地形对南北低空气流重力惯性波稳定度的影响

在南北向低空急流下,通过简单二层模式讨论地形起伏对重力惯性波的影响,研究指出:(1)存在一个对重力惯性波稳定度无影响的函数和不产生不稳定重力惯性波地形函数;(2)地形起伏越大,不稳定重力惯性波越强;(3)无论南风或北风基流,都是南坡比北坡更有利于产生不稳定重力惯性波。最后,通过实例计算表明,动力分析结果与实况有较好的一致性。     

雅砻江、金沙江、澜沧江、怒江流域地形对水文气候的影响

雅砻江、金沙江、澜沧江、怒江(以下简称“四江”)发源于青藏高原东南部,流经横断山区和云贵高原,总集水面积约77.2万km~2。域内地形复杂,高差悬殊,其水文气候特性在三度空间具有明显的差异。 本文宏观分析了“四江”流域水文气候特性及其与地形、地势的关系,认为复杂的地形和高亢的地势是形成“四江”流域特殊水文气候条件的重要因素。     

大气模式设计中的两个问题

本文就大气模式设计中的两个问题:分辨率的确定和非绝热加热、耗散之间的虚假的不平衡的处理进行了讨论。还推导了决定水平和垂直分辨率的公式以及调整非绝热和耗散使其达到准平衡的办法。     

Resource use in the tropical karstlands of central Belize

Rural tropical ecosystems are subject to many traditional land uses that employ the indigenous karst resources: rock, water, soil, vegetation, and wildlife. Individual resource pressures often are subtle, but their combined impact can precipitate instability in the tropical karst environment, potentially resulting in disruption of food, water, and fuel supplies. The karst of central Belize was used intensively for some six centuries by Maya farmers, but between the 10th and 19th centuries AD most of it reverted to secondary forest. Commercial logging dominated the 19th and early 20th centuries, followed by the expansion of subsistence and commercial agriculture after 1945. In the 1980s resource use has accelerated as population and other pressures increase. Much karst remains forested, but there is increasing clearance for agricultural uses, particularly for citrus cultivation and small-scale mixed agriculture. Soil depletion has begun to occur, water resources are increasingly taxed, and some wildlife is threatened by habitat destruction and increased hunting. Lime production for the citrus industry has promoted quarrying, water extraction, and fuelwood use. Environmental stresses currently do not exceed the threshold of instability, but the rapidly developing rural economy warrants careful monitoring of resource pressures.     

成都市城市热岛特征初探

本文利用1986年夏季、1987年冬季市区观测资料和郊区气象站气候资料,分析了成都市热岛特征、热岛强度随时间的变化及绿化对城市小气候的影响。     

REVIEWS OF GEOGRAPHIC SOFTWARE

Geographic Software Reviewed in this article: THE DIFFUSION GAME . Christopher J. Lovelock and Charles B. Weinberg . MAPIT . Raymond J. Kalush , Jr . SIMODEL . Peter A. Williams and A. Stewart Fotheringham . WEATHER FRONTS . P. C. Moyer . WORLD DYNAMICS . Mark Lewis Baldwin     

任意空间剖面图打印的实用程序

本文介绍了一个根据测站的经度(或纬度)打印任意空间剖面图的实用程序,通过自定义坐标,可打印在国家气象局制的6300号底图上。本程序采用BASIC语言,已在 Apple-Ⅱ上实现,对其中的部分语句修改后,也可以用于IBM-PC等其它微机上,用本程序制图,速度快,准确性高,可作为日常性的天气分析预报工具。     

为全民创业提供优质气象服务在全民创业中加快气象事业发展--在江西省气象局党组扩大会议上的讲话(摘录)

结合部门实际。对江西气象部门如何领会和贯彻落实2005年全省领导干部会议精神,提出了具体的指导意见。讲话指出,全省各级气象部门干部职工,要把思想和行动进一步统一到全省领导干部会议精神上来,围绕为全民创业提供优质气象服务,找准自己的位置,为不同创业主体提供精细化、个性化的气象服务产品。拓宽为全民创业服务的气象信息传递渠道,强化安全气象和资源气象服务,开展全民创业技能培训和创业资讯服务,营造优化有利于全民创业的气象政务环境。努力满足全民创业对气象服务的迫切需求。讲话还强调,全省气象干部职工要强化创业理念,大力培育气象创业文化;加强气象能力建设,加快提升气象现代化水平和效益;适应中国气象事业发展战略,加快全省新一轮气象业务技术体制改革;坚持改革创新,做大做强做优气象科技服务;加强队伍建设,为事业发展提供智力支持和组织保证,努力在全民创业的热潮中,实现江西气象事业在新的起点上更快更好的发展。另外。讲话在总结分析上半年工作的基础上,结合全省领导干部会议精神。对2005年下半年的工作进行了全面的部署。认为2005年下半年,全省气象部门要狠抓目标管理,积极做好气象服务工作,下大力气促科技服务上新台阶;要加强与有关部门的共建共享工作。及时完成“十一五”规划的编制。大力推进业务技术体制改革和现代化建设;要加强党建和气象文化建设,并根据《江西省气象局关于加强基层台站建设的实施意见》,以及《全省县（市、区）气象局“五大工程”建设考评办法》。抓好基层台站建设。     

Monitoring directions and rates of change in trees outside forests through multitemporal analysis of map sequences

This study explores the potential of historical maps to detect, measure and monitor changes of trees outside forests. The main goal is to assess local-level changes of scattered trees and orchards and their land-use determinants in two areas in Southern Germany between 1901/1905 and 2009. Firstly, overall landscape changes are recorded. Secondly, the spatial-temporal trajectories of scattered trees and their land-use determinants are identified. Thirdly, changes in quantity and fragmentation patterns of traditional orchards are analyzed in their relationship to overall land-cover change. The results confirm major losses in scattered trees, mainly due to urbanization, agricultural intensification, and land abandonment. They further reveal that, while orchards have persisted in total area, they have undergone critical changes toward a simplified landscape structure and loss of the traditional land-use mosaic, which is a characterizing feature of high nature value landscapes. Multi-temporal assessment showed that most trends have been continuous and did not change directions over time, but rather accelerated during periods of rapid change (most dramatically in the 1950-1990 period). The case of orchards and scattered trees illustrates a major problem of cultural landscapes in Europe: Semi-natural landscape features of high nature value are threatened by both intensification and abandonment of land uses. This makes their conservation a potentially costly enterprise, as both opportunity costs for lost alternative land uses and for conservation management costs arise.     

Agricultural land use dynamics in the Brazilian Amazon based on remote sensing and census data

The potential impact of deforestation in the Brazilian Amazon on greenhouse gas emissions to the atmosphere calls for policies that take account of changes in forest cover. Although much research has focused on the location and effects of deforestation, little is known about the distribution and reasons for the agricultural uses that replace forest cover. We used Landsat TM-based deforestation and agricultural census data to generate maps of the distribution and proportion of four major agricultural land uses throughout the Brazilian Amazon in 1997 and 2007. We built linear and spatial regression models to assess the determinant factors of deforestation and those major agricultural land uses - pasture, temporary agriculture and permanent agriculture - for the states of Pará, Rondônia, and Mato Grosso. The data include 30 determinant factors that were grouped into two years (1996 and 2006) and in four categories: accessibility to markets, public policies, agrarian structure, and environment. We found an overall expansion of the total agricultural area between 1997 and 2007, and notable differences between the states of Pará, Rondônia, and Mato Grosso in land use changes during this period. Regression models for deforestation and pasture indicated that determinant factors such as distance to roads were more influential in 1997 than in 2007. The number of settled families played an important role in the deforestation and pasture, the effect was stronger in 2007 than 1997. Indigenous lands were significant in preventing deforestation in high-pressure areas in 2007. For temporary and permanent agricultures, our results show that in 1997 the effect of small farms was stronger than in 2007. The mapped land use time series and the models explain empirically the effects of land use changes across the region over one decade.