基于灰色关联度模型的区域滑坡敏感性评价

数理统计和机器学习模型如支持向量机(support vector machine,SVM)等,在区域滑坡敏感性评价中得到广泛的应用.但这些模型的建模过程往往较复杂,如在对机器学习进行训练和测试时难以选取合理的非滑坡栅格单元,而且有较多的模型参数需要确定.为提高滑坡敏感性评价建模的效率和精度,提出基于灰色关联度的敏感性评价模型.灰色关联度模型能有效计算各比较样本与参考样本之间的定量的关联度,具有建模过程简洁和评价精度高的优点,该模型目前在区域滑坡敏感性评价中的应用还没有引起研究人员的足够关注且有待进一步拓展.拟将灰色关联度模型用于浙江省飞云江流域南田—雅梅图幅(南田地区)的滑坡敏感性评价,并将得到的评价结果与SVM模型的敏感性评价结果作对比分析.结果显示,灰色关联度模型在高和极高敏感区的滑坡预测精度优于SVM模型,而在中等敏感区的滑坡预测精度略低于SVM模型;整体而言,灰色关联度模型对整个南田地区滑坡敏感性分布的预测精度略高于SVM模型.对两个模型建模过程的对比结果显示,灰色关联度模型建模较简单,具有比SVM模型更高的建模效率,为滑坡敏感性评价提供了一种新思路.     

西北区域气象计量实验室综合能力比对结果分析

分析评价西北区域参加实验室比对的试验结果,及时发现问题并进行纠正,总结实施实验间比对工作的经验,提高实验室检定/校准能力和质量管理水平。参加比对的计量检定实验室分别对气压、温度、湿度、风速比对样品进行比对试验,用归一化偏差(En)进行统计分析。2011年西北区域气象计量检定的温度、湿度、气压实验室比对结果为满意,风速实验室比对结果为较满意。该次比对的实验数据客观、真实、可信,是对各参加比对实验室检定/校准能力的综合评价,较为客观地反映了各技术机构检定装置的测量能力、检定人员的技术水平以及西北区域气象计量标准装置的现状。     

Distribution of dissolved organic carbon in and near the Prydz Bay, Antarctica

INTRODUCTIONDissolvedorganiccarbon (DOC)makesupthesecondlargestofthebioactivepoolsofcar bonintheocean ,secondtothelargestpoolofdissolvedinorganiccarbon .Theglobaldissolvedorganiccarbonpoolisestimatedtobe 6 85Gt,avaluecomparabletothemassofCO2 intheat mosphere (Hedges,1 992 ) .Thesizeofthereservoir,aswellasitsdynamics ,indicatesthatDOCplaysacentralroleintheoceancarboncycle .AsitrelatestogreenhousegasessuchasCO2 andassociatesclimatecycle ,oceanicDOCbiogeochemicalcycleshavebeenoneoftheh…     

Diurnal Variations of Carbon Dioxide, Methane, and Nitrous Oxide Vertical Fluxes in a Subtropical Estuarine Marsh on Neap and Spring Tide Days

Measuring fluxes of greenhouse gases (GHGs) is fundamental to estimating their impact on global warming. We examined diurnal variations of carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O) vertical fluxes in a tidal marsh ecosystem. Measurements were recorded on neap and spring tide days in April and September 2010 in the Shanyutan wetland of the Min River estuary, southeast China. Here, we define a positive flux as directing into the atmosphere. CH₄ fluxes on the diurnal scale were positive throughout, and CH₄ emissions into the atmosphere on neap tide days were higher than on spring tide days. CH₄ releases from the marsh ecosystem on neap tide days were higher in the daytime; however, on spring tide days, daily variations of CH₄ emissions were more complex. The marsh ecosystem plays a twofold role in both releasing and assimilating CO₂ and N₂O gases on the diurnal scale. Average CO₂ fluxes were positive on the daily scale both on neap and spring days and were greater on the neap tide days than on spring tide days. Diurnal variations of N₂O fluxes fluctuated more. Over the diurnal period, soil temperature markedly controlled variations of CH₄ emissions compared to other soil factors, such as salinity and redox potential. Tidal water height was a key factor influencing GHGs fluxes at the water–air interface. Compared with N₂O, the diurnal course of CO₂ and CH₄ fluxes in the marsh ecosystem appeared to be directly controlled by marsh plants. These results have implications for sampling and scaling strategies for estimating GHGs fluxes in tidal marsh ecosystems.     

中国东部农耕区土壤微生物碳的分布及影响因素

对中国东部不同纬度带的6个地区的土壤微生物碳进行了研究。结果表明土壤微生物碳的分布受地理位置的影响较为明显:由北向南,东北地区的土壤微生物碳要高于其他地区。作为土壤有机质变化的灵敏度指标———微生物熵(微生物碳/总有机碳),在同一耕作方式下,其在不同地区的变化受土壤利用方式的影响较为明显:在连作系统下,菜地>粮地;而在轮作系统下,粮食-蔬菜轮作>蔬菜-蔬菜轮作。利用相关性分析寻求影响微生物碳分布的环境因素,结果表明,微生物碳(Micro-C)与土壤有机碳(TOC)、全氮(TN)、土壤含水率呈极显著正相关,而有机碳和全氮的分布主要受地理位置的影响。对不同土壤类型的微生物碳和微生物熵进行相关性分析,结果显示pH、年均温、含水率、TOC和TN是主要影响因素,关键影响因素因土壤类型不同而各异。     

Modeling the effects of riparian planting strategies on stream temperature: Increasing suitable habitat for endangered Formosan Landlocked Salmon in Shei‐Pa National Park,Taiwan

Reducing or stabilizing the stream temperature of ChiChiaWan Creek is a crucial work for Formosan Landlocked Salmon because ChiChiaWan Creek is the only one habitat for this endangered species. Planting trees in the riparian zone would be one of the alternatives. The purpose of this study was to evaluate the effects of several planting strategies on daily maximum stream temperature along the river. The results showed the effective vegetative shading angles should be more than 50° along ChiChiaWan Creek to reduce the direct solar radiation heating effectively. Upstream planting with 70° vegetative shading angle could be the most effective way among all the scenarios. However, this planting strategy could not improve the worst situations in summer because of the large solar elevation angles. The upstream planting in ChiChiaWan Creek was strongly recommended because the canopies could be easier to extend to totally cover the narrow width of river producing the most effective shades. Practicing the upstream planting with 90° vegetative shading angle can increase more than 1 km long suitable habitats for the endangered Salmon in summer. Alternatively, the west‐side planting scenario was the second effective way for temperature reduction. Our result provided a useful suggestion for the authorities in charge of saving the Formosan Landlocked Salmon, particularly under the stress of global warming. Copyright © 2011 John Wiley & Sons, Ltd.     

Study of stable isotopes for highly deformed aquifers in the Hsinchu-Miaoli area, Taiwan

This study was based on the analysis of isotopic compositions of hydrogen and oxygen in samples from precipitation, groundwater and stream water. In addition, parts of groundwater samples were dated by carbon-14 and tritium. These data are integrated to provide other views of the hydrologic cycle in the Hsinchu-Miaoli groundwater district. The groundwater district is principally composed of Pleistocene and Holocene aquifers. The Pleistocene aquifers are highly deformed by folding and faults into small sub-districts with areas of only tens of square kilometers. These aquifers are exclusively recharged by local precipitation. The Holocene aquifers cover narrow creek valleys, only tens of meters in thickness. The local meteoric water line (LMWL), constructed from rainfall samples in the Hsinchu Science Park, is described by the equation δD=8.02δ¹⁸O+10.16, which agrees with the global meteoric water line. In addition, the precipitation isotopic compositions can be categorized into two distinct end members: typhoon type and monsoon type. The groundwater isotopic compositions are perfectly located on an LMWL and can be considered a mixture of precipitations. Based on the mass balance of isotopic compositions of oxygen and hydrogen, infiltration is more active in the rainy season with depleted isotopic compositions. The amount of infiltration during May–September is roughly estimated to comprise at least 55% of the whole year’s recharge. The isotopic compositions of stream water are expressed by a regression equation: δD=7.61δ¹⁸O+9.62, which is similar to the LMWL. Although precipitation isotopic compositions are depleted during summer time, the isotopic compositions contrarily show an enriched trend in the upstream area. This is explained by the opposite altitude effect on isotopic compositions for typhoon-related precipitations.     

超高压变质岩矿物中的显微构造缺陷:来自TEM和FTIR研究的证据

超高压变质矿物的某些显微构造缺陷可能指示了岩石短暂和快速抬升过程。文中报道了中国大别山双河地区超高压硬玉石英岩矿物显微构造缺陷的透射电镜(TEM)和Fourier变换红外光谱(FTIR)的研究结果。用TEM研究方法,在硬玉石英岩中硬玉包裹体内发现了亚微米级天然蒙钠长石(MA,C2/m)、高钠长石(HA,C)和低钠长石(LA,C)三种多形变体。表明岩石在折返过程经历过高温变质作用(>930℃),以及退变质过程的快速冷却;在石英包裹体内发现了纳米级柯石英和石盐子矿物,提供了柯石英转变为石英以及峰期变质条件下高盐流体存在的证据。"名义上无水矿物"(NAMs)的结构水(OH/H2O)是以缺陷形式赋存于矿物结构中。FTIR分析结果显示硬玉、石榴石、金红石和石英中结构水的平均含量分别为1000×10-6、(900~1600)×10-6、>2000×10-6和<4×10-6,硬玉石英岩全岩含水量为(490~600)×10-6,表明在高压-超高压变质作用过程中,地壳或原岩中的水可以通过这些NAMs携带到地球深部。该类显微构造缺陷可能是大陆碰撞造山带在高应变速率下的局部弱化和深部断层作用的结果。     

Geochemistry of Alkaline—Ultrabasic Rocks in the Jijie Complex,Lufeng,Yunnan

is paper is concerned with the geochemical features of major elements,transition metal elements,large ion lithophile elements,rare-earth elements and Sr isotopes in alkaline-ul-trabasic rocks in the Jijie complex of Lufeng,Yunnan Province,which is located in southern Sichuan-Yunnan rift zone,one of Luoci alkaline-ultrabasic complexes in central Ynnnan,Moreover,its origin pertaining primary magma,magma soure region,fractional crystallization,etc.are also discussed in the present paper.     

酸雨的研究进展及厦门酸雨研究的趋势

本文综述了国内外酸雨的研究现状；包括酸雨的来源、成因、模式、影响及防治对策；介绍了酸雨的研究趋势；并着重就厦门地区今后酸雨的研究方向提出也作者的看法。