Population,urbanization and economic scenarios over the Belt and Road region under the Shared Socioeconomic Pathways

The countries throughout the Belt and Road region account for more than 60% of the world's population and half of the global economy. Future changes in this area will have significant influences on the global economic growth, industrial structure and resource allocation. In this study, the proportion of the urban population to the total population and the gross domestic product were used to represent the levels of urbanization and economic development, respectively. The population, urbanization and economic levels of the Belt and Road countries for 2020–2050 were projected under the framework of the IPCC's shared socioeconomic pathways(SSPs), and the following conclusions are drawn.(1) The population, urbanization and economic levels in the Belt and Road region will likely increase under all five pathways. The population will increase by 2%–8%/10 a during 2020–2050 and reach 5.0–6.0 billion in 2050. Meanwhile, the urbanization rate will increase by 1.4%–7.5%/10 a and reach 49%–75%. The GDP will increase by 17%–34%/10 a and reach 134–243 trillion USD.(2) Large differences will appear under different scenarios. The SSP1 and SSP5 pathways demonstrate relatively high urbanization and economic levels, but the population size is comparatively smaller; SSP3 shows the opposite trend. Meanwhile, the economy develops slowly under SSP4, but it has a relatively high urbanization level, while SSP2 exhibits an intermediate trend.(3) In 2050, the population will increase relative to 2016 in most countries, and population size in the fastest growing country in Central Asia and the Middle East countries will be more than double. Urbanization will develop rapidly in South Asia, West Asia and Central Asia, and will increase by more than 150% in the fastest growing countries. The economy will grow fastest in South Asia, Southeast Asia and West Asia, and increase by more than 10 times in some counties with rapid economic development.     

若尔盖等地风能资源评价

本文用平均风速和最大风速法对若尔盖等三地的韦伯分布参数k、c进行估算,并用韦伯分布计算风能的指标。计算表明:若尔盖、红原属风能可利用区,用风力发电是有利用价值的;阿坝属风能贫乏地区。     

Comparison of the response of Atlantic cod (Gadus morhua) in the high-latitude regions of the North Atlantic during the warm periods of the 1920s–1960s and the 1990s–2000s

Concern about future anthropogenic warming has lead to demands for information on what might happen to fish and fisheries under various climate-change scenarios. One suggestion has been to use past events as a proxy for what will happen in the future. In this paper a comparison between the responses of Atlantic cod (Gadus morhua) to two major warm periods in the North Atlantic during the 20th century is carried out to determine how reliable the past might be as a predictor of the future. The first warm period began during the 1920s, remained relatively warm through the 1960s, and was limited primarily to the northern regions (>60°N). The second warm period, which again covered the northern regions but also extended farther south (30°N), began in the 1990s and has continued into the present century. During the earlier warm period, the most northern of the cod stocks (West Greenland, Icelandic, and Northeast Arctic cod in the Barents Sea) increased in abundance, individual growth was high, recruitment was strong, and their distribution spread northward. Available plankton data suggest that these cod responses were driven by bottom-up processes. Fishing pressure increased during this period of high cod abundance and the northern cod stocks began to decline, as early as the 1950s in the Barents Sea but during the 1960s elsewhere. Individual growth declined as temperatures cooled and the cod distributions retracted southward. During the warming in the 1990s, the spawning stock biomass of cod in the Barents Sea again increased, recruitment rose, and the stock spread northward, but the individual growth did not improve significantly. Cod off West Greenland also have shown signs of improving recruitment and increasing biomass, albeit they are still very low in comparison to the earlier warming period. The abundance of Icelandic cod, on the other hand, has remained low through the recent warm period and spawning stock biomass and total biomass are at levels near the lowest on record. The different responses of cod to the two warm events, in particular the reduced cod production during the recent warm period, are attributed to the effects of intense fishing pressure and possibly related ecosystem changes. The implications of the results of the comparisons on the development of cod scenarios under future climate change are addressed.     

A2和B2排放情景下气候变化对福建省水稻生产的阶段性影响

选择IPCC排放情景特别报告(SRES)中的A2和B2方案,利用区域气候模式PRECIS构建的气候变化情景文件与作物模型(CERES-Rice)耦合,采用雨养与灌溉两种方式,并综合考虑未来CO2浓度增加带来的直接增益效应,模拟了未来2020s及2040s两个时段气候变化对福建省水稻生育期与产量的影响。结果表明:无论是雨养方式还是灌溉方式,未来全省各稻区水稻生育期都将缩短,并且随着温度增高,2040s时段缩短的时间较2020s更长,单季稻生育期缩短时间最长,可达15~20 d。雨养条件下,除了闽东南双季稻区后季稻在2020s时段表现为2.3%(A2)和3.1%(B2)较小幅度的增产外,其他稻区各种稻作制度下的水稻产量较之BASE均出现了不同幅度的减产。闽西北稻区后季稻减产幅度最大,2020s时段A2和B2情景下减产幅度依次为6.9%和10.2%,2040s时段减产幅度进一步加大至14.1%和15.6%。闽东南稻区后季稻模拟结果较为乐观,尤其是在灌溉条件下表现为不同幅度的增产,两种情景下分别增产了1.7%、3.9%。双季稻种植区的后季稻产量稳定性均不如早稻和单季稻的,且随着温度升高,到2040s产量不稳定性有增加的趋势。灌溉在一定程度上可以缓解未来高温天气带来的产量波动。从全省的总产变化趋势来看,A2和B2两种排放情景模拟的结果都不容乐观,即使采用充分灌溉的方式,也依旧表现为减产。2020s时段,两种情景下分别减产0.74%与2.44%;2040s时段,两种情景下减产为3.50%与3.23%。未来早稻和单季稻生长季的土壤水分条件将变得不如目前湿润,与之相关的灌溉需要量均有所增加。     

Improvement of groundwater resources potential by artificial recharge technique: A case study of Charf El Akab aquifer in the Tangier region,Morocco

In arid and semi-arid zones, water is the most vulnerable resource to climate change. In fact, various techniques such as artificial recharge are adopted to restore aquifers and to ensure aquifer sustainability in relation to the accelerated pace of exploitation. Morocco is a Mediterranean country highly vulnerable to climate change, many of its main aquifers are subjected to excessive drawdowns. This technique is practiced to increase potentiality of these aquifers. In the Northwestern area of Morocco, the significant development experienced by Tangier City in the industrial, tourism, and commercial sectors will lead to increased water requirements-up to 5 067 L/s (159.8 mm3) by 2030. However, the Charf El Akab aquifer system, subject to artificial recharge, is the only groundwater resource of Tangier region; hence, a rational management context is needed to ensure aquifer sustainability, and optimized exploitation under the background of differing constraints, such as increased water requirements, and climate change impacts. This work aims to respond, for the first time, to the Charf El Akab aquifer overexploitation problem, and to evaluate the future scenarios of its exploitation in the event of failure of one of the superficial resources. This work also presents a synthesized hydrodynamic modeling based on the results of the numerical simulations carried out using Feflow software for 2004 (date of cessation of injections) and 2011 (date of resumption of these facilities), making it possible to evaluate the impact of the artificial recharge on the piezometric level of the aquifer on a spatiotemporal scale. Finally, the exploitation scenarios have shown that the aquifer of Charf El Akab will not adequatly provide for the region's water requirements on the future horizon, entailing an optimal management of water resources in the region and an intentionally increased recharge rate.     

Exploring land use policy scenarios with the use of a cellular automata-based model: urban sprawl containment and sustainable development in Thessaloniki

This study addresses the issue of urban sprawl through the application of a cellular automata (CA)-based model in the area of Thessaloniki, Greece. The model integrates a multiple regression model at the regional level with a CA model at the local level. New urban land is allocated in a disaggregated field of land units (cells) taking into account a wide range of data. Particular emphasis is placed on the way zoning regulations and land availability data are inserted into the model, so that alternative land use policy scenarios could be examined. Thessaloniki, a typical Mediterranean city, is used as a case study. The model is used to compare two scenarios of urban growth up to year 2030; the first one assuming a continuation of existing trends, whereas the second one assuming the enactment of various land use zoning regulations in order to contain urban sprawl.     

Everyday work: A survey of the 2014 Applied Geography Conference

A selection of application papers presented at the 2014 Applied Geography Conference in Atlanta, Georgia are included in this special issue of Applied Geography. The wide-ranging topics of the papers reflect the many directions Geography is applied to solve practical issues in our society.     

Littering in context(s): Using a quasi-natural experiment to explore geographic influences on antisocial behavior

Social science literature suggests that neighborhood-based visual cues have substantive effects on individuals' littering behaviors. Experimental research on this topic typically alters the appearance of a selected public location, and then monitors changes in littering due to these tightly controlled esthetic changes. The general finding is that littering occurs more frequently in relatively disorderly settings. The current paper extends this work by testing whether or not the same finding holds in more “real life” situations, wherein the operative visual cues come directly from the environment rather than through experimental manipulation. Specifically, the paper empirically identifies two study sites that serve similar functions in their urban system, but that differ markedly in contextual features. At the first site (#1), visual cues include liquor stores, vacant structures, and a noisy interstate highway. Notable visual cues at site #2 are scenic vistas, well-maintained housing, and greenspaces. When the same quasi-natural littering experiment was conducted at both locations, the littering rate was significantly higher at site #1 compared to site #2 (after controlling for individual-level demographic attributes). This result adds value to the applied geography community, as it confirms that spatially-based attributes do influence individual behaviors in a manner consistent with controlled, comparatively acontextual experimental findings. Additionally, the results implicate policy strategies that might be useful for counteracting antisocial urban behavior.     

全球气候变化中的人类活动视角:社会经济情景的演变

社会经济情景的设定是全球气候变化研究的基础,也是气候变化影响评估的关键环节.本文回顾了社会经济情景的发展过程,阐述了共享社会经济路径的主要特点和最新发展趋势,介绍了区域社会经济情景的构建及在灾害风险领域中的应用,最后对共享社会经济路径的发展进行了展望.     

Statistical downscaling of summer temperature extremes in northern China

Two approaches of statistical downscaling were applied to indices of temperature extremes based on percentiles of daily maximum and minimum temperature observations at Beijing station in summer during 1960-2008. One was to downscale daily maximum and minimum temperatures by using EOF analysis and stepwise linear regression at first, then to calculate the indices of extremes; the other was to directly downscale the percentile-based indices by using seasonal large-scale temperature and geo-potential height records. The cross-validation results showed that the latter approach has a better performance than the former. Then, the latter approach was applied to 48 meteorological stations in northern China. The cross-validation results for all 48 stations showed close correlation between the percentile-based indices and the seasonal large-scale variables. Finally, future scenarios of indices of temperature extremes in northern China were projected by applying the statistical downscaling to Hadley Centre Coupled Model Version 3 (HadCM3) simulations under the Representative Concentration Pathways 4.5 (RCP 4.5) scenario of the Fifth Coupled Model Inter-comparison Project (CMIP5). The results showed that the 90th percentile of daily maximum temperatures will increase by about 1.5℃, and the 10th of daily minimum temperatures will increase by about 2℃ during the period 2011-35 relative to 1980-99.