长江三角洲都市连绵区城市规模结构演变研究

本文选取长江三角洲都市连绵区7个年份的城市人口规模数据,分别从城市规模等级结构、首位度、城市规模分形以及城市规模的空间演化等层面对城市规模结构的演变进行了分析,初步揭示了长江三角洲都市连绵区规模结构的分布特征和演变规律,并对其空间演变特征进行了总结。

长江三角洲都市连绵区城市体系的分形特征

分形研究是现代理论地理的重要内容之一,分形维数是刻画城市体系结构的有效参数。为定量分析长江三角洲都市连绵区城市体系的分形特征,通过计算豪斯道夫维数分析了长江三角洲城市体系规模分布的分形特征,通过计算关联维数和集聚维数,从城市要素的空间相关性和城市随机集聚的向心性两方面,分析了长江三角洲都市连绵区城市体系空间结构的分形特征。测算结果表明:(1)城市体系规模结构符合位序-规模分布类型,但首位城市的垄断性还很强,处于由首位型分布向序列型分布转变的过程之中,中间位序的城市数量偏少,城市之间呈竞争发展态势;(2)城市体系空间结构呈现出均匀分布的特征,城市的空间关联性强,空间相互作用强度大。在上述结论的基础上对长江三角洲都市连绵区城市体系的优化发展提出了建议。

基于“三生空间”的土地利用转型与生态环境效应——以长江三角洲核心区为例

以长江三角洲核心区为例,利用1990、2000、2010年3期遥感影像解译获取土地利用变化数据,按照“生产-生态-生活”土地利用主导功能分类,通过土地利用转移矩阵、生态环境质量指数、土地利用转型的生态贡献率等方法,定量分析长江三角洲地区土地利用转型、时空格局特征与生态环境效应。结果表明：（1）1990~2010年,长三角地区基于“三生用地”的土地利用转型表现为生产用地减少,生态用地稳定,及生活用地快速增加。（2）长三角地区生态环境质量指数从1990年的0.470持续降至2010年的0.444,整体质量有所恶化,较高质量区和高质量区面积与比重保持稳定。（3）1990~2010年,长三角地区同时存在生态改善和恶化的两种趋势,生态环境改善小于环境恶化的趋势。城镇和农村生活用地、工矿生产用地对农业生产用地的挤占则是导致生态环境质量恶化的重要原因。

长江三角洲平原区静压桩施工方法

桩基础是由埋设在地基中的多根桩体将建筑物的荷载传递到持力土层中,以此来满足建筑的承载力和沉降要求,是目前建筑行业应用较为广泛的一种基础形式。文章以国内某大型污水处理厂施工经验为依托,介绍了静压法预应力管桩的施工过程,可以为其他项目的施工选择提供参照依据。

皖江示范区与长三角协调发展

皖江城市带承接产业转移示范区是安徽参与长三角分工合作的一个重要载体,也是一个重点,既能加快安徽的发展,又可以为长三角地区经济结构调整产业升级提供广阔的空间。就皖江示范区与长三角协调发展的客观必然性、皖江城市与长三角区域合作的经验、皖江城市参与长三角区域合作的未来目标和合作机制的创新进行了探讨。

高度重视农村小区域经济发展

经济学界所研究的区域经济．范围涵盖广阔．从面积上看．一般都在十几万、几十万平方公里以上．有的达到数百万平方公里乃至上千万平方公里．如东盟自由贸易区、长江三角区、珠江二角区等。

长江三角洲核心区绿地系统时空演变特征及生态服务价值评估

在经济建设与环境保护矛盾突出的背景下,研究区域绿地系统时空演化特征,探讨人为因素对绿地系统生态服务的影响,对于改善绿地资源管理、促进区域永续协调发展具有重要意义。本研究基于景观生态学研究方法和生态服务价值当量因子评估法,运用ArcGIS 10.2软件的空间分析功能,对1990-2015年长江三角洲核心区绿地系统时空演化特征及生态服务价值进行了分析。结果表明:(1)长三角核心区绿地景观规模随时间的变化具有阶段性特征,呈现先扩大后缩减的态势;绿地景观与其他土地利用类型的转移存在阶段性与指向性特征;绿地景观格局总体上表现为初期集聚同质化、后期破碎异质化。(2)长三角核心区绿地系统生态服务价值随时间变化明显,不同绿地景观类型有不同的阶段性特征;长三角核心区绿地系统生态服务类型中,调节服务对于绿地系统整体生态服务价值贡献最大。(3)长三角核心区绿地系统生态服务价值在空间上呈现南北不均衡的特征,总体上呈南高北低态势,其中杭州市绿地系统生态服务价值在不同阶段均最高。区域地形地貌是影响区域生态服务价值的一个重要因素。

我国三大经济区域竞争力的比较研究(上)

经济竞争力是综合国力的主要表现。为了使我国的国际经济竞争力得到充分而有效的发挥 ,本文从发达国家主要竞争力培育的经验中 ,系统地分析和研究了我国两洲一环地区的竞争力基础、条件和优势 ,供各地决策者参考。

浙江引资缘何落后

近年来,浙江省吸引外资力度不断加大,外资投资领域进一步拓宽。然而同上海、江苏相比还存在很大差距。在吸引外资尤其是世界五百强方面,浙江一直落后于苏沪,以2002年为例,浙江实际利用外资的总量仅为江苏的27.3%,上海的41.7%。世界500强企业已有400多家在苏浙沪落户,其中在上海投资的有300家,引资就达100多亿美元。

2021年上半年经济数据出炉 江苏PK浙江 GDP总量、人均收入,谁走在前面?

随着2021年上半年经济数据出炉,全国各省份之间的你追我赶再次"重燃"。江苏和浙江作为近年来经济比较活跃的省份,两者有着太多的相似:都位于我国东部沿海地区,而且江苏省的南部地区和浙江省的北部地区,都是长江三角洲核心区的组成部分。也因如此,大家喜欢将它们放在一起比较。从2021年上半年经济运行数据看,两省份的经济发展各有什么特点?

Surface Water Pollution in the Yangtze River Delta:Patterns and Countermeasures

On the basis of field investigations, observations andexperimental data combined with environmental monitoring information,the status and the spatial and temporal patterns of surface waterpollution over the past ten years in the Yangtze River Delta havebeen assessed. The water quality of large rivers is still very goodbut most of the medium-sized and small rivers have been veryseriously polluted. The appearance of black and odorous conditions inrivers in the urban areas has increased due to serious pollution byorganic matter with consequent high oxygen demand. Annual increasesin N and P concentrations in lakes have accelerated eutrophication.The water quality of river sin small towns is rapidly deteriorating.The main sources of surface water pollution include industrial anddomestic sewage, animal manures, chemical fertilizers in farmland,and polluted sediments in rivers and lakes.

Carbon dioxide emissions from cities in China based on high resolution emission gridded data

Based on the China high resolution emission gridded data （I km spatial resolution）, this article is aimed to create a Chinese city carbon dioxide （CO2） emission data set using consolidated data sources as well as normalized and standardized data processing methods. Standard methods were used to calculate city CO2 emissions, including scope I and scope 2. Cities with higher CO2 emissions are mostly in north, northeast, and eastern coastal areas. Cities with lower CO2 emissions are in the western region. Cites with higher CO2 emissions are clustered in the Jing-Jin-Ji Region （such as Beijing, Tianjin, and Tangshan）, and the Yangtze River Delta region （such as Shanghai and Suzhou）. The city per capita CO2 emission is larger in the north than the south. There are obvious aggregations of cities with high per capita CO2 emission in the north. Four cities among the top 10 per capita emissions （Erdos, Wuhai, Shizuishan, and Yinchuan） cluster in the main coal production areas of northern China. This indicates the significant impact of coal resources endowment on city industry and CO2 emissions. The majority （77%） of cities have annual CO2 emissions below 50 million tons. The mean annual emission, among all cities, is 37 million tons. Emissions from service-based cities, which include the smallest number of cities, are the highest. Industrial cities are the largest category and the emission distribution from these cities is close to the normal distribution. Emissions and degree of dispersion, in the other cities （excluding industrial cities and service-based cities）, are in the lowest level. Per capita CO2 emissions in these cities are generally below 20 t/person （89%） with a mean value of 11 t/person. The distribution interval of per capita CO2 emission within industrial cities is the largest among the three city categories. This indicates greater differences among per capita CO2 emissions of industrial cities. The distribution interval of per capita CO2 emission of other cities is the lowest, indicating smaller differences of per capita CO2 emissions among this city category. Three policy suggestions are proposed： first, city CO2 emission inventory data in China should be increased, especially for prefecture level cities. Second, city responsibility for emission reduction, and partition- ing the national goal should be established, using a bottom-up approach based on specific CO2 emission levels and potential for emission reductions in each city. Third, comparative and bench- marking research on city CO2 emissions should be conducted, and a Top Runner system of city CO2 emission reduction should be established.

Contamination of PAHs in Sludge Samples from the Yangtze River Delta Area

To ascertain the contaminated conditions of polycyclic aromatic hydrocarbons （PAHs） in sludge and to evaluate the risk of application of this sludge for agricultural purposes, 44 sludge samples obtained from 15 cities in the Yangtze River Delta area of China were investigated using capillary gas chromatography/mass spectrometry （GC/MS） after ultrasonic extraction and silica gel cleanup. PAHs＇ contents ranged from 0.0167 to 15.4860 mg kg^-1 （dry weight, DW） and averaged 1.376 mg kg^-1, with most samples containing 〈 1.5 mg kg^-1. Pyrene （PY）, fluoranthene （FL）, benzo[b]fluoranthene （BbF）, indeno[1,2,3-cd]pyrene （IND）, benzo[a]pyrene （B[a]P）, and benzo[g,h,i]perylene （BghiP） were the most dominant compounds, ranging from 0.1582 to 0.2518 mg kg^-1. Single PAH, such as naphthalene （NAP, 2-benzene rings）, phenanthrene （PA, 3-benzene rings）, PY （4-benzene rings）, and FL （3-benzene rings）, had high detection rates （76.1%-93.5%）. The distribution patterns of PAHs were found to vary with the sludge samples; however, the patterns showed that a few compounds with 2- and 3-benzene rings were commonly found in the samples, whereas those with 4-, 5-, and 6-benzene rings were usually less commonly found. All the 44 sludge samples were within the B[a]P concentration limit for sludge applied to agricultural land in China （〈 3.0 rag kg^-1）. The probable sources of PAH contamination in the sludge samples were petroleum, petroleum products, and combustion of liquid and solid fuel. The concentrations and distributions of the 16 PAHs in sludge were related to sludge type, source, and treatment technology, together with the physicochemical properties.

Prediction of China's Submerged Coastal Areas by Sea Level Rise due to Climate Change

Based on the simulation with the Ocean-Atmosphere Coupled Model CCSM and Ocean Model POP under the green- house gas emission scenario of the IPCC SRES A2 （IPCC, 2001）, and on the earth crust subsidence and glacier melting data, the relative sea level change is obtained along the coast of China in the 21 st century. Using the SRTM elevation data the submergence of coastal low land is calculated under the extreme water level with a 100-year retum period. The total flooding areas are 98.3× 10^3 and 104.9× 10^3 km2 for 2050 and 2080, respectively. For the three regions most vulnerable to extreme sea level rise, i.e., the coast of Bohai Bay, the Yangtze River Delta together with neighboring Jiangsu Province and northern Zhejiang Province, and the Pearl River Delta, the flooded areas are 5.0× 10^3, 64.1×10^3 and 15.3 × 10^3 km2 in 2050 and 5.2 × 10^3, 67.8×10^3 and 17.2 × 10^3 km2 in 2080, respectively.

Characterization of Air Pollution in Urban Areas of Yangtze River Delta,China

The hallmark of development in the Yangtze River Delta(YRD) of East China has been sprawling urbanization. However, air pollution is a significant problem in these urban areas. In this paper, we investigated and analyzed the air pollution index(API) in four cities(Shanghai, Nanjing, Hangzhou and Ningbo) in the YRD from 2001 to 2012. We attempted to empirically examine the relationship between meteorological factors and air quality in the urban areas of the YRD. According to the monitoring data, the API in Shanghai, Nanjing, Hangzhou slightly declined and that in Ningbo increased over the study period. We analyzed the inter-annual, seasonal, and monthly variations of API, from which we found that the air quality had different temporal changes in the four cities. It was indicated that air quality was poor in winter and spring and best in summer. Furthermore, different weather conditions affected air quality level. The wind direction was considered as an important and influential factor to air pollution, which has an impact on the accumulating or cleaning processes of pollutants. The air quality was influenced by the different wind directions that varied with seasons and cities.

Efficiency Pattern and Spatial Strategy of Ports in Yangtze River Delta Region

This paper measures the efficiency of ports in the Yangtze River Delta Region(YRDR) in 2008 and 2013 using port berth quantity, quay length, and human resources as input indicators, using cargo and container throughput as output indicators, and considering traditional(foreign trade dependence and industrialization level) and modern environmental factors(traffic line density, financial development level, and informatization level). To achieve such aim, this study constructs a multi-stage data envelopment analysis model(DEA) that identifies effective port decision-making units(DMUs) and generates a highly accurate conclusion by eliminating the interference from the exogenous environment and random errors. First, the external environment significantly affects port efficiency, with the traditional environmental factors showing huge fluctuations and the modern environmental factors producing great benefits. Second, the efficiency of ports in YRDR has increased from 2008 to 2013 primarily because of their pure technical efficiency. Third, the weighted standard deviation ellipse(SDE) analysis results reveal that the efficiency pattern of ports significantly deviates from their throughput pattern, while the center of SDE of port efficiency moves from the eastern coastal regions to the northwest regions. Based on these findings, this paper proposes spatial development strategies for YRDR, such as creating an unblocked environment where spatial elements can freely circulate, intensifying port-city joint development, implementing differentiated policies, and focusing on the spatial collaboration of port efficiency.

Application of Multi-agent Models to Urban Expansion in Medium and Small Cities: A Case Study in Fuyang City,Zhejiang Province,China

In this study, three-phase satellite images were used to define rules for the allocation of time and space in construction land resources based on a complex adaptive system and game theory. The decision behavior and rules of government agent, enterprise agent and resident agent in construction land growth were explored. A distinctive and dynamic simulation model of construction land growth was built, which integrated multi-agent, GIS technology and RS data and described the interaction among influencing agents, Taking Fuyang City in the Changjiang River Delta as an example, an assessment process for the remote sensing data in construction land and scenario planning was constructed. Repast and ArcGIS were used as simulation platforms. A simulation of the spatial pattern in land-use planning and the setting of scenario planning were conducted by using the incomplete active game, which was based on different natural, social and economic levels. Through this model, a simulation of urban planning space and decision-making for Fuyang City was created. Relevant non-structured problems arising from urban planning management could be identified, and the process and logic of urban planning spatial decision-making could thus be improved. Cell-by-cell comparison showed that the simulation accuracy was over 72%. This model has great potential for use by government and town planners in decision support and technique support in the policy-making process.

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.

CLOBAL CHARM OF THE CHANGJIANG RIVER DELTA

Based on the theory of geo-economy,under the new situation of global economy,information network and China’s entry into WTO,also with the holding of APEC (in 2001) and the International Exposition in the near future,the Changjiang (Yangtze) River Delta is striding toward the spectacular international multi-polar situation and becomes one of core regions with high-speed development. Facing the ocean and world all along,leading the progressive tides of the age and scintillating the splendor of the nation,she does advance with time. Through a long period of irrigation projects construction and intensive operation of lands in previous agricultural society,the artificial wetland ecosystem with a positive cycle had ever been formed in this region. At present,environmental pollution and urban expansion resulted from post-industrialization are being rectified. The delta will be the paradigm of industrial and agricultural modernization along the sustainable development road. With the rapid development of urbanization,she has been one of the regions with the highest density population and high urbanization level. Taking the Changjiang River estuary and the Hangzhou Bay as two parts,she is continuously strengthening and adjusting her interior structure,expanding mothball space and constructing the oriental modern "logistics center" to link the whole world. The butterfly-style urban system of the Changjiang River Delta is flying,probably engendering earthshaking "butterfly effect".