The relationship between precipitation heterogeneity and meteorological drought/flood in China

In this study, we investigated the spatial and temporal characteristics of precipitation heterogeneity and meteorological drought/flood in China based on the precipitation-concentration degree (PCD) and the integrated meteorological drought index. We also studied the corresponding relationship between precipitation heterogeneity and meteorological drought/flood in China by using Spearman correlation analysis and canonical correlation analysis. The results show that: (1) The severity of meteorological drought/flood exhibited a spatial pattern of gradual change from Northwest to Southeast China. (2) With a higher PCD and a delayed precipitation-concentration period (PCP), the drought severity was higher but the flood severity was lower. In contrast, with a lower PCD and an early PCP, the drought severity was lower and the flood severity was higher. (3) The correlation between meteorological drought/flood and PCD was significant. The higher the PCD, the longer the duration of drought and more frequently, the droughts occurred, and vice versa. It is concluded that PCD and PCP were significantly correlated with meteorological drought/flood in China.     

长沙市土地利用格局变化的空间粒度效应

基于2003年、2006年、2009年及2013年的遥感图像对长沙市土地利用进行分类,在ArcGIS 10.0、ENVI 4.8、Fragstats 4.0和Excel 2007软件的支持下,通过上推尺度像元的比例占优法改变空间粒度,从类型水平和景观水平上分析了土地利用格局变化的粒度效应。得出以下结论：① 类型水平上,随着粒度的增大,各土地类型的指数呈现出3种变化趋势:增大、减小及无明显规律;随着时间的变化,空间粒度越小,对斑块密度及斑块形状指数变化的影响越明显。空间粒度越大,对斑块结合度和斑块集聚度变化的影响越明显。② 景观水平上,随着粒度的增大,蔓延度指数先减小后基本不变;香农多样性指数和香农均匀度指数缓慢减小;随着时间的变化,蔓延度指数呈减小的趋势,香农多样性指数和均匀度指数呈增大的趋势。90 m是本研究中分析空间粒度的最佳值。     

新疆天然水化学特征区域分异及其地质成因

为研究新疆天然水化学特征区域分异及成因,采集、分析和田地区51组天然水样,收集已发表的新疆其它地区天然水化学数据103组。数据说明：南疆天然水总溶解性固体（TDS)（1 589.4 mg/L）是北疆天然水（513.5 mg/L）的3.1倍;83.33%和89.59%的北疆天然水TDS和TH符合中国饮用水卫生标准,南疆天然水TDS和TH达标率分别为62.26%和70.75%。北疆天然水水化学类型主要为Ca-HCO₃和Ca·Mg-HCO₃·SO₄,南疆天然水水化学类型主要为Na·Ca-Cl·SO₄和Na·Mg-Cl·SO₄。南北疆天然水化学特征区域差异与南北疆地质构造分区重合。地质构造演化的不同,为南北疆天然水提供不同物源;水文气象差异加剧了其天然水化学组分差异。     

利用CR-InSAR技术研究鲜水河断层地壳形变

利用CR-InSAR技术对鲜水河断层形变进行了研究。通过GAMMA软件对研究区获取的6幅安装角反射器（CR）后的ASAR数据进行处理,确定了道孚、七美和瓦日3个CR点在影像中的位置并提取它们的差分相位,在此基础上,建立了3个CR点观测模型并解算得到了它们的形变量。与实测的水准测量结果进行比较,结果表明,CR点形变监测结果与水准监测结果基本一致。     

“080825”上海大暴雨综合分析

利用常规天气资料以及非常规高密度观测资料、物理量场资料、云图资料以及PWV可降水汽资料等,对2008年8月25日上海地区的强对流暴雨进行了分析.分析表明三支气流在长江中下游及江南北部地区交汇有利于低涡的生成发展,为上海强对流天气的发生提供了有利的天气背景条件;中低纬度系统相互作用为上海强对流暴雨天气提供了水汽、能量和触发条件.在大暴雨开始前12～24小时,水汽、能量和中低层大的正涡度有向长江下游汇合的趋势,在上海附近逐渐形成强的位势不稳定.上升运动集中在1个经度左右非常窄的地区,是产生特强降水原因之一.GPS/PWV探测可以及时了解大气水汽总量的变化,仅靠本地上空的水汽全部落下是远远不够的,还需要大量的水汽辐合.对流云团合并,云核合并后强烈发展移动缓慢同样是产生特强降水原因之一,在对流云团的后侧,对应温度梯度最大,是降水最强的地方.     

对山东莒县地声极微震观测系统的初步研究

一般情况下都是采用深井系统观测地声和极微震,但却很少有人研究井系统对记录的影响。本文首先从理论上探讨了深井中能够存在的波型。在轴对称条件下有四种波:P、S首波、stoneley波和简正波;在非轴对称条件下,存在非对称的stoneley波、简正波、液体波和S首波。频率较低时,仅存在对称和非对称的stoneley波。其次计算了浅井系统对计录的影响,浅井中记录的信号与原始波形非常接近,可近似作为原始信号。比较深井和浅井的理论和观测结果可知,深井系统能降低噪声,提高信噪比,但使信号发生较大的畸变;而浅井系统的环境噪声较高,但获得的信号非常接近原始波形。最后介绍了在上述结果的指导下所建立的山东省莒县地声台网。     

地表水地震反应的历史地震资料分析

长江下游地区江河湖潭广泛分布.在历史地震文献中,这些陆域地表水的地震反应记录屡见不鲜,是历史地震研究有价值的资料.但是,历史地震资料中地表水地震反应的研究很不充分,各种地震烈度表中均未将陆域地表水的反应作为地震烈度影响的标志.作者信箱:朱升初,zhu shengchu@126.com     

基于残差网络结构的道路语义分割

从高分辨率光学遥感影像中提取地物信息受到广泛关注,道路提取是其中一项重要任务.设计了一种基于残差网络结构的深度学习神经网络模型,并将该模型与FCN网络模型和U-Net网络模型输出结果进行了对比.结果表明,本文方法不仅在F1得分和IOU上均优于其他两个模型,并且在提取的道路平滑度和图像噪声处理方面也具有一定的优势.     

Characteristics, loss and gain of atmospheric carbonyl compounds in winters of 2008–2010 in Pearl River Delta region, China

Formaldehyde (HCHO), acetaldehyde (CH₃CHO) and acetone (CH₃COCH₃) were measured at Wanqingsha (WQS) in south China during November-December 2008–2010. Carbonyl compound pollution characteristics under the influence of the financial crisis (FC) were studied. Atmospheric carbonyl compound concentrations in the 2008 and 2009 sampling periods were affected by the 2008 FC. The industrial downturn plus the high closing down number of the small enterprises with limited emission treatment during the FC played an important role in the reduction of the industry-related CH₃CHO and CH₃COCH₃. In 2010, the recovery of industrial activities occurred, but affected by traffic restriction enforcement in Guangzhou over the Asian Games period, HCHO concentration (daytime 7.59?±?2.59 μg m^?3) was lower than expectation. Carbonyl compounds in WQS site were highly influenced by regional pollution transport from different upwind urban cities and industrial districts in the north-northwest to northeast wind sector in winter. Also, the interaction of the winter monsoon with the warm ocean along the coastline as well as day and night boundary layer mixing height variation affected carbonyl compound concentrations in WQS. The daytime mean dry deposition losses of HCHO and CH₃CHO were first time model-estimated for 2009 and 2010. For loss of HCHO in the early afternoon, photolysis was the dominant sink, followed by dry deposition and removal by OH radical (?OH), while for CH₃CHO, dry deposition was dominant. For the gain of HCHO and CH₃CHO, the production rates during early afternoon in 2009 and 2010 were estimated by an indirect approach.     

地震安全性评价中的多方案比较工作方法

在对秦山核电二期工程建设项目地震动参数的复核中采用了多方案比较方法。由于新增的地震地质资料不会改变原报告对地震地质研究的结论,近十多年地震的活动对工作区地震背景的影响没有发生根本变化。在分析研究本地区具有代表性的不同潜在震源区的划分方案后,采用相对应的地震动参数衰减关系进行地震危险性概率分析计算,与确定性方法计算结果比较后确定秦山核电二期扩建工程厂址极限安全地震动SL-2复核结果为0.15g。本次复核工作的技术路线可以为相似类型的重大工程地震参数复核参考。