at the post-glacial transgression maximum and the wave belly lines protruded seawards from the wave belly point in the mouth of the PCRE. Under the wave belly control tidal currents converge to or diverge from the wave展开更多
Seasonal changes in sea level, tidal range, wind, riverine discharges, nearshore SSC (suspended sediment concentration) and bed-level of intertidal flat at 4 different sites were shown. In addition, the statistical re...Seasonal changes in sea level, tidal range, wind, riverine discharges, nearshore SSC (suspended sediment concentration) and bed-level of intertidal flat at 4 different sites were shown. In addition, the statistical relationships between the dynamics and the behavior of the sediment surface were examined. The average intertidal elevation seems negatively correlated to sea level while positively correlated to nearshore SSC. The effect of wind on seasonal cycle of average intertidal elevation is not evident although wind is an important factor governing short-term erosion/accretion events. The influence of riverine discharges on seasonal cycle of deltaic intertidal flats is masked by other factors. It is concluded that seasonality on mudflats is more complicated than on beaches.展开更多
The Changjiang River (Yangtze) is one of the fastest growth areas of container transportation in China. Rail, road and water transportation have competed against each other for container transportation in the Chang-ji...The Changjiang River (Yangtze) is one of the fastest growth areas of container transportation in China. Rail, road and water transportation have competed against each other for container transportation in the Chang-jiang River main line and its delta area. It is of significance to assess these different transportation modes scientifically in order to organize container transportation efficiently in this area and make decision for integral plan and construction of transportation system in this area. This paper outlines application of fuzzy comprehensive evaluation to appraise different modes of typical direction of containers. Twelve assessment indexes were decided. Membership functions were formulated. Evaluation results indicated that road transportation was optimal mode in the Changjiang River delta area, however water transportation was the primary way in the Changjiang River main line.展开更多
River-mouth bar is a fundamental element to constitute a delta system, and its internal facies architectures are vital to reconstruct delta evolution history and study high-resolution sequence stratigraphy. Changxing ...River-mouth bar is a fundamental element to constitute a delta system, and its internal facies architectures are vital to reconstruct delta evolution history and study high-resolution sequence stratigraphy. Changxing Island is a representative mouth-bar complex in the modern Changjiang Delta. Its vertical stacked strata produced by delta progradation were first studied by detailed facies analysis of core CX03, and then a general facies architecture and evolution history of mouth-bar complexes in the modern Changjiang Delta were discussed through a comparative study of 5 different cores and historical charts. A progradational deltaic sequence has generally a similar internal facies architecture, composed of massive muddy deposits of prodelta and delta-front slope facies at the bottom, sand-dominated deposits of delta-front platform, inter-bar channel and mouth-bar facies at the middle, and heterolithic deposits of tidal flat and saltmarsh facies at the top. There is a significant time lag for the initial formation of channel-mouth bar systems between Chongming and Jiuduansha Islands. Compared with subtidal flats, sedimentation rates on intertidal flats were highly accelerated, potentially resulting from weakening wave and tidal strength over extensive intertidal flats and increasing human embankment activities in the last few centuries. These findings provide some new clues to understand modern and ancient mouth-bar evolution and resultant sequence strata in tide-dominated deltas.展开更多
Stable isotopes are increasingly used to investigate seasonal migrations of aquatic organisms. This study employed stable isotopes(δ^(13) and δ15N) for Coilia nasus from the lower Yangtze River and the adjacent East...Stable isotopes are increasingly used to investigate seasonal migrations of aquatic organisms. This study employed stable isotopes(δ^(13) and δ15N) for Coilia nasus from the lower Yangtze River and the adjacent East China Sea to distinguish different ecotypic groups, ascertain trophic nutrition positions, and reflect environmental influences on C. nasus. δ^(13)C signatures of C. nasus sampled from Zhoushan(ZS), Chongming(CM), and Jingjiang(JJ) waters were significantly higher than those from the Poyang Lake(PYL)(P < 0.05). By contrast, δ^(15)Nsignatures of C. nasus in ZS, CM, and JJ groups were significantly lower than those in PYL group(P < 0.05). Basing on δ^(13) and δ^(15)Nsignatures, we could distinguish anadromous(ZS, CM, and JJ) and non-anadromous(PYL) groups. The trophic level(TL) of anadromous C. nasus ranged from 2.90 to 3.04, whereas that of non-anadromous C. nasus was 4.38. C. nasus occupied the middle and top nutrition positions in the marine and Poyang Lake food webs, respectively. C. nasus in Poyang Lake were significantly more enriched in δ^(15)N but depleted in δ^(13), suggesting that anthropogenic nutrient inputs and terrigenous organic carbon are important to the Poyang Lake food web. This study is the first to apply δ^(15)Nand δ^(13) to population assignment studies of C. nasus in the Yangtze River and its affiliated waters. Analysis of stable isotopes(δ^(15)Nand δ^(13)) is shown to be a useful tool for discriminating anadromous and non-anadromous C. nasus.展开更多
This work aims to analyze the spatial and temporal variability of aerosol optical depth (AOD) from 2000 to 2012 in the Changjiang River Delta (CRD), China. US Terra satellite moderate resolution imaging spectrorad...This work aims to analyze the spatial and temporal variability of aerosol optical depth (AOD) from 2000 to 2012 in the Changjiang River Delta (CRD), China. US Terra satellite moderate resolution imaging spectroradiometer (MODIS) AOD and Angstrom exponent (a) data constitute a baseline, with the empirical orthogonal functions (EOFs) method used as a major data analysis method. The results show that the maximum value of AOD observed in June is 1.00±0.12, and the lowest value detected in December is 0.40±0.05. AOD in spring and summer is higher than in autumn and winter. On the other hand, the a-value is lowest in spring (0.86±0.10), which are affected by coarse particles. High a-value appears in summer (1.32±0.05), which indicate that aerosols are dominated by fine particles. The spatial distribution of AOD has a close relationship with terrain and population density. Generally, high AODs are distributed in the lowlying plains, and low AODs in the mountainous areas. The spatial and temporal patterns of seasonal AODs show that the first three EOF modes cumulatively account for 77% of the total variance. The first mode that explains 67% of the total variance shows the primary spatial distribution of aerosols, i.e., high AODs are distributed in the northern areas and low AODs in the southern areas. The second mode (7%) shows that the monsoon climate probably plays an important role in modifying the distribution of aerosols, especially in summer and winter. In the third mode (3%), this distribution of aerosols usually occurs in spring and winter when the prevailing northwestern or western winds could bring aerosol particles from the inland areas into thecentral regions of the CRD.展开更多
基金Under the auspices of the National Natural Science Foundation of China (No. 70373029)
文摘The policy of land transfer has greatly influenced the macro economy of China with the commencement of another innovation of land use system. Therefore, it is urgent to put forward some rational and feasible suggestions for local government to manage the market of land transfer. Moreover, it is important in the field of study on agricultural land use change to analyze the spatial differentiation and structural specification of land transfer, which are caused by rural households’ behavior. This paper selected 11 factors covering four aspects of rural households’ family structure, family location, family income structure and the natural quality of land resources, all of which influence the behavior differentiation of rural households, to establish the index model indicating spatial differentiation of land transfer. Results show that the spatial differentiation of land transfer can be divided into four degrees and three categories through analyzing rural households’ questionnaires from Shanghai, Nanjing and Taizhou in the Changjiang (Yangtze) River Delta. Since up to 80% of rural households belong to middle degrees, it can be concluded that the rural land market develops evenly in the study areas. And it is also indicated that the natural quality of land resources and the maximum income of rural land are most important factors influencing the spatial differentiation of land transaction. Considering different factors, the countermeasures can be carried out to enhance the spatial differentiation of land transfer so as to promote economic development and social security of rural China. All in all, both micro- factors and macro-factors influencing rural households’ behavior of rural land transfer should be taken into account in order to make spatial differentiation and structural specification of rural land transfer notable.
基金Under the auspices of K. C. WANG Education Foundation Hong Kong+1 种基金 the National Postdoctoral Foundation of China and Key Project of Chinese Academy of Sciences (No. KZCX3-SW-331)
文摘Dating data, altitude of Neolithic sites, climatic changes from sedimentary records and previous research results were collected and analyzed to detect possible connections between climatic changes and human activities in the Changjiang River Delta in the Neolithic Age. The results indicated that hydrological changes greatly impacted the human activities in the study region. Low-lying geomorphology made the floods and sea level changes become the important factors affecting human activities, especially the altitude change of human settlements. People usually moved to higher places during the periods characterized by high sea level and frequent floods to escape the negative influences from water body expansion, which resulted in cultural hiatus in certain profiles. However, some higher-altitude settlements were not the results of climatic changes but the results of social factors, such as religious ceremony and social status. Therefore, further research will be necessary for the degree and types of impacts of climatic changes on human activities in the study area at that time.
基金Under the auspices of National Social Science Project(No.08BJY048:11CRK005)Humanities and Social Sciences of Ministry of Education(No.11YJA630176)
文摘China is entering a critical and accelerating phase of urbanization.As one of the most urbanized regions in China,the Changjiang(Yangtze)River Delta has experienced dramatic urbanization and urban transformation.However,in the recent years,many changes have taken place in this region and there is limited attention to the regional urbanization path evolution,its problems and the way to solve these problems.Therefore,we should revisit the urbanization process in the Changjiang River Delta again.In this paper,we revisited urbanization paths of the Changjiang River Delta by data analysis,influence factors of urbanization by the Gray Relational Analysis,and major challenges to urbanization of the Changjiang River Delta by theoretical considerations.We found that the urbanization of the Changjiang River Delta had experienced several stages of large-scale spatial and urban system restructuring.Within the Changjiang River Delta,Shanghai,Zhejiang and Jiangshu had experienced different urbanization path with local characteristics.But with their development model gradually converging,their urbanization model is also converging.We also found that the major influence factors affecting the Changjiang River Delta urbanization were dynamic change and urbanization was driven by different key factors in different socio-economic development stages.Meanwhile,the Changjiang River Delta urbanization is facing many problems such as existing institutional arrangements,including the hukou(household registration)system and others which can not meet the needs of current socioeconomic development and urbanization.Therefore,it is imperative to promote institutional innovation and adopt a new urbanization development strategy for the sake of the orderly and sustainable urbanization development in the Changjiang River Delta.
基金Supported by the Marine Public Welfare Research Project(No.200805063)the National Natural Science Foundation of China(Nos.41076023 and 41106065)+1 种基金the Basic Fund Project of National Science and Technology Ministry(No.2008FY220300)the Coastal Investigation and Research Project of China(No.908-02-02-05)
文摘自从迟了的更新世,水下的 Changjiang (Yangtze ) 河三角洲的沉积外形为二地上凿穿, CJK07 和 CJK11 基于岩性学和有孔虫类分析被学习,与标明日期的 14C 一起。四沉积外形被识别的、也就是河的、潮汐的公寓,近海,并且 prodelta 外形。河的沉积外形由河的隧道组成落后扔,河的点酒吧扔,并且泛滥平原扔没有 benthic 有孔虫类一般来说显示出一个鳍向上的序列。生硬泥土的层在核心 CJK07 躺河的存款,显示在最后冰川的最大值(LGM ) 期间的长期的暴露环境。在在 13-7.5 cal ka BP 附近的冰期后的海平面的上升期间,潮汐的扁平的外形在核心 CJK11 被扔,由丰富的淤泥泥土两行诗描绘了。能在不同盐分之环的种类统治 subtidal 公寓有孔虫目的集合,当几乎没有有孔虫类完全在 intertidal 被发现时。近海当海水平在 7.5 cal ka BP 附近到达了它的高水平时,环境是主要沉积环境,与 10 的最大的累积率, mm/a 在核心 CJK11 发现了。自从 3 cal ka BP, Prodelta 沉积在核心 CJK11 被扔了,在 Changjiang 河三角洲的形成以后。在在核心 CJK07 和 CJK11 之间的沉积外形的差别由于他们的地点:当核心 CJK11 在 LGM 期间在一条切入的山谷时,核心 CJK07 在一块河间地。而且,核心 CJK07 标明日期的 AMS 14 C 给穷人看按年代先后的顺序,显示沉积被自从在核心 CJK07 的 7.7 cal ka BP 被 Changjiang 河三角洲 depocenter 的向南方的移动引起的现代水动力学力量离开侵蚀,扔的强壮的潮汐的水流和那沉积重做。
文摘The Changjiang River Delta is a delta of tremendous scale which is formed under the control of tide and tidal currents. The study on the role of tide and tidal currents in the process of formation and development of the Changjiang River Delta can provide a typical example for the ocean-continent interaction process in the east area of our country. The tide and tidal currents in the Bohai Sea, Yellow Sea and East China Sea at the post-glacial transgression maximum are simulated, the sediment transport field in the Paleo-Changjiang River Estuary(PCRE) and its peripheral area at that time is calculated, and the seabed erosion/accretion pattern is obtained according to the divergence of sediment transport rate. The results show that a distinctive wave belly of standing tidal wave existed at the post-glacial transgression maximum and the wave belly lines protruded seawards from the wave belly point in the mouth of the PCRE. Under the wave belly control tidal currents converge to or diverge from the wave
基金This work was supported by the National Natural Science Foundation of China (Grant No. 40076027) the National Excellent Youths Foundation of China (Grant No. 49825161) the Ministry of Education of China.
文摘Seasonal changes in sea level, tidal range, wind, riverine discharges, nearshore SSC (suspended sediment concentration) and bed-level of intertidal flat at 4 different sites were shown. In addition, the statistical relationships between the dynamics and the behavior of the sediment surface were examined. The average intertidal elevation seems negatively correlated to sea level while positively correlated to nearshore SSC. The effect of wind on seasonal cycle of average intertidal elevation is not evident although wind is an important factor governing short-term erosion/accretion events. The influence of riverine discharges on seasonal cycle of deltaic intertidal flats is masked by other factors. It is concluded that seasonality on mudflats is more complicated than on beaches.
文摘The Changjiang River (Yangtze) is one of the fastest growth areas of container transportation in China. Rail, road and water transportation have competed against each other for container transportation in the Chang-jiang River main line and its delta area. It is of significance to assess these different transportation modes scientifically in order to organize container transportation efficiently in this area and make decision for integral plan and construction of transportation system in this area. This paper outlines application of fuzzy comprehensive evaluation to appraise different modes of typical direction of containers. Twelve assessment indexes were decided. Membership functions were formulated. Evaluation results indicated that road transportation was optimal mode in the Changjiang River delta area, however water transportation was the primary way in the Changjiang River main line.
基金funded by the National Natural Science Foundation of China(Nos.41776052,41476031)the China-ASEAN Maritime Cooperation Fund,the National Programme on Global Change and Air-Sea Interaction(No.GASI-GEOGE-03)the Open Research Fund of State Key Laboratory of Estuarine and Coastal Research(No.SKLEC-KF201506)
文摘River-mouth bar is a fundamental element to constitute a delta system, and its internal facies architectures are vital to reconstruct delta evolution history and study high-resolution sequence stratigraphy. Changxing Island is a representative mouth-bar complex in the modern Changjiang Delta. Its vertical stacked strata produced by delta progradation were first studied by detailed facies analysis of core CX03, and then a general facies architecture and evolution history of mouth-bar complexes in the modern Changjiang Delta were discussed through a comparative study of 5 different cores and historical charts. A progradational deltaic sequence has generally a similar internal facies architecture, composed of massive muddy deposits of prodelta and delta-front slope facies at the bottom, sand-dominated deposits of delta-front platform, inter-bar channel and mouth-bar facies at the middle, and heterolithic deposits of tidal flat and saltmarsh facies at the top. There is a significant time lag for the initial formation of channel-mouth bar systems between Chongming and Jiuduansha Islands. Compared with subtidal flats, sedimentation rates on intertidal flats were highly accelerated, potentially resulting from weakening wave and tidal strength over extensive intertidal flats and increasing human embankment activities in the last few centuries. These findings provide some new clues to understand modern and ancient mouth-bar evolution and resultant sequence strata in tide-dominated deltas.
基金financially supported by the Special Fund for Agro-scientific Research in the Public-Interest(Grant No.201203065)the National Natural Science Foundation of China(Nos.31172407+1 种基金1472280)the Specialized Research Fund for the Doctoral Program of Higher Education(No.20123104110006)
文摘Stable isotopes are increasingly used to investigate seasonal migrations of aquatic organisms. This study employed stable isotopes(δ^(13) and δ15N) for Coilia nasus from the lower Yangtze River and the adjacent East China Sea to distinguish different ecotypic groups, ascertain trophic nutrition positions, and reflect environmental influences on C. nasus. δ^(13)C signatures of C. nasus sampled from Zhoushan(ZS), Chongming(CM), and Jingjiang(JJ) waters were significantly higher than those from the Poyang Lake(PYL)(P < 0.05). By contrast, δ^(15)Nsignatures of C. nasus in ZS, CM, and JJ groups were significantly lower than those in PYL group(P < 0.05). Basing on δ^(13) and δ^(15)Nsignatures, we could distinguish anadromous(ZS, CM, and JJ) and non-anadromous(PYL) groups. The trophic level(TL) of anadromous C. nasus ranged from 2.90 to 3.04, whereas that of non-anadromous C. nasus was 4.38. C. nasus occupied the middle and top nutrition positions in the marine and Poyang Lake food webs, respectively. C. nasus in Poyang Lake were significantly more enriched in δ^(15)N but depleted in δ^(13), suggesting that anthropogenic nutrient inputs and terrigenous organic carbon are important to the Poyang Lake food web. This study is the first to apply δ^(15)Nand δ^(13) to population assignment studies of C. nasus in the Yangtze River and its affiliated waters. Analysis of stable isotopes(δ^(15)Nand δ^(13)) is shown to be a useful tool for discriminating anadromous and non-anadromous C. nasus.
文摘This work aims to analyze the spatial and temporal variability of aerosol optical depth (AOD) from 2000 to 2012 in the Changjiang River Delta (CRD), China. US Terra satellite moderate resolution imaging spectroradiometer (MODIS) AOD and Angstrom exponent (a) data constitute a baseline, with the empirical orthogonal functions (EOFs) method used as a major data analysis method. The results show that the maximum value of AOD observed in June is 1.00±0.12, and the lowest value detected in December is 0.40±0.05. AOD in spring and summer is higher than in autumn and winter. On the other hand, the a-value is lowest in spring (0.86±0.10), which are affected by coarse particles. High a-value appears in summer (1.32±0.05), which indicate that aerosols are dominated by fine particles. The spatial distribution of AOD has a close relationship with terrain and population density. Generally, high AODs are distributed in the lowlying plains, and low AODs in the mountainous areas. The spatial and temporal patterns of seasonal AODs show that the first three EOF modes cumulatively account for 77% of the total variance. The first mode that explains 67% of the total variance shows the primary spatial distribution of aerosols, i.e., high AODs are distributed in the northern areas and low AODs in the southern areas. The second mode (7%) shows that the monsoon climate probably plays an important role in modifying the distribution of aerosols, especially in summer and winter. In the third mode (3%), this distribution of aerosols usually occurs in spring and winter when the prevailing northwestern or western winds could bring aerosol particles from the inland areas into thecentral regions of the CRD.