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1.
Spatially explicit urban expansion models that can trace urban development in the past and predict the expansion scenarios in the future are indispensable for examining urban planning policies. This paper demonstrates a new urban expansion scenario (UES) model by coupling one “bottom-up” cellular automata (CA)-based model and one “top-down” system dynamics (SD)-based model. By implementing the UES model in Beijing, the urban evolution from 1991 to 2004 was simulated and the UESs from 2004 to 2020 were predicted. The results suggest that a dilemma of urban expansion versus limited water resource and environment deterioration exists. Dealing with such a dilemma remains a challenge for the local government.  相似文献   

2.
This paper investigates the developing spatial and social division of labor in the Greater Shanghai chemical industry. This industry experienced strong growth after the Asian financial crisis, when policy support was extended beyond “new economy” industries to include traditional manufacturing sectors. Based on a conceptualization that emphasizes the role of producer-user networks and interactive learning as a basis for ongoing innovation and business success, an explorative study was designed to investigate the supplier and customer linkages in different locations of the Greater Shanghai region. The results suggest that inter-firm networks are not extensive and often involve limited producer-user interaction. Important chemical firms in the region concentrate on business with their established international customer basis, use state-controlled distribution channels or rely on intermediaries that act as knowledge brokers. Neither of these practices of market interaction includes intensive information exchange and feedback on products, customer experience and demand changes. As such, these practices do not provide a sound basis for self-sustained growth or innovation in the future. The paper concludes that regional policy needs to support the establishment of combined “bonding” and “bridging” relations between chemical producers and their user industries.  相似文献   

3.
In 1996, Ontario conservation authorities are 50 years old. This paper reviews the origins and founding principles of the conservation authority programme. After describing recent events in Ontario water management, the six founding principles—watershed jurisdiction, local initiative, a provincial-municipal partnership, coordination and cooperation, a healthy environment required for a healthy economy, and a comprehensive approach—are used to examine the practices of the Upper Thames River Conservation Authority (UTRCA). Conclusions suggest that the six principles were and are sound, although they have been ‘rediscovered’ under new names. The formation of new forms of partnerships and broadening the funding base have been the UTRCA's primary responses to recent developments in Ontario resource management. Given the strong probability of future changes, conservation authorities and all other public and private resource managers must create new ways of delivering an even greater level of service to the public.  相似文献   

4.
Jansson and Glasser (Jansson, K.N., Glasser, N.F., 2008. Modification of peripheral mountain ranges by former ice sheets: the Brecon Beacons, southern UK. Geomorphology 97, 178–189.) have recently provided unconventional interpretations of selected glacial erosional and depositional landforms in the Brecon Beacons, UK, based on remotely sensed imagery. These new interpretations contradict well-established and reliable evidence for the origins and ages of certain glacial landforms of this upland area and elsewhere. They suggest that during a post-Last Glacial Maximum (LGM) ice-sheet event ice flowed up supposed, essentially “fluvial” valleys producing “glacial lineations” and depositing marginal moraines at the valley heads and on cirque floors. We argue that their interpretations of some key landforms are incorrect and that they have ignored much of the previous dating and field geomorphological evidence. Sedimentary and morphological evidence (e.g., lack of erratic content; convex planform with respect to the headwall; relatively large height range of moraines; and close association with headwall extent, height, and steepness) all indicate that higher level cirque-floor and valley-head moraines in the Brecon Beacons (> c. 400 m) were formed by cirque glaciers. Available dating evidence indicates a Younger Dryas age. We demonstrate that the supposed “fluvial” valleys, comprising trough heads with steep headwalls, have more nearly parabolic than V-shaped cross profiles indicating substantial glacial modification. Field evidence shows that proposed key exemplar post-LGM glacial lineations are in fact debris flow deposits. We conclude that whilst the adoption of a macroscale approach can shed new light on large-scale, ice-sheet movements, this approach should not be undertaken without consideration of the associated field evidence.  相似文献   

5.
符文颖  吴艳芳 《地理学报》2017,72(8):1361-1372
外资知识密集型制造业进入中国市场,对中国制造业升级转型起着一定的作用。本文围绕区域制度环境和区域吸收能力,探讨影响知识密集型企业进入方式的区域环境,旨在揭示知识密集型产业的外商进入方式的地理驱动机制,有利于加深理解在经济发展方式转型的时代背景下,区域与城市获得外生技术发展动力的机制。采用从1982-2014年德国在华投资企业数据库,结果发现,德国知识密集型制造企业在中国的投资呈现由沿海地区向内陆地区扩张、沿海中心城市向周边城市扩散的时空趋势,并且在1995年后,其进入方式从合资为主向独资为主转变。逻辑计量模型显示,德国知识密集型制造企业的进入方式受到多项区位因子的影响,其中地方人力资源水平和产业专业化水平是知识密集型制造企业选择以合资方式的进入中国市场的重要区位因素,表明区域知识吸收能力是形成全球—地方战略协同的关键变量;另一方面,实际使用外资存量和地方专利授权量这两个区位影响因素则会显著促成知识密集型制造企业采用独资的进入决策,反映了区域制度环境对吸引以知识产权保护为战略核心的知识密集型制造业的作用。  相似文献   

6.
王琛  郭一琼 《地理研究》2018,37(7):1297-1307
作为区域经济的重要载体,地方产业抵御经济危机的弹性影响机制却鲜少有研究且尚无定论。以电子信息产业为例,利用中国工业企业调查数据库,运用回归分析的法探讨了影响地方产业弹性的主要因素。研究发现：中国电子信息产业的经济弹性存在着地域差异;地方产业内企业的异质性、龙头企业的影响力、地方产业的开放性、动态性和业务结构对电子产业的经济弹性均有显著的正向影响。在中国现阶段的经济制度背景下,轮轴式的地方产业结构可能比小企业为主的产业区更能促进当地的产业弹性。地方政府在扶持地方产业发展的过程中,不仅要保持地方产业内企业的异质性、动态性和开放性,也要注重发挥龙头企业的带领作用。  相似文献   

7.
区域的中心—腹地关系一直是区域与城市发展领域关注的经典内容。全球化和信息化的推进产生了“流空间”和“中心流理论”,为现代城市间关系的研究提供了理论支撑,企业联系流反映的城市间关系受到学者的广泛关注,但多数研究聚焦在“整体空间”的城市网络特征表述,少有从特定问题出发,在更广阔的“非本地”范围研究中心城市与腹地的关系。论文基于1990—2018年县域尺度的企业流数据,研究北京与河北(本地)和京津冀区域外(非本地)的企业联系的时空格局和影响因素,从企业联系视角为北京与河北的经济落差提供解释,主要结论如下： ① 1990—2018年北京的本地性企业联系较弱,企业联系较强的县市主要集中在非本地,尤其是长三角等地区,非本地联系是北京企业联系的主要形式。从投资金额来看,北京与本地联系最强的行业为制造业,与非本地(主要是长三角)联系最强的行业为租赁和商务服务业;从建立分支数来看,北京与本地和非本地联系最强的行业都为金融业。② 北京的本地企业联系主要受本地的经营环境(金融环境、政府干预、政策环境)和区位条件(地理邻近)的影响,非本地企业联系主要受关键资源(政治资源、科技投入)、经营环境(经济开放)和市场潜力(消费水平)的影响。河北综合承载力较弱、与首都产业链不协调和不匹配等问题给北京与之建立本地联系上带来了一定的阻力,使北京倾向于与具有更优越市场潜力和经营环境的城市建立跨区域的非本地联系。  相似文献   

8.
T.C. Hales  J.J. Roering 《Geomorphology》2009,107(3-4):241-253
In the Southern Alps, New Zealand, large gradients in precipitation (< 1 to 12 m year− 1) and rock uplift (< 1 to 10 mm year− 1) produce distinct post-glacial geomorphic domains in which landslide-driven sediment production dominates in the wet, rapid-uplift western region, and rockfall controls erosion in the drier, low-uplift eastern region. Because the western region accounts for < 25% of the active orogen, the dynamics of erosion in the extensive eastern region are of equal importance in estimating the relative balance of uplift and erosion across the Southern Alps. Here, we assess the efficacy of frost cracking as the primary rockfall mechanism in the eastern Southern Alps using air photo and topographic analysis of scree slopes, cosmogenic radionuclide dating of headwalls, paleo-climate data, and a numerical model of headwall temperature. Currently, active scree slopes occur at a relatively uniform mean elevation ( 1450 m) and their distribution is independent of hillslope aspect and rock type, consistent with the notion that frost cracking (which is maximized between − 3 and − 8 °C) may control rockfall erosion. Headwall erosion rates of 0.3 to 0.9 mm year− 1, measured using in-situ 10Be and 26Al in the Cragieburn Range, confirm that rockfall erosion is active in the late Holocene at rates that roughly balance rock uplift. Models of the predicted depth of frost activity are consistent with the scale of fractures and scree blocks in our field sites. Also, vegetated, paleo-scree slopes are ubiquitous at elevations lower than active scree slopes, consistent with the notion that lower temperatures during the last glacial advance induced pervasive rockfall erosion due to frost cracking. Our modeling suggests temporally-averaged peak frost cracking intensity occurs at 2300 m a.s.l., the approximate elevation of the highest peaks in the central Southern Alps, suggesting that the height of these peaks may be limited by a “frost buzzsaw.”  相似文献   

9.
唐山市钢铁工业发展特征及动力机制分析   总被引：2，自引：0，他引：2  
唐山市钢铁工业自20世纪80年代以来一直为唐山市的支柱产业,90年代以来,省属特大型企业唐钢和地方钢铁企业都得到了迅速发展,在唐山市经济总量中占据着举足轻重的地位。本文详细分析唐山市钢铁产业的发展过程,探讨改革开放以来影响城市最具代表性产业的驱动因素。研究表明,基于本地化的区域产业基础和国家引导下的制度因素是唐山市钢铁工业迅速发展的主要驱动力,企业在动态的环境中适应和创新的能力则是内在因素。产品结构雷同、彼此利益独立使企业之间面临着激烈竞争,因此建议发挥政府的协调作用,引导地方企业调整工艺流程和产品结构,扶植相关产业,促进区域经济整体发展。  相似文献   

10.
The paper seeks to illuminate everyday work practices in the economic spaces of Malaysia's business process outsourcing (BPO) industry. It draws upon empirical evidence from call centre staff and promotes analytical sensitivity to the experience of labour and spatiotemporal relations within the offshore back offices of multinational corporations located in Cyberjaya, Malaysia. The analysis provides an empirical snapshot of how IT‐facilitated work practices in the global information economy are embedded and socially reproduced in everyday settings. To this end, the paper engages anthropologically with BPO labour, and critiques ‘globalist’ representations of economic and social transformation frequently articulated through an abstract, dehumanized space of networks and flows often seen to wash over local places, culture and people.  相似文献   

11.
Recent Growth and Structural Change in Chinese Cities   总被引：1，自引：1，他引：0  
《Urban geography》2013,34(1):68-80
This paper examines one aspect of emerging urban industrial systems: the extemalization, or out-sourcing, of business services from the manufacturing sector. Drawing upon Williamson's ( 1975,1990) seminal research on transaction costs economics, the paper demonstrates conceptually that externalization is integrally linked to the vertical disintegration of firms. The empirical portion of the paper uses surveys of small manufacturers located in the Chicago metropolitan region to identify the extent to which five basic business services are externalized. Thereafter, two logit models are developed to evaluate the influence of factors that may contribute to the externalization of basic services. The modeling results indicate that the size of firms and their previous extemalization experience significantly influence the externalization decision.  相似文献   

12.
Holocene coastal evolution in New South Wales has been interpreted essentially as the unfolding of the impact of marine transgression. Sea level on this coast supposedly reached its present height at 6–6.5 ka, and varied < 1 m since then. The early Holocene rise of the sea has been considered the key factor (“forcing function”) in dune migration, coastal sand barrier development, and the evolution of estuaries. Episodic storminess during the late Holocene has been seen as an important, though secondary, factor in beach erosion and dune mobilisation. An alternate interpretation presented here challenges the concept of the marine transgression as the primary “forcing function”. It (a) attributes early Holocene dune mobilisation to climate rather than the rising sea; (b) shows that the sea reached its present level by 7 ka and rose to at least + 2 m until 1.5 ka; (c) links late Holocene dune activity to local disruption of vegetation rather than to regional episodic storminess; (d) demonstrates a fall of 2°C in sea surface temperature after 3 ka that coincides with the onset of barrier erosion; (e) recognises the imprint of at least three tsunamis in the coastal sedimentary record.  相似文献   

13.
This paper provides data on the landforms, soils, and sediments within a unique northern Michigan landscape known as the Grayling Fingers, and evaluates these data to develop various scenarios for the geomorphic development of this region. Composed of several large, flat-topped ridges that trend N–S, the physiography of the “Fingers” resembles a hand. Previously interpreted as “remnant moraines”, the Grayling Fingers are actually a Pleistocene constructional landscape that was later deeply incised by glacial meltwater. The sediments that comprise the Fingers form a generally planar assemblage, with thick (>100 m), sandy glacial outwash forming the lowest unit. Above the outwash are several meters of till that is remarkably similar in texture to the outwash below; thus, the region is best described as an incised ground moraine. Finally, a thin silty “cap” is preserved on the flattest, most stable uplands. This sediment package and the physiography of the Fingers are suggestive of geomorphic processes not previously envisioned for Michigan.Although precise dates are lacking, we nonetheless present possible sequences of geomorphic/sedimentologic processes for the Fingers. This area was probably a topographic high prior to the advance of marine isotope stage 2 (Woodfordian) ice. Much of the glacial outwash in the Fingers is probably associated with a stagnant, early Woodfordian ice margin, implying that this interlobate area remained ice-free and ice-marginal for long periods during stage 2. Woodfordian ice eventually covered the region and deposited 5–10 m of sandy basal till over the proglacial outwash plain. Small stream valleys on the outwash surface were palimpsested onto the till surface as the ice retreated, as kettle chains and as dry, upland valleys. The larger of these valleys were so deeply incised by meltwater that they formed the large, through-flowing Finger valleys. The silt cap that occupies stable uplands was probably imported into the region, while still glaciated. The Fingers region, a col on the ice surface, could have acted as a collection basin for silts brought in as loess or in superglacial meltwater. This sediment was let down as the ice melted and preserved only on certain geomorphically stable and fluvially isolated locations. This study demonstrates that the impact of Woodfordian ice in this region was mostly erosional, and suggests that Mississippi Valley loess may have indirectly impacted this region.  相似文献   

14.
Literature on transboundary knowledge flows has primarily focused on foreign direct investment (FDI) spillover effects in emerging economies during the last decades. Little has been known, however, about whether or not and how foreign firms learn from local firms to enhance their innovation performance. The existing literature on clusters lays much emphasis on the variety of knowledge sources in the process of innovation, but it largely ignores the social and institutional barriers to transboundary knowledge flows. This article argues that for foreign firms operating in emerging economies, the issues about legitimacy and liability of foreignness might inhibit “outsiders” from effective knowledge sourcing; therefore, the social and institutional structure in a region plays a no less significant role than knowledge per se. Based on a large-scale firm-level database from China's information and communications technology (ICT) industry, this article reveals that local innovativeness of indigenous firms significantly stimulates and enhances innovation of foreign firms. It is interesting to find that whereas related variety of a region fails to exert positive influences, ownership diversity and a low extent of market concentration that reflect the openness of a local innovation system significantly affect innovation performance of foreign firms. It calls for more studies on local institutional and social construction of interfirm knowledge flows.  相似文献   

15.
近年来,生产网络已经成为研究热点,其对纳入网络中不同企业和地方的技术升级、价值增加和获得具有重要意义。本文以洛杉矶时装业生产网络为对象,深入分析其生产网络的运行体制,吸取成功经验。研究表明,时尚区内密集的社会网络和开放的劳工市场,快速与时尚的生产理念,地理空间聚集,各公司之间竞争、合作、信任关系以及商贸促进区对区域发展的调节与治理等都是其取得成功的重要条件。  相似文献   

16.
A landslide-hazard map is intended to show the location of future slope instability. Most spatial models of the hazard lack reliability tests of the procedures and predictions for estimating the probabilities of future landslides, thus precluding use of the maps for probabilistic risk analysis. To correct this deficiency we propose a systematic procedure comprising two analytical steps: “relative-hazard mapping” and “empirical probability estimation”. A mathematical model first generates a prediction map by dividing an area into “prediction” classes according to the relative likelihood of occurrence of future landslides, conditional by local geomorphic and topographic characteristics. The second stage estimates empirically the probability of landslide occurrence in each prediction class, by applying a cross-validation technique. Cross-validation, a “blind test” here using non-overlapping spatial or temporal subsets of mapped landslides, evaluates accuracy of the prediction and from the resulting statistics estimates occurrence probabilities of future landslides. This quantitative approach, exemplified by several experiments in an area near Lisbon, Portugal, can accommodate any subsequent analysis of landslide risk.  相似文献   

17.
Wolfgang Rmer 《Geomorphology》2008,100(3-4):312-327
In southern São Paulo the Serra do Mar is characterized by three distinct terrain types: 1) highly dissected areas with closely spaced ridges and accordant summit heights; 2) multiconvex hills; and 3) terrains with highly elevated watershed areas, irregular summit heights, and locally subdued relief. The development of this landscape is considered to be the result of the Cenozoic block-faulting and of the influences that are exerted by the differing lithological and structural setting of block-faulted compartments on weathering and erosion processes.In areas characterized by pronounced accordant summits the close coincidence between hillslope angle and the angle of limiting stability against landsliding points to a close adjustment of hillslope gradients and the mechanical properties of the regolith. The relative height of the hillslopes is functionally related to the spacing of the valleys and the gradient of the hillslopes. In areas with a regular spacing of v-shaped valleys and uniform rocks, this leads to the intersection of valley-side slopes in summits and ridges at a certain elevation. This elevation is determined by the length and steepness of the valley-side slopes. Therefore, the heights of the summits are geometrically constrained and are likely to indicate the upper limit of summit heights or an “upper denudation level” that is adjusted by hillslope processes to the incising streams. Accordant summit heights of this type are poor indicators of formerly more extensive denudation surfaces as it is also likely that they are a result of the long-term adjustment of hillslopes to river incision.The steep mountain flanks of block-faulted compartments on the other hand, comprise regolith-covered hillslopes that are closely adjusted to the maximum stable gradient as well as rock-slopes that are controlled by the rock-mass strength. Their summits are usually not accommodated into uniform summit levels. Highly elevated watershed areas exhibiting a subdued relief are detached from the base level response. On granitoid rocks these areas are often characterized by the rocky hills and domal rock outcrops. However, differences in the elevation of interfluves and summits between rocks of differing resistance and in the elevation of lithologically distinct individual fault-blocks imply that long-term weathering and erosion has transformed and lowered these landscapes. Therefore, these areas cannot be interpreted as a remnant of a pre-uplift topography and it appears to be unlikely that the height of the summits correlates with formerly more widespread planation surfaces in the far hinterland.The studies indicate that concepts such as the parallel retreat of hillslopes cannot account for the observed differences in the landscape. It is suggested that the Serra do Mar is consumed from the Atlantic and the inland side by spatially non-uniform developmental states. These states are determined by local differences in the coupling and distance to the regional base level and sea-level or are due to lithological and structural controls between and within the block-faulted compartments.  相似文献   

18.
Local content laws have the potential to promote positive synergies between the extractive sectors and African economies. However, their success is a negotiated outcome of interaction between actors. The objective of the article is to emphasize the mechanisms by which local content requirements are negotiated between actors in Ghana’s oil and gas industry, by drawing on Foucault’s concept of power. Data for the study were obtained through interviews, observations and secondary sources. The author found that complex registration systems, administrative details, and financial and technological requirements constituted the micromechanisms of power at play in determining how the local content law was applied in practice. The article demonstrates how these factors limit the activities of small and medium-scale enterprises (SMEs) in the oil and gas sector. The author concludes that the institutional context, the capacity of local SMEs, and the techniques and practices of multinational corporations (MNCs) shape the extent of local participation in Ghana’s oil and gas industry.  相似文献   

19.
K. Stüwe  J. Robl  S. Matthai 《Geomorphology》2009,108(3-4):200-208
A simple numerical landscape evolution model is used to investigate the rate of erosional decay of the Yucca Mountain crest in Nevada, USA — a location proposed as a permanent repository for high level radioactive waste. The model is based on a stream power approach in which we assume that the rate of erosion is proportional to the size of the catchment as a proxy for water flux and to the square of the topographic gradient. The proportionality constants in the model are determined using the structural history of the region: extensional tectonics has dissected the region into a series of well-defined tilt blocks in the last 11 my and the ratio of fault displacement and gully incision during this time is used to scale the model. Forward predictions of our model into the future show that the crest will denude to the level of the proposed site between 500,000 years and 5 my. This prediction is based on conservative estimates for all involved parameters. Erosion may be more rapid if other processes are involved. For example, our model does not consider continuing uplift or catastrophic surface processes as they have been recorded in the region. We conclude that any “total system performance analysis” (TSPA — as has been performed for the Yucca Mountain region to predict geological events inside the ridge) must consider erosion as an integral part of its predictions.  相似文献   

20.
王文宇  任卓然  李伟  贺灿飞 《地理研究》2021,40(12):3287-3301
近年来,逆全球化趋势上升,许多国家对中国竖起贸易壁垒,在此背景下,如何提升城市的出口韧性已成为重要研究议题。现有文献普遍关注本地产业结构与区域韧性的关系,发现多样化产业结构有助于缓解贸易壁垒造成的外部冲击,但是较少探讨外部市场结构的作用。本文使用2001—2016年中国海关数据库贸易数据,引入市场关联概念,首次构建市场相关多样化指标,研究在贸易壁垒冲击下,中国城市出口市场相关多样化对城市出口韧性的影响。研究发现：① 市场相关多样化程度较高的城市,表现出更高的城市出口韧性,其可借助互补性的出口经验和风险分散的市场结构,减小贸易壁垒产生的直接和间接影响。② 外资比例较高、具有国家级经济开发区的城市,由于城市内部企业集聚程度高和信息交流频繁,更容易发挥市场相关多样化的作用。③ 城市相关多样化的市场结构很难抵抗发达国家（地区）贸易壁垒带来的冲击。本文认为地方政府应高度重视城市出口韧性,积极招商引资、申请经济开发区、保持对外联系,推动企业集聚、多举办展会以促进企业间贸易经验交流,尤其是要促进发展中国家的出口信息扩散,要积极引导本地企业利用本地已有贸易市场信息,拓展新市场。  相似文献   

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