华北地区中强地震活动特征及趋势探讨

通过对1900－2001年8月100多年来华北地区中强地震（M≥5.0）活动的研究，得出了一系列关于本地区中强地震活动的特征：地震活动主要发生在地表构造带的交汇部位、地震活动存在四个活动时段、地震活动存在明显迁移性；并对本地区未来的地震活动趋势进行了探讨，认为华北地区未来一段时间仍有发生M≥5.0级地震的可能。     

Climate change regionalization in China(1961–2010)

Since climatic condition is the important foundation for human subsistence and development and the key factor in sustainable development of economy and society, climate change has been a global issue attracting great attentions of politicians, scientists, governments, and the public alike throughout the world. Existing climate regionalization in China aims to characterize the regional differences in climate based on years of the mean value of different climate indexes. However, with the accelerating climate change nowadays, existing climate regionalization cannot represent the regional difference of climate change, nor can it reflect the disasters and environmental risks incurred from climate changes. This paper utilizes the tendency value and fluctuation value of temperature and precipitation from 1961 to 2010 to identify the climate change quantitatively, and completes the climate change regionalization in China(1961–2010) with county administrative regionalization as the unit in combination with China's terrain feature. Level-I regionalization divides China's climate change(1961–2010) into five tendency zones based on the tendency of temperature and precipitation, which are respectively Northeast China-North China warm-dry trend zone, East China-Central China wet-warm trend zone, Southwest China-South China dry-warm trend zone, Southeast Tibet-Southwest China wet-warm trend zone, and Northwest China-Qinghai-Tibet Plateau warm-wet trend zone; level-II regionalization refers to fourteen fluctuation regions based on level-I regionalization according to the fluctuation of temperature and precipitation.     

京津冀地区1985–2000期间林地变化的时空格局及其影响因素（英文）

林地是维护生态安全,实现区域可持续发展的根本基础资源。林地变化可能导致一些生态环境问题,包括土壤侵蚀,水资源短缺,干旱加剧以及生物多样性的丧失。本文以景观生态学和逻辑回归模型为基础,探讨了京津冀地区1985-2000期间林地变化的时空格局及其影响因素。格局分析结果表明,林地景观破碎化正在下降和林地形状变得越来越规则。通过建立Logistic回归模型,这项研究旨在探讨这一区域1985-2000期间林地变化的重要变量。对于京津冀地区1985-2000期间林地变化而言,土壤有机质含量,坡度(5°),到最近村庄的距离以及人均国内生产总值是最重要的解释变量。研究表明,空间异质性会影响到林地变化的逻辑回归模型的可预测性。     

Morphological change of natural pipe outlets in blanket peat

Peatlands are important carbon stores and many have natural pipes (tunnels) that transport water and carbon. Pipes are often viewed as passive and slowly changing features of peatland landscapes, particularly for sites that are relatively undisturbed by land management. However, there is a lack of data on pipe morphology change over time. This paper presents the first survey of natural pipe outlets in a peatland in which morphological changes in pipe outlets through time were measured. Three surveys of natural pipe outlets between 2007 and 2010 were conducted in a 17.4 ha, relatively undisturbed, blanket‐peat‐covered catchment in northern England. 27 of the 91 pipe outlets mapped in the first survey had perennial discharge and these outlets were significantly larger and shallower than those from ephemerally‐flowing pipes. The cross‐sectional area of 85% of pipe outlets changed (increased or decreased) during the study, with 20% of pipe outlet areas changing by more than 50 cm² (equivalent to a median 207 % change in area for this upper fifth of pipes) up to a maximum of 312 cm² for one pipe outlet. During the study, 18 pipe outlets completely infilled, while four new ones appeared. Mean pipe outlet area increased between August 2007 and July 2009 but decreased from July 2009 to April 2010. The largest changes in pipe morphology occurred between July 2009 and April 2010, which spanned the coldest winter for 31 years in the UK. During this period there was a significant increase in the proportion of vertically‐elongated pipes and a decrease in the proportion of circular pipes. Pipe outlet morphology in blanket peat catchments is shown to be dynamic and may respond relatively quickly to changes in flow or extreme events, linked to short‐term changes in weather and hence potentially to longer‐term changes in climate or land management. Copyright © 2011 John Wiley & Sons, Ltd.     

中国乡村聚落地理研究进展及趋向

近年来, 随着中国新农村建设的不断推进, 乡村发展问题日益受到学术界的重视。作为聚落地理学重要分支的乡村聚落地理学重新受到关注。了解乡村聚落地理学的研究现状, 掌握其研究趋向, 不仅是学术发展的需要, 也是促进中国城乡协调发展, 推动新农村建设的需要。在查阅大量相关文献的基础上, 本文首先简要叙述了国外乡村聚落地理的研究进展, 认为国外的相关研究成果值得中国借鉴;然后简单分析了中国乡村聚落研究进展, 并从乡村聚落生态、乡村聚落空间特征及其演化、乡村聚落发展问题、乡村聚落综合研究等4 个方面对近年来中国乡村聚落研究的主要内容进行概括和分析;最后, 在分析国内外乡村聚落研究进展的基础上, 本文认为中国未来乡村聚落研究的主要趋向应为:中国工业化、城镇化过程中乡村聚落演变趋势预测研究;中国不同发展水平区域乡村聚落的模式研究;中国不同地貌形态区乡村聚落的研究;新聚落的构建研究;跨学科综合性研究。     

深部冲击倾向煤岩循环加卸载的纵波波速与应力关系试验研究

研究了单轴循环加卸载条件下深部冲击倾向煤岩样应力与纵波波速的耦合关系,基于煤岩试样在弹性阶段纵波波速变化梯度大,塑性阶段波速变化趋于平缓的特征建立了应力与纵波波速之间的试验关系模型,并对模型参数进行了分析。研究表明：①由于闭合的孔隙和裂隙又重新张开,颗粒之间的压实程度减弱,煤岩试样卸载过程中,随着应力的降低,波速也降低;②部分裂隙和孔隙在压密阶段发生永久闭合,造成应力降低后再无法张开,因此下一循环的开始纵波波速值要大于第一个循环开始时的波速值;③与实测值的相关系数计算结果表明,试验关系模型具有较高的拟合度,很好地体现了试样纵波波速变化对载荷的敏感程度。     

重庆市多年大气混合层厚度变化特征及其对空气质量的影响分析

根据2000—2005年逐日4个时次的常规气象资料,采用国家标准GB/T 3840—91中规定的方法计算并分析了重庆主城区大气混合层厚度的频率分布、时间变化等基本特征;在此基础上,进一步以2005年为例分析了混合层厚度与空气污染指数的相关关系。结果表明:重庆市大气混合层厚度以0—800 m范围出现频率最高,多年平均值为428 m;混合层厚度的季节变化和日变化特征明显。与1980—1990年相比,2000—2005年期间年平均混合层厚度总体上有所增加。混合层厚度与空气污染指数的相关性分析显示,月平均混合层厚度和月平均API呈显著负相关(r=-0.72);分析表明,大气混合层厚度是影响城市空气质量的重要因素。     

Comparison of short-term seacliff retreat measurement methods in Del Mar, California

Seacliff retreat has been variously characterized as the recession rate of the cliff top, of the cliff base, and as the bulk recession rate based on volumetric changes of the entire cliff face. Here, these measures of retreat are compared using nine semi-annual airborne LiDAR (Light Detection And Ranging) surveys of southern California seacliffs. Changes in the cliff base location (where the steeply sloping cliff face intersects the beach) include cliff retreat owing to basal erosion, but also reflect changes in beach sand level and basal talus deposits. Averaged over the 2.5 km alongshore study span, the cliff base actually prograded seaward about 12 cm during the 4-year study. Cliff top change was dominated by few, relatively large (several meters) localized retreats. Cliff face changes, that include failures and deposits anywhere on the cliff profile, had a relatively small mean magnitude compared to cliff top changes and were more widely distributed alongshore. However, the similar alongshore averaged, cumulative cliff top and net bulk cliff face end-point retreat (14 and 19 cm, respectively) suggest that mean cumulative cliff top retreat can potentially be a viable surrogate for mean net cumulative cliff-wide erosion (and vice versa) over relatively short time periods. Cliff face erosion occurred repeatedly at some locations, confirming the presence of seacliff erosion hot-spots during the study period.     

45 a来宁夏雷暴气候统计特征及趋势分析

 利用1961—2005年宁夏逐日雷暴资料,利用数理统计、小波分析等方法,揭示出了宁夏雷暴天气气候统计特征和演变趋势。结果表明,宁夏总体上属中雷区,年平均出现雷暴日为86.62 d,年际变化幅度大,多、少雷暴年均有7 a,雷暴日最多年为118 d,最少年为65 d;45 a来雷暴的发生有逐渐减少的趋势,并以3.072 d/10a的气候倾向率递减,且存在3~4 a的较短周期和8 a左右的较长周期振荡;雷暴多发生在3—10月,主要集中出现在夏季,尤以7月突出,有明显的季、月变化,冬季雷暴出现的概率非常低;初雷日平均出现在4月中旬,终雷日平均出现在9月中旬,全区平均雷暴初终日间日数为139 d左右;雷暴发生有明显的日变化特征,有双峰型和单峰型之分,集中出现在11:00—22:00时,其中,15:00时前后为雷暴发生高频时;雷暴的发生与地形、地势有密切关系。     

60年来大气中二氧化碳浓度数据的趋势方程研究

通过讨论已有的60年来大气中CO₂浓度数据的分布状态,采用趋势分析方法,给出了具体趋势方程形式.与冰芯分析或观测数据对比结果表明,趋势方程曲线与已有数据基本符合,随后初步给出了2010年至2016年间大气中CO₂浓度预测值.