STUDY ON CANONICAL AUTOREGRESSION PREDICTION OF METEOROLOGICAL ELEMENT FIELDS*

Through extension of canonical correlation to the analysis of meteorological element fields (MEF), a concept from combination of canonical autocorrelation with canonical autoregression (CAR) is developed for short-term climatic prediction of MEFs with a formulated scheme. Experimental results suggest that the scheme is of encouraging usefulness to a weak persistence MEF,i.e., rainfall field and, in particular, to a strong persistance one like a SST field.     

地震信息融媒体公共服务研究

地震信息传播已进入实时、全面、多维的公共服务时代，单一媒体地震信息服务已无法满足政府、社会公众和地震行业需求，地震信息向融媒体公共服务模式发展。本文对地震信息内容服务需求及特点、地震媒体平台功能特色、融合式媒体信息服务模式等进行分析，对地震信息融媒体公共服务进行研究，旨在提高地震信息服务效率与用户满意度，促进地震信息化建设科学、健康发展。     

面向交通行业的地理信息管理与服务平台研究

针对目前北京市交委地理数据分散,数据共享困难,数据应用和管理不便等问题,实施了地理信息管理与服务平台建设。本文分析了交通委需求现状,提出平台总体建设方案,设计了地理信息管理与服务系统、平台管理维护系统、二次开发接口三个子系统。利用线分类法对地理数据资源进行整合分类,最终形成资源目录,解决了异源异构道路数据匹配关键技术问题。本系统已建成使用,系统的建设达到了顶层设计的要求,实现了资源共享、多源和历史空间数据的统筹管理。     

厦门旧城建设步行街区的初步研究

以厦门旧城区西南部为例,对商业街土地利用和商服业现状作了详尽的调查和分析,在阐述旧城区商业街存在总体地位下降,以服装店为主的零售商业功能过于突出,购物环境容量不足等现实问题的基础上,提出以“步行街区”作为厦门旧城商业街更新发展的对策,并据此对步行街区建设涉及到的部分问题进行了探讨。     

A modified ISBA surface scheme for modeling the hydrology of Athabasca River Basin with GCM-scale data

A soil–vegetation–atmosphere transfer model (SVAT), interactions between the soil–biosphere–atmosphere (ISBA) of Météo France, is modified and applied to the Athabasca River Basin (ARB) to model its water and energy fluxes. Two meteorological datasets are used: the archived forecasts from the Meteorological Survey of Canada’s Global Environmental Multiscale Model (GEM) and the European Centre for Mid-range Weather Forecasts global re-analysis (ERA-40), representing spatial scales typical of a weather forecasting model and a global circulation model (GCM), respectively. The original treatment of soil moisture and rainfall in ISBA (OISBA) is modified to statistically account for sub-grid heterogeneity of soil moisture and rainfall to produce new, highly non-linear formulations for surface and sub-surface runoff (MISBA). These new formulations can be readily applied to most existing SVATs. Stand alone mode simulations using the GEM data demonstrate that MISBA significantly improves streamflow predictions despite requiring two fewer parameters than OISBA. Simulations using the ERA-40 data show that it is possible to reproduce the annual variation in monthly, mean annual, and annual minimum flows at GCM scales without using downscaling techniques. Finally, simulations using a simple downscaling scheme show that the better performance of higher resolution datasets can be primarily attributed to improved representation of local variation of land cover, topography, and climate.     

Seasonal variations and mechanism for environmental control of NEE of CO_2 concerning the Potentilla fruticosa in alpine shrub meadow of Qinghai-Tibet Plateau

The study by the eddy covariance technique in the alpine shrub meadow of the Qing-hai-Tibet Plateau in 2003 and 2004 showed that the net ecosystem carbon dioxide exchange (NEE) exhibited noticeable diurnal and annual variations, with more distinct daily changes during the warmer seasons. The CO2 emission of the shrub ecosystem culminated in April and September while the CO2 absorption capacity reached a maximum in July and August. The absorbed carbon dioxide during the two consecutive years was 231.4 and 274.8 g CO2·m-2 respectively, yielding an average of 253.1 gCO2·m-2 per year: that accounts for a large proportion of absorbed CO2 in the region. Obviously, the diurnal carbon flux was negatively related to temperature, radiation and other atmospheric factors. Still, minute discrepancies in kurtosis and duration of carbon emission/absorption were detected between 2003 and 2004. It was found that the CO2 flux in the daytime was similarly affected by photosynthetic photon flux density in both years. Temperature appears to be the most important determinant of CO2 flux: specifically, the high temperature during the plant growing season inhibits the carbon absorption capacity. One potential explanation is that soil respiration is enhanced under such condition. Analysis of biomass revealed that the annual net carbon fixed capacity of aboveground and belowground biomass was 544.0 in 2003 and 559.4 g Cm"2 in 2004, which coincided with the NEE absorption capacity (63.1 g C·m-2 in 2003 and 74.9 g C·m-2 in 2004) in the corresponding plant growing season.     

网络化基础地理信息分发服务体系设计研究

本文对我国基础地理信息的网络化分发服务体系进行了顶层设计研究,提出该体系在机构形式上由协调机构、数据中心、数据交换中心以及资质认证中心等组成,在业务系统上由门户网站系统、信息认证系统、信息分发服务系统、产品制作管理系统和广域联网系统等构成,主要功能包括基础地理信息搜索、检索、浏览、在线处理、销售、下载以及地理信息技术支持等。     

基于多协议的地理信息服务集成

设计了多协议地理信息服务集成框架,探讨解决了其中的关键问题,实现了从不同地理信息服务获取的影像数据、矢量数据和DEM数据的无缝集成。     

CHAMP卫星cm级精密定轨

在卫星定位导航数据综合处理软件（PANDA软件）的基础上，解算了2002年年积日126～131d CHAMP卫星的精密轨道，并通过与GFZ精密轨道的比较、GPS观测值的验后残差和SLR观测值检验等3种方式进行了轨道精度的评估。结果显示，本文的轨道精度在径向为4～5cm，切向和法向为6～8cm。     

一种基于位置的移动服务系统的设计与实现

基于位置的移动服务需要设计高效、稳定和可扩展的体系结构与开发方式，提出了一种基于Web服务的LBS体系结构（WS-LBS），并设计了WS-LBS系统框架，实现了空间信息服务的构建与发布机制，扩展了终端用户，实现了一个WS-LBS原型系统。