基于虚拟耕地方法的中国粮食生产布局诊断

为研究我国区域粮食生产空间布局问题,运用虚拟耕地方法和对比方法对我国粮食生产空间布局进行诊断。首先,用人均农村人口粮食产量的虚拟耕地量表征我国粮食生产的空间布局现状,发现其存在“高值区相对集中,低值区相对分散”、区域间差异明显的特点。高值区集中于东北和内蒙古、长江中下游以及江南丘陵的北部地区;其次,主要从水土资源、自然灾害等方面构建包含8个具体指标的评价指标体系对我国31个省级行政区的粮食生产适宜度进行定量评价。发现我国不同区域间的粮食生产适宜度存在显著差异,区域粮食生产适宜度整体上呈现东高西低的空间分布规律,其中,高适宜度区域主要分布在我国的东北、黄淮海、华中、华南和西南各省区,低适宜度区域主要分布在西北、华北和东南沿海的福建、江西等省区;最后,构建粮食生产布局协调指数作为我国不同区域粮食生产布局调整的依据,发现北方11个省区粮食生产布局过密,南方16个省区粮食生产布局过疏。研究方法具有一定的创新性,但是,在粮食生产适应性评价的指标选择等方面尚存在明显的不足,研究结果和结论都有待进一步完善。     

基于西部开发战略的丽江市发展定位初探

国家实施西部大开发战略以来,西部地区的经济、社会、基础设施、生态建设等各项事业取得快速发展。但是,西部地区的经济发展水平、居民收入水平与全国平均相比差距仍较大,公共服务领域不足等问题依然突出。以丽江市为例,分析了丽江过去30 a的经济包括旅游业的发展状况,比较了其小康社会和现代化指标完成情况,分析结果表明,纵向上丽江在经济发展上取得了跨越式的发展,但横向对比全国其他地区和城市,在经济尤其在社会发展方面还有很大差距,少数民族问题尤为突出。最后结合丽江的区域和旅游发展实际,讨论了今后国家西部开发政策的倾斜和定位,指出加强财政转移支付,制定少数民族社会文化发展战略以及支持西部偏远少数民族地区的经济区规划和建设是这一定位的重点。
     

中国碳排放态势与绿色经济展望

中国从2007年开始已成为世界温室气体排放第一大国,减排的国际压力越来越大。本文采用国际能源署公布的国别时间系列数据(1990-2007),系统分析了中国碳排放的现状、特点及历史变化;从经济发展、能源消费、经济全球化、社会转型等多方面解析了中国未来碳排放总量将会继续增长的基本态势。同时,从绿色技术、可再生能源的发展、生态城市建设等方面论述了中国未来必然成为世界绿色经济大国的可能性。最后,为了实现中国从排放大国走向绿色经济大国,提出了理论上需要深入研究的几个问题,即:碳排放速度与不同空间尺度问题,经济转型与反转型,碳排放的责任与国界。     

中国银行业与中国的碳金融发展

本文介绍了碳金融的定义以及中国构建完善碳金融体系的背景,指出我国的CDM市场虽然是全球最大的CDM市场,但碳金融还处于起步阶段,缺乏国际CERs定价权,CDM项目存在巨大的风险,这些问题亟需解决。中国的银行业作为中国金融机构的主要组成部分,在构建完善的碳金融市场上起到了十分关键的作用。分析了目前中国银行业参与碳金融的现状及存在的问题,提出了中央银行和中国商业银行介入碳金融的方法。中央银行应与商业银行相互配合使中国的碳金融市场尽快发展和完善。     

Phosphorus flows and use efficiencies in production and consumption of wheat, rice, and maize in China

Increasing fertilizer phosphorus (P) application in agriculture has greatly contributed to the increase of crop yields during the last decades in China but it has also increased P flows in food production and consumption. The relationship between P use efficiency and P flow is not well quantified at national level. In present paper we report on P flows and P use efficiencies in rice, wheat, and maize production in China using the NUFER model. Conservation strategies for P utilization and the impact of these strategies on P use efficiency have been evaluated. Total amounts of P input to wheat, rice, and maize fields were 1095, 1240, and 1128 Gg, respectively, in China, approximately 80% of which was in chemical fertilizers. The accumulation of P annually in the fields of wheat, rice, and maize was 29.4, 13.6, and 21.3 kg ha⁻¹, respectively. Phosphorus recovered in the food products of wheat, rice, and maize accounted for only 12.5%, 13.5%, and 3.8% of the total P input, or 3.2%, 2.6%, and 0.9% of the applied fertilizer P, respectively. The present study shows that optimizing phosphorus flows and decreasing phosphorus losses in crop production and utilization through improved nutrient management must be considered as an important issue in the development of agriculture in China.     

Accumulation levels and characteristics of some pesticides in human adipose tissue samples from Southeast China

This paper presents a comprehensive study of pesticide levels and bio-accumulation characteristics in human adipose tissues among residents of Southeast China. A large number of adipose samples (n = 633) were selected for 58 pesticides and were analyzed by high sensitive Gas Chromatography-Tandem Mass Spectrometry (GC-MS/MS). The results showed that POPs pesticides were frequently detected, including 2,4′-DDD, 2,4′-DDE, 2,4′-DDT, 4,4′-DDD, 4,4′-DDE, 4,4′-DDT, α-HCH, β-HCH, γ-HCH, δ-HCH, hexachlorobenzene (HCB), and mirex. Other detected pesticide species were dicofol, methamidophos and chlordimeform, which have rarely been reported. Comparing to different countries, the concentrations of total DDT and HCH in these three Chinese southeastern sites were in the middle range, whereas the HCB and mirex were in the lower end. A significant correlation was observed between region as well as age and POPs pesticide levels. Some pesticide residue levels were also found significantly correlated to occupation. However, there was no significant correlation between gender and pesticides. Meanwhile, it is interesting to find that mortality of malignant tumors tends to associate with the pesticides levels in human adipose tissue. More importantly, the measured data presented in this study provide realistic information which is useful for assessing human exposure to pesticides in the general population of Southeast China.     

沿海城市土地集约利用水平演变研究——以大连市为例

根据城市土地集约利用涵义,综合考虑沿海城市化进程中城市土地集约利用的经济、社会与环境效益,选取了大连市1997—2007年8项指标,运用主成分分析法进行城市土地集约利用水平评价。在评价基础上结合大连城市发展特征,分析了城市土地集约利用水平演变趋势和阶段性。结果表明,大连城市土地集约利用水平逐年提高,且具有缓慢的连续性和骤增的阶段性特征。连续性提高是由于城市人口、经济聚集、经济容量增大、人口密度增加、城市设施局部优化完善使城市土地集约利用水平不断提高;阶段性提高是由于建成区土地面积扩张期伴随大幅度城市用地结构的优化调整和城市设施的整体完善过程,使城市土地集约利用水平显著提高。     

Occurrence, bioaccumulation and potential sources of polybrominated diphenyl ethers in typical freshwater cultured fish ponds of South China

To determine the potential input sources of polybrominated diphenyl ethers (PBDEs) to fish farming environments in South China, samples of seven various environmental matrices were collected from October 2006-September 2007. Tri- to deca-BDEs were detected in all samples analyzed, with mean concentrations (±standard deviations) at 5.7 ± 3.6 ng/L in pond water, 15 ± 11 ng/g dry wt. in pond sediment, 12 ± 3.8 ng/g dry wt. in bank soil, 21 ± 20 ng/g lipid wt. in fish, and 93 ± 62 ng/g lipid wt. in fish feeds. In addition, BDE-209 was the major constituent in all samples except fish and BDE-47 was predominant in fish samples. Relatively high abundances of BDE-49 were detected in all the samples compared to those in the penta-BDE technical products. Several bioaccumulation factors were evaluated. Finally, statistical analyses suggested that fish feed, as well as pond water at a lesser degree, may have been the major source of PBDEs in freshwater farmed fish.     

Eco-health evaluation for the Shanghai metropolitan area during the recent industrial transformation (1990-2003)

Shanghai is a cosmopolitan city and one of the most important economic centers in China, but is saddled with serious environmental problems resulting from a recent industrial transformation. This paper examines the interactive relationships between economic growth, eco-efficiency of urban metabolism, and environmental performance of the Shanghai metropolitan area since the 1990s using 15 indicators. This study has revealed an enhanced eco-efficiency of water and energy use as well as an improved overall environmental quality in the central urban districts of Shanghai. Both TGDP (total GDP) and GDP per capita increased rapidly at the annual rate of 16.28% and 15.91%, respectively. In contrast, energy consumed per 10000RMB YUAN GDP (ECG), water consumed per 10000RMB YUAN GDP (WCG), wastewater discharged per 10000RMB YUAN GDP (WWDG), and waste gases emitted per 10000RMB YUAN GDP (WGEG) decreased at the annual rate of 9.34%, 10.69%, 14.57%, and 8.52%, respectively. The rapid decline in ECG, WCG, WWDG, and WGEG indicates an enhanced eco-efficiency of urban metabolism. However, uncontrolled emission of wastes from domestic instead of industrial sources adversely affected the overall environmental quality. In addition, suburban areas have undergone rapid economic growth at the cost of human health deterioration, as measured by mortalities and relative mortality ratios of three major diseases (tumor, respiratory disease, and trauma/toxicosis). With Shanghai serving as the "locomotive" driving the economy of the Yangtze River Basin, effective pollution control policies and a network of regional coordination are urgently needed in the globalization and ecological security of the entire area.