第四纪与环境     

李秉成 《地球科学与环境学报》2001,23(2):63-64

目前最大的环境问题是由人类排放CO  相似文献   

BOOK REVIEWS     

《The Professional geographer》1988,40(1):116-131

Books reviewed in this article: Boundary Control and Legal Priniciples . Curtis M. Brown , Walter G. Robillard and Donald A. Wilson . Lost Initiatives: Canada's Forest Industries, Forest Policy, and Forest Conservation . R. Peter Gillis and Thomas R. Roach . The Navajo Atlas: Resources, People, and History of the Dine Bikeyah . James M. Goodman . The City and the Sign . M. Gottdiener AND Alexandros Ph . Lagopoulos , EDS. The Comfortable House: North American Suburban Architecture 1890–1930 . Alan Gowans . Arabic-Islamic Cities. Building and Planning Principles . Besim Salim Hakim . Contemporary Climatology . Ann Henderson -Sellers and Peter J. Robinson . A Trace of Desert Waters . Samuel G. Houghton . Geography, Resources and Environment. Vol. 1: Selected Writings of Gilbert F. White. Vol. 2: Themes from the Work of Gilbert F. White . Robert W. Kates AND Ian Burton , ED. Spatial Dimensions of Unemployment and Underemployment (A Case Study of Rural Punjab) . Gopal Krishan . Maps of the Holy Land: Cartobibliography of Printed Maps, 1475–1900 . Compiled by Eran Laor , assisted by Shoshana Klein . The Geography of Third World Cities . Stella Lowder . A Perspective on U.S. Farm Problems and Agricultural Policy . Lance Mc Kinzie , Timothy G. Baker AND Wallace E. Tyner . Soil Erosion and Its Control. R.P.C . Morgan , ED Geopolitics . Patrick O'Sullivan . Landscape, Meanings and Values . Edmund C. Penning -Rowsell AND David Lowenthal , EDS.  相似文献   

The 14-year Performance of a Compacted Clay Liner used as Part of a Composite Liner System for a Leachate Lagoon     

Craig?B.?LakeEmail author  R.?Kerry?Rowe 《Geotechnical and Geological Engineering》2005,23(6):657-678

The migration of contaminants through a 2.9 m thick compacted clay liner (CCL) for a landfill leachate lagoon is examined 14 years after construction. The clay liner formed the lower portion of the composite liner system but the geomembrane (GM) was found to have defects that had allowed leachate to migrate between the GM and CCL. Chloride, sodium, potassium, calcium and magnesium pore water profiles through the CCL are examined. It is shown that chloride migrated approximately 1.7 m into the CCL during the 14 years of the lagoon operation, sodium approximately 1.2 m, and potassium 0.7 m. Diffusion and sorption data from laboratory diffusion testing are utilized in combination with a finite layer contaminant transport model to predict field contaminant migration profiles through the composite liner system and to establish the time of ‘failure’ of the geomembrane at sometime between 0 and 6 years after installation. Relatively high sorptive uptake of potassium by the CCL soil is observed from batch testing and diffusion testing with field data suggesting an even larger amount of sorption. It is hypothesized that organic sludge matter at the base of the lagoon is responsible for potassium uptake from the leachate. This field case highlights the importance of the compacted clay liner as part of the composite liner system in acting as a diffusion barrier during the lifetime of the lagoon as well as using relatively non-conservative contaminants such as chloride and sodium to estimate geomembrane ‘failure’ times  相似文献   

通用电子政务平台开发及其在“数字城市”中的应用   总被引：2，自引：1，他引：1  

孙俊 《测绘科学》2005,30(1):22-24

本文系统地论述了目前电子政务和"数字城市"的建设要求,提出了开发通用电子政务平台来快速构建各类城市管理部门的电子政务应用系统,形成"数字城市"各专业应用的思路,并介绍经过多年开发和应用的通用电子政务平台NetOffice特点,最后以地房籍管理信息系统为例来阐述了电子政务平台在"数字城市"的重要组成部分———国土资源和房产管理的应用情况。  相似文献   

An ontology-based multicriteria spatial decision support system: a case study of house selection     

Jacek MALCZEWSKI  Mohammadreza JELOKHANI-NIARAKI 《地球空间信息科学学报》2012,15(3)

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直管公房管理系统设计与实现     

樊文有  汪家锴  龚杰 《测绘科学》2012,37(2):83-85

为了提供实时、准确的公房信息,使住房保障管理工作更加高质高效,本文提出了构建基于MapGIS的直管公房管理系统。本文以MapGIS开发平台为基础,根据公房数据的特征,设计并实现了该系统,重点介绍了该系统的设计方案、功能和开发实现。  相似文献   

Determination of ammonia emission rates from a tunnel ventilated chicken house using passive samplers and a Gaussian dispersion model     

Ronald L. Siefert  Joseph R. Scudlark 《Journal of Atmospheric Chemistry》2008,59(2):99-115

Atmospheric deposition can provide a significant fraction of the nitrogen loading to coastal waters. The Delmarva Peninsula, on the eastern shore of the Chesapeake Bay, is a region with intense poultry production that may supply a significant source of atmospheric ammonia (NH₃). There is a need to quantify ammonia NH₃ from representative growing methods in this region in order to more accurately estimate agricultural NH₃ emissions and to develop best management practices. In this study, NH₃ emissions were determined at an 18,600-bird tunnel-ventilated chicken house using a modified sampling grid (a planar arrangement normal to the length of the house) with Ogawa passive samplers to characterize the emission plume downwind from the house. This improvement in the sampling strategy, compared to a previous study, simplified the inverse Gaussian plume analysis which improved the confidence in the emission factors. In this study, a total of four separate plume characterizations were conducted over the final 3 weeks of the 6-week broiler grow-out cycle. The mean emission factor observed at the tunnel-ventilated house, 0.13 g NH₃–N/bird-day, was an order of magnitude lower than that previously observed at a nearby side-wall ventilated house. Although not all growing variables were measured, the large difference in emission factors between the two ventilation regimes suggest that modern, tunnel-ventilated houses may result in a significant decrease in NH₃ emissions compared with traditional growing methods. This variability in emission factors underscores the need for characterizing chicken houses under various conditions and determining the factors that control these atmospheric emissions.  相似文献   

IEU-Net高分辨率遥感影像房屋建筑物提取   总被引：1，自引：0，他引：1  

王振庆  周艺  王世新  王福涛  徐知宇 《遥感学报》2021,25(11):2245-2254

房屋建筑物作为人类活动的主要场所,快速准确地将其从高分辨率遥感影像中提取出来,对促进遥感信息在防灾减灾、城镇管理等方面的应用具有重要意义。本文基于深度学习,提出了高分辨率遥感影像房屋建筑物像素级精确提取方法。首先,针对样本图像边缘像素特征不足现象,以U-Net模型为基础提出IEU-Net模型,设计了全新的忽略边缘交叉熵函数IELoss并将其作为损失函数,另外添加Dropout和BN层在避免过拟合的同时提高模型训练速度和鲁棒性。其次,为解决模型特征丰富度有限的问题,引入形态学建筑物指数MBI,与遥感影像RGB波段一同参与到模型的分类过程。最后,在模型预测时与IELoss相对应采用忽略边缘预测策略从而获得最佳建筑物提取结果。实验对比分析表明：本文方法能有效克服样本边缘像素特征不足问题并抑制道路、建筑物阴影对结果的影响,提升高分辨率遥感影像中房屋建筑物的提取精度。  相似文献   

略阳县农居房屋抗震现状调查与评价研究     

郭光玲  郭瑞  徐乾 《震灾防御技术》2021,16(3):492-500

为精准识别贫困山区农居房屋结构现状完好程度,本文开展略阳县境内41894栋农居房屋抗震现状实地调查,搜集整理域内孕灾环境和致灾因子强度,统计分析域内各行政镇（办）经济水平、农居房屋抗震结构类型和震害等级,预测震害矩阵,计算平均震害指数,并评价抗震能力。研究结果表明:域内农居房屋抗震结构类型包括土木结构、砖木结构和砖混结构;域内农居房屋在VI度地震作用下基本完好的比例为74.04%,在VII度地震作用下发生轻微破坏以下震害等级的比例为83.45%,在VIII度地震作用下发生中等破坏以下震害等级的比例为85.46%;域内农居房屋在地震烈度为VI、VII、VIII、IX、X度时的平均震害指数分别为0.13、0.23、0.32、0.49、0.71,抗震性能较差,不满足“小震不坏、中震可修、大震不倒”的抗震设防目标。  相似文献   

基于分层分户图的室内外一体化三维模型构建与应用     

汪剑章  韦昭宁 《测绘与空间地理信息》2017,40(Z1)

房产三维是三维GIS的应用重点,分层分户图的三维建模更是房产三维建设的重要组成部分.本文对比了3 Ds Max建模、平面拉伸建模和分层分户图建模方法,分析了分层分户图建模优势,重点研究了分层分户图建立三维模型的方法.  相似文献