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Daniel J. Foley Itiya P. Aneece Pardhasaradhi G. Teluguntla Adam J. Oliphant 《International Journal of Digital Earth》2020,13(8):939-975
ABSTRACT The overarching goal of this study was to perform a comprehensive meta-analysis of irrigated agricultural Crop Water Productivity (CWP) of the world’s three leading crops: wheat, corn, and rice based on three decades of remote sensing and non-remote sensing-based studies. Overall, CWP data from 148 crop growing study sites (60 wheat, 43 corn, and 45 rice) spread across the world were gathered from published articles spanning 31 different countries. There was overwhelming evidence of a significant increase in CWP with an increase in latitude for predominately northern hemisphere datasets. For example, corn grown in latitude 40–50° had much higher mean CWP (2.45?kg/m³) compared to mean CWP of corn grown in other latitudes such as 30–40° (1.67?kg/m³) or 20–30° (0.94?kg/m³). The same trend existed for wheat and rice as well. For soils, none of the CWP values, for any of the three crops, were statistically different. However, mean CWP in higher latitudes for the same soil was significantly higher than the mean CWP for the same soil in lower latitudes. This applied for all three crops studied. For wheat, the global CWP categories were low (≤0.75?kg/m³), medium (>0.75 to <1.10?kg/m³), and high CWP (≥1.10?kg/m³). For corn the global CWP categories were low (≤1.25?kg/m³), medium (>1.25 to ≤1.75?kg/m³), and high (>1.75?kg/m³). For rice the global CWP categories were low (≤0.70?kg/m³), medium (>0.70 to ≤1.25?kg/m³), and high (>1.25?kg/m³). USA and China are the only two countries that have consistently high CWP for wheat, corn, and rice. Australia and India have medium CWP for wheat and rice. India’s corn, however, has low CWP. Egypt, Turkey, Netherlands, Mexico, and Israel have high CWP for wheat. Romania, Argentina, and Hungary have high CWP for corn, and Philippines has high CWP for rice. All other countries have either low or medium CWP for all three crops. Based on data in this study, the highest consumers of water for crop production also have the most potential for water savings. These countries are USA, India, and China for wheat; USA, China, and Brazil for corn; India, China, and Pakistan for rice. For example, even just a 10% increase in CWP of wheat grown in India can save 6974 billion liters of water. This is equivalent to creating 6974 lakes each of 100?m³ in volume that leads to many benefits such as acting as ‘water banks’ for lean season, recreation, and numerous ecological services. This study establishes the volume of water that can be saved for each crop in each country when there is an increase in CWP by 10%, 20%, and 30%. 相似文献
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《Norsk geografisk tidsskrift. Norwegian journal of geography》2012,66(5):291-300
Women workers in Export Processing Zones (EPZs) in Sri Lanka are often exposed to harsh working conditions and a range of negative social experiences due to their perceived low social status. Research has demonstrated that they experience both empowerment and disempowerment as a result of formal employment. The authors explore the differences between female Sri Lankan EPZ workers who felt empowered (n = 2196) and those who did not (n = 107), and investigate factors that contribute to empowerment. The analysis reveals a significant difference between the two groups of workers: empowered women had a longer history of employment service, saved significantly more money, and contributed much less to their family than non-empowered women. There were no significant differences in social experiences between the groups. However, the work-related variables used to investigate reported influential factors in empowerment demonstrated that as savings increased so too did the likelihood of empowerment. Conversely, as the proportion of the contribution to the family income increased, the odds of reporting empowerment decreased. The findings suggest that work factors may not be the most important in the establishment of and/or reporting empowerment but rather earnings management and contribution to household appear to be a more significant determining factor. 相似文献
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利用我国2011-2015年典型产业淘汰落后产能数据,研究了通过淘汰落后产能实现产业结构减排的净能源节约量,评价了不同行业在节能中发挥的作用,分析了全国范围内典型产业转型能源节约量的动态变化情况。估算结果表明：2011-2015年淘汰落后产能的年净能源节约量分别为1357.77万、1245.70万、1067.32万、981.42万和483.70万tce,期间累计净能源节约预期达到5135.91万tce;电力、水泥、造纸、炼铁、焦炭、炼钢和铁合金7个行业部门2011-2015年累计淘汰落后产能净能源节约量之和占到20个行业部门净能源节约量的90%;河北省、山东省和山西省淘汰落后产能能源节约量最为突出,占全部能源节约量的近28%。 相似文献
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A method to map riparian exotic vegetation (Salix spp.) area to inform water resource management 
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下载免费PDF全文 Hydrological processes within riparian environments worldwide are impacted when introduced species invade. Monitoring and management at substantial expense, are subsequently required to combat deleterious effects on the environment and stream hydrology. Willow species (Salicaceae: Salix spp.) introduced into Australia have spread throughout many riparian systems causing adverse environmental impacts, with high rates of water extraction when located within stream beds (in‐stream willows) thus altering hydrology. Strategies exist to manage willows; however, simpler, more cost‐effective methods are required to map and monitor spatial and temporal distributions. A method is presented to discriminate willow stands from surrounding native riparian vegetation using a single, very high 2 m resolution multispectral WorldView‐2 satellite image. A combination of spectral bands ‘coastal blue’ (400–450 nm), ‘red’ (630–690 nm), ‘red edge’ (705–745 nm) and ‘near infrared2’ (860–1040 nm), minimum noise fraction transformation, median filtering and maximum likelihood supervised classification provided the highest discriminatory power within a 25 km2 study area. Of the spectral bands, coastal blue, red edge and near infrared2 are new bands that are not available in other multispectral sensors. These bands proved critical to the success of discriminating willows from other land cover categories (overall accuracy of 97%). Stream channels were defined by incorporating a LiDAR‐derived digital elevation model to discriminate between willows on stream banks and within stream beds. Canopy area estimates of in‐stream willows, coupled with water savings estimates from willow removal, suggest removal of 10.4 ha of Salix fragilis canopy from within river channels in the study area will potentially return 41 ML year?1 to the environment. The method presented improves our understanding of willow impacts on hydrology and aids decisions regarding willow removal for water resource management. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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银行业改革与国有商业银行网点空间布局——以中国工商银行和中国银行为例 总被引：3，自引：1，他引：2
伴随着国有商业银行股份制改革,中国国有商业银行在全国的网点布局发生了战略性变化。在经营效益的驱动下,银行采取集中化策略,大幅度减少基础网点数目,而增加支行数目。两类网点地理分布的空间不均衡性加大,地理集中度上升。网点布局向主要经济增长极集中,而从边疆地区与落后地区撤离。对中国工商银行和中国银行基础网点及支行空间分布统计分析表明,两者的两类网点的地理分布在股份制改革后均发生了较大的变化,基础网点更加接近主要客户群体,支行则更加集中在经济发展较好的地区。结合自身的业务优势与特点,两者在两类网点的区位选择上也有一定的差别。国有商业银行经营效益导向的网点布局战略将可能带来落后地区的金融排斥问题。 相似文献
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Global climate change mitigation action is hampered by systematic under-assessment of national ‘fair shares’, largely on the basis of perceived national interests. This paper aims to inform discussions centred on South Africa’s nationally determined contribution (NDC) by estimating (1) emissions reduction pathways for the country using the Climate Equity Reference Calculator (CERC) assuming a maximum 2°C aggregate warming target and (2) the likely economy-wide net mitigation costs or savings associated with reaching these pathways if known lower-cost mitigation measures, identified through the national mitigation potential analysis, are prioritised. The cumulative net savings associated with achieving the CERC ‘fair share’ emissions pathway, assuming the moderate use of low carbon power generation measures, would reach $5.3 billion by 2030. Net savings could be substantially greater reaching $46.8 billion by 2030 assuming power generation focuses on moving towards full decarbonisation. An unconditional commitment to the mitigation action implied by the ‘fair share’ emissions pathway therefore seems reasonable and prudent purely from the point of view of net country-wide savings. Only if power generation moves towards full decarbonisation would there be a reasonable chance of achieving the more ambitious CERC domestic emissions pathway. However, the significant additional cost associated with achieving the domestic emissions pathway should be conditional on international assistance.
Key policy insights
South Africa can only achieve its ‘fair share’ of the global mitigation effort if greater use is made of renewable energy options, and can realise significant net savings if it does so.
Further emissions reductions would incur costs and require significant upscaling of the share of renewable energy and full implementation of all non-power generation mitigation measures available.
Committing to this further mitigation action contingent on international finance would both strengthen the nation’s position in climate negotiations and support the provision of finance for those vulnerable developing nations that bear little or no responsibility for climate change.
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灰岩样品的主要成分为碳酸钙,而镁、钾、钠、铝、钛、铁、锰的含量非常低,测试的灵敏度要求很高。该文采用一次溶矿电感耦合等离子体法直接测试灰岩中的镁、钾、钠、铝、钛、铁、锰。实验表明：在5％的盐酸介质中测试镁、钾、钠、铝、钛、铁、锰能取得很好的效果。通过测试国家标准样品,与国家标准值相比较,分析结果基本一致,准确度和精密度均令人满意,镁、钾、钠、铝、钛、铁、锰元素的相对标准偏差≤0．07％。钙元素的标准偏差≤0．15％。 相似文献
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