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Brazilian semi‐arid regions are characterized by water scarcity, vulnerability to desertification, and climate variability. The investigation of hydrological processes in this region is of major interest not only for water planning strategies but also to address the possible impact of future climate and land‐use changes on water resources. A hydrological distributed catchment‐scale model (DiCaSM) has been applied to simulate hydrological processes in a small representative catchment of the Brazilian northeast semi‐arid region, and also to investigate the impact of climate and land‐use changes, as well as changes associated with biofuel/energy crops production. The catchment is part of the Brazilian network for semi‐arid hydrology, established by the Brazilian Federal Government. Estimating and modelling streamflow (STF) and recharge in semi‐arid areas is a challenging task, mainly because of limitation in in situ measurements, and also due to the local nature of some processes. Direct recharge measurements are very difficult in semi‐arid catchments and contain a high level of uncertainty. The latter is usually addressed by short‐ and long‐time‐scale calibration and validation at catchment scale, as well as by examining the model sensitivity to the physical parameters responsible for the recharge. The DiCaSM model was run from 2000 to 2008, and streamflow was successfully simulated, with a Nash–Sutcliffe (NS) efficiency coefficient of 0·73, and R2 of 0·79. On the basis of a range of climate change scenarios for the region, the DiCaSM model forecasted a reduction by 35%, 68%, and 77%, in groundwater recharge (GWR), and by 34%, 65%, and 72%, in streamflow, for the time spans 2010–2039, 2040–2069, and 2070–2099, respectively, could take place for a dry future climate scenario. These reductions would produce severe impact on water availability in the region. Introducing castor beans to the catchment would increase the GWR and streamflow, mainly if the caatinga areas would be converted into castor beans production. Changing an area of 1000 ha from caatinga to castor beans would increase the GWR by 46% and streamflow by 3%. If the same area of pasture is converted into castor beans, there would be an increase in GWR and streamflow by 24% and 5%, respectively. Such results are expected to contribute towards environmental policies for north‐east Brazil (NEB), and to biofuel production perspectives in the region. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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Peter Kedron 《The Professional geographer》2013,65(3):385-395
Canada's adoption of international climate commitments, national emissions standards, and incentive programs drove expansion of biofuel production using available first-generation technologies in feedstock-rich regions. Market saturation and the emergence of second-generation technologies shifted government support away from first-generation technologies, placing pressure on regional production clusters. This article analyzes how Canadian biofuel firms restructured their value-chain activities in response to those technological and policy changes. The ability to access technologies and navigate multiscalar policy contexts shapes restructuring. Geographic patterns of cellulosic innovation are identified, and the role of firms and policy in regional industrial reorganization is discussed. 相似文献
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Despite the enormous applications of photosynthesis in global carbon budget and food security, photosynthesis research has not been adequately explored as a research focus in Nigeria. Previous works on C3 and C4 plants in Nigeria were mainly on the use of anatomical characteristics to delimit plant species into their respective pathways, with no attention being paid to its applications. In this review, past and present knowledge gaps in this area of study are elucidated. Information used in this review were sourced from referred research articles and books in reputable journals. The results revealed that C3 and C4 plants are distributed among 21 genera and 11 families in Nigeria. In addition there is dearth of informatio such that only three genera have been classified based on diverse photosynthetic pathways with no information found on the physiological and biochemical characterization of these genera. Moreover, further research is also suggested for tackling new challenges in the area of food productivity and climate change. 相似文献
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Domestic Combustion of Biomass Fuels in Developing Countries: A Major Source of Atmospheric Pollutants 总被引：3，自引：0，他引：3
J. Ludwig L. T. Marufu B. Huber M. O. Andreae G. Helas 《Journal of Atmospheric Chemistry》2003,44(1):23-37
Biomass burning has important impacts on atmospheric chemistry and climate. Fires in tropical forests and savannas release large quantities of trace gases and particulate matter. Combustion of biofuels for cooking and heating constitutes a less spectacular but similarly widespread biomass burning activity. To provide the groundwork for a quantification of this source, we determined in rural Zimbabwe the emissions of CO2, CO, and NO from more than 100 domestic fires fueled by wood, agricultural residues, and dung. The results indicate that, compared to open savanna fires, emissions from domestic fires are shifted towards products of incomplete combustion. A tentative global analysis shows that the source strength of domestic biomass burning is on the order of 1500 Tg CO2–C yr–1, 140 Tg CO–C yr–1, and 2.5 Tg NO–N yr–1. This represents contributions of about 7 to 20% to the global budget of these gases. 相似文献
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ABSTRACTThe inherently global, connected nature of aviation means that carbon leakage from aviation policy does not necessarily behave similarly to leakage from other sectors. We model carbon leakage from a range of aviation policy test cases applied to a specific country (the United Kingdom), motivated by a desire to reduce aviation CO2 faster than achievable by currently-planned global mitigation efforts in pursuit of a year-2050 net zero CO2 target. We find that there are two main components to leakage: one related to passenger behaviour, which tends to result in emissions reductions outside the policy area (negative leakage), and one related to airline behaviour, which tends to result in emissions increases outside the policy area (positive leakage). The overall leakage impact of a policy, and whether it is positive or negative, depends on the balance of these two components and the geographic scope used, and varies for different policy types. In our simulations, carbon pricing-type policies were associated with leakage of between +50 and ?150% depending on what is assumed about scope and the values of uncertain parameters. Mandatory biofuel use was associated with positive leakage of around 0–40%, and changes in airport landing costs to promote more fuel-efficient aircraft were associated with positive leakage of 50–150%.Key policy insights
Carbon leakage in aviation policy arises from airline responses (typically positive leakage) and passenger responses (typically negative leakage).
Depending on the geographical scope, policy type and values for uncertain parameters, leakage may be between around ?150 to +150%.
Of the policies investigated in this study, leakage was typically most negative for carbon pricing and most positive for environmental landing charges.
Absolute values of leakage are smallest where policies are considered on the basis of all arriving and departing flights.
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《Norsk geografisk tidsskrift. Norwegian journal of geography》2012,66(3):178-191
The author analyses the state powers steering biofuel development in two European Union (EU) Member States: Finland and Sweden. The different biofuel developments of these countries are approached through the concept of assemblages, which allows analysis of how the spatiality of national development is constituted in relation to the increasingly global development of biofuels. The approach illustrates how national policies implemented by Finland and Sweden are multiscaled in their origins and mediated by the agents of these assemblages. Materials in the study consist of EU and national policy documents, and 16 interviews from the key biofuel agents in Finland and Sweden. The author explains the differentiation of national biofuel assemblages through their distinguishing topologies, advocacy groups, and the properties of national policy instruments. The results demonstrate how Finnish and Swedish policies have influenced national biofuel developments. The EU's biofuel policies have diverging impacts nationally as they are translated into the specific patterns of biofuel production, consumption, and trade. Consequently, the agents of biofuel assemblages affect the transference of biofuel policies that originate from multiple scales into the national policy frameworks of the Member States. 相似文献
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Ethanol from corn stover is expected to play an important role in achieving the Energy Independence and Security Act 2007 target of 136.25 billion liters (36 billion gallons) of biofuel by 2022. The 2010 USDA biofuel strategic report estimates that 16.3 billion liters (4.3 billion gallons) of biofuel from crop residues such as corn stover and straw is possible. Corn stover is expected to provide the majority of the estimated biofuel from crop residues, especially from the Midwestern US Corn Belt. A major concern related to removing corn stover is potential negative hydrologic and water quality impacts. The overall goal of this study was to estimate the watershed scale environmental impacts of corn stover removal in an agricultural watershed in the Midwest US. Soil and Water Assessment Tool was used to simulate the impacts associated with three corn stover removal rates (38%, 52% and 70%). The stream flow, nitrate and mineral phosphorus loading were reduced, and sediment and organic nitrogen loading were increased at the watershed outlet with all three stover removal scenarios. The stream flow was reduced by 1.4%, 2.0% and 2.7% from the baseline scenario (no stover removed) at 38%, 52% and 70% stover removal rates, respectively. The sediment loading increased by 19.7%, 22.5% and 29.0%, organic nitrogen increased by 0.8%, 2.0% and 5.5%, mineral phosphorus decreased by 11.7%, 15.5% and 21.0%, and nitrate decreased by 2.0%, 3.2% and 5.3% from the baseline scenario at the watershed outlet with 38%, 52% and 70% stover removal rates, respectively. The model results also indicate that the watershed response to stover removal is sensitive to watershed characteristics and management inputs, such as, slope and amount of fertilizer applied. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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Sumira Malik Shristi Kishore Jutishna Bora Vishal Chaudhary Anjali Kumari Preeti Kumari Lamha Kumar Abhaya Bhardwaj 《洁净——土壤、空气、水》2023,51(3):2200044
In the past few years, microalgae have gained huge recognition from the scientific community due to their potential applications in the production of a broad array of bio-based products varying from biofuels to nanoparticles. Due to their elevated growth rate, high tolerance to various types of abiotic stresses, and complex metabolic capacity, microalgae can be used as promising tools for the attainment of a circular bioeconomy. Moreover, they can simply utilize nutrients from wastewater for biorefinery purposes, resulting in resource recovery coupled with wastewater treatment. However, due to their sub-optimal yields and high production costs, microalgae-based bio-products have not yet been commercialized. This review provides insights into the employment of microalgae as an efficient bioresource for the treatment of wastewater with simultaneous enactment as a biorefinery to produce biofuels, biochar, bioplastic, fertilizers, and other high-value bioproducts. Furthermore, the application of microalgal nanoparticles in wastewater treatment and prospects for genetic modification of microalgae for enhanced biorefinery capabilities have also been briefly highlighted. 相似文献
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