SIMPLE MARKOV CHAIN MODEL OF SMOG PROBABILITY IN THE SOUTH COAST AIR BASIN OF CALIFORNIA

The simple Markov chain model approximates sequences of episode days for those air-monitoring stations with sufficient data for analysis. The conditional probability for episode days shows a distinct regional pattern, with highest values over the inland valleys and decreasing values toward the coast.     

THE SIGNIFICANCE OF POTENTIAL-DENSITY REGRESSIONS

Strong correlations have been observed between potential indices and the densities of spatial variables. The conventional null hypothesis of bivariate regression is inappropriate for testing their significance. A randomization test is proposed and is applied to 1975 US population data by state. The resulting relationship has a significant correlation, but its slope could occur frequently under the null hypothesis. The correlation is shown to be related to the spatial autocorrelation of densities by constructing arrangements with prescribed values of the modified Moran index.     

PRODUCTIVITY OF AMERICAN PH.D.-GRANTING DEPARTMENTS OF GEOGRAPHY

Reviews of geographic software in this article:

DEMO-GRAPHICS: WORLD POPULATIONS AND PROJECTIONS.

ESP

GAUSS.

CEMODEL S. Damus

LIMDEP. William H. Greene

MICROSTAT 4.1

OTIS

PCIPS. (Personal Computer Image Processing System). H.J. Meyers and R. Bernstein.

REGRESSION ANALYSIS OF TIME SERIES (RATS)

SPSS/PC+

URBAN DATA MANAGEMENT SOFTWARE (UDMS)     

THE GEOGRAPHY OF MASTODON EXTINCTION

Geographic Software Reviewed in this article:

LIFE TABLES and the LESLIE MATRIX. CONDUIT

MENTMAP2. Lawrence W. Carstensen Jr.

PC-MATLAB, Version 1.0. The Math Works, Inc.

QUICKMAP, version 1.0. Sammamish Data Systems, Inc.

SYSTAT: THE SYSTEM FOR STATISTICS, Version 2.1, Systat Inc.

USA DISPLAY. Instant Tecall     

A MEASURE OF DISPARITY

The Thornthwaite method for computing evapotranspiration has been employed in a variety of climatic realms. Recently, the equation for computing potential evapotranspiration has been shown to underestimate measured moisture losses in dry environments. This study presents monthly calibration equations that enhance the reliability of the Thornthwaite estimates of evapotranspiration for California stations. Six years of calibrated monthly potential evapotranspiration are compared with lysimetermeasured evapotranspiration at Davis and with other estimates of evapotranspiration for this site.     

气候变化对中国大雾的影响

1 Introduction The global environmental problem caused by climatic warming has attracted increasing attention of the scientific communities, the public and governments of various countries. The mean temperature of the recent decade is the highest of the p…     

中国雾区的分布及其季节变化

1 Introduction Fog is a weather phenomenon that horizontal visible distance is reduced within 1 km by plenty of water drops and particles of ice crystal. It not only has unfavorable influence on the traffic of water, land and air, but also brings serious …     

AMERICAN COUNCIL OF LEARNED SOCIETIES

SUMMARY

The greatest deficiency in American geography is substantive research leading to scholarly publication. By comparison, teaching much more adequately developed so that the need for improvement there is not so urgent. I am convinced however that a majority American geographers respect scholarship and are eager to see improved in quantity and quality.

One of the chief obstacles to the initiation of active research programs by many geographers is a poor development of a sense of problem.

An important stimulation to the development of personal research programs would be the organization of geographical meetings of relatively small size in which active rsesearch workers reported on their progress and findings. Emphasis could be on exchange of ideas, debating of controversial issues and the development of research programs rather than upon the reading of formal papers. Instructors in small colleges and high schools could be inspired to undertake local research problems so that they become expert on heir local areas. This was characteristic of such teachers in Japan.

Our national professional organization, including i t s annual meetings, has become so large that such a n intimate program involving ritical discussion is difficult to attain.

Up to the present time the regional divisions have not developed a consistently distinctive and important function in the national organization. Their usefulness is not comonensurate with the degree of representation which they at present have on the Council of the AAG.

It is my hope that the regional divisions may see fit to undertake this function of stimulating personal and group research as t heir main function and plan their annual meetings accordingly. I do not propose to blueprint these meetings too precisely, but I will go so far as to say that in my judgment they should be occasions for mental stretching. They shoufd be pitched at a high level so that they will attract mature minds and seriousscholars. The total effect of such meetings should be to toughen intellectually those in attendance through providing opportunities for professional debate and discussion. I would make every effort to encourage participation in these programs by both youngsters and old sters, by alert high school teachers and those in college and university faculties so that the lifting effects of the regional meetings would be felt throughout all ranks and ages. I would favor the development of field excursions provided they are planned with genuine professional values in mind; values not limited to observation alone but focused so as to stimulate controversy and healthy debate.     

LOOKING BACK ON 50 YEARS OF WORLD REGIONAL GEOGRAPHY

Abstract

International Perspectives on Natural Disasters: Occurrence, Mitigation, and Consequences., Joseph P. Stoltman, John Lidstone, and Lisa M. DeChano (eds.) Dordrecht: Kluwer Academic Publishers, 2004. 480 pp. ISBN: 1402028504 (also available as ebook, ISBN: 1402028512) Cost: $169 (hardbound, with CD-ROM).

Teaching Geography, Phil Gersmehl The Guilford Press. New York. 2005. 278 pages + CD-ROM (PC/Mac compatible) ISBN 1-59385-155-3 (hardcover) $70.00 ISBN 1-59385-154-5 (paperback) $40.00     

THE ARCHIVES OF THE ASSOCIATION OF AMERICAN GEOGRAPHERS

Although numerous courses in geographic information systems (GIS) have been introduced into the geography curriculum over the past few years, there has been remarkably little debate over the issues involved. This paper first discusses the arguments for geography as an appropriate disciplinary setting for GIS teaching at the undergraduate level. This is followed by a discussion of the nature of GIS courses and their appropriate place in the undergraduate geography curriculum. The final section of the paper describes the NCGIA Core Curriculum project and examines its significance in this broader context.     

REPORT OF THE AAG DELEGATE TO THE CANADIAN ASSOCIATION OF GEOGRAPHERS

Formal program evaluation is one of the most widely used tools for program termination decisions in universities. By understanding and anticipating program evaluation, a farsighted geography department can convert it from a threat into a strategy for survival in the 1980s. In the process, many departments will be renewed and improved.     

A Glimpse of Steel Manufacture

Abstract

Abstract

This article explores the relationship between the values that teachers bring to the classroom and their performance. The insights are drawn from the National Science Foundation-funded Finding A Way project that was undertaken by the National Council for Geographic Education. I argue here that without understanding the values and beliefs of classroom teachers, professional development initiatives might, in the end, make little difference in what goes on in the classroom.     

DYNAMICS IN THE STRUCTURAL FORM OF PROPERTY TAXES∗

Because the property tax is structurally tied to market values of dwellings through the assessment function, rapidly increasing market values may beget rapid increases in property taxes. Public awareness of this process was instrumental in California's 1978 passage of the Jarvis-Gann Amendment. Millage rates should be indexed to counterbalance changes in market values.     

塔克拉玛干沙漠周边地区极端弱降水的时空变化特征

选用塔克拉玛干沙漠周边40个气象站1961-2009年日降水资料和4个极端弱降水指标,分析该地区极端弱降水的时空变化特征。采用M-K法和F检验对各站点降水指标的变化趋势及变化率进行检验和计算,并利用Monte Carlo模拟进行区域显著性检验。由 Copula函数得到两降水指标的联合分布,计算两降水指标的联合重现期。结果表明：（1）年最长连续无降水日数（CDD）多为80～100 d,呈显著减少趋势;出现频率最高的每年日降水量小于降水日序列25%分位数的日数（D₂₅）为0～10 d,呈显著增加趋势;每年日降水量小于降水日序列25%分位数的总降水量（P₂₅）的值集中在0～1.5 mm,2～3 mm的 P₂₅从2000年才开始出现;出现频率最高的每年日降水量小于降水日序列25%分位数的日平均降水量（I₂₅）为0.1～0.3 mm,I₂₅超过0.4 mm的情况极少出现。（2）CDD与D₂₅和P₂₅各自五年一遇值的空间分布相反。除CDD和D₂₅均大于各自五年一遇值的联合重现期较长外,其余各类型联合重现期较短。沙漠周边地区发生不同类型极端弱降水事件的概率不同。     

ON THE SENSITIVITY OF CONCLUSIONS ABOUT THE BASES OF COGNITIVE DISTANCE

The “ecological fallacy’ inherent in two studies of the correlation of cognitive distance with objective distance and travel time is considered. The studies reach opposite conclusions using similar types of data, but both involve different types of aggregation of cognitive-distance judgments. It is shown that, under certain circumstances, correlations based on aggregate data can lead to reverse conclusions to those based on more behaviorally valid disaggregate data. Hence such aggregation is unjustifiable and, as a result, neither study's conclusions can be relied upon.     

塔克拉玛干沙漠沙尘演变及气候因素分析

Based on the sand dust storms data and climatic data in 12 meteorological stations around sand dust storm originating areas of the Taklimakan Desert, we analyzed the trends of the number of dust storm days from 1960 to 2005 as well as their correlations with temperature, precipitation, wind speed and the number of days with mean wind speed 〉 5 m/s. The results show that the frequency of dust storm events in the Taklimakan region decreased with the elapse of time. Except Ruoqiang and Minfeng, in the other 10 meteorological stations, the frequency of dust storm events reduces, and in 4 meteorological stations of Kuqa, Korla, Kalpin and Hotan, the frequency of dust storm events distinctly decreases. The temperature has an increasing trend, while the average wind speed and the number of days with mean wind speed ≥ 5 m/s have decreasing trends. The correlation analysis between the number of days of dust storms and climatic parameters demonstrates that wind speed and the number of days with mean wind speed 〉 5 m/s have strong positive correlation with the number of days of dust storms, with the correlations coefficients being 0.743 and 0.720 （p〈0.01）, respectively, which indicates that strong wind is the direct factor resulting in sand dust storms. Whereas precipitation has significant negative correlation with the number of days of dust storms （p〈0.01）, and the prior annual precipitation has also negative correlation, which indicates that the prior precipitation restrains the occurrence of sand dust storms, but this restraining action is weaker than the same year＇s precipitation. Temperature has negative correlation with the number of dust storm days, with a correlations coefficient of -0.433 （p〈0.01）, which means that temperature change also has impacts on the occurrence of dust storm events in the Taklimakan region.     

ON THE LETTERING OF MAPS

This is one of a series of guest articles written on invitation by senior members of the geographic profession.     

A NOTE ON THE GEOGRAPHY OF SPORT

The recent phenomenon of relative metropolitan decline and non-metropolitan growth is set into two broader frameworks: first, decentralization is an expected consequence of earlier industrialization and metropolitanization; and, second, the change follows a parallel shift in power, industrialization, and urbanization from the core to the periphery of the country. Evidence is found for both. The older industrial states thus exhibit non-metropolitan growth, whereas many newly industrializing states continue to show vigorous metropolitanization.     

VIEWS OF THE AAG: RESULTS OF THE LONG RANGE PLANNING MEMBERSHIP SURVEY

In this issue THE PROFESSIONAL GEOGRAPHER presents the first two reports in a series on the Association's long-range planning process, which was described by Past President Marcus in May. David Morgan outlines here the results of a survey of members' attitudes on a number of important questions.     

Monitoring: a Method of Diagnostic Course Evaluation

Abstract

This report describes the results of an attempt to analyze and evaluate a college course for diagnostic purposes. A monitor was used to observe the course, to generate additional information with pre-course and mid-course questionnaires, and to assist the professor and the class in interpreting and acting on the values of the monitoring process as well as two conditions necessary for its success.