SPATIAL DIFFERENTIATION OF LAND TRANSFER——Case Study of Shanghai, Nanjing and Taizhou in Changjiang River Delta

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 I l 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.

ENVIRONMENTAL CHANGE AND ITS IMPACTS ON HUMAN SETTLEMENT IN THE CHANGJIANG RIVER DELTA IN NEOLITHIC AGE

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.

Revisiting and Rethinking Regional Urbanization in Changjiang River Delta,China

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.

Sedimentary facies of the subaqueous Changjiang River delta since the late Pleistocene

The sedimentary facies of the subaqueous Changjiang （Yangtze） River delta since the late Pleistocene was studied based on lithology and foraminifera analysis for two boreholes, CJK07 and CJK11, along with 14C dating. Four sedimentary facies were identified, namely fluvial, tidal flat, offshore, and prodelta facies. The fluvial sedimentary facies is comprised of fluvial channel lag deposits, fluvial point bar deposits, and floodplain deposits, showing a fining-upward sequence in general with no benthic foraminifera. A layer of stiff clay overlies the fluvial deposits in core CJK07, indicating a long-term exposure environment during the Last Glacial Maximum （LGM）. During the postglacial sea-level rise around 13-7.5 cal ka BP, the tidal flat facies was deposited in core CJK11, characterized by abundant silt-clay couplets. Euryhaline species dominate the subtidal fiat foraminiferal assemblages, while almost no foraminifera was found in the intertidal fiat. The offshore environment was the major sedimentary environment when the sea level reached its highest level around 7.5 cal ka BP, with a maximum accumulation rate of 10 mm/a found in core CJK11. Prodelta sediments have been deposited in core CJK11 since -3 cal ka BP, after the formation of the Changjiang River delta. The difference in sedimentary facies between core CJK07 and CJK11 is due to their location： core CJK07 was in an interfluve while core CJK11 was in an incised valley during the LGM. Furthermore, AMS 14C dating of core CJK07 shows poor chronological order, indicating that the sediments were reworked by strong tidal currents and that sediment deposited since -7.7 cal ka BP in core CJK07 was eroded away by modem hydrodynamic forces caused by the southward shift of the Changjiang River delta depocenter.

Study on the Role of Tidal Currents in the Process of Formation and Development of the Changjiang River Delta

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

FUZZY COMPREHENSIVE EVALUATION OF CONTAINER TRANSPORTATION MODES ALONG THE CHANGJIANG RIVER MAIN LINE AND ITS DELTA AREA

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.

Seasonal changes in coastal dynamics and morphological behavior of the central and southern Changjiang River delta

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.

FACTORIAL ANALYSIS OF ANNUAL EROSION-ACCRETION CYCLES OF TIDAL FLATS IN THE FRONT AREA OF THE SOUTHERN CHANGJIANG RIVER DELTA

Based on surveyed data from seven coastal sections and the collected data of wind, sea level, tide, nearshore suspended sediment concentration and river flux from adjacent stations, this paper deals with regressive correlation between monthly average flat elevation and monthly average figures of the influential factors. All sections except one which is located within the river mouth showed negative correlation between flat elevation and sea level and between flat elevation and tidal range, with correlation coefficients being 0.53- 0.91(-0.77 on the average) in the former condition and 0.56- 0.97 (-0.80 on the average) under the latter. Each of the sections with available suspended sediment concentration (SSC) data shows a positive correlation between flat elevation and SSC, with correlative coefficients being 0.35-0.97 (0.66 on the average). Only two sections (one in the Changjiang River Estuary and the other in the Hangzhou Bay) which are similar to beaches in sediment grain size and slope gradient showed a negative correlation between flat elevation and onshore wind frequency and between flat elevation and average wind velocity, with correlative coefficients being respectively -0.57 and -0.69 (-0.63 on the average) in the former situation and -0.61 and -0.75 (-0.68 on the average) in the latter. Other sections did not show uniform relationship between flat elevation and wind conditions. Due to local marine factors the nearshore SSC in the studied area is negatively correlated with the Changjiang River sediment flux (r=-0.78), which results in false negative correlation between flat elevation and river sediment flux. The paper also gives sediment dynamic and morphodynamic explanation for the above correlations. Sea level rise results in the spread of breaker zone from subtidal area to intertidal area and then increases the intertidal water energy. The larger the tidal range, the stronger the tide currents and the easier for the flat to be eroded. The higher the SSC of flood water, the easier for the sediment to deposit down. Because of correlations among the influential factors, it is difficult to give the prime one which dominates the erosion and accretion processes in tidal flats.

THE INVESTMENT CIRCUMSTANCES AND ITS CLASSIFICATION APPRAISAL OF CHANGJIANG RIVER DELTA

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Internal Facies Architecture and Evolution History of Changxing Mouth-Bar Complex in the Changjiang(Yangtze)Delta,China

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.

Analysis of spatio-temporal variability of aerosol optical depth with empirical orthogonal functions in the Changjiang River Delta, China

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.

成渝双城经济圈与长三角地区医疗合作比较

比较成渝双城经济圈与长三角地区在医疗合作目标、医疗资源存量、医疗机构合作、医保合作、应急医疗合作、医疗科技合作等方面的差异和特点,提出成渝双城经济圈医疗合作要以优化医疗资源配置、推动优质资源下沉为主要目标,优先推动医保一体化,加强双城医疗技术合作,鼓励社会力量办医等建议。

长三角地区低碳经济发展水平及空间相关性研究

为推动我国低碳经济发展,基于低碳经济相关内涵构建DPSIRM低碳经济评价指标体系,使用熵权TOPSIS法对长三角地区41个城市低碳经济发展水平进行测度与分析。研究发现:2010-2014年长三角地区低碳经济发展水平出现倒退,2015-2019年发展情况逐渐好转;省域低碳经济发展水平对比可见,上海最优,江苏省和浙江省为第二梯队,安徽省综合表现欠佳;近十年长三角地区65.85%的城市低碳经济发展处于低水平区。以上结果显示长三角地区低碳经济发展水平差异较大且整体偏低。

长江三角洲南部地区晚更新世年代地层和海水进退

根据长江三角洲晚第四纪 4个钻孔详细的测年和微体古生物分析结果 ,对该区约 110kaBP来的地层进行了年代学划分 ,并且重建了晚更新世海侵海退过程。研究发现 ,形成于 12 0～ 110kaBP的蓝灰色硬土是本区晚更新世底界的标志 ,而晚更新世顶界的标志是形成于 17～ 10kaBP的暗绿色或棕黄色硬土。晚更新世早期 110～ 6 0kaBP间 ,本区主要发育河流相的含砾砂 ,但其中 10 0～ 80kaBP间发生一次较弱海侵 ,以溺谷相沉积为主。晚更新世中期 6 0～ 2 2kaBP ,沉积物经历粗 -细 -粗 3个阶段 ,分别是 6 0～ 4 0、4 0～ 34和 34～ 2 2kaBP。其中第 2阶段在西部地区出现硬土层 ,而中东部地区 6 0～ 2 2kaBP期间海侵层连续 ,且在 4 3～ 4 0和 34～ 2

长三角城市群重心移动及其驱动因素研究

长三角城市群在整个中国的区域发展战略中具有十分重要的地位,为深入把握这一地区发展的空间变化态势、更好地指导长三角地区的发展实际,在测算和分析1994～2004年间长三角城市群重心位置及其变化趋势的基础上,深入探讨了近些年长三角城市群重心移动的驱动因素。结果显示,1994年以来,长三角地区的城市群重心向西北方向移动了超过20 km,重心所在位置由苏州和嘉兴的交界处移至苏州市中心附近。而从其变化的趋势来看,未来的城市群重心仍将偏向西北方向,落到苏州和无锡的交界地带。这种态势的出现主要是由于长三角内部各城市受到其自然和区位条件、经济发展以及社会环境等诸多因素的影响,使得其发展呈现出一定的差异性,进而驱动了各城市不同程度的发展及其在整个长三角地区地位的转变,并最终致使城市群重心向自然区位条件优越、经济社会发展较快的西北方向移动。

海平面上升对长江三角洲附近沿海潮滩和湿地的影响

于1988-1991年，对长江三角洲附近沿海潮滩和湿地进行较全面的调查，利用高程-面积法、沉积速率法，井引进未来冲淤趋势参数，对全区14个典型潮滩断面进行海平面上升影响的估算。结果表明，当海平面上升0．5m和1．0m时，全区潮滩面积分别比1990年的减少9．2％和16.7％；湿地面积减少20％和28％，并发生高级类型向低级类型的逆向演替。各岸段损失率相差悬殊，以侵岸段较大，淤涨岸段将减缓淤涨，甚至转为侵蚀。

都市圈旅游空间结构演变研究——以长三角都市圈为例

旅游空间结构演变研究,对优化都市圈旅游空间结构、促进都市圈整体旅游地形成和发挥都市圈旅游空间效应与功能有重要意义。以旅游人数和旅游收入为指标,利用赫芬达尔指数和位序—规模模型进行分析,并结合长三角都市圈旅游发展实际考察其旅游空间结构演变态势。结果表明,长三角都市圈旅游者和旅游收入空间分布趋向分散,各城市旅游发展相对差异不断缩小,其旅游发展趋向均衡化。长三角都市圈旅游发展实际也显示,其旅游空间结构呈现多中心、网络化和一体化特点。从长期来看,长三角都市圈旅游空间结构演变趋向高水平均衡。借鉴空间相互作用理论,认为以可达性、互补性和替代性为必要条件,以集聚和扩散作用为主要形式,以资金、技术、人员、信息和经验等的流动为主要内容,各城市旅游空间相互作用推动了都市圈旅游空间结构不断由低水平均衡向高水平均衡演变。旅游企业扩张和旅游客流流动带动了旅游资金、技术、人员、信息和经验等的集聚和扩散,推动了都市圈旅游空间结构演变。

城市旅游竞争潜力时空格局演化及其结构合理性评价——以长江三角洲地区为例

选取资源产品竞争力、市场服务竞争力、旅游保障竞争力三大指标体系,采用熵值法赋予权重,对长三角城市旅游竞争潜力进行横向上的测度,引入SSM模型,纵向测算1998～2008年城市旅游竞争潜力指标要素的结构偏离分量和竞争力偏离分量,在此基础上,评价指标要素的结构效果指数和竞争力效果指数。结果表明:长三角城市旅游竞争潜力时空格局上存在显著差异,表现为以上海、南京、杭州、苏州为中心的城市旅游竞争潜力较高,始终处于区域的高值状态,形成四强鼎立的空间格局,城市间旅游竞争潜力差异呈现扩大化,指标要素的结构上存在不合理,与之相对应的旅游竞争潜力并不完全匹配。通过横向纵向两方面清晰的对比反映不同城市旅游竞争潜力指标的弱项和缺陷,客观准确地表现不同城市旅游竞争潜力大小,为长三角地区不同城市提升旅游竞争潜力提供定量依据与理论参考。

基于分形的城市体系经济规模等级演变研究

利用区域城市体系经济规模等级分形理论,选取长江三角洲1995-2009期间4个年份的县级以上行政单位经济发展数据,计算了经济规模等级分形维数。以该地区城市体系经济规模等级分形维数的演变特征为载体,探讨了长江三角洲地区城市体系经济规模等级演变规律。结果表明：①虽然当前长三角地区各城市的经济社会发展水平差异较大,中心城市垄断性仍然较强,但其均匀化趋势明显。②经济规模等级的空间梯度特征明显,经济规模等级的均匀性随着距离区域核心城市距离的扩大而降低。③产业空间布局层次化逐步分明,中心城市的第三产业比重不断提升,区域控制能力不断增强,与以第二产业为主导的中小城市形成有机整体,区域经济竞争力整体得到提升。