概念性土壤侵蚀模型的建立及在紫色土小流域的应用

概念性土壤侵蚀模型在描述流域基本过程的同时对参数要求较低,现有概念性模型中计算产沙所需参数主要靠律定或借鉴经验值。该文介绍了1个无需流域出口产沙量长序列观测资料来律定且能适用于研究流域的概念性土壤侵蚀模型。模型中引入了分布式水文模型WetSpa Extension作为水文模块,结合流域内试验小区上建立的流量—产沙量经验关系计算侵蚀量,再结合泥沙输移比构建起产沙模块。通过在紫色土地区小流域的应用表明,模型能够得到较合理的流域出口产流量、产沙量以及侵蚀率的空间分布等模拟结果,在没有试验小区的邻近流域地区也具有推广性,且能作为评价水保措施效益的有力工具。该概念性模型对于流域出口泥沙资料稀少的地区具有很高的应用价值和协助流域管理的 潜力。     

词汇的意义

词的意义可以被划分为概念意义和联想意义。联想意义又再次被划分为内涵意义，社会意义，情感意义，反射意义。搭配意义和主题意义。     

基于语料的英汉情感隐喻对比研究

认知语言学家们认为隐喻不仅是人类认知和思维的工具,而且在情感概念中也起着重要的作用。本文在现代认知隐喻理论的框架下基于一定的语料对英汉两种语言中5种基本情感隐喻——爱情、快乐、伤悲、愤怒和恐惧进行了对比研究,结果发现英汉两种语言情感隐喻表达式背后的概念隐喻在类指层面上存在许多相同之处;在特指层面上存在文化上的差异。     

IMPACTS OF LAND COVER CHANGE SCENARIOS ON STORM RUNOFF GENERATION: A BASIS FOR MANAGEMENT OF THE NYANDO BASIN,KENYA

The effects of conceptual land cover change scenarios on the generation of storm runoffs were evaluated in the Nyando Basin. The spatial scenarios represented alternatives that vary between full deforestation and reforestation. Synthetic storm events of depths 40, 60 and 80 mm were formulated according to the rainfall patterns and assumed to have durations corresponding to the runoff times of concentration. The Natural Resource Conservation Service–Curve Number model was used to generate runoff volumes within the sub‐catchments, which were subsequently routed downstream to obtain effects in the whole basin. The simulated land cover change impacts were evaluated relative to values obtained from the actual land cover state of the basin in the year 2000. From the results, an agricultural land cover scenario constituting of about 86 per cent of agriculture indicated increased runoff volumes in the entire basin by about 12 per cent. An agricultural‐forested land cover scenario with 40 and 51 per cent of forest and agriculture respectively revealed reduced runoff volumes by about 12 per cent. Alternatively, a scenario depicting a largely forested land cover state with about 78 per cent of forests reduced the runoff volumes by about 25 per cent according to the model estimates. Runoff volumes in the basin were also likely to reduce by about 15 per cent if the appropriate land cover scenario for the respective sub‐catchments were to be assumed for runoff management purposes. Considering the prevalent data uncertainty, the study effectively highlights the potential hydrological vulnerability of the basin. The results obtained can form a basis for appropriate catchment management of the area. Copyright © 2012 John Wiley & Sons, Ltd.     

SPS暴雨概念模式的研究—物理机制及对北美大陆的降雨分析和预报

经１９６６－１９９４年的观测与研究，提出了一个适合北半球的暴雨预报概念模式，并讨论了它的物理机制及对北美地区降雨分析的结果。     

A new perspective on functional redundancy and phylogenetic niche conservatism in soil microbial communities

Functional redundancy in soil microbial communities seems to contradict the notion that individual species have distinct metabolic niches in multi-species communities.All soil microbiota have the metabolic capacity for"basic"functions(e.g.,respiration and nitrogen and phosphorus cycling),but only a few soil microbiota participate in"rare"functions(e.g.,methanogenesis and mineralization of recalcitrant organic pollutants).The objective of this perspective paper is to use the phylogenetic niche conservatism theory as an explanation for the functional redundancy of soil microbiota.Phylogenetic niche conservatism is defined as the tendency for lineages to retain ancestral functional characteristics through evolutionary time-scales.The present-day soil microbiota is the result of a community assembly process that started when prokaryotes first appeared on Earth.For billions of years,microbiota have retained a highly conserved set of core genes that control the essential redox and biogeochemical reactions for life on Earth.These genes are passed from microbe to microbe,which contributes to functional redundancy in soil microbiota at the planetary scale.The assembly of microbial communities during soil formation is consistent with phylogenetic niche conservatism.Within a specific soil,the heterogeneous matrix provides an infinite number of sets of diverse environmental conditions,i.e.,niches that lead to the divergence of microbial species.The phylogenetic niche conservatism theory predicts that two or more microbial species diverging from the same clade will have an overlap in their niches,implying that they are functionally redundant in some of their metabolic processes.The endogenous genetic factors that constrain the adaptation of individuals and,thus,populations to changing environmental conditions constitute the core process of phylogenetic niche conservatism.Furthermore,the degree of functional redundancy in a particular soil is proportional to the complexity of the considered function.We conclude with a conceptual model that identifies six patterns of functional redundancy in soil microbial communities,consistent with the phylogenetic niche conservatism theory.     

新林林业局森林资源动态分析与综合评价

以新河林业局两次森林资源规划设计调查数据为依据，分析了该局的森林资源动态变化，做出了综合评价，并对该地区的林业发展提出了建议。     

云南公路建设环境影响评价指标体系研究

基于压力—状态—响应概念框架，并充分考虑云南山区社会环境和自然环境的特点，提出了云南公路建设项目环境评价指标体系。该指标体系以公路建设和运营对环境造成的压力作为基础指标，从时间和空间两方面的作用确定不同建设阶段的状态、响应指标。该指标体系涵盖面广，综合性强，适于公路交通各阶段环境影响评价使用。     

当前中国农村的贫困问题

20世纪中国农村贫困人口的快速下降得到了国际社会的广泛好评。但是进入新世纪以后，农村贫困问题并没有继续得到明显改善，贫困人口数量保持刚性稳定，过去对贫困人口数量的估算也受到了各方面的质疑。贫困人口生计脆弱性、妇女贫困等一系列的贫困问题仍然十分严峻。本文从我国贫困人口数量、贫困人口分布、贫困结构和贫困程度以及贫困人口生计等角度，总体叙述了当前中国农村的贫困问题。     

农作物种植面积“一张图”遥感监测业务设计及应用

【目的】农作物种植面积遥感监测是世界农业大国农情遥感监测业务的主要内容,监测结果也是政府宏观监测与生产管理的重要依据。所以农作物种植面积"一张图"遥感监测业务的设计及应用为农业生产定量化管理提供进一步服务。【方法】文章在农作物种植面积"一张图"概念定义的基础上,提出了基于低、中高空间分辨率2种数据源的"一张图"遥感监测技术方案,并采用EOS/MODIS、GF-1/WFV数据实现了全球、中国大陆区域冬小麦空间分布"一张图"的监测方案应用。【结果】农作物种植面积"一张图"概念的提出,是从监测范围与监测内容上对农作物种植面积遥感监测业务的规范,对遥感监测技术从基础研究向实际应用具有推动作用。【结论】现有遥感数据、分类识别技术能够保证"一张图"遥感监测业务方案的实施与实现。限制遥感数据向"一张图"成果转化的技术瓶颈,是遥感监测自动识别技术的精度与能力。在今后较长一个时期内,从全球及国家尺度出发,开展作物光谱分布规律研究,进而提出普适性较高的算法,是提高全球、国家尺度农作物种植面积"一张图"遥感监测业务效率的主要途径。