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641.
欧盟于2020年10月出台了《欧盟甲烷减排战略》,以支撑其中长期温室气体减排目标。该战略共提出了五个领域的24个行动方案。欧盟将油气行业作为重点,设置了两个强制性的政策来完善能源部门的温室气体监测、报告和核查制度,并禁止天然气放空和燃烧。农业领域以加强全生命周期甲烷排放核算、减排技术等方面研究,编制最佳减排实践和技术清单为主要措施。在废弃物管理领域,欧盟将主要修订废弃物管理方面的立法和废水处理标准并加强监管。全球层面,欧盟提出希望联合包括中国在内的主要油气进口国家,推动建立全球性的监测、报告和核查标准,分享其甲烷超级排放源探测的卫星数据等措施。我国提出2060碳中和愿景后,下一阶段温室气体减排将会从能源相关二氧化碳减排为主扩展到全部温室气体减排。建议我国和欧盟在甲烷减排方面开展广泛合作,借鉴欧盟的经验,尽快制定我国甲烷减排近期、中期、远期目标和行动计划,推广甲烷减排技术,加强科学研究和技术研发,探索在国家碳市场交易体系中纳入甲烷等非二氧化碳气体的时机和方案,鼓励大型能源企业加入国际甲烷减排倡议以提高能力,逐步完善我国甲烷减排相关政策和制度环境,打造我国在低碳领域的经济和技术竞争力。  相似文献   
642.
This Impacts article proposes strategies for mitigating negative impacts of urbanization in rural locations in the United States. Issues addressed include impacts of population growth and development, loss of agricultural lands, and impacts of climate change on agriculture and rural communities. Conclusions are supported by stakeholder survey data, geographic information systems-based data, and desktop reviews of research journal publications. We propose a sustainable, diversified approach that supports mitigation of issues, including increasing demand on food production and decline of rural communities. A key issue that we address is where we will find suitable landscapes to reduce enough food for 9.6 billion people living in 2050.

Urban and rural development planners are grappling with solutions to escalating impacts global populations, stresses on food production, and effects of climate change. Solutions are identified, including strengthening rural and urban contexts by establishing connected and interdependent links that support diversification of rural and urban contexts as viable solutions to these issues.

Diversified rural-to-urban sustainable agriculture production is a promising approach to addressing climate change impacts. Organic agriculture principles exhibit strong diversity and are accredited by United States Department of Agriculture as the only federally certified sustainable agriculture practice in the United States. Sustainable agriculture practices are evolving into profitable diversified alternative food sources. We offer substantiated alternative solutions for remediating impacts of urbanization on rural agriculture and communities. Collectively, these solutions can strengthen symbiotic relationships between sustainable agriculture and rural communities, addressing our growing population issues and preserving our dwindling farmlands and rural communities.  相似文献   

643.
为了提升防灾减灾系统的运行效率,研究应急物流设施选址-分配问题,构建考虑设施可靠性要素的双目标混合整数规划模型,以最小化系统总成本和最大化客户需求覆盖率为目标,确定应急物流中心的选址区位和各节点间各种物资的分配方案;考虑即使是选中开放的设施,也存在一定的中断概率,因此以不同情形表示开放设施中存在中断设施的情况;最后,通过MATLAB实现NSGAII算法,对模型求解,得出灾害发生时应急物流设施需求覆盖率与系统总成本的关系,为灾害发生后救援系统救灾成本和受灾点需求满足程度的权衡优化,提供可参考思路。  相似文献   
644.
ABSTRACT. A mathematical model to predict water quality in a surface-groundwater system is under development. This project is being sponsored by the Environmental Protection Agency. The ultimate goal of this study is to obtain cause and effect relationships between pollutant sources and the ensuing concentrations at different locations in a basin. Several programs are used to model the various hydrologic processes occurring in nature, namely: rainfall, runoff, flow in surface bodies of water, infiltration, and groundwater flow. At every time step in the simulation, the water quantity computations for the above hydrologic models are performed first. Subsequently, the results of these computations, typically in the form of flow velocities, are used as input to the water quality calculations. The water quality routines involve the modeling of the associated physical, chemical, and biological processes. In this study, emphasis is being placed on pollution in agricultural areas. Accordingly the Lake Apopka basin in Central Florida is being used as the application site.  相似文献   
645.
利用信息技术建立农村信息服务体系   总被引:6,自引:0,他引:6  
以学校信息公共服务体系为依托,以网络、通讯、电视等信息技术为基础,建立雅安星火科技网、农民科技110、电视网络”三套信息服务系统,同时用三套信息服务系统向农民传输信息。这对指导农业生产的产前、产中和产后管理,农业结构调整,改造传统农业,推动农业信息化和智能化的发展,实现农业和国民经济可持续发展,具有十分重要的作用和意义。  相似文献   
646.
Corrales N  Campos M 《Chemosphere》2004,57(11):1613-1619
The influence that different styles of olive-orchard management (conventional, integrated, and organic) exert on the predator Chrysoperla carnea has been studied to strengthen this insect’s role in the integrated management against pests. For this, the adult chrysopid populations were determined by McPhail traps, and laboratory examinations were made of certain biological characteristics of the first generation of adults captured in each of the olive orchards studied. The chrysopid populations increasing significantly during some months in the integrated and organic olive orchard. The most abundant species in all the zones was C. carnea, representing 95% of all captures in the conventional olive orchard. It was found that the larvae from the integrated olive orchard took longer to develop, while the pupae from the organic orchard evolved most rapidly to adulthood. The highest mortality rate was for larvae in the conventional olive orchard. The fecundity of the females from the organic orchards was significantly greater, presumably due to their greater longevity and shorter pre-oviposition period. These results can be used to improve conservation strategies and to increase C. carnea populations and their predatory activity.  相似文献   
647.
An observational study was conducted at the watershed scale using land cover (vegetation) data to assess the absence or presence of riparian buffers in three northeastern Missouri watersheds. Forests and grasslands lying within a 61 m (200 ft) parallel band directly adjacent to streams were considered “buffers” for improving or protecting water quality and were characterized according to their length, width, and vegetation type. Results indicated that riparian buffers were abundant throughout the watersheds but were typically narrow along first‐order and second‐order streams; in many cases they may not have been wide enough to provide adequate stream protection. At least 90 percent of all streams had buffer vegetation immediately adjacent to the streambanks, but as few as 31 percent of first‐order streams had buffers extending to 61 m from the stream on at least one side. On‐site evaluations are needed to determine the condition of these forests and grasslands and their ability to process nonpoint source pollutants. The results will be useful for providing natural resource managers with knowledge of current watershed conditions as well as in identifying specific locations for future conservation efforts within each watershed.  相似文献   
648.
This article makes an assessment of the following key natural resources in the Okavango Delta: arable land, basket-making resources, fish stocks, and river reeds. Non-data-intensive socio-economic indicators (as opposed to conventional data-intensive indicators) of trends in resource prices, trends in labour time for resource extraction, substitution of less preferred commodities, maximum sustainable yield and perceived scarcity were utilized to assess the scarcity of the resources. The study reveals that basket-weaving resources, land for flood recession arable (molapo) agriculture, and river reeds are increasingly becoming scarce in the harvesting areas, whereas fish stocks are still abundant. It is recommended that appropriate policies should be introduced for the management of natural resources. Property rights could be granted to communities to manage natural resources such as fish and veld products in line with the wildlife model for community based natural resources management (CBNRM). In addition, the authors suggest that the Government of Botswana should take the responsibility for allocating land for molapo arable farming in order to make it more accessible.  相似文献   
649.
ABSTRACT: This paper examines irrigation water supply deficit and associated risk indicators due to random climate events and potential effects on irrigated food production during the period 1996 to 2025 for seven river basins in the USA, China, and India. An integrated water and food model with global scope is applied for the analysis. The global climate regime during 1961 to 1990 is used to generate 30 climatic scenarios for the time period 1996 to 2025, and these scenarios are applied to the model in order to characterize the randomness of precipitation, runoff, and evapotranspiration, which affects both irrigation water supply and demand. The risk with random climate events is represented by reliability, variability, and vulnerability from different perspectives. Regarding irrigation water supply, Colorado will bear an increasingly unstable situation although the average water supply relative to the demand will maintain at a relatively high level; selected basins in China and India indicate that significantly lower levels of reliability and more deleterious affects from drought can be expected, but under a less variable condition due to assumed water storage increase. From 1996 to 2025, the effects of water deficits on irrigated food production are characterized with a nonlinear phenomenon and food production loss will be more sensitive to irrigation water supply deficit in the future. Future work following this paper needs to consider the impact of global climate change and the water quality of the irrigation return flow and result verification by local studies.  相似文献   
650.
Procedures that increase the sustainability of agriculture often result in animals being treated more humanely:both livestock in animal and mixed farming and wildlife in arable farming. Equally, procedures ensuring humane treatment of farm animals often increase sustainability, for example in disease control and manure management. This overlap between sustainability and humaneness is not coincidental. Both approaches can be said to be animal centered, to be based on the fact that animal production is primarily a biological process. Proponents of both will gain from recognition of commonality and development of cooperation. A collaborative approach to humane sustainable agriculture will benefit animals, people, and the environment.  相似文献   
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