Suchergebnisse

Currently, concerns are increasing that climate change may intensify natural disasters, like droughts, floods and storms which pose risks to human society, especially at the coastal urban area. This thesis studies climate change, water shortage and flood risks as well as human response measures in the highly urbanized Pearl River Delta (PRD) area in South China. Analysis on climate change in the PRD area is based on existing datasets and model projections, with an integration of literature results. Findings indicate significant climate change in both the past and future of the area, with a trend of increasing mean temperature, fluctuating precipitation, rising sea level and increasing typhoon intensity as well as the frequency of extreme weather events. In particular, the annual mean temperature in the PRD area is likely to rise by around 3℃ and precipitation to increase slightly but with greater fluctuations by 2100, while the sea level is projected to rise with an annual rate of 0.33cm to 1cm in this century. Climate change is likely to increase rainfall variability, drought intensity and duration, and damages on water-related infrastructure by extreme weather events, which all increasingly threaten the local freshwater availability. The water supply situation is becoming more complicated along with the population growth, economic development and difficulties in response/management. Hence, ensuring sufficient freshwater availability is one of the major water management challenges for all the PRD cities. Taking Hong Kong as a case study, this thesis highlights six interrelated risks within the context of climate change, namely: drought, rainstorm/flood events, sea-level rise, water pollution, social management and policy gaps. It suggests that for a sustainable future, Hong Kong needs to invest in improving water self-sufficiency, diversify water sources and conduct aggressive public awareness to increase individual adaptation to predicted climate change impacts. Flood implications of climate change trends are pronounced in most of the cities in PRD as well. The frequency and intensity of extreme weather and climate events have assumed significant change, together with continuing development in flood-prone areas, which increase both the scale and degree of urban flood risk. Further estimation was made on the flood risk in the 11 cities of PRD area from both aspects of the probability of a flood occurrence and the vulnerability of the cities. The results suggest that the exposure and sensitivity of Hong Kong, Macao, Shenzhen and Guangzhou are very high because of highly exposed populations and assets located in lowland areas. However, the potential vulnerability and risk is low due to high adaptive capacities in both hard and soft flood-control measures. A novel framework on flood responses is proposed to identify vulnerable links and response strategies in different phases of a flood event. It further suggests that the flood risks can be reduced by developing an integrated climate response strategy, releasing accurate early warning and action guidance, sharing flood related information to the public and applying the advantages of social network analysis. Further, an agent-based model is developed as an instrument to simulate the process by which individual households optimize benefits through flood response investment and damage control. The model implements a subjective response framework in which households appraise inundation scenarios according to warnings, and decide whether to invest in mitigation measures to reduce potential inundation damages. Households may have variant flood response preferences and activities but they all require investments which are consequently considered as part of the final flood losses. A case study was carried out in the Ng Tung River basin, an urbanized watershed in Northern Hong Kong. First results underline that in-time, accurate and wide-covered flood warning plays a significant role in reducing flood losses. And earlier investments in responding measures are more efficient than late activities. This dynamic agent-based modeling approach finally demonstrates its capacity to analyze the interactions between flood inundation and households responses. Overall, findings of this study help understand the level of climate change impacts and vulnerability in water domain, which are vital to gauge the cities' risks and corresponding responses and therefore inform decisions about how best to deal with emerging climate-related water risks like drought and flood. ; Es wird zunehmend befürchtet, dass der Klimawandel Naturkatastrophen (wie Dürren oder Stürme) intensivieren könnte. Dies stellt ein Risiko für menschliche Gesellschaften da, insbesondere in urbanen Küstengebieten. Die vorliegende Dissertation beschäftigt sich mit dem Zusammenhang von Klimawandel, Wasserknappheiten und Flutrisiken sowie menschlichen Reaktionen auf diese Veränderungen im stark urbanisierten Perlfluss Delta (PRD) in Südchina. Eine Analyse auf Basis des existierenden Datensatzes sowie verschiedene Modellprojektionen werden mit der Ergebnissen der ausgewerteten Literatur kombiniert, welche signifikante Klimaveränderungen für das PRD in Vergangenheit und Zukunft diagnostizieren. Der Klimawandel schreitet in dieser Region voran, was sich in höheren Durchschnittstemperaturen, Niederschlagsfluktuationen, einem Anstieg des Meeresspiegels, höherer Taifun-Intensität sowie dem gehäuften Auftreten von Extremwetterereignissen äußert. Insbesondere die Durchschnittstemperatur im PRD wird sich bis 2100 um ca. 3°C erhöhen, während die Niederschläge zwar leicht zunehmen, aber auch stärkere Schwankungen aufweisen werden. Der Meeresspiegel wird in diesem Jahrhundert laut aktueller Prognosen um 0,33 bis 1cm pro Jahr steigen. Der Klimawandel wird somit wahrscheinlich die Niederschlagsvariabilität, die Intensität und Dauer von Dürren und die Beschädigung der Wasserinfrastruktur durch Extremwetterereignisse beeinflussen. Diese Veränderungen gefährden die lokale Verfügbarkeit von Trinkwasser. Probleme bei der Bereitstellung von Wasser gehen mit Bevölkerungswachstum, ökonomischer Entwicklung und Problemen im Management bzw. bei der Problembearbeitung einher. Die Bereitstellung von Trinkwasser in ausreichenden Mengen ist daher eine der wesentlichen Herausforderungen für das Wassermanagement aller Städte im PRD. Bezogen auf den Fall Hongkong arbeitet die vorliegende Dissertation sechs miteinander verknüpften Risiken im Kontext des Klimawandel heraus: Dürren, Extremniederschläge/Überflutungen, Anstieg der Meeresspiegels, Wasserverschmutzung, soziales Management and lückenhafte politische Regulierung. Um einer nachhaltigen Zukunft entgegenzusteuern muss Hongkong in eine verbesserte Selbstversorgung mit Wasser investieren, seine Wasserquellen diversifizieren und offensive Aufklärungskampagnen durchführen, um die individuelle Anpassung an die prognostizierten Klimawandelfolgen zu erhöhen. Aktuelle klimatische Trends haben ausgeprägte Implikationen für das Flutrisiko in den meisten Städten des PRD. Die Frequenz und Intensität extremer Wetterereignisse wird sich signifikant verändern. Zusammen mit der kontinuierlichen urbanen Entwicklung in für Überflutungen anfälligen Gebieten steigt somit das Risiko für Überflutungen in städtischen Räumen. Daher wurde eine Abschätzung des Überflutungsrisikos für die 11 Städte im PRD bezüglich der Aspekte Wahrscheinlichkeit von Überflutungen und Verwundbarkeit der Städte vorgenommen. Die Ergebnisse zeigen, dass die Gefährdung (exposure) und Sensitivität zentraler Städte (Hongkong, Macao, Shenzhen und Guangzhou) auf Grund ihrer stark gefährdeten Bevölkerungen und der Konzentration von Aktiva in tiefliegenden Gebieten besonders hoch ist. Allerdings können die potenzielle Vulnerabilität und das Risiko im Falle ausgeprägter Anpassungskapazitäten (durch harte und weiche Maßnahmen der Flutkontrolle) gering sein. Ein innovativer Rahmen zur Reaktion auf Flutereignisse wird vorgeschlagen, welcher verwundbare Links und Handlungsmaßnahmen in den verschiedenen Phasen eines Flutereignisses identifiziert. Das Flutrisiko kann verhindert werden, wenn integrierte Handlungsstrategien für Klimaveränderungen entwickelt, akkurate Frühwarnungen und Handlungsanweisungen herausgegeben, überflutungsbezogene Informationen mit der Öffentlichkeit geteilt und die Vorteile der sozialen Netzwerkanalyse genutzt werden. Darüber hinaus wird ein agentenbasiertes Modell entwickelt. Dieses dient der Simulation der Prozesse, durch welche einzelne Haushalte ihre überflutungsbezogenen Handlungs- und Schadenskontrollmaßnahmen optimieren. Das Modell implementiert einen auf subjektive Reaktionen abzielenden theoretischen Rahmen, in welchem Haushalte Flutszenarien auf Grund bestehender Warnungen entwickeln und entscheiden, ob sie in Verhinderungsmaßnahmen investieren, um potenzielle Schäden durch Überflutungen zu reduzieren. Haushalte können verschiedene Präferenzen und Handlungsstrategien bezüglich Überflutungen besitzen, aber sie alle implizieren Investitionen, die daher als Teil der Verluste durch Überflutungen betrachtet werden. Eine Fallstudie wurde im Ng Tung-Becken, einem stark urbanisierten Wassereinzugsgebiet im nördlichen Hongkong, durchgeführt. Erste Ergebnisse zeigen, dass rechtzeitige, genaue und flächendeckende Flutwarnungen eine signifikante Rolle für die Reduzierungen von Verlusten durch Überflutungen spielen. Zudem sind frühzeitige Investitionen in Handlungsmaßnahmen effizienter als erst spät durchgeführte Aktivitäten. Dieser dynamische, auf einem agentenbasierten Modell beruhende Ansatz demonstriert somit seine Kapazität zur Analyse von Überflutungsrisiken und die Effekte der Handlungsmaßnahmen einzelner Haushalte. Insgesamt verbessern die Ergebnisse dieser Studie unser Verständnis von Klimawandelauswirkungen und Vulnerabilitäten im Wassersektor. Dies ist entscheidend, um das Risiko für Städte und sich daraus ergebende Handlungsmaßnahmen abschätzen, und um informierte Entscheidungen bezüglicher sich abzeichnender klimabezogener Wasserrisiken wie Dürren oder Überflutungen treffen zu können.

Free trade between the United States and Mexico is credited with having developed one of the largest bilateral trading relationships in the world. Yet Mexico-United States trade has been significant for more than a century. Our objective is to show how bilateral trade increased independently of the trade agreement that took effect in 1994, and to specify the other reasons why trade grew. We measure trade flows from the 1880s to the present and estimate a gravity model for the period 1948-2006. The gravity model shows that the fundamental characteristics of Mexico and the United States explain the volume of trade independently of the trade agreement. The trade agreement reduced uncertainty which likely had a positive effect on trade flows. Our analysis does not estimate the quantitative impact of reduced uncertainty but shows that proximity and size of the market were more significant that the trade agreement.

Climate change has become one of the most challenging issues facing the world. Chinese government has realized the importance of energy conservation and prevention of the climate changes for sustainable development of China's economy and set targets for CO2 emissions reduction in China. In China industry contributes 84.2% of the total CO2 emissions, especially manufacturing industries. Data envelopment analysis (DEA) and Malmquist productivity (MP) index are the widely used mathematical techniques to address the relative efficiency and productivity of a group of homogenous decision making units, e.g. industries or countries. However, in many real applications, especially those related to energy efficiency, there are often undesirable outputs, e.g. the pollutions, waste and CO2 emissions, which are produced inevitably with desirable outputs in the production. This paper introduces a novel Malmquist-Luenberger productivity (MLP) index based on directional distance function (DDF) to address the issue of productivity evolution of DMUs in the presence of undesirable outputs. The new RAM (Range-adjusted measure)-based global MLP index has been applied to evaluate CO2 emissions reduction in Chinese light manufacturing industries. Recommendations for policy makers have been discussed.

China has achieved significant progress in terms of economic and social developments since implementation of reform and open policy in 1978. However, the rapid speed of economic growth in China has also resulted in high energy consumption and serious environmental problems, which hindering the sustainability of China's economic growth. This paper provides a framework for measuring eco-efficiency with CO2 emissions in Chinese manufacturing industries. We introduce a global Malmquist-Luenberger productivity index (GMLPI) that can handle undesirable factors within Data Envelopment Analysis (DEA). This study suggested after regulations imposed by the Chinese government, in the last stage of the analysis, i.e. during 2011–2012, the contemporaneous frontier shifts towards the global technology frontier in the direction of more desirable outputs and less undesirable outputs, i.e. producing less CO2 emissions, but the GMLPI drops slightly. This is an indication that the Chinese government needs to implement more policy regulations in order to maintain productivity index while reducing CO2 emissions.

PurposeThis study examines the effects of CLS and DS on companies' WCME and analyses the differences in WCME at company and market levels.Design/methodology/approachThis study adopts the DEA approach, regression, differences, and additional analyses to achieve its objectives. This study employs 235 non-financial companies and 1,175 company-year observations from eight active industries in the United States from 2016 to 2020.FindingsThe findings indicate that CLS and DS strategies positively influence companies' WCME. Additionally, WCME differed across size categories and industries, with large companies and those operating in the communication services industry showing better WCME. By contrast, WCME did not differ between the periods before and during the COVID-19 pandemic.Practical implicationsThis study scrutinizes the impact of CLS and DS strategies on companies' WCME to bridge the gap in this field. It extends the investigation of competitive strategies as explanatory variables for a company's WCME and examines the differences in companies' WCME at the company and market levels, which may assist decision-makers in improving their strategies and efficiencies for continuous improvement.Originality/valueThis study enhances current knowledge by uncovering the influence of CLS and DS strategies on improving companies' WCME, an underexplored topic. It also explores companies' WCME trends and patterns regarding company size, industry type, and the pandemic period to draw interesting conclusions about the essence of WCME.

The Chinese government announced to cut its carbon emissions intensity by 60%–65% from its 2005 level. To realize the national abatement commitment, a rational allocation into its subunits (i.e. industries, provinces) is eagerly needed. Centralized allocation models can maximize the overall interests, but might cause implementation difficulty and fierce resistance from individual subunits. Based on this observation, this article will address the carbon emission abatement quota allocation problem from decentralized perspective, taking the competitive and cooperative relationships simultaneously into account. To this end, this article develops an integrated cooperative game data envelopment analysis (DEA) approach. We first investigate the relative efficiency evaluation by taking flexible carbon emission abatement allocation plans into account, and then define a super-additive characteristic function for developing a cooperative game among units. To calculate the nucleolus-based allocation plan, a practical computation procedure is developed based on the constraint generation mechanism. Further, we present a two-layer way to allocate the CO2 abatement quota into different sub-industries and further different provinces in Chinese manufacturing industries. The empirical results show that five sub-industries (Processing of petroleum, coking and processing of nuclear fuel; Smelting and pressing of ferrous metals; Manufacture of non-metallic mineral products; Manufacture of raw chemical materials and chemical product; Smelting and pressing of non-ferrous metals) and two provinces (Guangdong and Shandong) will be allocated more than 10% of the total national carbon emission abatement quota.