A forecast analysis on world population and urbanization process

The continuous growth of world population and the intensification of urbanization process create a challenge to environment quality and sustainable development around the world. In this paper I tried to conduct a forecast analysis of near-future urbanization related population growth worldwide, based on recent demographic trends. Such an analysis can provide important insights into the prospects for changes in the size and composition of world population and in urbanization process. Optimal polynomial functions were used to fit historical trajectories of population dynamics, and the detailed forecasts of the population mainly over the period 2010–2030 were conducted and analyzed. If the past pattern continues, world total population would increase to 7.94–8.33 billion in 2030 and the annual growth is expected to continually decline in the forecast period. Global total population would stop increasing during the period 2050–2060 and would not exceed 9.5 billion in the future. The total population of Africa, Asia, Oceania, South America, North & Central America would separately increase to 1.35–1.41, 4.86–5.65, 0.04–0.05, 0.44–0.45, and 0.71–0.72 billion in 2030. Europe’s total population is forecast to decline to 0.64–0.67 billion in 2030. World’s rural population is expected to grow to the maximum during the period 2015–2020 and would greatly decline after that period. Global rural population would reach 3.12–3.41 billion in 2030. Rural population in Asia and Africa is estimated to increase and achieve the maximum around 2025 and decline thereafter. For other regions, the rural population would continually decline in the forecast period. Urban population in the world would continually grow and reach 4.72–5.00 billion in 2030, an increase of 48.6–57.8%. However the annual growth of urban population is expected to increase to the maximum (6.86 million/year) during the period 2020–2025 and then decline in the following years. Urban population is projected to continually grow in all regions excepting Europe. Europe’s urban population is expected to decline in the period 2010–2030. Urbanization process worldwide, represented by the ratio urban population versus total population (RUT) and the ratio rural population versus urban population, is expected to continue during the period 2010–2030. The RUT of the world is projected to reach 0.5 before 2010 and would continue to increase in the forecast period. Global RUT is estimated to reach 0.56 in 2030. However, the regional patterns of urbanization process would be diverse. Europe’s RUT is estimated to continually decline in the forecast period and reach 0.68 in 2030. The RUT for Africa and Caribbean would continually increase before 2030, while the RUTs for Asia and South America are estimated to achieve their maximums around 2025 and decline in the following years. Oceania and North & Central America would thoroughly realize urbanization (≈1) during the periods 2020–2025 and 2025–2030. The expansion of world population and urbanization will continually exert a stronger stress to environment quality and sustainable development in a near future. However we may expect this situation would start to change from mid-21st century after total population has achieved its maximum. Readers should send their comments on this paper to BhaskarNath@aol.com within 3 months of publication of this issue.     

从世界银行对二滩水电站环境影响评估中得到的启示

本文介绍了二滩水电站环境影响评价，以及世界银行评估过程中专家提出的一系列环境问题，并结合我院１０多年来的环境影响评价工作简述几点启示，供参考。     

1991／1992年世界气象灾害评述

1991/1992年是厄尔尼诺年,也是全球自然灾害频发、重灾事件突出的异常年份。本文对发生在1991/1992年厄尔尼诺事件期间的全球主要气象灾害进行简介和评述。     

Analysis of Sediment Retention in Western Riverine Wetlands: The Yampa River Watershed,Colorado, USA

We quantified annual sediment deposition, bank erosion, and sediment budgets in nine riverine wetlands that represented a watershed continuum for 1 year in the unregulated Yampa River drainage basin in Colorado. One site was studied for 2 years to compare responses to peak flow variability. Annual mean sediment deposition ranged from 0.01 kg/m² along a first-order subalpine stream to 21.8 kg/m² at a sixth-order alluvial forest. Annual mean riverbank erosion ranged from 3 kg/m-of-bank at the first-order site to 1000 kg/m at the 6^th-order site. Total sediment budgets were nearly balanced at six sites, while net export from bank erosion occurred at three sites. Both total sediment deposition (R² = 0.86, p < 0.01) and bank erosion (R² = 0.77, p < 0.01) were strongly related to bankfull height, and channel sinuosity and valley confinement helped to explain additional variability among sites. The texture and organic fraction of eroded and deposited sediment were relatively similar in most sites and varied among sites by watershed position. Our results indicate that bank erosion generally balances sediment deposition in riverine wetlands, and we found no distinct zones of sediment retention versus export on a watershed continuum. Zones of apparent disequilibrium can occur in unregulated rivers due to factors such as incised channels, beaver activity, and cattle grazing. A primary function of many western riverine wetlands is sediment exchange, not retention, which may operate by transforming materials and compounds in temporary sediment pools on floodplains. These results are considered in the context of the Hydrogeomorphic approach being implemented by the U.S. government for wetland resource management.     

三峡库区场地建筑安全评价研究

三峡水库自 2 0 0 3年蓄水后 ,水对斜坡 (滑坡 )的软化作用和库岸再造大大改变了库区的工程地质条件 ,库区的地质灾害严重制约了库区移民迁镇工程 ,场地建筑安全评价显得尤为重要。笔者根据库区工程地质的特点 ,提出了场地建筑适宜性评价的指标体系 ,建立了场地建筑安全评价人工神经网络模型。通过对红石包滑坡进行各种工况下的稳定性评价 ,利用稳态坡形、坡角工程地质类比法对红石包进行库岸再造的预测 ,对三峡库区巴东县新城区红石包油库建筑进行安全评价。为库区移民迁镇工作提供科学依据。     

Elements of resilience after the World Trade Center disaster: reconstituting New York City's Emergency Operations Centre

In this paper we examine the reconstitution of the Emergency Operations Centre (EOC) after its destruction in the World Trade Center attack, using that event to highlight several features of resilience. The paper summarises basic EOC functions, and then presents conceptions of resilience as understood from several disciplinary perspectives, noting that work in these fields has sought to understand how a natural or social system that experiences disturbance sustains its functional processes. We observe that, although the physical EOC facility was destroyed, the organisation that had been established to manage crises in New York City continued, enabling a response that drew on the resources of New York City and neighbouring communities, states and the federal government. Availability of resources--which substituted for redundancy of personnel, equipment and space--pre-existing relationships that eased communication challenges as the emergency developed and the continuation of organisational patterns of response integration and role assignments were among the factors that contributed to resilience following the attack.     

Monitoring and management of streambank erosion and natural revegetation on the lower Gordon River,Tasmanian Wilderness World Heritage Area,Australia

The wash from high-speed tourist cruise launches causes erosion of the formerly stable banks of the lower Gordon River within the Tasmanian Wilderness World Heritage Area. Speed and access restrictions on the operation of commercial cruise vessels have considerably slowed, but not halted erosion, which continues on the now destabilized banks. To assess the effectiveness of restrictions, bank erosion and natural revegetation are monitored at 48 sites using erosion pins, survey transects, and vegetation quadrats. The subjectively chosen sites are grouped on the basis of geomorphology and bank materials. The mean measured rate of erosion of estuarine banks slowed from 210 to 19 mm/year with the introduction of a 9 knot speed limit. In areas where cruise vessels continue to operate, alluvial banks were eroded at a mean rate of 11 mm/yr during the three-year period of the current management regime. Very similar alluvial banks no longer subject to commercial cruise boat traffic eroded at the slower mean rate of 3 mm/yr. Sandy levee banks have retreated an estimated maximum 10 m during the last 10–15 years. The mean rate of bank retreat slowed from 112 to 13 mm/yr with the exclusion of cruise vessels from the leveed section of the river. Revegetation of the eroded banks is proceeding slowly; however, since the major bank colonizers are very slow growing tree species, it is likely to be decades until revegetation can contribute substantially to bank stability.     

A training consultancy for an Ethiopian I.D.A. urban programme evaluated

The author contributed to a short ‘in service’ course for staff engaged on a World Bank upgrading project for Ethiopian housing. The project includes both the building of new houses by self‐build co‐operatives on the periphery of Addis Ababa, and the upgrading of a dense inner city area in conditions of acute deprivation. The paper is a highly personal account of the author's impressions of the value of such initiatives.     

Environmental anomalies at the World Trade Center: evidence for energetic materials

Investigators monitoring air quality at the World Trade Center, after the September 11th attacks, found extremely high levels of volatile organic chemicals as well as unusual species that had never been seen before in structure fires. Data collected by the U.S. Environmental Protection Agency indicate striking spikes in levels of benzene, styrene, and several other products of combustion. These spikes occurred on specific dates in October and November 2001, and February 2002. Additionally, data collected by researchers at the University of California Davis showed similar spikes in the levels of sulfur and silicon compounds, and certain metals, in aerosols. To better explain these data, as well as the unusual detection of 1,3-diphenylpropane, the presence of energetic nanocomposites in the pile at Ground Zero is hypothesized.     

A forecast analysis on fertilizers consumption worldwide

This study aimed to make a review and forecast on fertilizers consumption worldwide in order to provide basal data for the decision-making of fertilizers production and for the environmental impact assessment of fertilizers application. It was found that fertilizers consumption was dependent on human population and the increase of fertilizers consumption was mainly resulted from expansion of human population. The univariate linear model, y=a+rx(t), where y is the fertilizers consumption, x(t) is the total human population at year t, r is the annual fertilizers consumption per capita, was used to fit historical data of fertilizers consumption, and the forecasts during 2010 to 2030 were given in detail. Model analysis showed that world’s per capita annual consumption of total fertilizers, nitrogenous fertilizers, phosphate fertilizers, and potash fertilizers, were 34.6, 24.4, 6.6, and 3.7 kg, respectively. Per capita annual consumption of total fertilizers for Asia, Africa, Caribbean, Oceania, North & Central America, Europe, and South America were 38.8, 5.9, 6.8, 114.0, 62.9, −0.9, and 43.6 kg, respectively. Compared to the current level, the world’s total fertilizers consumption would reach 226,150,381 Mt by 2030, an increase of 32.1% against current level. Worldwide consumption of nitrogenous fertilizers, phosphate fertilizers, and potash fertilizers would reach 141,800,601, 50,961,129, and 33,388,650 Mt by 2030, increasing 37.5, 25.8, and 21.2% based on current levels. Consumption of total, nitrogenous, phosphate, and potash fertilizers in Asia and Africa would increase 54 to 55% and 40 to 60% by 2030, respectively. Total fertilizers consumption in North & Central America would see an increase of 39.4% by 2030, and in South America and Oceania it would increase by 30.9 and 64.7%, respectively. By 2030, Caribbean’s consumption for total fertilizers would increase 2.8%. Europe’s total fertilizers consumption was forecast to continuously decline and would have a decrease of 2.4% by 2030. Annual relative growths of consumption of total fertilizers, nitrogenous fertilizers, phosphate fertilizers, and potash fertilizers for the world, Africa, Asia, and South America were forecast to decrease in the forecast period. For North & Central America, annual relative growths of consumption of total fertilizers and nitrogenous fertilizers would decrease and the others would increase annually by 2030. Annual relative growths of consumption of total fertilizers, phosphate fertilizers, and potash fertilizers for Oceania were forecast to rise annually by 2030. Europe’s annual relative growths of consumption of total fertilizers and potash fertilizers would decrease in the future.