Long-term trends of polychlorinated biphenyls and chlorinated pesticides in franciscana dolphin (Pontoporia blainvillei) from Southern Brazil

Selected POPs were analyzed in blubber samples of Pontoporia blainvillei from Southern Brazil to appraise temporal trend over a 10 year period (1994-2004). Overall, levels of POPs were relatively low, especially when compared to Northern Hemisphere concentrations. Apart from Mirex and PCBs, which showed stable concentrations, DDTs, HCB, CHLs, Dieldrin levels presented a slight decrease over the studied period. In addition, the increase in the PCBs/DDTs ratio supports the idea that inputs of DDTs are decaying faster than PCBs.     

Spatio-temporal Patterns of Vegetation Change in Kazakhstan from 1982 to 2015

The Normalized Difference Vegetation Index (NDVI), as a key indicator of vegetation growth, effectively provides information regarding vegetation growth status. Based on the Global Inventory Monitoring and Modeling System (GIMMS) NDVI time series data for Kazakhstan from 1982 to 2015, we analyzed the spatial pattern and changes in the vegetation growth trend. Results indicated that the three main types of vegetation in Kazakhstan are cropland, grassland and shrubland, and these are distributed from north to south. While the regional distribution pattern is obvious, the vegetation index decreased from north to south. The average NDVI values of the three main vegetation types are in the order of cropland > grassland > shrubland. During the period from 1982 to 2015, the NDVI initially increased (1982-1992), then decreased (1993-2007), and then increased again (2008-2015). The areas where NDVI decreased significantly accounted for 24.0% of the total land area. These areas with vegetation degradation are mainly distributed in the northwest junction between cropland and grassland, and in the cropland along the southern border. The proportions of total grassland, cropland and shrubland areas that were degraded are 23.5%, 48.4% and 13.7%, respectively. Areas with improved vegetation, accounting for 11.8% of the total land area, were mainly distributed in the mid-east cropland area, and the junction between cropland and grassland in the mid-east region.     

中国强降水过程时空集中度气候趋势

1 Introduction Changes in climate variability and extrem es of weather and clim ate events have received increasing attention in the pastyears since these events have the strongestimpacton society. There hasbeen a widespread increase in heavy and extrem e…     

Marginalisation and demographic change in the semi-arid Karoo, South Africa

Semi-arid areas are often considered to be environmentally and economically marginal, a situation which has been exacerbated by economic change, shifts in agricultural production and land use, and changing state policy. These themes are explored with reference to a semi-arid landscape, namely the Karoo, which covers some 40% of the geographic space of South Africa and is used primarily for extensive livestock farming. Despite long-term decline in agricultural output, the traditional mainstay of the region, and weakening small town economies, the Karoo's population and the economies of its largest service centres are growing. There are, real socio-economic needs and development backlogs, and the situation has been exacerbated by recent political marginalisation. In this study, the small towns of the region are focal points of investigation and provide a lens to investigate the changing demographic and economic dynamics of the Karoo. Most of the region's population lives in these centres which are service, collection, and distribution points for what traditionally has been an agriculture-based regional economy. This paper explores the concept of marginalisation with specific reference to historical, economic, and demographic change.     

ON THE FREQUENCY OF PRECIPITATION-DAYS IN CALGARY,CANADA

Results of analyses of 86 years of precipitation records for Calgary, Canada, showed that there were three periods of above normal precipitation and three periods of precipitation significantly below normal. This pattern gave the precipitation climate a quasi-periodic appearance. The average number of precipitation-days was 134 per annum. The reduction in the frequency of precipitation-days in dry years was not as significant as the equivalent reduction in precipitation amounts. A significant upward trend in the frequency of precipitation-days, which correlated with a similar trend in cloud cover, was not repeated in precipitation amounts. The upward trend in both cloud cover and precipitation-day frequency is believed to be related to urban growth and the corresponding heat island. This enhancement is more pronounced in the fall and winter months than in the spring and summer.     

Definition and Determination of Laminae in Ozone Profiles

Ozone profiles measured by sondes often display thin layers of substantially enhanced or depressed ozone concentration, which are called laminae. Laminae are important because they reveal much stronger long-term trends than the ozone concentration itself and seem to be more sensitive to various factors. The paper presents our definition and method of determination of laminae in comparison with other methods of lamina definition. This is important for clarifying some differences between the lamina-related results of different authors and for examination of long-term trends in lamina characteristics. The sensitivity of long-term trends to changes of methods of lamina determination is tested and found small, without a noticeable influence of changes of methods on trends.     

An Overview of Long-Term Trends in the Lower Ionosphere Below 120 km

The increasing concentration of greenhouse gases in the atmosphere is expectedalso to modify the mesosphere and lower thermosphere (MLT region). However,the greenhouse cooling – instead of heating – at these heights is revealed by modelsand generally confirmed by observations. This should more or less affect variousionospheric parameters at these heights. The spatial and temporal structure oftemperature trends in the MLT region is quite complex and, therefore, such structureshould occur for trends in the lower ionosphere as well. In the lower part of theionosphere below about 90 km, the rocket measurements of electron density, theindirect phase reflection height measurements and the A3 radio wave absorptionmeasurements reveal trends corresponding to cooling and shrinking of the mesosphere,while riometric measurements of cosmic noise absorption provide inconclusive results.The radio wave absorption and rocket electron density measurements clearly display asubstantial dependence of trends on height. Ionosonde data show that there is amodel-expected trend in the maximum electron concentration of the E region ionosphere;foE is slightly increasing. On the other hand, the height of the normal E layer, h'E, isslightly decreasing. The nighttime LF radio wave reflection height measurements near95 km support an idea of increasing electron density. However, rather scarce rocketmeasurements display a negative trend in electron density at 90–120 km. The role ofthe solar cycle and other longer-term variability of natural origin in the determinationof observational trends must not be neglected. In spite of the general qualitativeagreement with model expectations, there is still some controversy between variousobservational trend results (hopefully, apparent rather than real), which needs to beclarified.     

An explanation of discrepancy in mesospheric temperature trends derived from ground-based LF phase-height observations

Bremer and Berger (J. Atmos. Solar Terr. Phys. 64 (2002) 805) applied a correction for trends in the NO concentration and α_eff in the interpretation of trends in the low frequency (LF) phase height measurements and obtained results less consistent with model simulations as well as the observed trends in mesospheric temperatures. The correction is shown to be too large most probably due to the application of inappropriate trends in α_eff of Chakrabarty (Adv. Space Res. 20 (1997) 2117), which yield a trend in electron density opposite to that which is observed. The discrepancy between the observational data and model-simulated trends of Bremer and Berger (J. Atoms. Solar. Terr. Phys. 64 (2002) 805) in the LF phase heights can be largely removed. Even more important, the trends in mesospheric temperatures inferred by Bremer and Berger (J. Atmos. Solar Terr. Phys. 64 (2002) 805) from trends in the LF phase heights without the inappropriate correction agree well with the results of analysis of a global set of results on trends in the mesospheric temperatures by Beig et al. (Rev. Geophys. 41 (2003) 1015).     

BOOK REVIEWS

Book Reviewed in this article: The City in Cultural Context . John Agnew, John Mercer, David Sopher, eds. Soils and Geomorphology Peter W. Birkeland. Urbanization and Settlement Systems, International Perspectives . L. S. Bourne, R. Sinclair, and K. Dziewoński. eds. An Introduction to Urban Historical Geography . Harold Carter. Overshoot, The Ecological Basis of Revolutionary Change . William J. Catton, Jr. Rivers of the World . Eberhard Czaya. Jewish Communities in Frontier Societies: Argentina, Australia and South Africa . Daniel J. Elazar with Peter Medding. Color in Public Spaces: Toward a Communication-Based Theory of the Urban Built Environment. Kenneth E. Foote. Spatial Statistics and Models. Gary L. Gaile and Cort J. Willmott, eds. Mega-Geomorphology. Rita Gardner and Helen Scoging, eds. Technological Change and Regional Development. Gillespie, ed. The Arid Lands: Their Use and Abuse. R. L. Heathcote. The Location of Industry in Britain. A. G. Hoare. Groundwater as a Geomorphic Agent . R. G. LaFleur, ed. Rural Public Services: International Comparisons. Richard E. Lonsdale and Gyorgy Enyedi, eds. Saving Water in a Desert City. William E. Martin, Helen M. Ingram, Nancy K. Laney, and Adrian H. Griffin. Water Resources: Distribution, Use and Management. John R. Mather. Transnationals and the Third World: The Struggle for Culture. Armand Mattelart. South Hadley, MA: USGS Digital Cartographic Data Standards. R. B. McEwen, R. E. Witmer, and B. S. Ramey, eds. The Ecosystem Concept in Anthropology. Emilio F. Moran, ed. Boulder, CO: Women, Men, and the International Division of Labor. June Nash and Maria Patricia Fernandez-Kelly, eds. Nuclear Power: Assessing and Managing Hazardous Technology. Martin J. Pasqualetti and K. David Pijawka, eds. Mary Somerville and the Cultivation of Science 1815-1840. Elizabeth Chalmers Patterson. An Introduction to Coastal Geomorphology. John Pethick. Late Quaternary Environments of the United States , Vol. 1, The Late Pleistocene. Stephen C. Porter, ed. Planning and Ecology. R. D. Roberts and T. M. Roberts, eds. Regionalism and the Pacific Northwest. William G. Robbins, Robert J. Frank, and Richard E. Ross, eds. Environment and Health. Anthony J. Rowland and Paul Cooper. Sunbelt/Snowbelt: Urban Development and Regional Restructuring. Larry Sawers and William K. Tabb, eds. The Bad Earth. Environmental Degradation in China. Vaclav Smil. Armonk, NY: Voyage into Substance: Art, Science, Nature, and the Illustrated Travel Account, 1760–1840. Barbara Maria Stafford. The Institute of British Geographers: The First Fifty Years. Robert W. Steel. Visions of the Past. Christopher Taylor and Richard Muir. Glacial Lake Agassiz. J. T. Teller and Lee Clayton, eds. The Tule Breakers: The Story of the California Dredge. John Thompson and Edward A. Dutra. The Balkan City 1400–1900. Nikolai Todorov. Explanation, Prediction and Planning: the Lowry model. Michael J. Webber. Mercedes Reales: Hispanic Land Grants of the Upper Rio Grande Region. Victor Westphall. The World Atlas of Revolutions. Andrew J. M. Wheatcroft. The West European City, A Social Geography. Paul White. Urban Elites and Mass Transportation. J. Allen Whitt. Princeton, NJ: Urban Life In Contemporary China. Martin King Whyte and William L. Parish. The Demand for Energy in the Soviet Union. David Wilson. London and Canberra: Rethinking Geographical Inquiry. J. David Wood, ed.     

REGIONAL AND TEMPORAL TRENDS IN POWER PLANT UNIT SITING, 1912–1978*

Regional trends in the siting of U.S. coal, gas, oil, and nuclear power plant units from 1912 to 1978 are examined. Results of a multivariate statistical analysis indicate that while these trends are comparatively individualistic, they tend to be governed more by factors affecting the choice of fuel than by regional differences in the siting process.