建立公路控制测量坐标系方法的探讨

近年来,公路控制测量中普遍采用GPS测量,多数测绘单位都是按照国家控制测量的方法和要求进行布设、测量,没有考虑公路测量的特殊性。这样就存在一个问题:施工单位现场用全站仪实测某两点之间的距离与用坐标反算的距离相差很大,无法满足作为工程施工的要求。针对这一问题,本文就如何建立公路控制测量坐标系的方法进行探讨。     

井筒十字中心线恢复标定方法探讨

在井筒十字中心线恢复标定工程中,由于现场条件限制,传统仪器无法架设,通过RTK、电子全站仪及电子手簿等手段和四等导线测量方法间接测定井筒十字中线点,快速精准,效果显著。     

琼东南盆地中央峡谷深水天然堤—溢岸沉积

中央峡谷位于琼东南盆地深水区,发育面积较广,内部天然堤—溢岸沉积发育。深水天然堤—溢岸可作为良好的油气储集体,深受油气工业界的关注。为了指导中央峡谷的油气勘探,利用三维地震资料,结合地震剖面以及均方根振幅属性对中央峡谷内部天然堤—溢岸沉积的形态和控制因素进行了分析,总结了天然堤—溢岸的沉积模式,并对其油气勘探前景进行了...     

ECHAM5-Simulated Impacts of Two Types of El Nio on the Winter Precipitation Anomalies in South China

The authors used an atmospheric general circulation model(AGCM) of European Centre Hamburg Model(ECHAM5.4) and investigated the possible impacts of eastern Pacific(EP) and central Pacific(CP) El Nio on the winter precipitation anomalies in South China.A composite analysis suggested much more rainfall during the mature phase of EP El Nio than in the case of CP El Nio,and their corresponding observed wet centers to be located in the southeast coast and the region to the south of the Yangtze River,respectively.Results obtained on the basis of model-sensitive run imply that the modelsimulated rainfall anomalies agree well with the observation,and the magnitude of simulated rainfall anomalies were found to be reduced when the amplitude of sea surface temperature anomaly(SSTA) forcing of EP and CP El Nio was cut down.These results imply that the rainfall anomaly in South China is very sensitive not only to the type of El Nio but also to its intensity.     

基于遥感数据的内蒙古草原灌丛物候变化研究

植被物候研究是全球气候变化研究的重要内容,但国际上有关干旱半干旱区灌丛物候变化的研究还很缺乏。为了探讨气候变化对内蒙古草原灌丛物候的影响,利用2000~2011年的MODIS EVI时间序列影像,采用动态阈值法得到6种灌丛12 a物候年际变化情况,结合样点附近气象站的气温和降水数据,分析了灌丛物候与气候变化的动态关系。结果表明：（1）内蒙古中西部草原灌丛返青期、枯黄期都呈现提前的趋势,生长季长度缩短;（2）春季均温升高和前一年秋冬降水增加可以提前灌丛返青期,是影响返青期的主要因素;（3）秋季降水减少和夏秋均温上升都利于枯黄期提前,夏季降水的作用则因灌丛种类不同而略有差异;（4）夏秋均温上升缩短了生长季长度,夏秋降水量、春季均温则多与生长季长度呈正相关。     

基于GIS的滇中城市群空间结构效益优化研究

在ArcGIS软件和云南基础地理数据支持下,对滇中城市群空间结构效益进行初步解析.结果表明：滇中城市群的突出优势在于人口规模大,经济发展水平较高,经济发展综合指数和城市化综合指数较大,其中昆明和玉溪的经济发展与城市化协调度较高,同时表现出空间差异;滇中城市群紧凑度较高,城市交通优势度相对较高,可达性较好,重要城市之间的空间联系较为紧密,但城市数量较少,规模效益相对欠缺.以实现城市群空间结构效益最大化为目标,在综合分析的基础上提出了滇中城市群方案.     

Mean Flow–Storm Track Relationship and Rossby Wave Breaking in Two Types of El-Nino

The features of large-scale circulation, storm tracks and the dynamical relationship between them were examined by investigating Rossby wave breaking(RWB) processes associated with Eastern Pacific(EP) and Central Pacific(CP) El-Nin o. During EP El-Nin o, the geopotential height anomaly at 500 hPa(Z500) exhibits a Pacific–North America(PNA) pattern. During CP El-Nin o, the Z500 anomaly shows a north positive–south negative pattern over the North Pacific. The anomalous distributions of baroclinicity and storm track are consistent with those of upper-level zonal wind for both EP and CP El-Nin o, suggesting impacts of mean flow on storm track variability. Anticyclonic wave breaking(AWB) occurs less frequently in EP El-Nin o years, while cyclonic wave breaking(CWB) occurs more frequently in CP El-Nin o years over the North Pacific sector. Outside the North Pacific, more CWB events occur over North America during EP El-Nin o. When AWB events occur less frequently over the North Pacific during EP El-Nin o, Z500 decreases locally and the zonal wind is strengthened(weakened) to the south(north). This is because AWB events reflect a monopole high anomaly at the centroid of breaking events. When CWB events occur more frequently over the North Pacific under CP El-Nin o conditions, and over North America under EP El-Nin o condition, Z500 increases(decreases) to the northeast(southwest), since CWB events are related to a northeast–southwest dipole Z500 anomaly. The anomalous RWB events act to invigorate and reinforce the circulation anomalies over the North Pacific–North America region linked with the two types of El-Nin o.     

新疆旅游中心地等级体系初构

根据新疆旅游业发展现状与存在的问题,阐明了确定新疆旅游中心地的必要性.以旅游中心地概念及克里斯泰勒中心地理论为基础,针对新疆旅游业发展中存在的"瓶颈"--交通问题,分析计算了通达性指数与网尼克指数两个指标,结合新疆各地区的旅游景点和酒店数日,确定了新疆旅游中心城市(中心地).利用以上四个指标进行聚类分析,划分了新疆旅游...     

滇中城市群发展的资源与环境基础分析

资源与环境是城市发展的重要影响因素,一个地区资源与环境基础状况及与城市发展的协调程度将对城市的发展起到推动或限制作用。发展滇中城市群、构建以昆明为核心的滇中大经济圈是促进云南省乃至我国西南地区社会经济快速发展和加快云南省城市化进程的重大举措。分析了滇中城市群发展的资源与环境基础及与之相协调的状况,并在此基础上对滇中城市群的发展提出一些自己的浅见,以期对滇中城市群的发展有所参考。