海南海棠湾海底微地貌多源声学特征、成因及其指示意义

海底微地貌不但可提供环境与工程地质评价信息,避免地质灾害发生和环境破坏,而且对渔业生态建设和沉积环境反演等也具有重要意义.为揭示海底微地貌的多源声学特征,成因及指示意义,利用在海南海棠湾获取的侧扫声呐、浅地层剖面、单道地震数据进行分析.识别出海底沙斑、小沙波、沙纹、礁石堆、基岩等自然微地貌,以及海底拖痕、管道、人工鱼礁、养殖网箱等人工微地貌.证实海底微地貌多源声学识别方法具有综合立体探测的优势,解译可靠性高;全新世以来,研究区如沙斑、小沙波、沙纹等自然微地貌,主要受较弱的水动力条件和沉积物供应不足制约,而人工微地貌主要由人类海洋活动造成,具体表现在基于人工鱼礁投放的海洋牧场建设、海洋养殖、拖网捕鱼以及海底管线敷设等方面;研究区地质条件总体良好,发生地质灾害风险小.     

一种改进的机载SAR基线估计方法

本文利用地面控制点对机载双天线雷达系统的基线参数进行估计.首先证实了基线长度的精度与控制点斜距差的精度是同数量级的,然后运用最小二乘法解算控制点的斜距差,并通过干涉相位信息和解缠相位信息对斜距相位差进行精化处理,得到精度较高的斜距相位差参加基线的解算.通过实验表明,该方法获得的基线参数精度较高.     

应用图像卷积运算提取城市范围

通过一种卷积算法,从遥感分类数据中计算城市用地比例,并以该比例作为划分城市和非城市区的阈值,进而提取城市范围。方法构建了评价提取结果的指标体系,以确定卷积模板大小和阈值的选取。以北京为研究区,利用2007年SPOT 5多光谱影像分类数据,对方法的可行性进行了验证。结合统计数据中的建成区面积,采用504种模板和阈值组合进行提取试验,讨论了模板和阈值对提取结果的影响。最终选择(205, 51)的模板和阈值组合,对城市范围进行提取。研究结果表明：(1)该方法解决了遥感监测的城市用地分布区与城市范围存在差异的问题,为城市研究基础数据的准备提供了新的方法;(2)阈值过高或过低会造成城市范围的明显缩小或扩大;较小的模板不利于消除随机误差,较大的模板则会导致结果过于平滑;(3)对于SPOT 5多光谱影像分类数据,模板大小在193—205像元(约4 km²)、阈值接近50时,提取结果最好。     

The Application of Sea-Surface Wind Detection with Doppler Lidar in Olympic Sailing

The mobile incoherent Doppler lidar(MIDL),which was jointly developed by State Key Laboratory of Severe Weather(LaSW) of the Chinese Academy of Meteorological Sciences(CAMS) and Ocean University of China,provided meteorological services during the Olympic sailing events in Qingdao in 2008.In this study,two experiments were performed based on these measurements.First,the capabilities of MIDL detection of sea-surface winds were investigated by comparing its radial velocities with those from a sea buoy.MIDL radial velocity was almost consistent with sea-buoy data;both reflected the changes in wind with time.However,the MIDL data was 0.5 m s 1 lower on average than the sea-buoy data due to differences in detection principle,sample volume,sample interval,spatial and temporal resolution.Second,the wind fields during the Olympic sailing events were calculated using a four-dimensional variation data assimilation(4DVAR) algorithm and were evaluated by comparing them with data from a sea buoy.The results show that the calculations made with the 4DVAR wind retrieval method are able to simulate the fine retrieval of sea-surface wind data-the retrieved wind fields were consistent with those of sea-buoy data.Overall,the correlation coefficient of wind direction was 0.93,and the correlation coefficient of wind speed was 0.70.The distribution of retrieval wind fields was consistent with that of MIDL radial velocity;the root-mean-square error between them had an average of only 1.52 m s 1.     

五里营氦气受水位影响分析

延庆地震台五里营井逸出氦气受该井动水位异常变化影响,每日数据扰动大,影响原来的日变形态.对仪器的集气装置进行改造,把地面集气改为水下集气.既解决氦气受水位异常变化的影响问题,减小观测环境变化对氦气观测的影响,提高观测质量,对今后可能记录的地震前兆信息提供保障,对其他有此测项的台站有一定借鉴意义.     

暴雨触发局部地震活动的一个典型例子:2010年6月广西凌云—凤山交界3级震群活动

在前期严重干旱的背景下,2010年6月27～30日广西西北部出现大暴雨过程,大范围积水成涝.降雨量最大的凌云、凤山交界于6月28日17时开始出现密集的微震活动,形成显著的震群事件.自6月28日至7月15日共记录地震2739次,其中2～2.9级(ML,下同)41次,3级以上地震3次,最大为7月1日10时27分3.2级地震...     

气象因子对哈密市大气可吸入颗粒物浓度的影响分析

采用2007-2008年哈密市气象及环境数据,分析可吸入颗粒物(PM10)对哈密市空气质量的影响以及风速风向、沙尘天气、降水、气温、气压、相对湿度与PM10浓度的相互关系.结果表明:哈密市的首要污染物为可吸入颗粒物.偏西风能够明显增大PM1o浓度.当平均风速＜2.0 m/s时,随着风速的增大PM10浓度逐渐减小;平均风...     

Metal concentrations in water and sediments from tourist beaches of Acapulco, Mexico

A survey on the metal concentrations (As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr, V, Zn) in beach water and sediments is reported from the tourist destination of Acapulco city on the Pacific coast of Mexico. The concentration of dissolved trace metals (DTMs) in beach water and acid leachable trace metals (ALTMs) in sediments indicated that they are anthropogenic in nature due to the increased tourist activities in the crowded beach locations. The statistical analysis indicates Fe and Mn play a major role as metal scavengers in both the medium (water and sediment) and the higher value of other metals is site specific in the study area, indicating that they are transported from the local area. Comparison results suggest that the beach water quality has deteriorated more than the sediments and special care needs to be taken to restore the beach quality.     

利用IRS-P5影像制作1∶50000 3D产品的试验研究

讨论了利用IRS-P5卫星遥感影像立体模型进行1∶50000 DEM,DOM,DLG等地理信息产品生产的相关问题,并进行了精度检测;同时与传统的航空摄影测量方法在原始资料获取、生产效率、工作量、数据成本等方面进行了对比分析。