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991.
在城市化进程不断加快的今天,城市地下空间开发利用已经成为提高城市容量、缓解交通、改善环境的重要手段。为全面深化对泰安城市地下空间的认识,有效挖掘城市后备空间资源的巨大潜力,通过综合集成钻孔编录、地质图件和数字地形图等多源地学数据,借助MapGIS三维地质建模软件,初步建立起泰安城市三维地质模型,以直观的方式表达工程岩土体空间分布等地质信息,为更好地保护利用泰安市地下空间提供地质依据。  相似文献   
992.
陆晓静  苏占胜  谭志强 《干旱气象》2014,(1):120-122,127
利用宁夏1991~2010年20 a凌汛期水文和气温序列资料,研究了宁夏凌汛期特征、凌汛灾害发生主要时段,黄河封河、开河集中期与日平均气温之间的关系。结果表明:宁夏凌汛特征为封开河时序相反,小流量、高水位行洪,受强冷空气影响较大;凌汛灾害主要发生在封河和开河期间;日平均气温正负转化日期与封、开河期有对应关系,宁夏封河集中期在12月20日至1月19日;开河集中日期在2月13~20日。在凌汛关键期结合MODIS遥感数据对凌汛灾害监测防范有一定指导意义。  相似文献   
993.
正1引言由国家气象中心开发的软件"农业气象测报业务系统(AgMODOS)",自2010年1月1日起正式在全国范围内投入业务使用。农业气象测报业务系统由系统管理、农业气象测报数据编辑和农业气象测报数据应用服务三个主程序,以及帮助文档、系统参数文件、输入输出表单模板、数据库文件等组成。参数设置、观测簿的建立、观测数据录入和编辑、农业气象观测要素和旬(月)基本气象要素报文的生成、数据文件上传等,是目前该软件在吉林  相似文献   
994.
由于自动气象站观测仪器自身问题和外部环境条件的影响,仪器有时发生机械故障和记录误差。文章列举了几种仪器的常见故障,并对故障原因进行分析,提出了解决办法,为控制气象数据质量,为维护和保障气象观测仪器正常运转提供参考。  相似文献   
995.
从逐分钟地面数据文件中读取正点前10分钟内任一分钟的分钟数据进行备用,以备在临近正点时自动气象站计算机系统出现故障的情况下作为电话口传报文之用,保证正点数据的及时有效传输,避免逾限报的发生。  相似文献   
996.
Information on the spatial and temporal pat- terns of surface carbon flux is crucial to understanding of source/sink mechanisms and projection of future atmospheric CO2 concentrations and climate. This study presents the construction and implementation of a terrestrial carbon cycle data assimilation system based on a dynamic vegetation and terrestrial carbon model Vegetation-Global-Atmosphere-Soil (VEGAS) with an advanced assimilation algorithm, the local ensemble transform Kalman filter (LETKF, hereafter LETKF-VEGAS). An observing system simulation experiment (OSSE) framework was designed to evaluate the reliability of this system, and numerical experiments conducted by the OSSE using leaf area index (LAI) observations suggest that the LETKF -VEGAS can improve the estimations of leaf carbon pool and LAI significantly, with reduced root mean square errors and increased correlation coefficients with true values, as compared to a control run without assimilation. Furthermore, the LETKF-VEGAS has the potential to provide more accurate estimations of the net primary productivity (NPP) and carbon flux to atmosphere (CFta).  相似文献   
997.
In this study, the high-accuracy multisource integrated Chinese land cover (MICLCover) dataset was used in version 4 of the Community Land Model (CLM4) to assess how the new land cover information affected land surface simulation over China. Compared to the default land cover dataset in CLM4, the MICL data indicated lower values for bare soil (14.6% reduction), nee- dleleaf tree (3.6%), and broadleaf tree (1.9%); higher values for shrub cover (1.8% increase), grassland (9.9%), cropland (5.0%), glaciers (0.5%), lakes (1.6%), and wetland (1.1%); and unchanged for urban areas. Two comparative CLM4 simulations were conducted for the 33-yr period from 1972 to 2004, one using the MICL dataset and the other using the default dataset. The results revealed that the MICL data produced a 0.3% lower mean annual surface albedo over China than the original data. The largest contributor to the reduced value was semiarid regions (2.1% reduction). The MICL-data albedo value agreed more closely with observations (MODIS broad- band black-sky albedo products) over arid and semiarid regions than for the original data to some extent. The simulated average sensible heat flux over China increased by only 0.1 W m 2 owing to the reduced values in arid and semiarid regions, as opposed to increases in humid and semihumid regions, while an increased latent heat flux of I W m-2 was reflected in almost identical changes over the whole region. In addition, the mean annual runoff simulated by CLM4 using MICL data decreased by 6.8 mm yr-1, primarily due to large simulated decreases in humid regions.  相似文献   
998.
PARASOL (Polarization & Anisotropy of Reflectances for Atmospheric Sciences coupled with Ob- servations from a Lidar) multi-channel and mul- ti-directional polarized data for different aerosol types were compared. The PARASOL polarized radiance data at 490 nm, 670 nm, and 865 nm increased with aerosol optical thickness (AOT) for fine-mode aerosols; however, the polarized radiances at 490 nm and 670 nm decreased as AOT increased for coarse dust aerosols. Thus, the vari- ation of the polarized radiance with AOT can be used to identify fine or coarse particle-dominated aerosols. Polar- ized radiances at three wavelengths for fine- and coarse-mode aerosols were analyzed and fitted by linear regression. The slope of the line for 670 nm and 490 nm wavelength pairs is less than 0.35 for dust aerosols. However, the value for fine-mode aerosols is greater than 0.60. The Support Vector Machine method (SVM) based on 12 vector features was used to discriminate clear sky, coarse dust aerosols, fine-mode aerosols, and cloud. Two cases were given and validated by AErosol RObotic NETwork (AERONET) measurements, MODIS (Mod- erate Resolution Imaging Spectroradiometer) FMF (Fine Mode Fraction at 550 nm) images, PARASOL RGB (Red Green Blue) images, and CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) VFM (Vertical Feature Mask) data.  相似文献   
999.
动三轴采集的试验数据点(剪应变与动剪模量和阻尼比之间)具有离散性和有限性,为方便应用需要对数据点进行拟合,但现有经验公式不一定很好吻合试验数据。为得到不同剪应变与对应的动剪模量和阻尼比之间的关系,本文利用最小二乘原理,对渤海某海洋平台地基土进行动三轴试验获得的动剪模量、阻尼比与剪切应变的数据进行了分段多项式的拟合。数据处理过程是先对剪应变值进行了压缩处理,然后再分段低次多项式拟合,得到多项式拟合参数。通过此项改进解决了正规方程解中的病态问题,且拟合效果良好。  相似文献   
1000.
The principal purpose of this paper is to extract entire sea surface wind's information from spaceborne lidar, and particularly to utilize a appropriate algorithm for removing the interference information due to white caps and subsurface water. Wind speeds are obtained through empirical relationship with sea surface mean square slopes. Wind directions are derived from relationship between wind speeds and wind directions im plied in CMOD5n geophysical models function (GMF). Whitecaps backscattering signals were distinguished with the help of lidar depolarization ratio measurements and rectified by whitecaps coverage equation. Subsurface water backscattering signals were corrected by means of inverse distance weighted (IDW) from neighborhood non-singular data with optimal subsurface water backscattering calibration parameters. To verify the algorithm reliably, it selected NDBC's TAO buoy-laying area as survey region in camparison with buoys' wind field data and METOP satellite ASCAT of 25 km single orbit wind field data after temporal-spa tial matching. Validation results showed that the retrieval algorithm works well in terms of root mean square error (RMSE) less than 2m/s and wind direction's RMSE less than 21 degree.  相似文献   
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