行政区划调整对政区位势的影响与定量化测度——以重庆市为例   总被引：4，自引：2，他引：2  

陈田  王开泳  陈妤凡 《地理科学》2018,38(5):654-661

行政区划调整是提升行政管理效率和促进经济发展的重要手段,由此改变政区的位势和发展轨迹,重塑城市发展活力和区域发展格局。政区位势的测度可以较好的评价行政区划调整的效能。建立基于生产函数的政区位势模型,以重庆市为案例,测算其设立直辖市前后的政区位势及其区划调整的相对区位势能,以探析影响政区位势变化的机制。研究表明：① 政区位势与该地的交通通达度、资源控制能力及综合发展规模有关;② 行政区划调整对政区位势变化具有正向作用,但该影响效果具有滞后效应;③ 设立直辖市对重庆市而言不仅意味着行政级别的提升,政区位势也不断上升,相对区位势能均大于1,但该提升幅度正从快速优化趋于平缓发展。  相似文献   

Role of Microphysical Parameterizations with Droplet Relative Dispersion in IAP AGCM 4.1     

Xiaoning XIE  He ZHANG  Xiaodong LIU  Yiran PENG  Yangang LIU 《大气科学进展》2018,35(2):248-259

  相似文献   

Validation and Spatiotemporal Distribution of GEOS-5-Based Planetary Boundary Layer Height and Relative Humidity in China     

Yidan SI  Shenshen LI  Liangfu CHEN  Chao YU  Zifeng WANG  Yang WANG  Hongmei WANG 《大气科学进展》2018,35(4):479-492

Few studies have specifically focused on the validation and spatiotemporal distribution of planetary boundary layer height(PBLH) and relative humidity(RH) data in China. In this analysis, continuous PBLH and surface-level RH data simulated from GEOS-5 between 2004 and 2012, were validated against ground-based observations. Overall, the simulated RH was consistent with the statistical data from meteorological stations, with a correlation coefficient of 0.78 and a slope of 0.9. However, the simulated PBLH was underestimated compared to LIDAR data by a factor of approximately two,which was primarily because of poor simulation in late summer and early autumn. We further examined the spatiotemporal distribution characteristics of two factors in four regions—North China, South China, Northwest China, and the Tibetan Plateau. The results showed that the annual PBLH trends in all regions were fairly moderate but sensitive to solar radiation and precipitation, which explains why the PBLH values were ranked in order from largest to smallest as follows: Tibetan Plateau, Northwest China, North China, and South China. Strong seasonal variation of the PBLH exhibited high values in summer and low values in winter, which was also consistent with the turbulent vertical exchange. Not surprisingly, the highest RH in South China and the lowest RH in desert areas of Northwest China(less than 30%). Seasonally, South China exhibited little variation, whereas Northwest China exhibited its highest humidity in winter and lowest humidity in spring,the maximum values in the other regions were obtained from July to September.  相似文献   

浙江省极端气温事件年代际变化特征及城乡差异分析     

郁珍艳  李正泉  张育慧  王阔 《气象科技》2016,44(6):972-978

采用百分位法确定了极端温度事件,通过t检验法、气候倾向率分析了极端温度事件的年代际及年际变化特征,基于核密度估计方法揭示了四季极端温度事件年代际变化特征及城乡差异。结果表明:极端高温和低温日数分别呈现以增加为主和以减少为主的变化特征,这种趋势随时间增强,东部沿海地区最显著。四季极端高温日数增多、强度增大,夏季增多最多、冬季最少,强度增大在春冬季最强。四季极端低温日数减少、强度减小,冬季减少最多,强度减小在春季最强。浙西地区极端温度事件的年际变率小于浙东地区,浙江城市地区四季极端高温强度更强、极端低温强度更弱。  相似文献   

Simulation and Regionalization of Daily Global Solar Radiation: A Case Study in Quebec,Canada     

D. I. Jeong  A. St-Hilaire  Y. Gratton  C. Bélanger  C. Saad 《大气与海洋》2016,54(2):117-130

Global solar radiation (GSR) is essential for agricultural and plant growth modelling, air and water heating analyses, and solar electric power systems. However, GSR gauging stations are scarce compared with stations for monitoring common meteorological variables such as air temperature and relative humidity. In this study, one power function, three linear regression, and three non-linear models based on an artificial neural network (ANN) are developed to extend short records of daily GSR for meteorological stations where predictors (i.e., temperature and/or relative humidity) are available. The seven models are then applied to 19 meteorological stations located across the province of Quebec (Canada). On average, the root-mean-square errors (RMSEs) for ANN-based models are 0.33–0.54?MJ?m^?2?d^?1 smaller than those for the power function and linear regression models for the same input variables, indicating that the non-linear ANN-based models are more efficient in simulating daily GSR. Regionalization potential of the seven models is also evaluated for ungauged stations where predictors are available. The power function and the three linear regression models are tested by interpolating spatially correlated at-site coefficients using universal kriging or by applying a leave-one-out calibration procedure for spatially uncorrelated at-site coefficients. Regional ANN-based models are also developed by training the model based on the leave-one-out procedure. The RMSEs for regional ANN models are 0.08–0.46?MJ?m^?2?d^?1 smaller than for other models using the same input conditions. However, the regional ANN-based models are more sensitive to new station input values compared with the other models. Maps of interpolated coefficients and regional equations of the power function and the linear regression models are provided for direct application to the study area.  相似文献   

一次长江流域梅雨降水中三种云量计算方案的对比研究          下载免费PDF全文

崔文君  智协飞  朱寿鹏  周志敏  王晓芳  李红莉 《大气科学学报》2016,39(2):209-220

采用NCEP分析场,选取2010年梅雨期长江流域的一次降水过程,分别基于Slingo方案、NCAR方案和钱氏方案,利用相对湿度计算云量,并以LAPS(Local Analysis and Prediction System)系统输出的云量分析场作为观测值,分别在高层(400 h Pa)与低层(850 h Pa),从宏观比较与统计分析的角度,与计算结果进行云量大小与区域分布的对比分析。结果表明,三个云量计算方案对云量中心位置的把握均较为准确,但对云量值的计算存在大小不等的误差。NCAR方案计算结果和LAPS输出场最为吻合,能够体现出云量大值区,但区域一般偏大;Slingo方案相较NCAR方案来说略差,但也能较好地描述云带分布;此外,钱氏方案计算出的云量值始终偏小,但其能够较好地描述云带轮廓与云量的分布特征。综合对比结果,NCAR云量计算方案比其余两者更优,且在低层(850 h Pa)表现尤为明显。  相似文献   

基于多像对的近景摄影测量相机对标定     

韩冰  盛业华  张卡 《测绘科学》2007,32(6):24-26

本文利用共线方程进行线性变换与非线性变换的方法实现非量测型相机标定,分三步求解相机内方位元素、透镜畸变参数、外方位元素,再利用解析相对定向方法进行固定相机对的相对模型参数的标定。利用多像对相对定向得到与绝对模型大小一致的立体模型,在求解地物尺寸大小这类不需要坐标数据的应用上非常有效。  相似文献   

GIS数据分析中权重确定的粗集方法研究   总被引：5，自引：3，他引：2  

李雯静  毋河海 《测绘科学》2007,32(1):70-72

介绍了粗集方法的基本概念,将其中的属性重要性与GIS中常用的权重分析相结合,提出了基于粗集分类思想在GIS数据分析的权重确定中的应用方法。与传统的多因子分析中的权重确定方法相比,该方法是一种基于数据自适应的方法,不需要人为干预,具有智能高效等优点。  相似文献   

盆地沉降分析及其应用   总被引：1，自引：0，他引：1  

张金川  李桂群 《中国海洋大学学报(自然科学版)》1995,(3)

沉积盆地发育过程中，沉降是盆地沉积充填的最基本条件，也是盆地发育的基础。本文所论述的西湖、基隆两凹陷之间的鞍部是东海陆架盆地重要的构造演化带。运用盆地沉降模拟原理，提出以构造沉降比重和相对沉降的概念进行系统分析。通过沉降模拟得出鞍部地区的盆地沉降具有时间及地域上的不均衡性特点，且有构造高点随时间迁移的趋势。进一步分析可见构造沉降比重值的大小与盆地发展演化阶段密切相关。  相似文献   

地磁场相对强度研究方法   总被引：1，自引：0，他引：1  

葛淑兰  石学法  张伟滨 《海洋地质与第四纪地质》2007,27(2):65-70

主要介绍了地磁场相对强度研究的两种方法:常规归一化方法和假-Thellier方法的基本原理和做法,探讨了前者选择不同归一化参数的一般原则,并对比了两种方法的差异,指出地磁场相对强度研究方法在目前海洋沉积物定年研究中的应用方向和前景。  相似文献