Population Growth In Regions Research Articles

Tropical cyclone activity in global warming scenario

Research efforts focused on assessing the potential for changes in tropical cyclone activity in the greenhouse-warmed climate have progressed since the IPCC assessment in 1996. Vulnerability to tropical cyclones becoming more pronounced due to the fastest population growth in tropical coastal regions makes it practically important to explore possible changes in tropical cyclone activity due to global warming. This paper investigates the tropical cyclone activity over whole globe and also individually over six different ocean basins. The parameters like storm frequency, storm duration, maximum intensity attained and location of formation of storm have been examined over the past 30-year period from 1977 to 2006. Of all, the north Atlantic Ocean shows a significant increasing trend in storm frequency and storm days, especially for intense cyclones. Lifetime of intense tropical cyclones over south Indian Ocean has been increased. The intense cyclonic activity over north Atlantic, south-west Pacific, north and south Indian Ocean has been increased in recent 15 years as compared to previous 15 years, whereas in the east and west-north Pacific it is decreased, instead weak cyclone activity has been increased there. Examination of maximum intensity shows that cyclones are becoming more and more intense over the south Indian Ocean with the highest rate. The study of the change in the cyclogenesis events in the recent 15 years shows more increase in the north Atlantic. The Arabian Sea experiences increase in the cyclogenesis in general, whereas Bay of Bengal witnesses decrease in these events. Shrinking of cyclogenesis region occurs in the east-north Pacific and south-west Pacific, whereas expansion occurs in west-north Pacific. The change in cyclogenesis events and their spatial distribution in association with the meteorological parameters like sea surface temperature (SST), vertical wind shear has been studied for Indian Ocean. The increase in SST and decrease in wind shear correspond to increase in the cyclogenesis events and vice versa for north Indian Ocean; however, for south Indian Ocean, it is not one to one.

Continuing land degradation: Cause–effect in Ethiopia's Central Rift Valley

AbstractThe Central Rift Valley (CRV) is one of the most environmentally vulnerable areas of Ethiopia. Most of the lowland in the CRV is arid or semiarid, and droughts occur frequently. We studied the dynamics of land use and cover and land degradation by analyzing Landsat data from 1973, 1985, and 2006 using Geographic Information Systems and remote sensing techniques. The analysis revealed that in the last 30 years, water bodies, forest, and woodland decreased by 15·3, 66·3, and 69·2 per cent, respectively; intensive cultivation, mixed cultivation/woodland, and degraded land increased by 34·5, 79·7, and 200·7 per cent. The major causes of land use and cover change (LUCC) and land degradation in the area were population and livestock growth in regions of limited resources, unsustainable farming techniques, the Ethiopian land tenure system and poverty. Lake level and area decline, and accelerated land degradation are the major environmental impacts of LUCC observed in the CRV. The environmental and socio‐economic consequences of LUCC and land degradation are far‐reaching. As a result of the expansion of land degradation over time, agricultural productivity has decreased and worsened food insecurity (shortages) and poverty in the Ethiopian CRV. In addition, if current trends in LUCC continue, Lake Abiyata will dry up by 2021. A detailed study of the degradation amount in relation to soil erosion, sediment yield to the lakes and catchment characteristics should be made using adaptable models; so as to guide the implementation of comprehensive and sustainable land use management by giving more attention to erosion prone areas. Copyright © 2010 John Wiley & Sons, Ltd.

Research Spotlight: Globalization of water can increase vulnerability to droughts

Water is vital for human life. Not only is it used for drinking, but it is also used for producing electricity, washing, cooking, and growing food. Lately there has been a disproportionate population growth in arid regions, and the demand for water in those regions exceeds the limited supply. However, food imports from other regions have in effect transported water to arid regions, because food is composed primarily of water.

The Determinants of Population and Employment Growth in Small Queensland Regions

This paper investigates the determination of population and employment changes for the 125 Local Government Areas of Queensland over the 1996–06 period. The intention is to determine the flow of causality from employment to population growth and/or vice versa. Unlike previous similar studies, the role of geographic location is formally investigated using techniques from the field of spatial data analysis. Overall, results of previous research are confirmed, in that there is some evidence of bi-directional causality. However, spatial effects are found to be important in the process of regional growth, with regional economic performance in part, determined by the outcomes experienced in neighbouring regions.

Neonatal screening for sickle cell disease in France

Background:As a result of population growth in African-Caribbean regions of overseas France, and now immigration essentially from North and sub-Saharan Africa to mainland France, neonatal screening for sickle cell disease...

Le dépistage néonatal de la drépanocytose en France

Accepted 3 October 2008 ABSTRACT Background: As a result of population growth in AfricanCaribbean regions of overseas France, and now immigration essentially from North and sub-Saharan Africa to mainland France, neonatal screening for sickle cell disease (SCD) has been performed in France since 1985 in Guadalupe and dependencies, as a universal test. After several pilot studies, screening was gradually extended to mainland France in 1996. Since 2000, the test has been performed at national level for all newborns defined as being ‘‘at risk’’ for SCD based on ethnic origin. Methods: A dry blood sample is obtained by heel stick and analysed by isoelectric focusing as a first-line method, followed by either high-performance liquid chromatography or acid agar electrophoresis for confirmation, whenever a variant haemoglobin is observed on isoelectric focusing. Results: In 2007, 28.45% of all newborns in mainland France were screened for SCD. Since 1996, a total of 3890 newborns have been found to have SCD, and they have been followed up by reference paediatricians. Conclusion: Although screening for SCD at birth in France is not universal, it appears that missed babies are relatively infrequent. Despite obvious sociological problems inherent to the at-risk population, the follow-up of SCD babies is rather successful. Due to the birth prevalence of SCD in France, especially in comparison with other common genetic diseases, screening all newborns regardless of ethnic origin is an issue that is being addressed.

Nature and the economy*

Summary In this lecture I first offer what one could call the World Bank view of the recent macroeconomic history of a number of countries in the poor and rich worlds. Secondly, I demonstrate how our view of macroeconomic history changes if Nature is included as a capital asset in production activities. I conclude that high population growth in the world's poorest regions (South Asia and sub‐Saharan Africa) has been an obstacle to the achievement of sustainable economic development in those areas. It is believed that people in those regions are, on average, less wealthy now than they were 35 years ago. When population growth is taken into account, the accumulation of manufactured capital, knowledge and human capital (health and education) has not compensated for the degradation of natural capital in South Asia and sub‐Saharan Africa and, in all probability, even in the United Kingdom and the United States. It is possible that China is an exception to the economic forces experienced in other areas of the world. Synthesis and applications. The conclusions drawn here are very tentative and there is much further work to be conducted in understanding how ecological concerns can be incorporated into economic theory. It is important, therefore, that growth economists, demographers, governments and international agencies take this approach.

Salinity tolerance of bermudagrass (Cynodon spp. L. C. Rich) cultivars and shoot Na, K and Cl contents under a high saline environment

SummaryIncreasing need for salt-tolerant turfgrasses continues due to population growth in arid and semi-arid regions where potable water is limited, while soil and existing water sources are salty. Bermudagrass (Cynodon spp. L. C. Rich) is widely used in these areas. Therefore, this experiment was conducted to evaluate the salt-tolerance of ten cultivars of bermudagrass under a high saline soil and water environment. Five salinity levels of irrigation water (3.30, 6.93, 10.2, 14.8 and 17.8 dS m–1) were prepared and 30 pots were surfaced-irrigated at each salinity level for 1 year. Overall top growth, root growth, K content and K:Na ratio were reduced by 75%, 45%, 77% and 94.5%, respectively; while leaf-firing, shoot Cl and shoot Na concentrations were increased by 4%, 498% and 356%, respectively, when the salinity increased from 3.3 dS m–1 to 17.8 dS m–1. Regarding the salt-tolerance of cultivars, ‘Tifway’ was superior in top growth, percentage leaf-firing, Na uptake and K:Na ratio, ‘ISF2’ in root growth, and ‘Tifdwarf’ in Cl uptake. Although ‘Tifway’ showed the greatest reduction in root dry weight, it had the lowest level of leaf-firing and lowest reduction in top growth, which could be due to having the lowest Na uptake. Cultivars exhibited marked differences in their response to salinity; however, no mortality was observed, indicating that all cultivars tolerated the salinity levels used in the experiment.

The Demographic Transition and The Emergence of Sustained Economic Growth

The demographic transition that swept the world in the course of the last century has been identified as one of the prime forces in the transition from stagnation to growth. The unprecedented increase in population growth during the early stages of industrialization was ultimately reversed and the demographic transition brought about a significant reduction in fertility rates and population growth in various regions of the world, enabling economies to convert a larger share of the fruits of factor accumulation and technological progress into growth of income per capita. This Paper examines various mechanisms that have been proposed as possible triggers for the demographic transition, assessing their empirical validity, and their potential role in the transition from stagnation to growth.

The Demographic Transition and the Emergence of Sustained Economic Growth

The demographic transition that swept the world in the course of the last century has been identified as one of the prime forces in the transition from stagnation to growth. The unprecedented increase in population growth during the early stages of industrialization was ultimately reversed and the demographic transition brought about a significant reduction in fertility rates and population growth in various regions of the world, enabling economies to convert a larger share of the fruits of factor accumulation and technological progress into growth of income per capita. This paper examines various mechanisms that have been proposed as possible triggers for the demographic transition, assessing their empirical validity, and their potential role in the transition from stagnation to growth.

Exploring past and future changes in the ecological footprint for world regions

The Ecological Footprint (EF) has received considerable attention as a useful indicator in the context of sustainable development. So far, it has mostly been applied as a static indicator. Here, we have derived a set of long-term EF scenarios for 17 world regions using the IMAGE 2.2 implementation of the IPCCs SRES scenarios. The scenarios are used to discuss potential trends in EFs in different world regions but also to analyse underlying trends driving changes in the EF. The baseline scenarios show the EF for real land use only (not accounting for CO 2) to increase further in the next few decades in most world regions, being driven by population growth, changes in human diets towards more land-intensive products and overall increases in consumption levels. Future crop yield improvements and technology development will partly offset these trends, resulting in decreasing per capita EFs, but increasing total EFs. In the longer term, EF development may strongly diverge on the basis of assumptions made in the different baseline scenarios (from 5.4 Gha at present to 6.0–8.2 Gha in 2050 depending on the scenario). The aggregated EF following the definition of Wackernagel et al. (Proc. Natl. Acad. Sci. 99 (2002) 9266–9271) (including virtual land for CO 2) increases more strongly, from 12.6 to 20–31 Gha depending on the different scenarios. An alternative scenario was developed to explore whether optimistic assumptions for changes in consumption and production patterns could limit the increase of the global EF, which limited EF increase to 15 Gha in 2050. This scenario still allowed for population growth and strong economic development in low-income regions.

The Demographic Transition and the Emergence of Sustained Economic Growth

The demographic transition that swept the world in the course of the last century has been identified as one of the prime forces in the transition from stagnation to growth. The unprecedented increase in population growth during the early stages of industrialization was ultimately reversed and the demographic transition brought about a significant reduction in fertility rates and population growth in various regions of the world, enabling economies to convert a larger share of the fruits of factor accumulation and technological progress into growth of income per capita. This paper examines various mechanisms that have been proposed as possible triggers for the demographic transition, assessing their empirical validity, and their potential role in the transition from stagnation to growth. (JEL: O11, O14, O33, O40, J11, J13)

Semiarid Crop Production from a Hydrological Perspective: Gap between Potential and Actual Yields

Rapid population growth in the dry climate regions, arable land scarcity, and irrigation expansion limitations direct our interest to possibilities of yield increase in rainfed agriculture. Literature, however, indicates large differences between actual and potential yields, and between yields on farmers’ fields and research stations. This article focuses on the determinants of these yield gaps and the windows of opportunity for yield increase on the farmer's field together with the agricultural challenges involved. The study links the conventional approach to estimate crop water requirements and dry spell effects on biomass production to a conceptual Green Water Crop Model. This model addresses the effects on crop yields of the sequential diversions of infiltrating rainfall (rainwater partitioning into runoff, plant available soil water, and deep percolation) and of different relations between nonproductive evaporation flow and productive transpiration flow, defined together as green water flow. Also, the effects of droughts and dry spells are analyzed. The model is used to demonstrate typical situations for semiarid and dry subhumid conditions (lengths of growing period (LGP) of 90 and 179 days, respectively) for maize (Zea mays (L.)) under on-station agricultural conditions. Based on detailed water flow analysis in a 3-year on-farm case study in the Sahel on pearl millet (Pennisetum glaucum (L.) Br.), the model is used to clarify the large scope for improved yield levels, achievable through land and water management securing that runoff losses and deep percolation are reduced and nonproductive evaporation losses minimized. The analysis indicates that poor rainwater partitioning and low plant water uptake capacity alone reduces estimated on-farm grain yields to 1/10th of the potential yields. This suggests that lack of water per se not necessarily is the primary constraint to crop growth even in drought prone areas of sub-Saharan Africa. The conclusion is that even a doubling of crop yields would be agro-hydrologically possible with relatively small manipulations of rainwater partitioning in the water balance.

Semiarid Crop Production from a Hydrological Perspective: Gap between Potential and Actual Yields

Rapid population growth in the dry climate regions, arable land scarcity, and irrigation expansion limitations direct our interest to possibilities of yield increase in rainfed agriculture. Literature, however, indicates large differences between actual and potential yields, and between yields on farmers’ fields and research stations. This article focuses on the determinants of these yield gaps and the windows of opportunity for yield increase on the farmer's field together with the agricultural challenges involved. The study links the conventional approach to estimate crop water requirements and dry spell effects on biomass production to a conceptual Green Water Crop Model. This model addresses the effects on crop yields of the sequential diversions of infiltrating rainfall (rainwater partitioning into runoff, plant available soil water, and deep percolation) and of different relations between nonproductive evaporation flow and productive transpiration flow, defined together as green water flow. Also, th...

Processes governing phytoplankton blooms in estuaries. I:The local production-loss balance

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 187:1-15 (1999) - doi:10.3354/meps187001 Processes governing phytoplankton blooms in estuaries. I: The local production-loss balance Lisa V. Lucas1,*, Jeffrey R. Koseff2, James E. Cloern1, Stephen G. Monismith2, Janet K. Thompson1,2 1United States Geological Survey, 345 Middlefield Road, MS #496, Menlo Park, California 94025, USA 2Environmental Fluid Mechanics Laboratory, Dept. of Civil and Environmental Engineering, Stanford University, Stanford, California 94305-4020, USA *E-mail: llucas@usgs.gov ABSTRACT: The formation and spatial distribution of phytoplankton blooms in estuaries are controlled by (1) local mechanisms, which determine the production-loss balance for a water column at a particular spatial location (i.e. control if a bloom is possible), and (2) transport-related mechanisms, which govern biomass distribution (i.e. control if and where a bloom actually occurs). In this study, the first of a 2-paper series, we use a depth-averaged numerical model as a theoretical tool to describe how interacting local conditions (water column height, light availability, benthic grazing) influence the local balance between phytoplankton sources and sinks. We also explore trends in the spatial variability of the production-loss balance across the topographic gradients between deep channels and lateral shoals which are characteristic of shallow estuaries. For example, under conditions of high turbidity and slow benthic grazing the highest rates of phytoplankton population growth are found in the shallowest regions. On the other hand, with low turbidity and rapid benthic grazing the highest growth rates occur in the deeper areas. We also explore the effects of semidiurnal tidal variation in water column height, as well as spring-neap variability. Local population growth in the shallowest regions is very sensitive to tidal-scale shallowing and deepening of the water column, especially in the presence of benthic grazing. A spring-neap signal in population growth rate is also prominent in the shallow areas. Population growth in deeper regions is less sensitive to temporal variations in tidal elevation. These results show that both shallow and deep regions of estuaries can act as sources or sinks for phytoplankton biomass, depending on the local conditions of mean water column height, tidal amplitude, light-limited growth rate, and consumption by grazers. KEY WORDS: Phytoplankton · Estuaries · Model · Benthic grazing · Bathymetry · Light Full text in pdf format NextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 187. Publication date: October 14, 1999 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 1999 Inter-Research.

Japan's population redistribution: A comparison with the United States

The purposes of this paper are, first, to analyze population distribution changes 1965-95 in Japan by four categories-the existing metropolitan area; new suburbs; new metropolitan area; and non-metropolitan area-by using the Hoover index, and, second, to compare the results obtained for Japan with those for the US presented in Nucci and Long (1995) and Long and Nucci (1997). To clarify the temporal changes in population distribution, the delineation of metropolitan areas needs to employ a floating principle rather than a fixed one, and the definition of metropolitan areas should be similar to that of Standard Metropolitan Statistical Areas (SMSA) used in the US. To meet these conditions, the Standard Metropolitan Employment Areas (SMEA) advocated by H. Yamada and K. Tokuoka are used in this article.In Japan, during the period 1965-75, there occurred a considerable population concentration due to a marked population increase in the old suburbs located in the core regions (such as Kanto, Tokai and Kinki) and to a large population decrease in non-metropolitan areas in the peripheral regions (such as Hokkaido, Tohoku, Hokuriku, Chugoku, Shikoku and Kyushu). During the period 1975-85, the difference between the population change rates of the core and the periphery levelled off. However, in the peripheral regions, the main category of population growth was the old central cities and depopulation in non-metropolitan areas continued. In the core regions, the category showing the largest rate of increase shifted from the old suburbs to the newly-added suburbs, implying population deconcentration from the old SMEAs. During 1985-95, deconcentration proceeded further in the core portion of the country. Meanwhile, in the peripheral regions, whereas the category showing the largest rate of increase finally shifted from the old SMEAs to the newer suburbs, non-metropolitan areas returned to recording a heavy population decrease.With respect to the 1965-95 period as a whole, the population increase in the newer SMEAs created in the non-metropolitan areas was negligible. Bearing in mind the depopulation of the non-SMEAs, this means that we cannot regard the overall trend of population redistribution as being counterurbanization.With regard to the Japan-US comparison, population deconcentration in the old metropolitan areas is common to both countries, but the following remarkable differences can be noted. First, in the US, the contribution of the new metropolitan areas created in the non-metropolitan areas to urbanization is more conspicuous than that of the new suburbs added to the old metropolitan areas. Second, whereas a clean break with the past in terms of population redistribution was found in the US, such a phenomenon was not observed in Japan. Third, in Japan, population growth in the core regions and depopulation in the peripheral regions are found throughout the period, whereas in the US, both types of region take on different change aspects and the spatial patterns of population redistribution are far more complicated.

Gonococcal infection and human fertility in sub-Saharan Africa.

An analysis is presented of the influence of Neisseria gonorrhoeae on human population growth in regions of sub-Saharan Africa where gonococcal infections are prevalent in sexually active adults. Combining epidemiological and demographic data within the framework of a mathematical model, we show that gonorrhoea has a major impact on fertility and, concomitantly, on net population growth in areas with a high prevalence of untreated infections. Specifically, a 20% prevalence in sexually active adults is predicted to induce a 50% reduction in net population growth. Model predictions are in good agreement with observed data from Uganda, and the sensitivity of the prediction to various complications, such as heterogeneity in sexual behaviour, is assessed. The analysis suggests that the predicted increase in fertility arising from expanded sexually transmitted disease (STD) control programmes in Africa to help combat the spread of human immunodeficiency viruses (HIV-1 and HIV-2) will help to offset the predicted demographic impact of AIDS in the worst afflicted areas. In other areas the rise in fertility associated with effective STD control will need to be countered by the linkage of STD control programmes with family planning initiatives.

Interregional Elderly Migration and Population Redistribution in Four Industrialized Countries

Though differing in cultures, languages, and socioeconomic attributes, the industrialized nations of the world share a common characteristic: relatively low fertility levels and relatively high proportions of elderly people. These elderly persons are not spread uniformly across their national territories; they exhibit distinct population geographies. This article examines the elderly migration and population redistribution process in four industrialized countries, identifies their principal retirement regions, and analyzes the sources of regional elderly population growth in these regions. It concludes that the United Kingdom and the United States are approaching the final stages of their "elderly mobility transition," whereas Japan is only entering the first stage, with Italy occupying a position somewhere in between.

Spatio-Temporal Structure of Population Growth in Urban Regions: The Cases of Tel-Aviv and Haifa, Israel

Despite the growing awareness of the urban field as an urban entity extending beyond metropolitan area boundaries, the research on its internal spatial structure is still scarce. This study aims for a description of the spatio-temporal structure of population growth in the urban regions of Tel-Aviv and Haifa. The spatio-temporal trends of population growth in these regions are traced and analysed by the application of a multi-variate regression model using a compound spatio-temporal polynomial power series. The analysis is performed adirectionally for each urban region as a whole and it is repeated separately for three different geographic sectors in each region. Structural differences were found to exist between the larger and smaller urban regions as well as among the different geographic sectors. It is demonstrated that in the smaller urban region of Haifa the structural pattern obtained for the whole urban region misrepresents the unique trends that pertain to different directions.

A computer system for hurricane hazard assessment

Rapid economic development and population growth in coastal regions of the U.S. has resulted in an increase in vulnerability of population and property to the hurricane hazard. State and local emergency management officials need a detailed information base of potential loss estimates to prepare sound emergency preparedness plans. A computer system, known as the Vulnerability Assessment and Mapping System (VAMS), has been designed to estimate the extent and spatial distribution of potential casualties, and losses to housing and commercial-industrial facilities as a result of hurricane landfall. The VAMS system is flexible as users can choose to consider different types of hurricanes with varying surge and wind patterns and points of landfall for determining potential loss estimates within a given study area. The results of the analysis can be displayed in computer-generated grid map form or as summary statistics in tabular form. The VAMS system is then applied to coastal portions of the Houston-Galveston metropolitan area in the State of Texas. The VAMS system is part of a comprehensive hurricane impact study for the Texas Governor's Division of Emergency Management.