城市轨道交通对房地产价值的影响研究——以武汉市轨道交通为例

城市轨道交通是一种快捷、高效、节能环保的大容量城市客运交通方式,而且对于沿线房地产的开发具有巨大的带动作用。本文定性分析了城市轨道交通对房地产价值的影响机理,并采用地价影响函数模型,对武汉城市轨道交通1号线地价影响函数相关参数进行了标定,定量研究证实了城市轨道交通对房地产价值的拉动作用,最后提出了武汉市轨道交通与房地产联合开发策略。     

Urban–rural ecological networks for landscape planning

Urban–rural landscape planning research is nowadays focusing on strategies and tools that support practitioners to design local areas where human and natural pressures interfere. A prominent framework is provided by ecological network studies, whose design regards the combination of a set of green areas and patches (nodes) interconnected through environmental corridors (edges). Ecological networks are key for biodiversity protection and enhancement, as they are able to counteract fragmentation, and to create and strengthen relations and exchanges among otherwise isolated elements. Biodiversity evolution, indeed, depends on the quantity and quality of spatial cohesion of natural areas. In this paper, we propose a methodological framework based on network modelling for the study and modelling of ecological networks. We use network properties and centrality measures (degree, clustering coefficient, and betweenness centrality) and take into account the intensity of the dispersal capacity by introducing the corresponding weighted centrality measures. We simulate the dynamics of ecological networks by monitoring the residual dispersal capacity and the number of connected components from three perspectives: random attacks, deterministic attacks according to decreasing betweenness centrality and influence of master plans. We demonstrate that spatial network analysis is useful to monitor the performance of ecological networks and support decision-making, management, and planning.The proposed methodology is applied to the case study of the peri-urban and urban areas of the town of Nuoro (Italy). Patches (nodes) have been selected among the ecosystems with target vegetal species Holm oak and cultivated and wild Olive while the connecting corridors (links) enable for seed dispersal.     

黄淮海平原农区县域土地利用景观格局分析及可持续利用建议

研究目的:系统分析黄淮海平原农区土地利用景观格局特征存在问题、形成机制及其优化调整思路。研究方法:用地理信息系统支持下的景观生态学格局定量分析方法,以土地利用现状图为工作底图,系统研究了曲周县的土地利用景观的空间格局指标。研究结果:曲周县的土地利用景观格局在我国广大农区具有代表意义,是我国农村土地利用方式及高人口密度综合作用的结果;景观人文干扰强,耕地在整个景观中占首要位置,水浇地、旱地和居民点的优势度明显高于其他景观类型。研究结论:应用景观生态学方法可以为土地可持续利用管理评价提供新的方法和视角,最后提出了以加强沟渠、防护林等廊道建设和促进农村城市化的平原农区优化景观格局的建议。     

Ecological networks: Are they enough for connectivity conservation? A case study in the Barcelona Metropolitan Region (NE Spain)

This paper extends the debate on corridor effectiveness at regional planning scale, by exploring the contribution to landscape connectivity of a proposed ecological network and the remaining non-urbanized matrix in the Barcelona Metropolitan Region (BMR). Using the Ecological Connectivity Index, we evaluated the expected connectivity loss after the development of the approved urban plans in the region. Thus, we compared the baseline (present-day) and the projected (after planned urban development) connectivity scenarios for total, forest and agricultural habitats. Then, we estimated the mitigation in connectivity loss when successively removing from plans those development sectors included in protected sites, first order corridors, and second-order corridors of the ecological network, and in the rest of land matrix. Estimations were done for all the BMR and for inside versus outside the set of sites currently protected.The ecological network and the rest of matrix contributed equally to mitigating the expected connectivity loss, but while the former was more effective for forest habitats, the latter was especially constructive for croplands. This was due to a heterogeneous distribution of habitats, protected reserves and urban development areas. Still, connectivity preservation within protected sites appeared to be highly dependent on what is going on outside the ecological network, as we observed in particular for agricultural habitats. This result extends at regional scale the statement that no park is an island, but is highly affected by the land use and land cover dynamics of its surroundings.     

DEREGULATION AND EFFICIENCY IN GRAIN TRANSPORT

In this paper, it is argued that removing restrictions on road transport will not be sufficient to encourage efficiency improvements in grain freight industry while rail authorities continue to operate as public monopolies. This is because of the structure of costs in the grain freight industry, which imply that road transport cannot compete with rail transport in areas where road is the more efficient mode. While the tendency for a regulated monopoly to cross-subsidise inefficient operations is common place, the focus in this analysis is on the nature of the cross-subsidy in the grain freight industry, and shows that it is a type of cross-subsidy that is well hidden by aggregation. A model of investment in a rail network is presented where the monopoly power afforded to the rail industry is shown to be due to economies of traffic density. A case study of the grain rail network in Western Australia is presented where it is shown that the rail authority has been able to maintain very uneconomic sections of rail line, despite the introduction of road competition and apparently competitive pricing practices.     

Sensitivity evaluation and land-use control of urban ecological corridors: A case study of Shenzhen,China

Constructing an urban ecological corridor system is a major component and critical factor of forming an effective network within an urban ecosystem. Shenzhen, as a highly urbanized area in China, is facing the dual pressures of urban development and ecological conservation. The ecological corridors in Shenzhen are being constantly eroded by urban expansion, resulting in an urgent need to carry out sensitivity evaluations and ecological land management studies. By identifying the spatial range of planned ecological corridors in Shenzhen, we develop a GIS-based ecological sensitivity evaluation model from the perspectives of soil environment, habitat conditions, geological hazards, and human disturbance. Management strategies are proposed with regard to macroscopic protection guidance and microscopic land-use control. The results show that there is little difference in the sensitivity grade of ecological corridors in Shenzhen. With regard to spatial distribution, the sensitivity level is high in the north and low in the south, with moderately sensitive corridors being the dominant type. Meanwhile, we design the land-use control program by taking into account the present management and new land demand and provide the path for implementing the withdrawal, reservation, occupation, and avoidance polices. The results of the sensitivity evaluation objectively reflect the eco-environmental condition of ecological corridors in Shenzhen. The classified and graded protection guidance and space regulatory framework proposed in this study are of significance for guiding the ecological conservation, land use, and sustainable development in urban contexts with similar issues.     

United States and Canadian Rail Freight-Rate Structures: A Carparative Analysis

This paper applies rail freight-rate theory to U.S. and Canadian grain movements for both domestic and export destinations. In this analysis it is established that grain freight rates in the U.S. are largely determined by distance, shipment size, frequency of shipments, intermodal competition, and geographical characteristics of route origins and destinations. Freight rates, therefore, vary depending upon routes. A comparison of U.S. export rates with Canada's statutory rate revealed that the U.S. rate levels, in 1979, were 4.3 and 2.9 times higher for hauling distances of 200 and 1,000 miles respectively in the lowest-rate route; while it was about 7.8 and 7.5 times higher for the same mileage in the highest-rate route. The extent to which the U.S. experience is relevant to Western Canada depends largely on the manner in which Canada's statutory rate is revised after the scheduled review in 1985–86.     

How integrated are world beef markets? The case of Australian and U.S. beef markets

The objective of the paper is to examine market integration between Australian and U.S. beef prices at the farmgate level. If these two prices are found to be integrated then it can be alleged that Australian beef prices can be used as a world price in empirical analyses and/or as a ‘reference price’ to measure the level of support accorded the U.S. beef sector. Co-integration analysis and a time-varying parameter estimation procedure based on the Kalman filter model are applied. The paper distinguishes between steer and cow beef segments and it uses monthly data over the 1972:1 to 1993:2 period. The results indicate that Australian and U.S. beef prices are co-integrated, albeit not fully and that the degree of convergence between the various price pairs has not substantially increased over time. The results also suggest that Australian prices can not unequivocally be adopted as a world price in empirical analyses.     

交通网络建设机制及绿色交通规划初探——以四川秦巴山区为例

实施交通网络建设机制研究,提出该区域交通网络建设的战略发展思路,建立持续可行的投入机制并加以贯彻实施,是绿色交通战略研究的重点之一。以四川秦巴山区为例,在已有的绿色交通网络体系构建的基础上,从交通网络建设投入和运行两方面进一步研究交通网络建设机制,并制定未来的绿色交通规划,构建以"经济效益最大化与环境承载最小化"的多目标优化模型,从定量的角度给出了绿色交通规划实施方案,以期为秦巴山区的绿色可持续发展提供决策依据。     

The Link between Poverty and Undernourishment: Uncovering a Methodological Flaw

In their Food Security Assessment , the U.S. Department of Agriculture uses income data and a cross-country Engel curve for food energy (energy–income curve) to estimate distribution-sensitive food gaps of developing countries. In a recent Review of Agricultural Economics paper, Senauer and Sur use the same methodology to estimate headcount ratios of undernourishment. We show that the estimated Engel curve underestimates individual food consumption and, hence, overestimates food gaps and headcount ratios due to a serious flaw in the methodology.     

A Cost Approach to Economic Analysis Under State-Contingent Production Uncertainty

This article explores the economics of input decision under production uncertainty. The article develops a methodology to specify and estimate cost-minimizing input decisions under a state-contingent technology. The analysis is applied to time series data on U.S. agriculture. It finds strong empirical evidence that expected output alone does not provide an appropriate representation of production uncertainty. The results provide empirical support for an output-cubical technology. This indicates that an ex post analysis of stochastic technology appears appropriate. The analysis also provides evidence that the cost of facing production risk has declined in U.S. agriculture over the last few decades.     

基于ArcGIS 10的土地利用总体规划图斑自动化综合

研究目的：探索按语义级别对土地利用总体规划图进行自动化图斑综合的新方法。研究方法：在ArcGIS 10中构建模型、制作模型工具并进行实例分析。研究结果：制定了图斑综合原则,利用模型构建器、Python脚本语言和一系列地理处理工具构建了模型并制作了模型工具;实现了按语义级别进行自动化的图斑综合：按属性挑选小图斑的合并对象时,在与小图斑所属行政区相同的前提下,遵循土地规划地类、土地用途区类型、建设用地管制区类型的先后顺序。研究结论：利用土地利用总体规划实际数据进行了实例分析,证明该方法切实可行,且自动化程度高。     

Measuring the Costs and Trade Effects of Phytosanitary Protocols: A U.S.–Japanese Apple Example

This article investigates the trade impact of Japan's decision in 2005 to revise its phytosanitary protocol for fire blight for U.S. apple imports but retain its codling moth protocol. The analysis presents a participation model to measure the economic costs of phytosanitary barriers to trade. The model provides an explicit cost of the phytosanitary barriers in terms of the structure of the protocols, an important advantage over the price-wedge methodology. This makes it possible to separate the economic costs of various protocols—in this case, the fire blight and codling moth protocols.     

Revisiting U.S. country of origin labeling trade damage estimates how does an equilibrium displacement model perform under different scenarios

Mexico and Canada successfully challenged the U.S. mandatory country of origin labeling (COOL) requirements for beef and pork as inconsistent with World Trade Organization (WTO) rules, which ultimately led to arbitration over the level of trade lost due to the COOL measure. During this phase of the dispute, Mexico, Canada, and the United States provided the Arbitration Panel with estimates of the trade losses caused by COOL that were produced using different quantitative methods. The U.S. estimates were based on an equilibrium displacement model (EDM). This article presents a version of the EDM used by the U.S. Government to calculate trade losses due to COOL. The Panel developed its own analysis combining econometric analysis and an EDM that used only supply-side information to calculate changes in Canadian and Mexican livestock trade. The U.S. EDM includes both the supply and demand sides of the market. We use the U.S. EDM and the Panel's assumptions to re-estimate the value of lost trade due to COOL. The inclusion of demand-side effects and domestic COOL costs produces lower estimated trade damages than those produced using the Panel's analysis, validating the EDM as a useful quantitative tool for this type of trade policy analysis.     

Does the Exchange Rate Matter to Agricultural Bilateral Trade between Canada and the U.S.?

This study examines the effects of the Canada–U.S. exchange rate on bilateral trade of agricultural goods between the two countries and on U.S. farm income. Special attention is given to agricultural trade between the two countries under the Canada–U.S. Free Trade Agreement (CUSTA). This study utilizes two time series models: the vector error correction model (VECM) and the vector moving average model (VMA) with quarterly time series data from 1983 to 2000. It is found that the exchange rate has a significant impact on U.S. agricultural trade with Canada, but the impact on U.S. agricultural price and income is insignificant. The exchange rate between the two currencies is found to be weakly exogenous in the U.S. agricultural sector, which answers a fundamental question about the role of the exchange rate in Canada–U.S. bilateral trade for agricultural products. In addition, the results point to a significant, though minimal, effect on bilateral trade due to CUSTA.     

The quantity and variety of households’ meat purchases: A censored demand system approach

This study investigates the demand for 10 disaggregated meat products by U.S. households. A censored demand system which imposes budget constraints in both observed and latent shares is estimated along with a detailed explanation of the estimation procedure. Additional details about the methodology not provided in previous studies should help researchers to empirically apply the model. An innovation of the study is to introduce the censored demand system model for studying the variety of a household's food purchases. Most households buy between seven and eight different products and hardly change the variety of their purchases with changes in meat expenditure.     

When markets reset,will we regain? Planning lessons from across the Atlantic Ocean

Globalisation and economic integration has brought new territorial and governance challenges. The interconnectedness of the economy, the need to remain competitive and to plan cities and regions sustainably has created new risks, given the uncertainty and magnitude of economic crises. This paper analyses how metropolises in Arizona (Phoenix and Tucson), U.S., and Portugal (Lisbon and Porto) have developed recently and how their stakeholders have been dealing with processes of metropolitan transformation. Recent regional planning is examined with the intent to understand whether stages of maturity, compact urban development patterns, regulatory and administrative planning traditions, and socio-economic and cultural systems influence territorial coherence. Two key findings stand out: First, anticipatory regional planning has the capacity to adapt to changing conditions in order to maintain and develop more sustainable and resilient territories; second, public spending oversight and programmatic firewalls allow corrections to be made before problems escalate out-of-control.     

Modelling the transportation of primary aggregates in England and Wales: Exploring initiatives to reduce CO2 emissions

Millions of tonnes of aggregates are transported across England and Wales each year, which causes constant concerns in regard to CO₂ emissions. Much of that concern arises out of the long journeys from quarries to construction sites, and the fact that the main mode of transfer is by road. The aim of this paper is to describe the construction of a spatial decision support system (SDSS) to examine the impacts of scenarios to reduce the level of CO₂ emissions. The SDSS is made up of a GIS containing a set of spatial models (including a spatial interaction model and a microsimulation model) underpinned by a detailed transport network of road and rail routes across England and Wales. The spatial interaction models are first calibrated to reproduce the existing set of flows of aggregates between quarries and local authority districts. The distance decay component is the travel distance equivalent across the road and rail networks. Based on these flows, linear models can be set up to estimate the amount of CO₂ emissions associated with the existing set of flows. Then a series of what-if scenarios are set up which look at how changes in any part of the geography of production, the level of demand in certain areas or the transport process will impact the CO₂ emissions. The paper demonstrates the capability of the SDSS in responding to the various spatial policies applied in different stages of the supply chain of the aggregates markets.     

Aggregating forest harvesting activities in forest plantations through Integer Linear Programming and Goal Programming

The inclusion of criteria related to the spatial patterns resulting from forest harvesting activities is an important component of forest planning. Harvesting operations are more efficient when the harvesting areas are clustered. Therewith, it is possible to reduce the displacement of machinery and costs related to construction and maintenance of the road network. In this context, the objective of this study was to evaluate different strategies for aggregating harvesting stands in a forest plantation. We applied two Goal Programming approaches aiming at aggregating harvesting stands and an Integer Linear Programming model for including road investments into strategic forest planning.     

The New Tomato Suspension Agreement: What Are the Implications for Trade Flows?

This paper examines the implications of the new tomato suspension agreement (signed on March 4, 2013, by the U.S. government and Mexican tomato producers) for trade in fresh tomatoes and processed tomato products. The empirical analysis is performed through a gravity model that accounts for vertical linkages between primary and processed goods. The estimated gravity parameters are used to implement suspension agreement scenarios. The results show that the new suspension agreement leads to considerable decreases in Mexico's exports of fresh tomatoes to the United States. These decreases are accompanied with various trade diversion and deflection effects. There are increases in Mexico's exports of processed tomato products to the United States and other countries, and in Mexico's exports of fresh tomatoes to non‐U.S. destinations. These increases do not amount, however, to considerable compensations of the decreases in Mexico's fresh tomato exports to the United States. The results also suggest that the initial 1996‐based suspension agreement has significantly smaller impacts on trade flows over the period that preceded the implementation of the new suspension agreement.