万年历同步采集和数据上报技术优化研究

通过高速电力线载波通信(high-speed power linecarrier communication, HPLC)技术采集用户用电信息,使用并发抄表方式不能保证全台区数据采集的同步性,也无法实现大规模的分钟级数据采集,无法实时感知用户用电信息变化。因此,探讨万年历同步采集和上报技术的优化方案,通过同步万年历,预设采集方案的方式,进行全台区所有用户用电信息同步采集,再通过采集数据项的数据变化量判断数据是否需要上报,以汇聚单帧数据载荷的方式上报,减少通信报文数量,提高数据上报效率,减少系统资源占用。本方案通过分钟级同步采集,根据数据变化量判断是否上报,提高上报数据的质量,实现感知用户分钟级用电信息的变化。

基于规划验收全过程的大比例尺地形图动态元数据研究

在地理信息领域,元数据描述地理数据集的内容、质量、现势性、表示方式、空间参照系、管理方式及数据集的其他特征。基于规划验收各关键环节更新地形图的工作过程,研究各环节的动态元数据表达结构及内容,并建立大比例尺地形图动态元数据分级体系和描述方法,以充分体现动态元数据结构设计的特点,将有利于GIS用户的分析、挖掘、应用,以及满足领导决策的需要。

Comparative Analysis of China Surface Air Temperature Series for the Past 100 Years

Temperature change plays a crucial role in global change sciences. In the past several decades, comprehensive find- ings have been achieved on temperature change in China for the past 100 years. Several time series have been created to illustrate the averaged surface air temperature for the country. The correlations of these series range from 0.73 to 0.97. It is also achieved in better data quality, wider spatial data coverage, improved homogeneity of time series, and enhanced reliability of findings. The results show an annual mean temperature increase by 0.78±0.27℃ per 100 years in China for the period 1906-2005. After prolonging the period till 2007, it is found that 2007 is rated as the warmest year in the past 100 years. Although all the series, except one, reflect temperature changes in the eastern part of China before the 1930s, they represent the general temperature change in most parts of the country after the 1930s.

Development of a GIS-based Decision Support System for Assessing Land Use Status

The objectives of this study are to assess land s ui tability and to predict the spatial and temporal changes in land use types (LUTs ) by using GIS-based land use management decision support system. A GIS databas e with data on climate, topography, soil characteristic, irrigation condition, f ertilizer application, and special socioeconomic activities has been developed a nd used for the evaluation of land productivity for different crops by integrati ng with a crop growth model-the erosion productivity impact calculator (EPIC). International food policy simulation model (IFPSIM) is also embedded into GIS fo r the predictions of how crop demands and crop market prices will change under a lternative policy scenarios. An inference engine (IE) including land use choice model is developed to illustrate land use choice behavior based on logit models , which allows to analyze how diversified factors ranging from climate changes, crop price changes to land management changes can affect the distribution of agr icultural land use. A test for integrated simulation is taken in each 0.1° by 0.1° grid cell to predict the change of agricultural land use types at globa l level. Global land use changes are simulated from 1992 to 2050.

Interannual salinity variability of the Northern Yellow Sea Cold Water Mass

This paper discusses the interannual variability of the Northern Yellow Sea Cold Water Mass(NYSCWM) and the factors that influence it,based on survey data from the 1976–2006 national standard section and the Korea Oceanographic Data Center,monthly E-P flux data from the European Centre for Medium-Range Weather Forecasts,and meridional wind speed data from the International Comprehensive Ocean-Atmosphere Data Set. The results show that:1) the mean salinity of the NYSCWM center has a slightly decreasing trend,which is not consistent with the high salinity center; 2) both the southern salinity front and the halocline of the NYSCWM display a weakening trend,which indicates that the difference between the NYSCWM and coastal water decreases; 3) the Yellow Sea Warm Current intrusion,the E-P flux of the northern Yellow Sea,and the strength of the winter monsoon will affect the NYSCWM salinity during the following summer.

Discussion of Influences on Snow Water Equivalent at Utah Snow Courses

Snow data collection systems in the western United States were originally designed to forecast water supply and may be subject to several sources of bias. In addition to climate change and weather modification effects, site-specific effects may be introduced from vegetation changes, site physical changes, measurement technique, and sensor changes. This paper examines changes in Utah＇s snowpack conditions over the past decade compared with all previous measurement years, focusing on the 15 snow courses with the longest observational record within the state of Utah. Although patterns in snowpack data consistent with those that would be expected due to temperature h as greater declines at lower elevations and latitudes--were not identified, snow water equivalent decreased at sites with significant increases in vegetation coverage. Additionally, we provide a list of 22 snow courses in Utah that are best-suited for long-term climate analysis.

The O1 Atmosphere Tide in the Mesosphere （80-100 km） in Wuhan, China （30° N, 114° E）

Horizontal winds in the mesosphere （80-100 km） were measured by meteor radar in Wuhan, China （30° N, 114° E） over a 45-month interval in 2002-2005 and the data examined to investigate the monthly mean behavior of the Ol tide. A clear seasonal variation in amplitude of the O1 tide ranging from -0.3 m/s to 2.6 m/s was observed. In most months, the northward and eastward components differed by about 7 lunar hours with the eastward component leading. Comparison of the amplitudes of the M2 and O1 tides suggests the O1 tide is quite stronger over Wuhan, China. The amplitude ratio of the O1 tide to the M2 tide is quite stronger than that the gravitational potential being 0.41. The vertical wavelength of the O1 tide differs on a monthly basis. Height profiles of the O1 tide showed obvious height variation. The O1 tide is stronger in January and July. In different month, the vertical wavelength for the O1 tide changes considerably at the same height. The year＇s variation trend of the northward and eastward components is very similar in both phase and amplitude.

Geomagnetic Field Measurement over Akure Using Ground Based Magnetometer Observatory

The geomagnetic field over Akure, southern Nigeria （7°15＇ N; 5°12＇ E） was investigated from direct observation for a period of two years （2005-2006）. Geomagnetic field over Akure was monitored and measured using a locally produced magnetometer. The geomagnetic data generated were evaluated at every local time hour. Diurnal, monthly and Seasonal effects were investigated. The results of the analyses from the magnetic data generated provide a comprehensive understanding of the geomagnetic variation over the region. This research validates the instrument and presents a direct measurement opportunity to capture the influence of local sources.

Analysis of spatial distribution and multi-year trend of the remotely sensed soil moisture on the Tibetan Plateau

Long-term highly accurate surface soil moisture data of TP(Tibetan Plateau)are important to the research of Asian monsoon and global atmospheric circulation.However,due to the sparse in-situ networks,the lack of soil moisture observations has seriously hindered the progress of climate change researches of TP.Based on the Dual-Channel soil moisture retrieval algorithm and the satellite observation data of AMSR-E(Advanced Microwave Scanning Radiometer for EOS),we have produced the surface soil moisture data of TP from 2003 to 2010 and analyzed the seasonal characteristic of the soil moisture spatial distribution and its multi-year changing trend in area of TP.Compared to the in-situ observations,the accuracy of the soil moisture retrieved by the proposed algorithm is evaluated.The evaluation result shows that the new soil moisture product has a better accuracy in the TP region than the official product of AMSR-E.The spatial distribution of the annual mean values of soil moisture and the seasonal variations of the monthly-averaged soil moisture are analyzed.The results show that the soil moisture variations in space and time are consistent with the precipitation distribution and the water vapor transmission path in TP.Based on the new soil moisture product,we also analyzed the spatial distribution of the changing trend of multi-year soil moisture in TP.From the comparisons with the precipitation changing trend obtained from the meteorological observation sites in TP,we found that the spatial pattern of the changing trend of soil moisture coincides with the precipitation as a whole.