Context of the suboxic layer in the Arabian Sea

The setting of the Arabian Sea is reviewed in order to examine which of the circumstances causing large oxygen depletion in the ocean are responsible for the suboxic layer (concentrations < 0.1 ml 1⁻¹) in the northern thermocline there. The wind field forces circulations that restrict but do not exclude exchange with the south, and a recent box-model interpretation of trichlorofluoromethane measurements indicates a modest throughflow for the layer of about 5 × 10⁶m^{3s −1}.The associated oxygen-flux divergence is roughly consistent with biochemical determinations of local oxygen-consumption rates, both approaches giving values (3–6 pl 1⁻¹ s^τ-1) that are modest in comparison with estimates elsewhere in the world ocean. Despite the high mean-annual surface productivity in the region (nearly 1gCm⁻² day⁻¹), it seems plausible that too little of this particulate matter is consumed at thermocline depths to cause an inflated oxygen demand there. Since the layer is neither an isolated pool, nor a sluggish backwater, nor a conspicuous oxygen sink, the suboxic concentrations must be due (as earlier proposed) to the low concentration in the water entering the layer from the south. That depletion in turn seems due to moderate consumption as the water travels the very long trajectories from its zone of sea-surface renewal (Lats. 40–50°S). Although large seasonal variations are expected in both throughflow volume transport and surface productivity (suggesting comparable changes in consumption rate), the volume of the suboxic layer seems big enough to buffer the oxygen levels there against any very noticeable overall variability.     

国内外生命历程与居住选择研究回顾和展望

1970年代后生命历程分析成为贯穿居住选择微观研究的核心方法。住房权属选择和居住流动是西方居住选择微观研究的主要内容。西方研究大多为应用生命历程观念将住房权属转换和居住流动决策与家庭生命历程和住房市场中的重要诱因联系起来,发现家庭特征、家庭生命周期变化和住房市场环境等都是居住选择的重要影响因素。对比西方的研究,中国城市居住选择微观研究非常缺乏,一些研究发现除了家庭特征和住房市场特征外,政府和工作单位的影响非常大。     

世界能源保障基本形势探讨

国家能源保障主要由能源供应的稳定性和能源使用的安全性两个部分组成。论文从影响能源保障的资源基础、能源生产与消费、能源贸易与运输、能源消费对环境的破坏等方面分析了世界能源保障的基本形势,世界能源保障还主要停留在能源供应的稳定性层面上,对使用安全性尽管在思想已经认识到,但是在行动上还远不尽人意,世界能源保障应该从目前主要追求供应稳定性向追求供应稳定性和使用安全性的双重目标转变。由能源生产、消费、贸易与运输等组成的世界能源保障基本格局,随着中国、印度等发展中国家能源国际化的进一步推进,正受到巨大的冲击并不断进行重组。     

Environmental psychology and the geographies of ethical and sustainable consumption: aligning, triangulating, challenging?

Human geographers' research into lay responses to burgeoning environmental issues has highlighted their mediated and contingent constitution. Situated within the discipline's cultural turn, this work has challenged prevailing informational and cognitive approaches to sustainability. In doing so, however, potentially informative concepts and findings from environmental psychology have been sidelined. In this paper I attempt a modest allying of the two sub-disciplines, outlining their differences and similarities, and arguing that environmental psychology can triangulate with human geography, as well as challenge tendencies within human geography literatures to simplify the 'psychological' subject.     

New populations in the British city centre: Evidence of social change from the census and household surveys

Encouraged by government policies to promote city centre living and to increase residential land use on brownfield sites, there has been considerable repopulation of the city centre. Through detailed small-area census analysis of Birmingham, Bristol, Cardiff and Swansea, supplemented by household surveys and key informant interviews, the research points to a range of population characteristics and changes occurring in the British city centre. Certain characteristics such as a high proportion of lone person households, fewer children and low car ownership remain fairly consistent. However, substantial population expansion affirms that a large part of the population is “new”. Between 1991 and 2001, men came to outnumber women, and each of the city centres saw a relative expansion of its young adult population. The new residents have a higher appreciation than longer term residents of proximity to work and leisure facilities, and of the stylishness of city centre living. Most of the new residents rent their accommodation, generally in flats, and the predominance of renting is associated with a transient attitude to city centre residence among the new population. Socio-economic evidence indicates a striking rise in social status or gentrification in all the city centres investigated, especially where high status private housing developments encourage the trend. With policies promoting residential development, the city centre is becoming increasingly socially exclusive.     

Consumption preferences and environmental externalities: A hedonic analysis of the housing market in Guangzhou

The urban housing market of China has been transformed since the 1980s from a centrally-planned to a free-market system. This study aimed to (1) investigate the position of outdoor environmental quality in house-buyers’ preferences; (2) assess monetary values attributed to environmental externalities by the hedonic pricing method (HPM); and (3) test the applicability of HPM in China. The study area was Guangzhou, the major city of south China with a booming real-estate market. A questionnaire survey was conducted with households in new residences sold in 2004. The main buying motives were improving living quarters and floor area. Security concerns and a preference for high-rise buildings were somewhat unexpected. Good outdoor environment, including green space provision, proximity to parks, and views of green space and water, carried significant hedonic values. Differences between the submarkets of old and new towns were found; new town households expected apartments in high-rise blocks, exclusive residential land use, and views of green space, while old town households preferred proximity to shopping areas and workplaces, green space within the development and proximity to nearby parks. The findings could help to fine tune the developing housing market to match supply with demand in quality terms. Values accorded to environmental attributes could justify funding for urban green spaces and nature conservation. The study verified the applicability of HPM to the housing context in China.     

Local housing price index analysis in wind-disaster-prone areas

This study examines the effect of severe wind events on the mean and variance of housing price indices of six metropolitan statistical areas (MSA) that are vulnerable to hurricanes and/or tornadoes. The research focuses on three areas that experienced significant tornado activity (Fort Worth-Arlington, Nashville, and Oklahoma City) and three hurricane-prone areas (Corpus Christi, Miami, and Wilmington, NC). An econometric time series model that captures the housing market responses to severe windstorms is utilized. The model estimates changes in the local housing price index (HPI) as a function of several control variables as well as dichotomous variables that correspond to the tornadoes and hurricanes. As expected, the statistical findings indicate an immediate but short-lived decline in housing prices following a tornado or hurricane. Somewhat surprising is the result that the impact on the housing market is remarkably consistent whether the wind event was a hurricane or a tornado. Hurricanes and tornadoes are vastly different in terms of the point probabilities of a hit, the scope of the affected area and the lead time that supports last minute preparation to mitigate damage. It appears that the market response to destruction of real property does not distinguish between the types of wind event that produced the damage to the region. Results suggest that windstorms result in an immediate one-half to two percent reduction in total MSA housing value. This corresponds to a range of $34 million to $580 million in lost housing value. Estimates indicate some differences in how long market values continue to decline in the periods following the wind event; however, most of the decline occurs within four quarters after the windstorm. These differences can be attributed to the particular time series characteristics of the specific housing markets and their respective housing price indices. The market serves the purpose of integrating and normalizing the losses. In so doing the market provides a metric— a method for calibrating and comparing structural damage caused by different phenomenon.

1988—2015年新疆农业用水时空变化与政策驱动研究

农业用水是人类开发利用水资源以及影响生态系统的主要扰动因素,科学定量农业用水是合理配置与调控区域水资源的基础工作。传统的农业用水统计只是记录了可测量的用水量,而水足迹则完整刻画了人类活动对水资源系统的压力表现。从水足迹理论出发,采用Cropwat软件计算了新疆1988—2015年近20种农作物生产水足迹总量,并利用Mann-Kendall趋势和突变检验的方法,分析了28年间新疆农作物水足迹的时空变化,探讨了农作物水足迹驱动因素及机制。结果表明：新疆农作物水足迹在28年间总量增加了256%;水足迹序列在2005年前后增长出现了突变,后一阶段增长率是前一阶段的3倍以上;从农作物水足迹中蓝水足迹与绿水足迹的构成看,农作物绿水足迹呈持续增加趋势,但其在农作物水足迹总量中的比例略有下降。进一步分析表明,农业种植规模的快速扩张是新疆农作物水足迹大幅度增加的根本原因,而脱贫致富、扶贫攻坚等经济发展需求下的政策（战略）支持是农业种植规模（灌溉面积）持续快速增长的核心驱动力。通过探究农作物水足迹的变化及原因,揭示了新疆农业用水的时空变化,以及农作物水足迹与国家、地方政策和社会活动之间的关系,可为深入解析新疆农业增长与水资源开发利用及生态环境之间的时空演化关系和相关决策与政策制定提供参考。     

长江干流水化学成因与风化过程CO2消耗通量解析

长江流域面积巨大,岩性多变,加之三峡大坝等重大水利工程的影响,干流河水的水化学成因存在较大争议。此外,以往研究中流域矿物风化过程的碳汇通量估算一般基于阳离子来源分析,但该算法通常涉及多种矿物端元的参数选取,结果具有不确定性。本次研究对长江干流水化学的时空演变进行了整体分析,并基于上游河水样品HCO₃~-含量的校正与计算,提出了一种计算矿物风化过程碳汇通量的新方法。研究结果表明,蒸发盐溶解、循环盐作用、矿物风化及硫酸盐溶解是控制长江干流河水离子组成的主要水文地球化学作用,而人类活动主要影响了离海距离3 000 km以内河水NO₃~-含量;长江上游干流硅酸盐风化消耗CO₂速率为1.16×10~5 mol/(km~2·a),碳酸盐风化消耗CO₂速率为4.75×10~5 mol/(km~2·a)。本研究有助于加深对长江干流主要水文地球化学作用的认识,丰富和完善碳循环研究理论。     

从能耗比论低熟富有机质页岩原位改质转化的经济可行性及增效途径

在原位改质技术开发中,对低熟页岩的巨大的油气资源潜力的技术可行性质疑不多,但由于致热页岩耗能巨大,经济可行性还面临重重质疑,也缺乏有力的定量论证。本文从能量守恒原理出发,对致热页岩过程中生成油气的获能和裂解有机质的耗能、页岩吸热耗能、围岩散热耗能分别进行了定量评价,得到了不同条件下的能耗比及其影响因素,结果表明：能耗比随TOC含量的升高快速增大,对倾油性的页岩,能耗比为3时对应的TOC含量≈4.2%,表明,当TOC含量较高时,有望通过大规模作业摊薄工程成本,使考虑工程成本之后的能耗比>1,即原位加热改质技术可以具有经济效益。从有关因素对能耗比的影响幅度来看,提高经济可行性的增效途径之一是探寻高效致热页岩、减少围岩传导耗热的技术;途径之二是探寻高效转化有机质为油气的技术,即探索具有催化效应/能力的技术,减少页岩吸热和致热时间;途径之三是探寻综合考虑能耗比、时间成本、工程成本的水平井综合布井技术。