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1.
Most scientific attention on port studies centers on deep sea ports, especially container ports. In this paper, in contrast, attention is focused on the spatial–temporal development of inland waterway ports on the Midstream Yangtze River from 2001 to 2013. The aim of this study is to assess two relevant and complementary questions of the hinterland evolution: its geographical extent and the coordination relationship with the inland port. To conduct the study, it was necessary to first identify the boundaries of the ports' hinterlands within the given timeframe. Then, the coupling coordination degree model was introduced to explore the underlying relationship between the port service and hinterland economy. Furthermore, to better depict the intricate economic characteristics of the hinterland, the development stage theory was applied in the models. The results highlight the emergence of a discontinuous hinterland at Wuhan Port and its reinforcement of primacy with respect to fierce hinterland rivalry. It also demonstrates that an interplay between major ports and their corresponding hinterlands evolves from the transitional stage, characterized by lagging port service, to the multi‐stage, wherein the supply of ports partly outstrips hinterland demand. 相似文献
2.
Xingxing Jin Guojian Hu Hailong Ding Shilin Ye Yuqi Lu Jinhuang Lin 《Growth and change》2020,51(2):833-851
The pledge of stock rights is a method for measuring the external horizontal connections of enterprises, which is more suitable to represent the city network compared with the vertical connections of enterprises. Meanwhile, it is greatly significant to express the relationships of regional spaces. The paper characterizes and explores the evolution of urban spatial structure with complex network research methods to enrich the relevant works on city networks in the Yangtze River Economic Belt from 2011 to 2017. The results are as follows: First, from 2011 to 2017, the pledge of stock rights among cities was enhanced significantly, and the trend of the city networks' characteristics become strengthened and more complicated. Second, cities in the Yangtze River Delta have relatively high connection values, however, cities in the western area are holding peripheral positions within the city network. Third, due to the advantages of economic agglomeration and radiation, the provincial capital have become the core nodes in the city network. Fourth, Shanghai, Hangzhou, and Nanjing have dominant positions within city networks in the Yangtze River Economic Belt. Particularly, Shanghai, as one of the leading financial centers in China, has a growing influence on other cities and gradually evolved into a regional growth pole city and the first core city. 相似文献
3.
The past decade has witnessed a blossoming of megaregional plans throughout China. However, it is still unclear whether megaregions delineated in these plans are based on a functionally integrated foundation or imagined by the government. This study takes the Central Yangtze River Megaregion (CYRM)—a cross-jurisdictional megaregion planned as a leading regional integration platform in Central China—as a case to examine the mismatch between the governmentally designated regions and functionally integrated regions. Specifically, this research employs the community detection algorithm to identify functionally integrated regions within the CYRM based on producer services networks, then associate the formation of these network-based regions with territorial factors. The results show that the integration of identified first-tier functional regions is subject to the provincial administrative divisions; whereas, the locally planned regions comply with the second-tier functionally integrated regions spatially. Besides, the regression results indicate that the territorial factors are significantly associated with the above spatial patterns. Hence, the region-making practices initiated by the local governments rather than the central government, are more consistent with the conditions of regional economic development. 相似文献
4.
Port competition in the Yangtze River Delta 总被引：1，自引：0，他引：1
Abstract: This paper canvasses the port development of the Yangtze River Delta. Initially, we consider changes in container trade in the region since the 1990s. Competition between the ports of Ningbo and Shanghai are studied by measuring the overlapping hinterland of container distribution for Zhejiang province. We then analyse the strategies pursued by international carriers and terminal operators to secure success in this increasingly competitive environment. 相似文献
5.
Based on the analysis of the water pollution spatial distribution characters of Yangtze River in Chongqing,a new method based on the integration of BP neural network and genetic arithmetic(GA) is proposed.For some shortcomings existed in the standard BP neural network,this method has ultimately overcome these shortcomings by combining the GA with BP artificial neural network through altering stimulating function,adding momentum factor to power value for BP algorithm and introducing genetic arithmetic to searching for the knots of the hidden layer,momentum factor and learning level.Using this method can easily overcome the difficulty of measuring the water prediction model's parameters.GIS is used as a tool for data management and spatial analysis,and the prediction result of the model for the water pollution spatial distribution characters of Yangtze River in Chongqing is visualized and explored with the precision of more than 78%. 相似文献
6.
[摘要]明清时期,黄淮合流,东入黄海,但黄河所携巨量泥沙逐渐淤塞中下游河床,汛期无法迅速泄水,淮河改道南下入江,变为长江支流。淮河南下,不仅给当地百姓的生命财产等造成重大损失,而且对周边环境造成重大影响,南下的淮河洪泽湖至长江段两岸,湖泊扩大、河流改道、土质恶化,甚至加剧了沿江地区的江岸崩塌,引发整个周边环境发生了沧海桑田的巨变。 相似文献
7.
基于DEM 的重庆长江流域水系分维估算 总被引：2，自引：0，他引：2
摘要：基于数字高程模型,本文利用ArcGIS9.3的水文分析模块,根据不同的集水面积阈值, 提取了重庆长江流域河网信息,通过网格法计算了相应的水系分维。根据集水面积阈值与水系分维的相互关系, 确定该流域水系分维值为1. 036,经计算得到的河网特征以及流域信息与实际河流水系特征及流域信息基本吻合。 相似文献
8.
研究旨在对长江下游微生物群落代谢多样性以及环境因子对它的影响进行分析,以期为长江下游地区生态环境的改善及修复做参考。通过Biolog-ECO技术分析了长江下游各江段水体微生物代谢多样性,探究各江段水质理化因子变化与微生物群落代谢多样性的关系。研究发现长江下游水质指标除TP、TN外,其他指标均符合Ⅱ类以上标准;微生物群落的整体代谢能力南京江段最强;微生物群落丰富度指数在南京江段最高;多样性指数与均匀度指数由高到低排列顺序为安庆江段、南京江段、靖江江段、铜陵江段、芜湖江段;RDA分析表明,水体理化因子TP、Pb对长江微生物代谢六大类碳源呈现正相关关系。综合水质指标和各江段微生物代谢多样性分析,长江下游水体安庆江段和南京江段的富营养化程度较高,TP、Pb对长江下游水体微生物群落代谢多样性具有促进作用。 相似文献
9.
长江中下游地区循环农业的发展 总被引：1，自引：1，他引：0
为长江中下游地区进一步开展循环农业的相关研究及制定相关政策,实现长江中下游地区循环农业的可持续发展,本研究系统阐述了长江中下游地区在我国农业发展中的重要地位及该地区循环农业具有历史悠久性、结构复杂性、模式多样性、技术先进性、功能高效性、发展可持续性等显著特征。并指出当前长江中下游地区存在着资源浪费、生态破坏、环境污染、劳力缺乏、意识淡薄、机制缺失等方面的问题,严重制约着循环农业的可持续发展。针对以上存在的问题,提出了今后在长江中下游地区推进循环农业应采取以下对策和措施：（1）提高认识;（2）制定规划;（3）完善制度;（4）增加投入;（5）培养人才;（6）扩大规模;（7）延长链条;（8）加强研发。 相似文献
10.
三峡库区(重庆段)植被覆盖变化分析及评价 总被引：1，自引：0，他引：1
摘要：为分析三峡库区（重庆段）植被及植被变化，利用2000—2015年MODIS 3级归一化植被指数16日合成产品MOD13A1，分析了长江沿线重庆段22区县植被指数的时空分布特征及变化趋势，结果表明：（1）在三峡库区蓄水后，长江沿线的植被表现为向好趋势，植被生长环境也有所改善，长江沿线东部地区，植被好转尤为明显。（2）距河道越远的区域，植被覆盖和植被环境越好。从行政区划角度看，东部区域植被生态环境最好，其次是中部区域、西部区域，主城区植被及生态环境较其余3个区域略显不足。植被好的区县（地区），平均高度值偏大。（3）三峡大坝完成175 m蓄水后较蓄水前（2000—2003年阶段），三峡库区175m蓄水后，远离河道区域，植被指数在春、秋、冬季节呈现增加趋势，夏季被指数呈减小趋势；近河道区域，植被指数在春季降低、秋季增加，夏、冬季有增有减。由于夏季全河道处于雨季，降雨偏多，河道会长期处于洪峰或高水位过程，河道被淹没的区域扩大;加之三峡蓄水后，夏秋季节河道上空薄云、碎云等云雾增加，即使夏半年三峡库区处于放水阶段，夏秋季节植被指数仍略有减小的趋势。冬半年河道基本不会出现高水位，河道内裸露土增加, 适于植被生长. 冬半年虽然处于蓄水阶段，但植被指数仍有增加趋势。 相似文献
11.
皖江地区湿地生态服务价值评估 总被引：4，自引：0，他引：4
皖江地区湿地是长江中下游流域的重要湿地,也是安徽省水网集中分布区,河流水系众多、湖泊库塘星罗棋布。【研究目的】通过对皖江地区湿地生态服务价值的估算,期望为有关部门进行区域规划和合理利用湿地资源提供科学依据;【方法】在调查和资料收集的基础上,参考Costanza等提出的17项生态系统服务功能,利用市场价值法、资产价值法、影子工程法、旅行费用法等评估方法,对皖江地区湿地9项生态服务价值进行了评估。【结果】表明：皖江地区湿地生态服务总价值为1061.21亿元/a,其中固碳价值最高,达434.22亿元/a,其次是水文调节价值、物质生产价值和净化环境价值,分别达到220.75亿元/a、163.50亿元/a和108.13亿元/a,再次是释放O2价值、供水蓄水价值和休闲旅游价值,最小的是文化科研和栖息地价值;皖江地区湿地直接价值214.84亿元/a,间接价值846.37亿元/a,间接价值远远大于直接价值。【结论】并提出了湿地的固碳功能对于全球气候变暖有很大的影响,应合理开发利用和保护湿地资源。 相似文献
12.
长江、青弋江芜湖段水体总有机碳含量及其影响因素的研究 总被引：1，自引：0，他引：1
地面环境水体中有机物数量是反映水体有机物污染程度的重要指标。为了了解长江、青弋江芜湖段水体有机物污染状况和水体质量,本文通过对长江、青弋江芜湖段水体周围环境状况现场考察,并分段采取了代表性水体样品,采用高温燃烧—非色散红外吸收法测定了水样总有机碳（TOC）含量,研究了其总有机碳含量变化及其影响因素。结果表明,长江、青弋江芜湖段水体中总TOC含量平均值分别为22.2±4.1 mg/L和22.6±2.7 mg/L,处于较高水平,青弋江个别区域TOC含量超过了40 mg/L。长江、青弋江芜湖段水体TOC的浓度均已超过国家一级标准,青弋江某些河段TOC浓度已远远超过了二级标准。 相似文献
13.
论长江经济带农业绿色发展 总被引：1，自引：0，他引：1
长江经济带发展是中国正在实施的五大区域协调发展战略之一。“生态优先、绿色发展”、“共抓大保护、不搞大开发”已成为长江经济带发展的主旋律和鲜明导向。长江经济带农业在中国农业及整个经济发展战略中占有极其重要的战略地位和举足轻重的作用。推动长江经济带农业绿色发展,已成为长江经济带绿色发展的重要内容和有力抓手,是全国上下共同面临的紧迫任务。当前,长江经济带农业绿色发展面临着诸多问题与挑战,如资源浪费、生态破坏、环境污染、灾害频发和农业生态系统退化等。为实现长江经济带农业绿色发展,应针对上述问题采取以下对策与措施：（1）充分利用耕地,全年绿色覆盖;（2）减少化肥施用,扩大生物养地;（3）加强绿色防控,实施生态减灾;（4）发展循环农业,“废物”再生利用;（5）实行“九良”配套,实现综合发展,即将良田、良制、良种、良法、良物、良境、良品、良策、良才相互协调和配合,共同推动长江经济带农业综合发展、全面发展、绿色发展、高质量发展和可持续发展。 相似文献
14.
The discussion on innovation networks of patents or papers has attracted many economic geographers; however, the Industrial Technology Innovation Strategy Alliance (ITISA) has been ignored, although it is also an important innovation form of firms, and the formation mechanism of alliance innovation networks is unclear. This study is based on the data of Shanghai high‐tech ITISAs between 2010 and 2015, and employs the methods of social networks and negative binomial regression to analyse the actor structure, spatial structure, and proximity mechanism of innovation networks of Shanghai high‐tech ITISAs. Results highlight the following: (a) Firms comprise the largest number of actors in alliance innovation networks, and universities, research institutions, and industry associations also play some roles. (b) The local and rooted characteristics of the innovation networks of ITISAs are obvious. The spatial distribution of innovation partners is mainly in Shanghai, and a few innovation actors are located in neighbouring cities, such as Suzhou, Hangzhou, and Ningbo in the Yangtze River Delta Urban Agglomeration. (c) Proximity significantly promotes the formation of innovation networks in an ITISA and contributes to the improvement of innovation ability, and organizational proximity plays a greater role than geographical proximity or cognitive proximity. 相似文献
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16.
Much of the literature on the location of producer services is concerned with their uneven spatial development across regions. Although this approach is useful, it proves to be limited, and a complementary analytical framework is required. This paper uses data from France's Annual Survey of Services to address producer service location from a novel perspective, that of the firm. A basic distinction is made between single site (compact) and multisite (network) producer service firms, and the natures of these two types are analyzed in terms of business strategies, location and performance. Further analyses are then based upon the distinctions between sales and servuction networks, and between specialized and diversified networks. Although significant for producing higher output levels, a network structure does not necessarily ensure a higher level of profitability. 相似文献
17.
长江经济带是中国经济社会发展水平较高的战略发展区域,现代化的农业生产方式为农业土地的可持续利用带来严重的压力,本研究旨在为长江经济带高质量、绿色发展提供科学依据、数据支撑与合理建议。本研究基于能值分析方法,通过对长江经济带2010—2018年投入产出项目计算并构建能值效率指标体系,对该地区农业投入产出的能值结构和效率进行深入研究。结果表明,长江经济带在2010—2018年间总能值投入和总能值产出均呈上升趋势,总能值产出始终低于投入,不可更新工业辅助能投入占比较高,农业土地利用结构不合理,资源利用效率较低,农业系统到2018年已发展为轻度不可持续状态,其中在这9年间对农业可持续状况影响最大的因素是投入结构。因此长江经济带需要积极调整农业投入结构,减小对外界辅助能值尤其是不可更新工业辅助能的依赖,提高资源利用效率,才能最终实现农业的可持续发展。 相似文献
18.
2009年秋季长江安徽-江苏段浮游植物群落的种类组成与空间特征 总被引：1，自引：0，他引：1
为了更好地了解长江安徽-江苏段浮游植物资源现状,并为该江段的生态环境评价和综合开发利用提供一定科学依据。根据种类组成、数量分布、生物量分布以及Mcnaughton优势度指数等多项生物学指标,分析浮游植物群落结构,并应用聚类分析法研究长江安徽-江苏段浮游植物的空间分布特征。结果表明：2009年秋季,长江安徽-江苏段共检出绿藻（Chlorophyta）、硅藻（Bacillariophyta）、蓝藻（Cyanophyta）、裸藻（Euglenophyta）、隐藻（Cryptophyta）5门27种;其中,硅藻种数最多,16种,占浮游植物总种数的59.3%;其次是绿藻,6种,占浮游植物总种数的22.2%;之后分别是蓝藻、隐藻、裸藻,分别为2、2、1种,分别占浮游植物总种数的7.4%、7.4%、3.7%;浮游植物优势种为巴豆叶脆杆藻（Fragilaria crotonensis）、意大利直链藻（Melosira italica）、隐头舟形藻（Navicula cryptocephala）、小环藻（Cyclotella）以及尖尾兰隐藻（Chroomonas acuta）;长江安徽-江苏段浮游植物数量变化在5.68×104~7.08×104 cells/L之间,平均为6.01×104 cells/L,生物量变化在30.43~34.73 μg/L之间,平均为32.46 μg/L;与以往的研究相比,长江江苏段浮游植物种类数减少,数量和生物量上升,说明长江江苏段的水质恶化,但浮游植物群落结构未发生明显变化,仍以硅藻为主要优势种,显示出长江江苏段水质的恶化程度尚不严重。浮游植物相似性聚类分析显示,长江安徽-江苏段的浮游植物群落结构大致聚为2类,南京、芜湖、江阴3站聚为一类,铜陵、安庆站聚为一类。 相似文献
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Luxikou River is one of shallow waterway in middle reach of Yangtze River.The navigational channal changes with the fluvial process of river. In the meanwhile,the shoals exist at the entrance of Zhigang and Zhonggang branch. It's difficult to maintain the waterway. The depth of waterway is kept upon 3.2 meters,and the carrying capacity of tank barge must be decreaed to pass through.For the demands of constructing the main channel of Yangtze River,the measements for stabilizing and improving must be carried out as soon as possible. 相似文献
20.
Abstract: The Se San is an important tributary river basin of the Mekong. In 1993, Vietnam began building the Yali Falls Dam 80 kilometres upstream of the point at which this westward flowing river enters Cambodia. Ninety indigenous communities along the Se San River in two provinces of north‐eastern Cambodia have been impacted severely by flooding, and a dramatically altered hydrological regime that affects fisheries and all other aspects of livelihood, such as river bank agriculture. Since 2000, when the first turbines were commissioned, the affected communities have been increasingly vocal regarding the impacts of Yali and the plans for several more dams on upper reaches of the river. A complex set of actors including non‐governmental organisations, village, district and provincial authorities, national committees in Cambodia and Vietnam, the Mekong River Commission and a range of international players have become involved in a two‐track process, which has nevertheless allowed little space for negotiation over the Se San River on the part of those most directly affected. This case has fundamental implications for governance and conflict management in the Mekong and more widely. The Australian Mekong Resource Centre has been working with local actors to document the Se San case as part of an international project on River Basin Management: a negotiated approach, in support of six cases that involve up‐scaling of grassroots river basin initiatives in Africa, Latin America and Asia. In this article, we illustrate the significance of and problematise negotiation as a socially and politically embedded conflict management principle, with reference to the Se San case. 相似文献