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61.
城市地质是基础地质理论在城市建设中的应用领域。基础地质调查成果是城市地质研究的基础。目前,我国城市地质研究中普遍存在基础地质薄弱、灾害地质调查忽视基本的成因分析、第四系覆盖区地质调查带有明显的盲目性、基岩出露区地质调查忽视基本结构构造分析等问题。基础地质调查在国民经济建设中的地位不应该被忽视。如果城市地质在城市建设和可持续发展中处于基础地位,基础地质则是基础中的基础。它成为薄弱环节,是严重的策略性失误。  相似文献   
62.
1952~2003年我国区域经济发展不均衡的 长期变化态势   总被引:2,自引:1,他引:2  
文中分别利用Gini、GE等指数,以实际人均国内生产总值(GDP)为指标,详细考查了从1952~2003年,我国省市区间经济发展不均衡的变化态势及其在东部-内陆、南方-北方、高城镇化-低城镇化地区等方向上的变化。人均实际GDP的Gini、GE等指数显示,从1952~2003年,我国省级区域经济发展不均衡的总体态势是以较缓慢的速度逐步增加。具体的变化是,随着时间的推移区域经济不均衡呈周期性地上升、下降运动。就我国省市区经济发展不均衡在空间上的变化而言,一是在沿海-内陆和高城镇化-低城镇化方向上,分别在1990s中期和1980s中期以前,我国省市区经济不均衡主要表现为区域内部不均衡,但区域之间不均衡则不断增加,并逐步成为省市区经济不均衡主要部分;一是,在北方-南方方向上,我国省市区经济不均衡则是一直表现为区域内部不均衡,区域之间不均衡对省市区经济不均衡的贡献一直显得微不足道。  相似文献   
63.
In this intervention article I contribute to discussions of moral economy by arguing that scholars should reconsider the nature of value. Neoliberalism considers only exchange value. As a consequence neoliberal policies try to manage problems such as climate change with economic systems and instruments that are mis-calibrated to the material realities they are meant to represent. Value has spatial and temporal characteristics. Recognizing the spatial and temporal dynamics of value leads to new means of resource valuation, such as extending the time-frame of instruments and changing the nature of privatization. In conclusion, I argue for the need for new theories of use value.  相似文献   
64.
Significant changes have been observed in the hydrology of Central Rift Valley (CRV) lakes in Ethiopia, East Africa as a result of both natural processes and human activities during the past three decades. This study applied an integrated approach (remote sensing, hydrologic modelling, and statistical analysis) to understand the relative effects of natural processes and human activities over a sparsely gauged CRV basin. Lake storage estimates were calculated from a hydrologic model constructed without inputs from human impacts such as water abstraction and compared with satellite‐based (observed) lake storage measurements to characterize the magnitude of human‐induced impacts. A non‐parametric Mann–Kendall test was used to detect the presence of climatic trends (e.g. a decreasing or increasing trends in precipitation), while the Standard Precipitation Index (SPI) analysis was used to assess the long‐term, inter‐annual climate variability within the basin. Results indicate human activities (e.g. abstraction) significantly contributed to the changes in the hydrology of the lakes, while no statistically significant climatic trend was seen in the basin, however inter‐annual natural climate variability, extreme dryness, and prolonged drought has negatively affected the lakes. The relative contributions of natural and human‐induced impacts on the lakes were quantified and evaluated by comparing hydrographs of the CRV lakes. Lake Abiyata has lost ~6.5 m in total lake height between 1985 and 2006, 70% (~4.5 m) of the loss has been attributed to human‐induced causes, whereas the remaining 30% is related to natural climate variability. The relative impact analysis utilized in this study could potentially be used to better plan and create effective water‐management practices in the basin and demonstrates the utility of this integrated methodology for similar studies assessing the relative natural and human‐induced impacts on lakes in data sparse areas. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
65.
Working through a Caribbean case study, this paper examines the networks and associations of Fair Trade bananas as they move both materially and morally from farms in St Vincent and the Grenadines to supermarkets and households in the United Kingdom. In doing so, the paper provides grounded empirical evidence of Fair Trade’s moral economy as experienced by banana producers in the Caribbean. The paper follows Nancy Fraser’s distinction between ways of framing justice to argue that, in order to transcend its complex postcolonial positionalities, the Fair Trade Foundation needs to include recognition in its moral economy as well as representation and redistribution. The paper compares the moral framework of Fair Trade as an ideology and social movement with the lived experience of certified Fairtrade banana farmers in the Windward Islands who work mostly for, rather than within, an idealized moral economy. The paper also contributes to several recent debates in the agri-food literature exploring the interconnections between production and consumption, the role of materiality in contemporary food networks, the historical and (post)colonial nature of food moralities, and links between political and moral economies of food. Following an outline of recent debates about the moral economies of food and its relation to Fair Trade as a movement, the paper dissects the moral economy of the Fairtrade Foundation, highlighting the historical and geographical, material and symbolic, gendered and generational ways that food producers in the Global South (in this case, banana farmers in St Vincent and the Grenadines) may be counterposed to ‘responsible’ consumers in the Global North. Despite the good intentions of those who promote the Fair Trade movement through the Fairtrade Foundation and the Fairtrade Labelling Organisation (FLO), our case study reveals a moral economy of non- (or partial) recognition, which has a range of unintended consequences and paradoxical effects.  相似文献   
66.
67.
中国区域性极端降水事件及人口经济暴露度研究   总被引:4,自引:1,他引:3  
基于中国1960-2014年771个气象站的逐日降水资料,选取有效降水序列95百分位数作为极端降水阈值,将既定持续时间尺度和连续面积上超过阈值的降水事件定义为区域性极端降水事件。采用强度-面积-持续时间(Intensity-Area-Duration,IAD)法,根据极端降水事件空间和时间上的连续性特征,对不同持续时间的区域性极端降水事件演变趋势及暴露于极端降水事件下的人口和国内生产总值进行研究。结果表明:(1)相对强度最大的区域性极端降水事件主要集中在1960-1968、1991-1999和2006-2013年3个时段;(2)区域性极端降水事件最强中心主要分布在长江以南和东北地区,发生在北方的多为单日极端降水,南方多为持续多日的极端降水;(3)1960-2014年区域性极端降水事件影响面积有所增大,相对强度变化不明显;(4)暴露于极端降水事件影响区域内的人口和国内生产总值均呈显著增大趋势,暴露人口最多的年份在1983年,达到2408万人/d,暴露国内生产总值最多的年份在1998年,达到20亿元/d。   相似文献   
68.
Since it was first proposed in 2000, the concept of the Anthropocene has evolved in breadth and diversely. The concept encapsulates the new and unprecedented planetary-scale changes resulting from societal transformations and has brought to the fore the social drivers of global change. The concept has revealed tensions between generalized interpretations of humanity’s contribution to global change, and interpretations that are historically, politically and culturally situated. It motivates deep ethical questions about the politics and economics of global change, including diverse interpretations of past causes and future possibilities. As such, more than other concepts, the Anthropocene concept has brought front-and-center epistemological divides between and within the natural and social sciences, and the humanities. It has also brought new opportunities for collaboration. Here we explore the potential and challenges of the concept to encourage integrative understandings of global change and sustainability. Based on bibliometric analysis and literature review, we discuss the now wide acceptance of the term, its interpretive flexibility, the emerging narratives as well as the debates the concept has inspired. We argue that without truly collaborative and integrative research, many of the critical exchanges around the concept are likely to perpetuate fragmented research agendas and to reinforce disciplinary boundaries. This means appreciating the strengths and limitations of different knowledge domains, approaches and perspectives, with the concept of the Anthropocene serving as a bridge, which we encourage researchers and others to cross. This calls for institutional arrangements that facilitate collaborative research, training, and action, yet also depends on more robust and sustained funding for such activities. To illustrate, we briefly discuss three overarching global change problems where novel types of collaborative research could make a difference: (1) Emergent properties of socioecological systems; (2) Urbanization and resource nexus; and (3) Systemic risks and tipping points. Creative tensions around the Anthropocene concept can help the research community to move toward new conceptual syntheses and integrative action-oriented approaches that are needed to producing useful knowledge commensurable with the challenges of global change and sustainability.  相似文献   
69.
利用NCEP/NCAR再分析和全国740站逐日降水资料,运用一点滞后相关等方法,对2007年夏季江淮流域强降水期间低频振荡的波动活动特征及其与降水低频变化的联系进行了分析。结果表明,在2007年夏季降水中,降水低频分量起着重要作用。降水的低频振荡主周期为10~30d,降水距平时间序列与10~30d低频分量具有较好的对应关系。低频扰动在对流层上层和低层都呈现波列状分布,且在降水活跃位相时,低频环流在高、低层具有斜压结构。在对流层上层,低频扰动有缓慢的东移倾向,相速度为每天2~3个经度。西风带中存在多次移动性波列向下游的传播,且在120°E以西以每天14经度的群速度向下游频散能量,表明10~30d低频波动具有明显的下游发展特征。在强降水开始5d前,低频波动与能量可起源于高纬的乌拉尔山附近,沿着西北-东南向的路径向下游传播。下游发展的低频波动为江淮流域带来了能量,为强降水的发生提供了条件。这些结果加深了人们对低频波动在江淮流域强降水过程中所起作用的认识,可为寻找江淮流域强降水过程预报线索提供科学依据。  相似文献   
70.
新疆北山裂谷带中出露有数量众多的镁铁-超镁铁岩,坡一铜镍矿位于北山裂谷金铜镍成矿带西部、坡北镁铁-超镁铁岩带西南部。经1989~2014年的持续勘查,坡北岩带中的坡一铜镍矿规模达到100万吨以上。笔者在前人工作的基础上,结合裂谷环境下成岩机制,分析了坡一铜镍矿成矿环境及成矿作用演化特征,树立了独特的多期岩浆成矿模式,建立了找矿标志,为成矿带镁铁-超镁铁岩浆硫化物型铜镍矿床建立了成矿模型,且对成矿远景做了探讨。  相似文献   
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