Nearshore water circulation and bar patterns at Coledale, New South Wales, were surveyed daily over thirty-six consecutive days, from 3 November to 8 December 1978, to identify sequences of changes that might occur in response to spring-to-spring tide cycles of fourteen days, changing barometric and wind conditions associated with the passage of anticyclonic weather systems across the coast, and day to day variation in the nearshore wave regime. During the survey the bar patterns tended to vary from transverse bars, through a composite arrangement incorporating longshore and transverse bars, to a longshore bar pattern as the tide changed from its spring to neap tide phase. However, this sequence was too brief to unequivocally establish variations in nearshore bar pattern that might be attributed to the fourteen day, spring-to-spring tide cycle. Nevertheless, morphologic changes occurring in response to wave regime fluctuation at Coledale were broadly in accord with studies from elsewhere by Dolan et al. (1979, 1982), and Clarke and Eliot (1982, 1983) in that bars and rips were systematically distributed along the beach. At Coledale, bars tended to relocate approximately 0.4 and 0.75 of the distance along the beach from its southern end. The preferred bar spacing closely matches hypothetical standing waves trapped between the headlands of the Coledale embayment. Temporally, the nearshore morphology is highly responsive to wave regime changes such that, as primary breaker heights decrease and remain below Hmax=1.0m, the bar pattern changes from longshore through mixed to transverse bar patterns within three to five days. On one occasion the bar pattern switched from a longshore to a transverse bar pattern within twenty-four hours.相似文献
Derek McDougall, Harold D. Lasswell and the Study of International Relations. University Press of America, Lanham, USA, 1984, pp.370. $16.50.
John W. Burton, Global Conflict: The Domestic Sources of International Crisis. Wheatsheaf Books, UK, 1984, pp.194. $54.00.
K.J. Holsti, The Dividing Discipline: Hegemony and Diversity in International Theory. Allen and Unwin, Boston and Sydney, 1985. pp.165. $39.95.
Hedley Bull (ed.), Intervention in World Politics. Clarendon Press, Oxford, 1984, pp. viii + 198. $31.00.
Hedley Bull, Justice in International Relations. 1983–84 Hagey Lectures, University of Waterloo, 1984, pp. iii + 36. No price given. (Available from University Publications Distribution Service, Dana Porter Arts Library, University of Waterloo, Waterloo, Ontario N2L3G1, Canada.)
Benedict Anderson, Imagined Communities: Reflections on the Origin and Spread of Nationalism. Verso Editions and NLB, London, 1983, pp. 160. £15.00.
Peter Calvert, Politics, Power and Revolution. An Introduction to Comparative Politics. Wheatsheaf Books, Brighton, 1983, pp.208. £5.95.
John Walton, Reluctant Rebels. Comparative Studies of Revolution and Underdevelopment. Columbia University Press, New York, 1984, pp.xii + 230 $US36.00 (cloth), $US10.00 (paper).
E. A. Tiryakian and R. Rogowski (eds), New Nationalisms of the Developed West. Toward Explanation. Allen and Unwin, Boston, 1985, pp.xii + 394. $69.00.
Peter H. Merkl and Ninian Smart (eds), Religion and Politics in the Modern World. New York University Press, New York, 1985, pp.276. No price given.
Richard Lowenthal, Social Change and Cultural Crisis. Columbia University Press, New York, 1984, pp.viii + 252. $US29.50.
Dietrich Fischer, Preventing War in the Nuclear Age. Rowman and Allanheld, Totowa, N.J./Croom Helm, London, 1984, pp. x + 236. $27.95.
F. Dyson, Weapons and Hope Harper and Row, New York, 1984, pp.340. $24.95.
John Langmore and David Peetz (eds), Wealth, Poverty and Survival. Australia in the World. George Allen and Unwin, Sydney, in association with the Australian Labor Party, 1983, pp. 225. 相似文献
The determinants of population and employment growth were explored from a broader interregional (as opposed to intraregional) perspective. Data for the 1970s, at the county level of disaggregation, were used to analyze the effects of economic, demographic, and climatic variables on population and employment growth in a simultaneous equation framework. The use of data from the more than 3000 US counties provides a considerably larger testing ground than those used in previous research. The point of departure was a conventional, general equilibrium model in which both households and producers are geographically mobile. The study's dependent variables refer to population, total, and manufacturing employment densities. Family income had a powerful effect in stimulating both population and employment density. A 10% increase in family income led to a 7.9% increase in total and a 9.2% increase in manufacturing employment densities. High family income must stand for high demand, and thus, firms are drawn to an area. High family income also drew households to an area. A 10% increase in family income led to a 5.5% increase in population density. High family income must represent "good" neighborhoods for households. High family income was positively correlated with population and employment density, but in other recent studies either a negative and significant relationship or an insignificant relationship were reported. Local taxes consist of the receipts of county government and those of municipalities, townships, school districts, and special districts within the county. The elasticities reported in Table 4 suggest that a 10% increase in such taxes resulted in about a 0.072% reduction in county population density during the decade. The Industrial Revenue Bonds (IRBs) and the percent of the labor force that is unionized are 2 potential policy instruments at the state level. The study results suggest that IRBs have not stimulated either manufacturing or total employment, and the coefficients were statistically insignificant in the structural equations. The elasticities imply that a 10% increase in percent union reduces total employment by 0.42% and manufacturing employment by 0.18%. The effect on population was tiny. Further, while not intended, the interstate highway program may have been a significant redistributor of population and employment but has not caused immigration of people and jobs from central cities. 相似文献
ABSTRACT This paper concerns the nature and extent of error introduced to regional input-output multipliers by errors associated with the estimation of regional purchase coefficients (rpc's). Using the Washington State input-output model and computer simulations, estimates of multiplier error are generated for two distinct sources of rpc error. The results indicate that multiplier error from both rpc sources may be significant and support the findings of previous studies which highlight the importance of error introduced to the household purchases column for multiplier accuracy. 相似文献
Excavations by the joint University of Khartoum/Southern Methodist University Butana Project in the area just north of Khashm el Girba on the upper Atbara River have uncovered a series of preceramic and early ceramic occupations by hunters and gatherers which date fromca 10,000 bp toca 6200 bp. The earlier sites show no direct relations with those of similar age in the northern Sudan, while the later, early ceramic sites show only minor similarities with contemporary occurrences in the central Nile Valley. Thus, it appears that the upper Atbara River Valley played no role in the development of the Khartoum Mesolithic and that Nilotic influences were late reaching the eastern Sudan.
Résumé Des fouilles entreprises par le projet Butana dirigé en commun par l'université de Khartoum et le Southern Methodist University dans la région juste au nord de Khashm el Girba sur le cours supérieur de l'Atbara, ont découvert une série d'occupations précéramiques et céramiques anciennes de chasseurs-cueilleurs, qui datent deca 10,000 bp àca 6200 bp. Les gisements les plus anciens ne semblent pas avoir eu de relations directes avec ceux de la même période dans le nord du Soudan, tandis que les gisements plus tardifs à céramiques ne montrent que de petites analogies avec des occupations contemporaines dans la vallée centrale du Nil. Il semble donc que la haute vallée de l'Atbara n'a joué aucun rôle dans le développement du Mésolithique de Khartoum et que des influences nilotiques n'atteignirent que bien plus tard le Soudan oriental.
The upper Mersey Valley was glaciated on three occasions during the Pleistocene. The youngest, Rowallan Claciation, probably commenced after 28000 years B.P. The maximum ice limit was attained before 13500 years B.P., and retreat occurred before 10000years B.P. Deposits associated with Rowallan Glaciation are weakly weathered chemically. They overlie moderately weathered deposits that were formed during the Arm Glaciation, which is inferred from relative dating data to have occurred before the Last Interglacial Stage. North of the deposits and ice limits of the Arm Glaciation extremely weathered tills and rhythmites occur. They were formed by ice of the Croesus Glaciation which is inferred to be of Early Pleistocene age or older. 相似文献
Tin mining, based largely on alluvial tin deposited along the line of the ancestral Ringarooma, began in 1875 and reached a peak in the period 1905-9. Output declined thereafter and, following a brief recovery during the Second World War, had virtually ceased by 1981. Neither the methods, location nor level of production remained constant during the mining era. The widespread use of hydraulic sluicing and the proximity of many mines to the main river were major factors contributing to the high rate of sediment supply, with the Briseis mine at Derby being the dominant source. Based on data from published and unpublished papers, and mine records, the variable nature of that supply was estimated using a procedure which takes account of the effects of storage and changing practices. Many input points supplied material but the overall pattern is one in which downstream reaches made later starts and reached later peaks, suggesting that they will continue to experience the effects of an increased sediment load for some time. 相似文献