California's population geography: lessons for a fourth grade class

Purpose of this paper is to present a model for teaching fourth grade children some aspects of the population geography of California from a nontextual approach. The objective is to interest and instruct children in the mobility of the people, and on the reasons why so many families have moved to California from other states. Students should be alerted not only to internal migration problems, but to the excess of births over deaths. Materials necessary for the lessons are transparencies, overhead projector, marking pencils, chalk and chalkboard. After showing the students that California population has approximately doubled every 20 years, the students should be encouraged to find reasons explaining why people have moved to the state, should be able to categorize those reasons under the terms industrial/manufacturing, agricultural, urban or recreational, should learn how to plot population distribution on a California regional outline map, and should attempt to explain why certain parts of California are more popular than others. The teaching model described in this paper may be replicated with modfications for any grade level and area of study.     

Internal migration patterns for U.S. foreign-born, 1985-1990

"Using 1990 census data, this paper calculates the flow [of the foreign-born population in the United States] between states and from abroad; also, a multinomial logistic regression model of destination choice is estimated for resettlers and for migrants from abroad. There are three major findings. Firstly, Florida and California are the largest recipients of foreign-born resettlers; New York is the biggest loser of secondary migrants. Secondly, the presence of large communities of Mexicans in California and Cubans in Florida are very attractive to both resettlers and migrants from abroad. Thirdly, immigrants that are most in need of ethnic support networks (i.e. new arrivals or immigrants with low human capital resources) are most likely to choose one of the traditional immigration states as a destination."     

A GEOGRAPHY OF NONPERMANENT RESIDENCE IN THE U.S.

Factor analysis is used to examine the movement patterns of nonpermanent residents, persons who were living somewhere other than their usual residence on the April 1, 1980 census day. Movement from usual to census residences converges on the Sunbelt states of Florida, Arizona, California, Texas and Louisiana. Movement in the other direction is more dispersed as evidenced by 14 distinct patterns of census to usual residence flows.     

URBAN DEVELOPMENT AND REDEVELOPMENT IN SAN FRANCISCO*

ABSTRACT. San Francisco has arisen as an “instant city” not once but three times: after the California Gold Rush (1849–1875), following the 1906 earthquake and fire (1906–1930), and with the modern high-rise city (1960–1985). These pivotal periods of intense city building, each about twenty-five years in duration, have been separated by a generation of relative stability. Current redevelopment activity raises an intriguing historical-geographical question: Is a fourth instant city in the making?     

HISPANIC MIGRATION AND POPULATION REDISTRIBUTION IN THE UNITED STATES*

The US Hispanic population has grown rapidly over the last two decades and remains geographically concentrated in nine states. Redistribution away from core states through internal migration has been largely offset by heavy immigration to traditional areas of Hispanic concentration. Geographical patterns of Hispanic miration show broad similarities to overall patterns of population redistribution in the United States. New York and California serve as key spatial redistributors or pivots in the Hispanic migration system.     

Demographic trends among Soviet Moslems (1959-79)

"The author discusses the distinctive demographic trends among Soviet Moslems, whose numbers are projected to rise from 44 million in 1979 to 64 million in the year 2000. This group is distinguished by high rates of natural increase, little mobility and low rates of linguistic assimilation. The rapid population growth among Moslems, especially those in Central Asia, poses problems of employment and of integrating these people into the Soviet economy."     

Land use legacies of the Ohio River Basin: Using a spatially explicit land use change model to assess past and future impacts on aquatic resources

Land uses and their legacies are a major driver of human impacts on the environment. Decision makers have recognized that the legacies of land-use activities continue to influence ecosystems, particularly aquatic ones, for decades or centuries. The main objectives of this paper are to develop land use legacy maps to (1) assess historical and future (predicted) shifts in dominant land use classes (urban, agriculture, forest) in the Ohio River Basin (ORB), and (2) determine the past and future location of catchments in the ORB exceeding critical land use thresholds (10% and 38% urban and agricultural use of catchment respectively) for water quality and other aquatic resources. Our land use legacy simulations show that approximately 80% of the ORB has remained as agriculture (∼37%), forest (∼34%), urban (∼7%) and other classes (∼2%) from 1930 to 1990. Within the remainder of landscape, agriculture to forest (∼16%) and agriculture to urban (∼1.5%) transitions were the most common land use changes between 1930 and 1990. Our forecast model shows that approximately 94% of the ORB will remain as forest (∼47.46%), agriculture (∼35.77%), urban (∼8.84%) and other classes (∼2.07%) between 2000 and 2050. 1.44% and 1.37% of the ORB is predicted to transition from forest to urban and agriculture to urban between 2000 and 2050, respectively. Our results also demonstrate that 13% and 74% of the catchments in the ORB already exceeded critical urban and agricultural land use thresholds in 1930, respectively. We predict that 37% of catchments in the ORB will have exceeded critical urban land use thresholds by 2050, whereas the proportion of catchments to exceed critical agricultural use will decrease to 45%.     

Changes in land use/cover mapped over 80 years in the Highlands of Northern Ethiopia

Despite many studies on land degradation in the Highlands of Northern Ethiopia, quantitative information regarding long-term changes in land use/cover (LUC) is rare. Hence, this study aims to investigate the LUC changes in the Geba catchment (5142 km²), Northern Ethiopia, over 80 years (1935–2014). Aerial photographs (APs) of the 1930s and Google Earth (GE) images (2014) were used. The point-count technique was utilized by overlaying a grid on APs and GE images. The occurrence of cropland, forest, grassland, shrubland, bare land, built-up areas and water body was counted to compute their fractions. A multivariate adaptive regression spline was applied to identify the explanatory factors of LUC and to create fractional maps of LUC. The results indicate significant changes of most types, except for forest and cropland. In the 1930s, shrubland (48%) was dominant, followed by cropland (39%). The fraction of cropland in 2014 (42%) remained approximately the same as in the 1930s, while shrubland significantly dropped to 37%. Forests shrank further from a meagre 6.3% in the 1930s to 2.3% in 2014. High overall accuracies (93% and 83%) and strong Kappa coefficients (89% and 72%) for point counts and fractional maps respectively indicate the validity of the techniques used for LUC mapping.     

Economic Impacts of AAG Conferences*

This paper estimates various economic impacts of the annual conferences of the Association of American Geographers (AAG) on the states in which they have been held, from 1983 to 1994. It uses data on the number of registrants at these conferences, the average expenditures and durations of stay of these individuals, and the sectoral distribution of these expenditures. Input-output analysis was employed to estimate the indirect and induced impacts on each state or province. Aggregate expenditures ranged from $890,000 (Denver in 1983) to $2.5 million (Toronto in 1990), while the effect on statewide output ranged from $1.64 million to $4.67 million (same cities). On average, state or provincial output increased by $2.86 million, 90.9 jobs were created, and $717,000 in personal income was generated. These impacts have gradually increased over the time period in question.     

Effects of natural flooding and manual trapping on the facilitation of invasive crayfish-native amphibian coexistence in a semi-arid perennial stream

Aquatic amphibians are known to be vulnerable to a myriad of invasive predators. Invasive crayfish are thought to have eliminated native populations of amphibians in some streams in the semi-arid Santa Monica Mountains of southern California. Despite their toxic skin secretions that defend them from native predators, newts are vulnerable to crayfish attacks, and crayfish have been observed attacking adult newts, and eating newt egg masses and larvae. For 15 years, we have observed invasive crayfish and native California newts coexisting in one stream in the Santa Monica Mountains. During that period, we monitored the densities of both crayfish and newt egg mass densities and compared these to annual rainfall totals. After three seasons of below average rainfall, we reduced crayfish numbers by manual trapping. Our long-term data indicated that crayfish did not fare well in years when rainfall is above the historic average. This invasive predator did not evolve with high velocity streams, and observations indicated that southern California storm events washed crayfish downstream, killing many of them. Newts exhibit increased reproduction in years when crayfish numbers were reduced. A comparison with a nearby stream that does not contain crayfish indicated that newt reproduction positively responded to increased rainfall, but that fluctuations were much greater in the stream that contains crayfish. We suggest that rainfall patterns help explain invasive crayfish/newt coexistence and that management for future coexistence may benefit from manual trapping.     

Ebbs and Flows in Recent U.S. Interstate Migration*

Interstate migration exchanges in the United States are temporally and spatially transitory. Both the early and mid-1980s exhibited significant fluctuations in the origins and destinations of U.S. migrants, while the late 1980s and early 1990s were even more unstable. Regions once favored by interstate movers such as the West and the South, while remaining attractive, showed evidence of declining favor in the early 1990s. Meanwhile, numerous states in the national interior regained their attractiveness, including several that gained net migrants for the first time in decades. California exhibited a major turnaround in its migration, perturbing the entire U.S. migration system.     

基于分县尺度的2020-2030年中国未来人口分布简

选取1982年、1990年、2000年和2010年人口普查数据,运用Logistic模型系统预测了2020年和2030年中国分县人口规模,定量分析了未来中国人口分布的基本布局、各地区人口增减变化以及城市群人口集聚度变化。研究认为：①2020-2030年中国未来人口空间分布的总体格局不会发生根本改变,东南半壁人口比例会有所减少,西北半壁人口比例会有所增加,但增减变化在0.1%~0.3%之间;②2010-2020年中国有1641个分县单元人口将仍呈增加趋势,占地规模和相应人口都在全国3/4水平,人口增加仍是主要特征;2020-2030年中国人口增加的分县单元将大幅减少到598个,人口减少地区占地规模和相应人口将占3/5以上,人口减少成为普遍现象。③中国21个城市群地区人口总量将由2010年的7.81亿增加到2020年的8.68亿和2030年的9.17亿,相应的人口集聚度也将由2010年的1.99逐步提高到2020年的2.17和2030年的2.33,城市群地区人口集聚规模和集聚程度在逐步提高,人口集聚态势更加明显。     

Marine Terraces and Quaternary Tectonism,Northwest Baja California,Mexico

Deformed marine terraces provide excellent measures of Quaternary tectonism along 400 km of the Pacific coast of Baja California between Ensenada and Punta Blanca. The nature and magnitude of deformation are well expressed by the present elevation of the marine limit, of Upper Pliocene or Lower Pleistocene age, which has been upwarped to 345m, 357m, and at least 195m in three separate localities, while occurring at lower levels elsewhere. Multiple terraces are found below this marine limit where appreciable uplift has occurred. Where relative subsidence has prevailed, fewer broader terraces or thick alluvial and eolian deposits occur. Terraces are further dislocated by NW-SE strike-slip faulting and by normal faults that trend NE-SW across the coast. Folding and faulting are less significant on the younger terraces than on the older features, and negligible for the Sangamonian terrace, except close to major faults. Crustal movements revealed by these terraces, and by similar features in southern California, Baja California Sur, and around the Gulf of California, are interpreted in terms of plate tectonics. Over the past 5 million years, the Peninsular Ranges have been carried northwestwards away from mainland Mexico, at an average rate of 6cm/yr, on the dis located limb of a spreading sea floor associated with the East Pacific Rise now found beneath the Gulf of California. The Pacific coast of the Peninsular Ranges comprises several discrete crustal slivers which, on the evidence of the marine terraces, have been warped and dislocated in response to tec tonic forces associated with rafting and subsequent crowding against transverse structures to the north. Uplift rates range as high as 1.0m/1000 yrs locally but are generally less, and are much less than rates found in the Transverse Ranges farther north. As in the latter province, basins typified by net sub sidence during Quaternary time are also found.     

Hispanic Community Types and Assimilation in Mex-America

I argue that discrepancies among Hispanic assimilation models can be interpreted through three distinct types of Hispanic communities—continuous, discontinuous, and new. Continuous communities were founded by Hispanics and Hispanics have always been the majority population. As a result, Hispanics have not assimilated as predicted by traditional models. Discontinuous communities were originally settled by Hispanics, but eventually were filled by a minority population. Since WWII, many of these communities have experienced a Hispanic demographic resurgence making assimilation more problematic. Hispanics in new communities are recent immigrants to Anglo dominant communities and are more apt to follow the traditional assimilation model.     

Econometric and learning curve estimation of U.S. potential oil supply

This study employs (1) a simple econometric model to generate a time series of drilling footage to the year 2040 and (2) learning models to estimate the oil reserve additions from that drilling, given scenarios of oil price and projected U.S. population. Reserve additions are estimated separately for the lower 48 states and Alaska regions by estimating separate drilling footage and learning models for each region. Generally, the estimates of potential supply from undiscovered oil fields and from extensions of known fields are more optimistic than recent estimates by others. For a $1989 price of about $20/barrel (bbl), which is similar to recent prices, the potential supply of oil is estimated to be approximately 60.7 billion bbl, with 95-percent confidence bounds of 54.3 and 67.1 billion bbl. For a price of $25.50/bbl, potential supply is estimated to be approximately 82 billion bbl, with 95-percent confidence bounds of 74.5 and 89.5 billion bbl. Although estimates of potential oil supply for the entire United States are more optimistic than other recent estimates, the part of that supply estimated to be forthcoming from Alaska is smaller than other recent estimates: 2.3 and 3.3 billion bbl for prices of about $20 and $25.50 per barrel, respectively. Thus, reserve additions from the lower 48 states through development drilling and through improved recovery and production technologies will become increasingly important to future U.S. oil supply.     

Using PETRIMES to estimate mercury deposits in California

In this article, we examine the use of an unconventional procedure, PETRIMES, to estimate mineral resources of mercury deposits in California. The study, which is based on the nonparametric discovery process model and Q-Q plots, suggests that a lognormal distribution is appropriate for the mercury deposits in California. The results of the assessment are summarized as follows: (1) the total number of mercury deposits in the population is approximately 165; (2) the median value of the largest undiscovered deposit size is 487 flasks; (3) the mean of the remaining mercury potential is 2,500 flasks; and (4) the population resource ranges from 1,040,000 to 4,300,000 flasks (at a 0.9 probability level).     

Climatic Perception

Abstract

Climate plays a strategic role in man's perception of the environment. Man's perception of climate influences his adjustment to the atmospheric environment. This study examines the climatic desirability of the conterminous United States as perceived by in-state college students in North Carolina, Arizona, Minnesota and Vermont. Based on climatic preference, the home states are perceived to be the most desirable states in the conterminous United States. In general, the climatic conditions in those states which are in close geographical propinquity to the sample states are also appealing to the students. In addition, Florida, Colorado and the West Coast states (especially California) are perceived as climatically desirable.     

CHARACTERISTICS OF THE AAG MEMBERSHIP IN 1982

A survey of members of the Association of American Geographers (AAG) in 1982 indicated that most were males, from middle class backgrounds, had attended public universities, held academic jobs, and had been born and educated in states bordering the Great Lakes plus California and Massachusetts. Information on characteristics and trends outlined in the study should be of value to the leadership of the AAG in making decisions relative to the future of the organization and the discipline.     

基于本底线的2008年北京奥运会客流量预测

依据多种调查资料和旅游本底趋势线理论,对2008年北京奥运会引致下的旅游客流量变化及客源结构进行细致的预测,主要结论如下:(1)奥运庆典引致下,未来3年北京市入境旅游进入一个超常增长期,客流量统计线将掀起一个"凸形峰",2007~2009年入境客流量分别达到433.6万、517.2万和465.3万人次,较起本底趋势线净增长8%、25%和10%;(2)国内旅游也将进入一个超常增长期,2007~2009年国内客流量分别达到14410万、17384万和16285万人次,较本底趋势线净增长4%、20%和8%。入境旅游的相对贡献率高于国内旅游;(3)奥运庆典引致下的北京市国际/国内客流量超常增长是一个具有特定周期的事件旅游,可划分为"奥前"、"奥中"和"奥后"三个阶段,本文依据客流量年内变化和奥运庆典生命周期,给出了2007~2009年3年各月客流量的预测值;(4)奥运盛典及其设施与活动像"磁场"吸引着国内外游客,结合近年来主要客源市场调查资料,给出了国际国内客源地客流量预测值。     

Transtensional fault-termination basins: an important basin type illustrated by the Pliocene San Jose Island basin and related basins in the southern Gulf of California, Mexico

Transtensional basins are sparsely described in the literature compared with other basin types. The oblique‐divergent plate boundary in the southern Gulf of California has many transtensional basins: we have studied those on San Jose island and two other transtensional basins in the region. One major type of transtensional basin common in the southern Gulf of California region is a fault‐termination basin formed where normal faults splay off of strike‐slip faults. These basins suggest a model for transtensional fault‐termination basins that includes traits that show a hybrid nature between classic rift and strike‐slip (pull‐apart) basins. The traits include combinations of oblique, strike‐slip and normal faults with common steps and bends, buttress unconformities between the fault steps and beyond the ends of faults, a common facies pattern of terrestrial strata changing upward and away from the faults into marine strata, small fault blocks within the basin that result in complex lateral facies relations, common Gilbert deltas, dramatic termination of the margin of the basin by means of fault reorganization and boundary faults dying and an overall short basin history (few million years). Similar transtensional fault‐termination basins are present in Death Valley and other parts of the Eastern California shear zone of the western United States, northern Aegean Sea and along ancient strike‐slip faults.