气候变化对秦皇岛地区降水量影响分析

以秦皇岛市为例,研究了气候变暖对地表降水量的影响.通过对51年来秦皇岛市气候、降水材料的分析得出结论:秦皇岛市近年来明显变暖,年平均气温上升约2℃,同时气候变干,降水量减少18.3%;气候变化会引起水循环的变化及水资源在时空上的重新分布以及水资源总量的改变,对流域内的水资源量影响十分显著.     

Indoor Air Quality at Salarjung Museum, Hyderabad, India

Deterioration of art objects at Salarjung Museum has been noticed such as blackening of white and pink pigments of Indian miniature paintings and other objects like pigments, paints, varnishes, coatings, silver ware, zari works, textiles, which are displayed in museum galleries. The cause of deterioration of the artifacts is attributed to air pollution. The outdoor air pollution levels with respect to suspended particulate matter, sulphur dioxide, oxides of nitrogen, ammonia, aldehydes and oxidants are observed to be high when compared with background environment and ambient air quality standards for sensitive areas. The indoor air quality levels in terms of various parameters including temperature and relative humidity (RH) observed to be more than the threshold limits. The climatic conditions coupled with polluted indoor air are the main causes for the deterioration of art objects. Hence remedial measures are suggested to avoid further deterioration of objects.     

CHARACTERISTICS AND CONTRIBUTING CAUSES OF AN ABNORMAL FREQUENCY OF FLOOD-PRODUCING RAINSTORMS AT CHICAGO1

ABSTRACT: Major hydrometeorological factors pertinent to defining and understanding the hydrologic characteristics of urban and other small-basin storms were investigated using data from a continuous 44-year operation of a recording raingage network in Chicago. Factors included: the frequency distribution of basin mean rainfall and its relation to storm maximum precipitation; the spatial distribution characteristics of each storm, including storm rainfall reduction factors which are widely used in hydrologic design problems; and weather-related causes related to the frequency and intensity of severe rainstorms in the Chicago area in recent years. Results have indicated that urban mean rainfall frequencies were overestimated in earlier studies in which they were derived from point/areal mean rainfall ratios obtained from much shorter records on rural networks. Reduction factors were found to vary between urban and rural storm systems due to urban-related effects. Two factors were found to be potential contributors to the characteristics of severe rainstorm occurrences at Chicago. These include urban-induced rain enhancement and an upward climatic trend in the occurrence of heavy rainfall events during the sampling period. Study results should be generally applicable to other large urban areas in the Midwest and other regions of similar precipitation climate.     

CLIMATIC VARIATION AND SURFACE WATER RESOURCES IN THE GREAT BASIN REGION1

ABSTRACT: There is mounting evidence that increasing amounts of atmospheric carbon dioxide may lead to significant changes in global climate during the next century. The possible effects of such climatic changes on surface runoff in the Great Basin Region of the western United States has been investigated by applying water balance models to four watersheds in Nevada and Utah. The most probable change, a 2°C increase in average annual temperature coupled with a 10 percent decrease in precipitation, would reduce runoff from 17 to 28 percent of the present mean, with drier basins showing the greatest change. Decreasing precipitation by 25 percent causes runoff reductions of 33 to 51 percent. Equivalent changes to a cooler and wetter climate show corresponding increases in runoff of approximately the same magnitude, but such a shift is not considered likely. Based on projected water requirements for the year 2000, a change to a warmer and drier climate would cause severe water shortages in many parts of the Great Basin.     

气候遥感解译法在区域气候研究中的应用

运用遥感手段进行气候资源普查和生态气候类型的划分,是现代应用气候的一种新的研究方法,也是遥感技术应用的一个新领域。研究实践证明,遥感技术对于下垫面气候研究具有独特的功能,特别是对地方气候分析提供了新的内容和手段。本文以内蒙古兴安盟科右中旗和突泉县为列,对气候遥感解译法进行初步分析和概述,以促进该研究法在区域气候研究中更广泛地推广和应用。     

GENERATION OF SYNTHETIC AND MISSING CLIMATIC DATA FOR PUERTO RICO1

ABSTRACT: Climatic data such as temperature, solar radiation, relative humidity, and wind speed have been widely used to estimate evapotranspiration. Moat of the solar radiation data and portions of the relative humidity data are either not available or missing from the records in Puerto Rico. Depending upon the availability and data characteristics of records, three methods (including a regression technique, an averaging of historical data, and a regional average) were used to generate missing data, and a time series analysis was used to synthesize a series of climatic data. The limitations and applicability of each method are discussed. The results showed that the time series analysis method can be successfully used to synthesize a series of monthly solar radiations for several stations. The regression technique and the regional average can be successfully applied to generate missing monthly solar radiation data. The regression technique and the averaging of historical data have been satisfactorily used to interpolate missing monthly relative humidity. The explained variance (R²) varied from 0.68 to 0.88, which are both significant at the 0.05 level of significance.     

Impact of Grazing Intensity during Drought in an Arizona Grassland

Abstract:  The ecological benefits of changing cattle grazing practices in the western United States remain controversial, due in part to a lack of experimentation. In 1997 we initiated an experimental study of two rangeland alternatives, cattle removal and high-impact grazing, and compared grassland community responses with those with more conventional, moderate grazing practices. The study was conducted in a high-elevation, semiarid grassland near Flagstaff, Arizona (U.S.A.). We conducted annual plant surveys of modified Whittaker plots for 8 years and examined plant composition shifts among treatments and years. High-impact grazing had strong directional effects that led to a decline in perennial forb cover and an increase in annual plants, particularly the exotic cheatgrass ( Bromus tectorum L.). A twofold increase in plant cover by exotic species followed a severe drought in the sixth year of the study, and this increase was greatest in the high-impact grazing plots, where native cover declined by one-half. Cattle removal resulted in little increase in native plant cover and reduced plant species richness relative to the moderate grazing control. Our results suggest that some intermediate level of cattle grazing may maintain greater levels of native plant diversity than the alternatives of cattle removal or high-density, short-duration grazing practices. Furthermore, episodic drought interacts with cattle grazing, leading to infrequent, but biologically important shifts in plant communities. Our results demonstrate the importance of climatic variation in determining ecological effects of grazing practices, and we recommend improving conservation efforts in arid rangelands by developing management plans that anticipate this variation.     

PAH Levels and Profiles in the Suspended Particulate Matter in Zagreb through Four Seasons

This paper presents the analysis of polycyclic aromatic hydrocarbons (PAHs) measured in all four seasons in suspendedparticulate matter (SPM) collected with a high-volume sampler on one measuring site in the northern part of Zagreb. About 30 samples of SPM were analysed for each season, including workdays and weekends and there were no differences amongst them. The concentrations of all PAHs were highest in winter andlowest in summer. The spring PAH concentrations were lower thanthe autumn ones, as the spring had more sunny and warm days. Theprofiles of PAH/BaP at the measurement sites showed that the mainsource of PAHs in spring and summer was traffic while asubstantial amount of autumn and winter PAHs, besides traffic,came from heating.     

间接制冷换热器除霜方案研究

目的对以载冷剂为冷媒,用于极端低温气候环境实验室的换热器的除霜问题进行研究,获得可行的除霜设计方案。方法从抑霜和融霜两个方面出发,设计包含变片距结霜换热器的内融霜和外融霜两种除霜方案,并搭建实验台对除霜方案进行实验研究。结果变片距结霜换热器迎风面结霜严重,背风面轻度结霜,内融霜可在3.5 min完成,而外融霜需要2倍的时间。内融霜结束后继续加热换热器,并配合新风置换可在20 min内除去化霜后的附着水。结论变片距结霜换热器能够有效对来流空气进行预除湿,抑制主换热器结霜,内融霜效果最好且目前以蒸汽为热源、内融霜为主、新风吹扫为辅的除霜系统已应用于大型气候环境实验室。     

大型气候环境实验室综合控制管理系统网络结构设计

开展了大型气候环境实验室综合控制管理系统设计,以满足实验室飞机气候环境试验需求。通过梳理大型气候环境实验室工艺系统组成,分析了试验任务对试验过程控制、试验测试、数据管理、试验监控和试验信息展示等多方面需求,明确了综合控制管理系统功能,进行系统划分。综合运用当下主流的工业自动化过程控制方式,进行了实验室综合管控系统设计。搭建了实验室的综合控制管理系统网络结构,定义了网络通讯方式。该网络结构可作为综合控制管理系统各组成部分开展深化设计依据。