Mechanisms for stronger warming over drier ecoregions observed since 1979     

Liming Zhou  Haishan Chen  Wenjian Hua  Yongjiu Dai  Nan Wei 《Climate Dynamics》2016,47(9-10):2955-2974

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定量降水预报技术进展   总被引：13，自引：7，他引：6       下载免费PDF全文

毕宝贵  代刊  王毅  符娇兰  曹勇  刘凑华 《应用气象学报》2016,27(5):534-549

对21世纪以来定量降水预报技术流程中的数值模式预报、统计后处理、检验评估和预报员作用4个方面的研究工作进行了归纳,主要进展包括:业务全球模式对于降水的预报能力持续提升,而发展高分辨率模式 (尤其是对流尺度模式) 和集合预报是提高定量降水预报精准化水平的主要途径,且将两者相结合以促进短期降水预报是发展趋势;统计后处理技术已发展到应用数据挖掘方法对海量预报数据中有效信息进行提取和集成,而再预报资料的出现将进一步促进统计后处理技术的发展;为解决评估精细化定量降水预报面临的新问题,多种新的检验技术得到发展和应用,如极端降水检验评分、空间检验技术及概率检验方法等;预报员在模式和后处理方法上能够提供的附加值越来越有限,但在预报流程中仍将处于核心地位,其角色将逐渐向帮助用户进行决策方向转变。文章指出,定量降水预报技术的发展所面临的挑战包括大气水汽观测及同化技术改进、暖区和复杂地形下暴雨预报等科学问题的解决。  相似文献   

A User‐centered Design for the Addition of Interactive Masking Capability within an existing Web GIS          下载免费PDF全文

John D. Morgan 《Transactions in GIS》2016,20(5):807-816

This article presents a case study of how a user‐centered design (UCD) approach was utilized during the addition of interactive masking capability to an existing web‐based geographic information system (Web GIS). By analyzing and discussing specific aspects of the user‐developer dialog within the context of a Web GIS software development life cycle, this article presents a case study for similar systems. The results of the UCD methodology is a discussion that presents a shift from an initial design to a new design that, based on user feedback, furthers the utility and usability of interactive masking within the Web GIS.  相似文献   

甘肃南祁连余石山地区变粒岩原岩恢复     

贾志磊  窦小雨  王金荣  张岱  侯荣娜 《甘肃地质》2016,25(2):9-14

余石山地区位于南祁连西南端,处在祁连—柴达木—阿尔金地块的交汇部位,构造复杂。长城纪熬油沟组中的变粒岩,由于变质程度较深,以及后期构造的影响,原岩的特征难以辨别。本文通过岩石地球化学方法,对该区变粒岩及其原岩进行了研究,结果显示其原岩为中酸性岩浆岩,结合高场强元素特征和高的碱含量,确定其原岩为正长岩类。  相似文献   

Pressure transient analysis of multistage fracturing horizontal wells with finite fracture conductivity in shale gas reservoirs     

Yu Dai  Xinhua Ma  Ailin Jia  Dongbo He  Yunsheng Wei  Cong Xiao 《Environmental Earth Sciences》2016,75(11):940

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A bi-modal model for Chinese cities: City size,car use and land rent     

Teqi Dai  Liang Wang  Binxue Zhou 《中国地理科学(英文版)》2016,26(5):589-598

China is experiencing rapid urbanization and motorization. Urban transport congestion poses a challenge to the cities of China. Policies have been made trying to control the car use and the land use in Chinese cities without sound modelling researches. The existing literature on monocentric city modelling has shown that the parameters are critical for the outcome of the modelling. Following the Alonso-type monocentric model, this paper introduces a bi-modal model to simulate the city size, the distribution of land rent and the modal substitution in Chinese cities. We set the key parameters according to the recent available data of China′s cities, and re-explain the hypothesis of the model. Then we make a sensitivity analysis to reveal the impacts of key parameters on the Chinese cities. According to the results, we find that the wage, the price of car use and the agriculture rent have significant impacts on city size. The land supply for the private transport or the public transport has the strongest impacts on car use and the level of transport congestion. The total population of the city and the wage level have strong impacts on land rent. Some results are counter-intuitive, but explainable. We also discuss implication of these results for policy making.  相似文献   

Structural analysis of compactive deformation in the incoming sedimentary section of the Hikurangi Subduction Margin, New Zealand:results from IODP 375 expedition     

Maomao Wang  Philip Barnes  Julia Morgan  Rebecca E Bell  Ake Fagereng  Heather M Savage  Demian M Saffer  Laura M Wallace  Katerina E Petronotis  Shipboard Scientists 《《地质学报》英文版》2018,92(Z1):157-157

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Upstream—Downstream Shifts in Peak Recruitment of the Native Olympia Oyster in San Francisco Bay During Wet and Dry Years     

Andrew L. Chang  Lindsay J. Sullivan  Steven G. Morgan  Matthew C. Ferner 《Estuaries and Coasts》2018,41(1):65-78

Understanding the conditions that drive variation in recruitment of key estuarine species can be important for effective conservation and management of their populations. The Olympia oyster (Ostrea lurida) is native to the Pacific coast of North America and has been a target of conservation efforts, though relatively little information on larval recruitment exists across much of its range. This study examined the recruitment of Olympia oysters at biweekly to monthly intervals at four sites in northern San Francisco Bay from 2010 to 2015 (except 2013). Mean monthly temperatures warmed at all sites during the study, while winter (January–April) mean monthly salinity decreased significantly during a wet year (2011), but otherwise remained high as a result of a drought. A recurring peak in oyster recruitment was identified in mid-estuary, in conditions corresponding to a salinity range of 25–30 and >16 °C at the time of settlement (April–November). Higher average salinities and temperatures were positively correlated with greater peak recruitment. Interannual variation in the timing of favorable conditions for recruitment at each site appears to explain geographic and temporal variation in recruitment onset. Higher winter/spring salinities and warmer temperatures at the time of recruitment corresponded with earlier recruitment onset within individual sites. Across all sites, higher winter/spring salinities were also correlated with earlier onset and earlier peak recruitment. Lower winter salinities during 2011 also resulted in a downstream shift in the location of peak recruitment.  相似文献   

A GIS-based method of risk assessment on no. 11 coal-floor water inrush from Ordovician limestone in Hancheng mining area,China     

Gelian Dai  Xiaoyuan Xue  Ke Xu  Lei Dong  Chao Niu 《Arabian Journal of Geosciences》2018,11(22):714

The no. 11 coal seam in the deep area of Hancheng mining area is mining in recent years, which is threatened by the water inrush from the Ordovician limestone aquifer. Coal-floor water inrush is governed by the water abundance of coal-floor aquifer, the water-resisting performance of coal-floor aquitard, and the pathway connecting the water source and the working face. To make an accuracy risk assessment of water inrush from the no. 11 coal seam floor, a GIS-based vulnerability index method (VIM) is adopted for its superior comprehensive consideration of more controlling factors, powerful spatial analysis, and intuitively display functions. This study firstly established an index system including the water pressure of the coal-floor aquifer, the unit water inflow, the thickness, the core recovery percentage, the thickness ratio of brittle rocks to ductile rocks, the thickness of effective aquitard, and the accumulated length of faults and folds, of which the former six indexes governed the water abundance of the coal-floor aquifer which was combined with the last two factors to determine the risk of coal-floor water inrush. Secondly, the thematic map of each controlling factor is established by GIS using the geological prospecting data, and the weight of each factor is determined by the analytic hierarchy process (AHP) after consulting the expert review panel. At last, a vulnerability index is obtained and used to assess the risk of coal-floor water inrush of the no. 11 coal seam. The risk of water inrush of the no. 11 coal seam of the study area was ranked to three zones: the southeastern shallow area in red color is the dangerous zone, the wide northwestern area in green color is the safe zone, and the transition area in yellow color is the moderate-risk zone. Compared with the actual water-inrush incidents, the risk assessment result was verified to achieve an accuracy of 82.35%, which is proved to be a dependable reference for the prevention and controlling of coal-floor water inrush of the no. 11 coal seam in Hancheng mining area.  相似文献   

中国东部四明山古夷平面遗迹特征与演化     

郑丽波  戴雪荣  张欢 《江苏地质》2018,42(4):543-551

古夷平面研究在地貌演化和新构造运动研究中占有极其重要的地位,但由于遭受构造运动和剥蚀作用的影响,很多古夷平面遗迹已无从清晰辨识。浙江四明山顶古近纪夷平古风化壳面的发现,为研究浙江东部甚至华东地区的新生代地貌演化提供了重要地质信息,同时为始新世和中新世时的古气候、古环境研究提供了重要物质证据。通过详细的野外地质调查,系统采集了该区5个点位的20个古风化壳样品和7个点位的15个现代风化壳样品,开展黏土矿物分析和玄武岩K-Ar年龄测试。研究确认四明山地区发育有2期古夷平面遗迹,即古近纪(E)和新近纪(N)古夷平面遗迹:第一期夷平面发育时间为65. 0～32. 2 Ma,解体和古夷平面遗迹保存时间为32. 2～21. 7 Ma;第二期夷平面发育时间为21. 7～10. 5 Ma,解体和古夷平面遗迹保存时间为10. 5～3. 0 Ma。研究区2期火山活动喷发所形成的玄武岩盖层有效保护了该区的古风化壳,从而使四明山古夷平面遗迹具有空间展布完整、剖面信息清晰等特征,呈现出由古夷平面(古风化壳)与玄武岩堆积面(现代风化壳)组成的"双风化壳"现象,为观察古夷平面遗迹特征提供了最佳场所。  相似文献