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1.
B. Ilbery  D. Maye 《Geoforum》2006,37(3):352-367
Local food is championed as one alternative response to industrial systems of food production and supply. While advocacy for local food is high, there is a lack of empirical evidence about the actual shape and scale of such food supply chains, especially from a retail perspective. Using supply chain diagrams, this paper presents a summary of ‘new’ agro-food geographies for five different retail types—farm shops, butchers, caterers, specialist shops, supermarkets/department stores—that all source local food from suppliers in the Scottish-English borders. Presented as five separate ‘shopping trips’, the paper examines where, how and why retailers source local food. Results reveal the complex nature of local food systems, especially in terms of intra-sector competitive dynamics (with a notable tension between direct forms of retail and established (independent) retailers), links and overlaps with ‘normal’ food retail systems and elastic notions of the ‘local’. The paper also draws a key distinction between locally produced and locally supplied food products.  相似文献   
2.
In response to the clearing of tropical forests for agricultural expansion, agri-food companies have adopted promises to eliminate deforestation from their supply chains in the form of ‘zero-deforestation commitments’ (ZDCs). While there is growing evidence about the environmental effectiveness of these commitments (i.e., whether they meet their conservation goals), there is little information on how they influence producers’ opportunity to access sustainable markets and related livelihood outcomes, or how design and implementation choices influence tradeoffs or potential synergies between effectiveness and equity in access. This paper explores these research gaps and makes three main contributions by: i) defining and justifying the importance of analyzing access equity and its relation to effectiveness when implementing forest-focused supply chain policies such as ZDCs, ii) identifying seven policy design principles that are likely to maximize synergies between effectiveness and access equity, and iii) assessing effectiveness-access equity tensions and synergies across common ZDC implementation mechanisms amongst the five largest firms in each of the leading agricultural forest-risk commodity sectors: palm oil, soybeans, beef cattle, and cocoa. To enhance forest conservation while avoiding harm to the most vulnerable farmers in the tropics, it is necessary to combine stringent rules with widespread capacity building, greater involvement of affected actors in the co-production of implementation mechanisms, and support for alternative rural development paths.  相似文献   
3.
胡永达 《地质论评》2016,62(S1):103-104
重要矿产资源尤其是战略性矿产的安全保障历来是世界各国关注的重点之一。关于战略性矿产的研究,欧美等发达国家和地区已经建立了一套比较成熟的理论和方法,并不定期更新战略性矿产目录。而我国对于战略性矿产的研究相对较晚,尚未形成统一的内涵意义、评价体系和方法。为此,本文在重新界定战略性矿产内涵基础上构建供应风险-经济价值二维评价体系,运用定性和定量相结合的评价方法综合评价我国主要矿产资源的战略性。  相似文献   
4.
Sand transport in the Colorado River in Marble and Grand canyons was naturally limited by the upstream supply of sand. Prior to the 1963 closure of Glen Canyon Dam, the river exhibited the following four effects of sand supply limitation: (1) hysteresis in sediment concentration, (2) hysteresis in sediment grain size coupled to the hysteresis in sediment concentration, (3) production of inversely graded flood deposits, and (4) development or modification of a lag between the time of a flood peak and the time of either maximum or minimum (depending on reach geometry) bed elevation. Construction and operation of the dam has enhanced the degree to which the first two of these four effects are evident, and has not affected the degree to which the last two effects of sand supply limitation are evident in the Colorado River in Marble and Grand canyons. The first three of the effects involve coupled changes in suspended-sand concentration and grain size that are controlled by changes in the upstream supply of sand. During tributary floods, sand on the bed of the Colorado River fines; this causes the suspended sand to fine and the suspended-sand concentration to increase, even when the discharge of water remains constant. Subsequently, the bed is winnowed of finer sand, the suspended sand coarsens, and the suspended-sand concentration decreases independently of discharge. Also associated with these changes in sand supply are changes in the fraction of the bed that is covered by sand. Thus, suspended-sand concentration in the Colorado River is likely regulated by both changes in the bed-sand grain size and changes in the bed-sand area. A physically based flow and suspended-sediment transport model is developed, tested, and applied to data from the Colorado River to evaluate the relative importance of changes in the bed-sand grain size and changes in the bed-sand area in regulating suspended-sand concentration. Although the model was developed using approximations for steady, uniform flow, and other simplifications that are not met in the Colorado River, the results nevertheless support the idea that changes in bed-sand grain size are much more important than changes in bed-sand area in regulating the concentration of suspended sand.  相似文献   
5.
铅锌资源供需形势分析及市场前景预测   总被引:1,自引:0,他引:1  
从资源保证程度、找矿前景、冶炼原料和金属产品的生产与需求、市场价格的变化趋势等几个方面,对铅锌资源的国内外市场的供需形势进行分析,并对其未来5年的市场前景进行了初步的预测。  相似文献   
6.
玉溪市萝卜子地水源地地下水允许开采量评价   总被引:1,自引:0,他引:1  
陈炜 《云南地质》2007,26(2):242-248
萝卜子地供水水源地,水文地质条件较复杂。利用多年地下水动态及抽水试验资料上,进行基岩富水地段地下水的补给量计算,以补给量作为该水源地的允许开采量合理。  相似文献   
7.
The limited precious coral (Coralliidae) resources in the Northwestern Pacific have been managed by Taiwan with a comprehensive management plan, by Japan with a strengthened set of management measures, and by China through the listing of such coral as a Category I national treasures. However, continuous increases in coral consumption and coral prices have stimulated overexploitation and poaching of the resource, and hence have undermined the effectiveness of these management schemes. This article discusses the current precious corals supply chain and suggests that the rise of China in purchasing substantial amounts of coral products was the underlying cause for overexploitation and poaching. Several gaps in the management schemes are also identified and discussed. The article finally concludes that there is an urgent need for establishing a cross-disciplinary integrated conservation policy and a regional management platform consisting of the three participating states to address all the relevant social and ecological issues.  相似文献   
8.
重点生态功能区主要承担着提供持续、稳定生态服务的功能,农户作为维护其主体功能的最基础单元和该区最主要的经济活动主体,面临着自然、社会、政策等多重压力,其交互作用不仅加剧了农户的生计脆弱性,更影响到该区主体功能的发挥,当前急需辨明多重压力对农户生计的影响,以便寻求有效的生计脆弱性减缓对策。本文以甘南黄河水源补给区为例,运用入户调查数据与有序Logistic回归模型等方法在识别农户遭受关键压力的基础上,进一步探讨生计压力的交互作用对生计资产可得性的影响。结果显示:① 甘南黄河水源补给区大多数农户遭受自然+经济型多重压力,其中,重点保护区、恢复治理区及经济示范区农户遭受的多重压力分别以自然+经济型、自然+经济型、经济+社会型为主。② 在多重压力的冲击下,重点保护区与恢复治理区农户除了社会资产可得性变化处于稳定状态,其余各类资产可得性变化几乎处于降低态势,而经济示范区农户的金融资产与社会资产的可得性变化处于稳定状态,其余各类资产可得性变化均处于降低态势。③ 婚嫁支出高与农牧产品价格下降、牲畜患病与人畜饮用水困难、子女学费支出高+婚嫁支出高+农牧产品价格下降+养老无保障、建房开支高与生态政策、子女就业困难与农业病虫害等压力的交互作用分别对自然资产、物质资产、金融资产、社会资产、人力资产等的可得性变化影响最强烈。  相似文献   
9.
通过对灌溉水田间入渗机理的研究 ,确定灌溉水田间入渗系数 ,制定合理的灌溉定额与灌溉时间 ,对地下水资源评价以及节约用水 ,发展高效农业非常重要。 1985~ 1996年间 ,在河西走廊的张掖平原堡进行了针对包气带水分运移的专门研究试验工作 ,以此为基础 ,对灌溉水田间入渗补给地下水的机理进行探讨  相似文献   
10.
赵立群  张敏  陈彤 《中国地质》2019,46(S1):105-109
金属矿产是经济社会发展的物质基础。本数据集采集了16种对国民经济发展有重要影响的大宗紧缺矿产(铁、锰、铜、铝、金、铅、锌、镍、铬)、优势矿产(钨、钼、锡、锑)及战略新兴矿产(锂、钴、钛)2006—2017年的世界及中国资源储量、原矿产量、消费量、贸易量及贸易金额等数据。数据集为Excel表格型数据,包含6个sheet表(世界资源量、中国查明资源储量、中国基础储量、中国原矿产量、中国原矿消费量、中国进出口量),旨在分析研究我国在工业化进程中后期阶段所需重要金属矿产的资源现状和供需趋势。数据集显示:①我国大宗紧缺矿产如铁、锰、铜、金等查明资源储量虽稳步增长,但开采消耗量大,使得基础储量增速缓慢;未来需求总量仍将维持高位,国内保障程度不足,进口量持续攀升。优势矿产资源钨、锑储采比低,后备资源接替不足,优势程度下降;②战略新兴矿产锂、钴、钛资源量、基础储量增长缓慢或呈下降态势,国内资源品质较差,难利用资源多;产量、消费量近十年快速增长,且未来将持续高增长,国内资源储量增长缓慢,供需矛盾凸显。该数据集对已有金属矿产供需数据的收集和总结,为今后金属矿产勘查及战略部署提供参考。  相似文献   
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