基于 Gamit 解算的 NNCORS 站点CGCS2000坐标的确定方法

本文以南宁市NNCORS站点为例,介绍了基于GAMIT的基线平差法和框架转换法求解NNCORS站点的CGCS2000坐标,分析了两种方法的求解精度,并对两种解算结果进行比较,为城市CORS站点CGCS2000坐标确定提供参考。     

An Overview of BCC Climate System Model Development and Application for Climate Change Studies

This paper reviews recent progress in the development of the Beijing Climate Center Climate System Model(BCC-CSM) and its four component models(atmosphere,land surface,ocean,and sea ice).Two recent versions are described:BCC-CSM1.1 with coarse resolution(approximately 2.8125°×2.8125°) and BCC-CSM1.1(m) with moderate resolution(approximately 1.125°×1.125°).Both versions are fully coupled climate-carbon cycle models that simulate the global terrestrial and oceanic carbon cycles and include dynamic vegetation.Both models well simulate the concentration and temporal evolution of atmospheric CO_2 during the 20th century with anthropogenic CO2 emissions prescribed.Simulations using these two versions of the BCC-CSM model have been contributed to the Coupled Model Intercomparison Project phase five(CMIP5) in support of the Intergovernmental Panel on Climate Change(IPCC) Fifth Assessment Report(AR5).These simulations are available for use by both national and international communities for investigating global climate change and for future climate projections.Simulations of the 20th century climate using BCC-CSMl.l and BCC-CSMl.l(m) are presented and validated,with particular focus on the spatial pattern and seasonal evolution of precipitation and surface air temperature on global and continental scales.Simulations of climate during the last millennium and projections of climate change during the next century are also presented and discussed.Both BCC-CSMl.l and BCC-CSMl.l(m) perform well when compared with other CMIP5 models.Preliminary analyses indicate that the higher resolution in BCC-CSM1.1(m) improves the simulation of mean climate relative to BCC-CSMl.l,particularly on regional scales.     

Intraseasonal Oscillation of the South China Sea Summer Monsoon and Its Influence on Regionally Persistent Heavy Rain over Southern China

The intraseasonal oscillation（ISO） in the South China Sea summer monsoon（SCSSM） and its influence on regionally persistent heavy rain（RPHR） over southern China are examined by using satelhte outgoing long wave radiation,NCEP/NCAR reanalysis,and gridded rainfall station data in China from 1981 to 2010.The most important feature of the ISO in SCSSM,contributing to the modulation of RPHR,is found to be the fluctuation in the western Pacific subtropical high（WPSH）,along with a close link to the Madden-Julian oscillation（MJO）.Southern China is divided into three regions by using rotated empirical orthogonal functions（REOFs）for intraseasonal rainfall,where the incidence rate of RPHR is closely linked to the intraseasonal variation in rainfall.It is found that SCSSM ISOs are the key systems controlling the intraseasonal variability in rainfall and can be described by the leading pair of empirical orthogonal functions（EOFs） for the 850-hPa zonal wind over the SCS and southern China.Composite analyses based on the principal components（PCs） of the EOFs indicate that the ISO process in SCSSM exhibits as the east-west oscillation of the WPSH,which is coupled with the northward-propagating MJO,creating alternating dry and wet phases over southern China with a period of 40 days.The wet phases provide stable and lasting circulation conditions that promote RPHR.However,differences in the ISO structures can be found when RPHR occurs in regions where the WPSH assumes different meridional positions.Further examination of the meridional-phase structure suggests an important role of northward-propagating ISO and regional air-sea interaction in the ISO process in SCSSM.     

Spectrum Analysis of Wind Profiling Radar Measurements

Unlike previous studies on wind turbulence spectrum in the planetary boundary layer, this investigation focuses on high-altitude （1-5 km） wind energy spectrum and turbulence spectrum under various weather conditions. A fast Fourier transform （FFT） is used to calculate the wind energy and turbulence spectrum density at high altitudes （1-5 km） based on wind profiling radar （WPR） measurements. The turbulence spectrum under stable weather conditions at high altitudes is expressed in powers within a frequency range of 2 × 10-5-10-3 s-1, and the slope b is between -0.82 and -1.04, indicating that the turbulence is in the transition from the energetic area to the inertial sub-range. The features of strong weather are reflected less obviously in the wind energy spectrum than in the turbulence spectrum, with peaks showing up at different heights in the latter spectrum. Cold windy weather appears over a period of 1.5 days in the turbulence spectrum. Wide-range rainstorms exhibit two or three peaks in the spectrum over a period of 15-20 h, while in severe convective weather conditions, there are two peaks at 13 and 9 h. The results indicate that spectrum analysis of wind profiling radar measurements can be used as a supplemental and helpful method for weather analysis.     

基于GPS垂向位移测定云南地区陆地水储量及其对累积降雨的响应机制

本文基于中国大陆构造环境监测网（陆态网）GPS台站垂向形变数据,通过主成分分析计算云南省6大流域陆地水负荷形变,并与降雨数据进行相关性分析和交叉小波分析。结果表明,云南省各流域陆地水储量变化相对于降雨在半年和年周期上分别存在1.5~2.25和3~6个月的滞后,不同周期滞后的叠加使陆地水储量与累积降雨量之间存在显著的负相关性,6大流域的降雨累积天数各不相同,均在47~109 d之间。本文由此提出一种云南地区陆地水储量对累积降雨的响应机制。     

2000—2019年鄱阳湖生态经济区水源涵养时空变化

水源涵养是生态保护的一个重要方面,对鄱阳湖生态经济区生态保护具有重要意义。本文基于InVEST模型,对鄱阳湖生态经济区2000—2019年产水和水源涵养时空变化进行了分析,并运用空间自相关探究了高程、坡度与水源涵养功能的空间关系。结果表明:①鄱阳湖生态经济区多年平均产水深度为971.04 mm,多年平均水源涵养深度为299.298 mm;②2000—2019年水源涵养深度先上升后下降,变化幅度较大,整体呈上升趋势;③水源涵养功能呈地域分布,重要区和极为重要区主要分布在东部和西北部林地,一般重要区分布在鄱阳湖平原;④水源涵养与高程和坡度呈正相关,高值多出现在高海拔和坡度较大的地区。     

多视角监控视频中动态目标的时空信息提取方法

监控视频中动态目标的精准定位与跟踪作为计算机视觉领域中重要的研究方向,近年来已成为监控领域的研究热点。传统视频动态目标检测仅依赖图像特征数据,忽略了与地理坐标系精准匹配,特别是对于多个摄像机覆盖的区域,拍摄的角度不同,投影后形成的图像空间分辨率也不同,因此,难以满足智能监控在复杂的地理场景中全方位时空信息感知。本文提出一种多摄像头协同的视频监控图像与地理空间数据互映射模型构建方法来获取动态目标的轮廓和地理位置等时空信息,首先建立监控图像信息与地理空间数据的互映射关系,将观测角度不同、尺度不同和空间分辨率的监控图像置于同一坐标系下,并在此基础上通过融合Canny算子与背景减法来检测目标的边缘信息;然后采用质心偏移算法还原目标在该场景的实际位置,从而实现多角度下连续跟踪,提升地理场景的时空理解力和分析力,提高动态目标的精准定位与跟踪能力。     

某农药化工企业密集区地下水污染评价

通过分析研究某农药化工企业密集区地下水水质及污染状况,按照国家有关标准,采用单指标评价法和内梅罗指数法对地下水的质量进行评价。评价结果显示：该区域地下水水质普遍较差,大部分为Ⅳ类及Ⅴ类水质,已不适于饮用。然后对该区域地下水污染进行评价,结果显示地下水有机和无机污染严重,并形成了以某农药化工企业为污染源并沿岩溶地下水流向的一个卤代烃类有机物污染羽,这表明造成该研究区岩溶地下水污染的主要污染源为某农药化工企业。最后根据评价结果,提出相应的控制地下水污染的建议和措施,为该地区制定地下水开发利用规划提供科学依据。