综合台站观测资料信息管理系统的技术特点

介绍了为配合闽南地震示范工程的开展而开发的《综合地震台观测资料信息管理系统》程序设计的基本原则、总体结构及功能,并给出了操作流程示意图和简要说明。     

超浅层顶管施工诱发地表沉降规律分析

随着社会化进程的推进,顶管法在各类城市地下管线的施工中得到广泛应用。超浅层顶管施工。绝大多数是在已建道路下进行的,施工时,易发生地表沉降,且沉降量很大,易破坏路面。为此,超浅层顶管施工对周围环境的影响已引起人们足够的重视,其施工及控制技术是目前迫切需要掌握的。利用有限差分软件FLAC3D对顶管施工过程中地表沉降进行模拟,旨在了解超浅层顶管施工引起的力学效应。对超浅层顶管施工引起的地表沉降作出预测,为采取措施减小地表沉降提供依据。     

GPS在湖南1：20万区域重力调查中的应用

GPS是现代高科技，它采用微型接收机，可以实现快速定位并取得测量点的3维座标。这种新技术在数字化地质、提高找矿效果等方面，应用前景广阔，侧重介绍了ASHTECH GPS接收机在区域重力调查中，怎样建立基准站与流动观测站、数据的传输与预处理和测量点3维座标的换算，以及应用数据自动生成布格异常等值线图。这项新技术的使用完全可以满足1：20万区域重力调查的精度要求。     

路堤荷载下碎石桩处理软基沉降计算

以沉降控制为目的的碎石桩复合地基,其沉降计算在设计、施工中具有重要地位。本文基于典型的桩土单元体模型,建立了复合地基体积压缩系数与复合地基弹性模量的关系,考虑施工中的时间因素及相应的固结度对沉降的影响,提出相应的沉降计算公式,并结合四川省遂-资高速公路软基变形监测的数据进一步验证其可行性。研究表明本算法计算值比实测沉降约大10% ～20%。填筑过程中,计算沉降历时曲线与实测曲线拟合较好,更接近实测值;在此基础上,初步探讨了影响路堤荷载下碎石桩处理软基沉降变化的因素,得出桩径、桩间距对其影响较为明显。同时结合本例,建议布桩时桩间距与桩径比值最好控制在2～4之间。     

Linking pesticides and human health: A geographic information system (GIS) and Landsat remote sensing method to estimate agricultural pesticide exposure

Accurate pesticide exposure estimation is integral to epidemiologic studies elucidating the role of pesticides in human health. Humans can be exposed to pesticides via residential proximity to agricultural pesticide applications (drift). We present an improved geographic information system (GIS) and remote sensing method, the Landsat method, to estimate agricultural pesticide exposure through matching pesticide applications to crops classified from temporally concurrent Landsat satellite remote sensing images in California. The image classification method utilizes Normalized Difference Vegetation Index (NDVI) values in a combined maximum likelihood classification and per-field (using segments) approach. Pesticide exposure is estimated according to pesticide-treated crop fields intersecting 500 m buffers around geocoded locations (e.g., residences) in a GIS. Study results demonstrate that the Landsat method can improve GIS-based pesticide exposure estimation by matching more pesticide applications to crops (especially temporary crops) classified using temporally concurrent Landsat images compared to the standard method that relies on infrequently updated land use survey (LUS) crop data. The Landsat method can be used in epidemiologic studies to reconstruct past individual-level exposure to specific pesticides according to where individuals are located.     

Multitemporal settlement and population mapping from Landsat using Google Earth Engine

As countries become increasingly urbanized, understanding how urban areas are changing within the landscape becomes increasingly important. Urbanized areas are often the strongest indicators of human interaction with the environment, and understanding how urban areas develop through remotely sensed data allows for more sustainable practices. The Google Earth Engine (GEE) leverages cloud computing services to provide analysis capabilities on over 40 years of Landsat data. As a remote sensing platform, its ability to analyze global data rapidly lends itself to being an invaluable tool for studying the growth of urban areas. Here we present (i) An approach for the automated extraction of urban areas from Landsat imagery using GEE, validated using higher resolution images, (ii) a novel method of validation of the extracted urban extents using changes in the statistical performance of a high resolution population mapping method. Temporally distinct urban extractions were classified from the GEE catalog of Landsat 5 and 7 data over the Indonesian island of Java by using a Normalized Difference Spectral Vector (NDSV) method. Statistical evaluation of all of the tests was performed, and the value of population mapping methods in validating these urban extents was also examined. Results showed that the automated classification from GEE produced accurate urban extent maps, and that the integration of GEE-derived urban extents also improved the quality of the population mapping outputs.     

基于CALIPSO卫星资料的京津冀地区MODIS卷云云顶高度订正

卷云在大气辐射中扮演着重要角色,对天气系统和气候变化产生重要影响。相比传统地基观测手段,卫星遥感更容易探测到高层卷云的信息,本文利用CALIOP主动遥感仪器可获取较为准确的薄卷云特性的特点,针对MODIS被动遥感探测器反演的薄卷云云顶高度的偏差开展订正研究。研究选取2013～2017年京津冀地区MODIS云产品,结合CALIPSO卫星的卷云云顶高度数据,基于交叉验证的方法得到线性拟合方案,对MODIS卷云云顶高度进行订正。订正后的MODIS与CALIPSO卷云云顶高度差值的分布区间由?3～2 km变为?2.0～2.5 km,峰值由?0.8 km左右变为0.2 km左右。订正效果随云顶高度和云光学厚度的不同有所变化,其中较低层卷云和光学薄卷云的订正效果更明显。     

区域地下水动态观测网优化的组合克立金方法

本文推导出了普通二变量及泛二变量组合克立金方程式．同时，给出了两种方法的估计误差标准差求解方程，可用于地下水动态观测网的密度优化；该方法还可用于地下水位、水中离子浓度的最优估计．     

Win View软件在云台1m望远镜上的应用

ＷｉｎＶｉｅｗ是一个用于图像采集和处理的高性能软件包。作为一个商业性的软件，在天文上的应用正日益广泛。本文结合配套的硬件设备，详细介绍了它的主要功能及在天文观测中的应用，以期对使用这套设备的观测者有所帮助     

东川泥石流站开放以来的回顾与展望

本文扼要介绍了中国科学院东川泥石流观测研究站对外开放三年来,在泥石流观测试验研究和防灾减灾工作中的新进展,同时也简述了站设基金课题、国家基金课题和中外合作交流项目的进展情况,并对今后的观测研究工作提出了展望和建议。