Adaptation of agriculture to warming in Northeast China

Northeast China comprises Heilongjiang, Jilin and Liaoning Provinces, with a total area of 790,000 km² and a population of about 107 million. Northeast China, located at relatively high latitudes, (from about 39 to 53°N), is one of the coolest regions in China with long and cold winters, a short growth season and frequent cold extreme events, which are adverse to agricultural production. However, since the 1980s, Northeast China has experienced significant warming with annual mean temperature rising by 1.0–2.5°C. The increase of accumulated temperature, the extension of the growth period and the recession of summer cool disasters all contributed to improved conditions for crop growth and led to a northward movement of the agricultural climate zone. In addition, the adaptation to warming including the adjustment of crop composition and structure as well as the adoption of advanced technologies greatly facilitated agricultural development. As a result, total grain production in the region increased rapidly. This paper describes in detail climate change, adaptation measures and final agricultural outcomes, alongside with economic and political factors and the role of different political actors in Northeast China.     

Climate simulations for 1880–2003 with GISS modelE

We carry out climate simulations for 1880–2003 with GISS modelE driven by ten measured or estimated climate forcings. An ensemble of climate model runs is carried out for each forcing acting individually and for all forcing mechanisms acting together. We compare side-by-side simulated climate change for each forcing, all forcings, observations, unforced variability among model ensemble members, and, if available, observed variability. Discrepancies between observations and simulations with all forcings are due to model deficiencies, inaccurate or incomplete forcings, and imperfect observations. Although there are notable discrepancies between model and observations, the fidelity is sufficient to encourage use of the model for simulations of future climate change. By using a fixed well-documented model and accurately defining the 1880–2003 forcings, we aim to provide a benchmark against which the effect of improvements in the model, climate forcings, and observations can be tested. Principal model deficiencies include unrealistically weak tropical El Nino-like variability and a poor distribution of sea ice, with too much sea ice in the Northern Hemisphere and too little in the Southern Hemisphere. Greatest uncertainties in the forcings are the temporal and spatial variations of anthropogenic aerosols and their indirect effects on clouds. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

抗动压井壁结构型式的模拟优化研究

安阳鑫龙矿业有限责任公司根据公司发展规划,对现有矿井进行全面技术改造和矿区扩建,计划在采动影响范围内建设一个新的风井。运用Flac3D数值模拟软件对不同结构形式的井壁(素混凝土、钢筋混凝土、井壁外侧加垫层的复合井壁、井壁内加垫块的复合井壁)进行模拟比较,同时研究不同垫块位置(刚度),进行模拟比较。得出井壁内加垫块的井壁结构较好、垫块位置(刚度)对井壁受力影响较小的结论。     

两种气候变化情景下中国未来的粮食供给

全球温室气体排放导致的全球温度的上升一直是国际社会关注的重点问题之一。利用IPCC（政府间气候变化专门委员会）SRES（排放情景特别报告）的A2（中-高）和B2（中-低）温室气体排放情景，结合区域气候模式PRECIS和CERES作物模型模拟和分析了未来不同的温室气体排放情景下，中国未来2020年、2050年和2080年各个时段粮食的供需情景，并结合未来社会经济的发展分析了气候变化对未来粮食供求的影响，探讨了不同的气候变化程度对未来中国粮食供应的影响。结果表明：如果不考虑CO2的肥效作用，未来我国三种主要粮食作物（小麦、水稻和玉米）均以减产为主，灌溉可以部分地减少减产幅度，如果单考虑CO2的肥效作用，三种作物的产量变化以增产为主。若保持959／6的粮食自给率，人口按照SRESA2和B2情景增长，到2030年的技术进步可使粮食年单产递增0．79／6以上，维持目前的种植比例和种植面积，B2情景下，气候变化对我国的粮食安全问题将不会构成威胁，而A2情景下，气候变化将会对我国可持续发展的粮食安全造成威胁。     

神农架南坡山前气流涌升效应对一次强风暴的触发和维持作用

利用宜昌多普勒天气雷达回波资料,分析了2001年7月2日发生在三峡坝区瞬间极大风速达28.8m·s-1的强对流风暴。结果发现:在环境风场为偏南气流的引导下,神农架南坡有一条中尺度辐合线,对流云在该辐合线附近生成和发展,然后沿神农架东缘东北移动并影响三峡坝区,表明神农架南坡的山前涌升效应对该强风暴有一定的触发和维持作用。     

水平变量配置对地转演变模拟的影响

从描述准地转、β-平面近似下的Rossby波方程组出发，在Arakawa A-E网格上，从频率和群速方面讨论了这五种网格的计算频散性。结果表明：D、C网格比其它网格对Rossby波产生的歪曲都要小。     

湿位涡诊断分析在东南亚强降水中的应用

文章应用湿位涡理论 ,分析了发生在东南亚夏季的两个强降水个例 ,讨论了湿位涡与东南亚强降水形成的关系。东南亚夏季具有利于强降水发生的湿位涡场分布特征 ;强降水的发展与湿位涡的变化有很好的对应关系 :当对流层低层MPV1<0、同时MPV2 ≥ 0时 ,易产生强降水 ;当对流层高层MPV1正值区与低层MPV1负值区相互作用 ,即高层下滑的干冷空气与低层上升的高温高湿空气交汇 ,容易贮存和释放湿对流不稳定能量 ,有利于强降水产生。湿位涡理论在东南亚强降水诊断中有很好的应用前景。     

西藏吨托滑坡的遥感解译发现及其特征

介绍吨托滑坡的彩红外航片解译及发现和彩红外正射影像地形图遥感综合调查，叙述吨托滑坡区域环境地质条件、滑坡基本特征；进行滑坡成因与发展趋势分析，提出滑坡防治方案建议。     

高放废物地质处置与岩石力学研究

高放废物处置库是一个特殊的深部地下工程,涉及大量的岩石力学问题。笔者简述了我国高放废物处置的技术路线和主要进展,探讨了处置库选址、设计、建造、性能评价中的主要岩石力学问题。     

探地雷达技术在探测边坡破碎带中的应用

探地雷达是利用高频电磁脉冲的反射对地下目的体及地质现象进行探测的一种高效浅层勘探方法，随着电子技术和计算机技术的不断发展，该技术的应用领域不断扩大。本文从探地雷达的基本原理出发，结合在浙江省金丽温高速公路某段边坡探测的应用实例，详细分析了破碎带的雷达图像特征。通过理论与实践的相互结合，证实利用探地雷达进行边坡破碎带探测是科学可行的，拓宽了该技术在岩土工程勘察中的应用，进一步表明该技术具有较强的推广潜力。