Seesaw Pattern of Rainfall Anomalies between the Tropical Western North Pacific and Central Southern China during Late Summer

It is well known that suppressed convection in the tropical western North Pacific(WNP) induces an anticyclonic anomaly,and this anticyclonic anomaly results in more rainfall along the East Asian rain band through more water vapor transport during summer, as well as early and middle summer. However, the present results indicate that during late summer(from mid-August to the beginning of September), the anomalous anticyclone leads to more rainfall over central southern China(CSC), a region quite different from preceding periods. The uniqueness of late summer is found to be related to the dramatic change in climatological monsoon flows: southerlies over southern China during early and middle summer but easterlies during late summer. Therefore, the anomalous anticyclone, which shows a southerly anomaly over southern China, enhances monsoonal southerlies and induces more rainfall along the rain band during early and middle summer. During late summer,however, the anomalous anticyclone reflects a complicated change in monsoon flows: it changes the path, rather than the intensity, of monsoon flows. Specifically, during late summers of suppressed convection in the tropical WNP, southerlies dominate from the South China Sea to southern China, and during late summers of enhanced convection, northeasterlies dominate from the East China Sea to southern China, causing more and less rainfall in CSC, respectively.     

北大西洋地区气候准20年周期的观测和模拟分析

北大西洋地区除了存在约70 a周期的AMO（Atlantic Multidecadal Oscillation,北大西洋年代际振荡）之外,历史长期气候记录中英格兰温度（Central England Temperature,CET）与格陵兰冰芯净雪累计率还存在显著的20 a周期波动。本研究利用CCSM4（Community Climate System Model version 4）耦合模式工业革命前控制试验（piControl）结果中的海表面温度（Sea Surface Temperature,SST）,通过10～50 a带通滤波与扩展经验正交函数（Extended Empirical Orthogonal Function,EEOF）分解,得到在北大西洋副极地海区存在准20 a振荡的逆时针旋转模态。此周期与其临近地区的CET、格陵兰冰芯净雪累计率的准20 a振荡周期相吻合,说明这种北大西洋副极地海区准20 a振荡的海洋模态与其临近地区的大气准20 a振荡之间可能存在相应的联系。进一步利用CAM4（the Community Atmosphere Model version4）大气模式,以北大西洋副极地海区准20 a振荡SST旋转模态为强迫场进行敏感性试验,进一步验证了这种联系。     

鲜水河下游泥石流发育分布特征研究

鲜水河下游流域处于鲜水河断裂带之南西,总体呈南北走向.受地层岩性、地质构造、新构造活动、河谷地貌演化及气候条件等的控制,流域内泥石流较发育,属泥石流中等发育区.泥石流以暴雨沟谷型泥石流为主,可见少量暴雨坡面型泥石流及古冰川泥石流.泥石流多集中发育于岩性相对软弱的板岩、千枚岩及砂岩与板岩互层的相对宽谷段,多为粘性泥石流.泥石流一般具有多期次发育特征,且规模逐次减小.流域内绝大部分泥石流处于停歇或衰退状态,现代活动性不活跃,现代活动泥石流频度低、规模小,且多发育于植被破坏较严重区域.流域内泥石流活动具有退化的特征,对当地人民生命安全及两河口水库的淤积等影响不大.     

陈代光教授对岭南历史地理研究的贡献

陈代光教授是我国一位著名历史地理学者.文章主要论述其在岭南广州、港澳、雷州等城市、南海海上丝绸之路交通、区域历史地理、广东历史地图集编纂、地名、中国历史地理教材建设、历史地理人才培养,以及历史地理为社会经济发展服务等方面的学术成就和重要贡献,以作为对陈代光教授的一种纪念,同时唤起社会各界对这门又古又今、既要看书、又要走路的学科的关注.     

1958-2017年太湖蒸发量年际变化趋势及主控因子

湖泊蒸发对气候变化非常敏感,是水文循环响应气候变化的指示因子,因此研究湖泊蒸发的控制因素,对于理解区域水文循环有重要意义.本文利用太湖中尺度涡度通量网避风港站观测数据校正JRA-55再分析资料,驱动CLM4.0-LISSS模型,并利用2012-2017年涡度相关通量数据和湖表面温度数据检验模型模拟蒸发结果,验证了该模型在太湖的适用性;估算了1958-2017年间太湖的湖面蒸发量,并利用Manner-Kendall趋势检验分析了湖面蒸发的变化趋势,寻找太湖实际蒸发的年际变化的主控因子.结果如下:校正后的JRA-55再分析资料模拟的太湖蒸发与观测值之间存在季节偏差,但是季节偏差在年尺度上相互抵消,再分析资料可用于年际尺度太湖蒸发变化的模拟;1958-2017年间太湖蒸发量以1977年为界,先下降(-3.6 mm/a),后增加(2.3 mm/a);多元逐步回归结果表明,向下的短波辐射是太湖1958-2017年间太湖蒸发变化的主控因子,向下的长波辐射、气温、比湿也对湖泊蒸发年际变化有一定影响,但是风速对蒸发量的年际变化影响不大.     

Late glacial fans in the eastern Skagerrak; depositional environment interpreted from swath bathymetry and seismostratigraphy

The origin of acoustically transparent fan deposits overlying glacial till and ice-proximal sediments on the southern margin of the Norwegian Channel has been studied using high-resolution seismic-reflection profiles and multibeam bathymetry. The first deposits overlying glacigenic sediments are a series of stacked, acoustically transparent submarine fans. The lack of glaciomarine sediments below and between individual fans indicates that deposition was rapid and immediately followed the break up of the Late Weichselian ice cover. The fans are overlain by stratified glaciomarine sediments and Holocene mud. Because of the uniformity of this drape, the upper surface of the fan deposits is mimicked at the present seafloor, and the bathymetric images clearly show the spatial relationship of the fans to bedrock ridges and the presence of braided channel-levee systems on the surface of the youngest fans. The acoustically transparent character of the fan deposits indicates that they comprise silt and clay, and their lobate form and lack of internal stratification indicates that they were deposited by debris flows. The channel-levee morphology indicates deposition from more watery hyperconcentrated fluid flows. The fan sediments were either derived from 1) erosion of Mid Weichselian lake deposits in southern Skagerrak or 2) from Late glacial ice-margin lake deposits, ponded against the Norwegian Channel ice stream, which collapsed catastrophically when the lateral support was removed as the ice disintegrated. Fans composed almost exclusively of fine-grained sediment need not, therefore, rule out an origin in a deglacial setting relatively close to the former margins of glaciers and ice sheets.     

读《古典文献论丛》

《古典文献论丛》集中了赵逵夫先生近二十年来在文献学领域的研究成果,在文献学理论、出土文献、敦煌文献、宋前戏剧文献、诗赋文献等方面贡献颇多。这部论文集充分体现了赵逵夫先生厚重的传统目录学观念、在历史文献研究中清晰的历史概念和在宏观视野下进行微观研究的学术理念。     

滁州市不可移动文物管理信息系统设计和实现

以滁州市为例,在WebGIS技术支持下,通过设计和实现不可移动文物普查与管理数据库、地图基本操作、空间查询分析、文物风险评估以及文物信息输出等功能,改进文物普查与管理工作的方法和手段,提高管理工作的效率和信息化水平,为科研及文物普查管理部门提供辅助决策支持的新思路和新方法.     

复杂工程系统优化设计初探--以某泥石流防治工程系统的优化设计为例

以某泥石流防治工程系统的优化设计为例 ,建立了优化模型 ,分析确定了模型参数 ,并利用基于随机模拟的遗传算法对模型进行了求解。对其他泥石流防治工程系统的优化设计具有重要指导意义 ,对复杂工程系统的优化设计也具有普遍的参考价值     

基于兰利法的泥石流临界雨量实验研究

分析了目前泥石流临界雨量确定常用方法存在的问题 ,以及泥石流临界雨量实验研究中实验降雨量确定的随意性和盲目性 ,提出以兰利 ( Langlie)法为指导进行实验 ,使实验降雨量的确定有了理论依据 ,减少了取得可靠实验结果所需实验次数 ,从而使泥石流临界雨量实验研究更趋完善和可行