Abstract This paper takes poverty-stricken county as the basic unit, and selects net income per peasant to study the poverty status in Hebei Province during 1986–2000. Temporal and spatial changes of poverty-stricken areas are analyzed. The result shows that poverty-stricken areas in Hebei Province distributed concentratedly and the areas decreased during 1986–2000, the net income per peasant was on the rise with an increasing speed in off-poverty counties being slightly higher than that in poverty-stricken counties, but the growth rate was extremely unstable, rising slowly in off-poverty counties while dropping in poverty-stricken counties. The main driving forces that influenced temporal and spatial changes were economic development of the whole province, ecological environment quality, infrastructure conditions and radiation of the key city. On this basis, some anti-poverty countermeasures suitable to local conditions are proposed. 相似文献
The global urbanization process poses a serious challenge to achieving sustainable development. The significance of sustainable urbanization has been increasingly appreciated, yet, very little empirical evidence has been provided for this prospect. In this paper, we use the Human Development Index and the ecological footprint to measure the sustainability of the coastal Liaoning area. We then use the quadrant map approach to determine the relationship between sustainability and urbanization. The results show that the coastal area has made progress in sustainable urbanization in the social dimension. Improvement in the environmental dimension has been dynamic. Our results indicate that sustainable urbanization is a dynamic, multi-dimensional progress that requires regular monitoring and reevaluation. This paper also highlights the importance of choosing more complete indicators for measuring the sustainability of urbanization, as no single model or measurement is sufficient for quantifying the different dimensions of sustainability. 相似文献
Environmental regulations frequently mandate the use of “best available” science, but ensuring that it is used in decisions around the use and protection of natural resources is often challenging. In the Western US, this relationship between science and management is at the forefront of post-fire land management decisions. Recent fires, post-fire threats (e.g. flooding, erosion), and the role of fire in ecosystem health combine to make post-fire management highly visible and often controversial. This paper uses post-fire management to present a framework for understanding why disconnects between science and management decisions may occur. We argue that attributes of agencies, such as their political or financial incentives, can limit how effectively science is incorporated into decision-making. At the other end of the spectrum, the lack of synthesis or limited data in science can result in disconnects between science-based analysis of post-fire effects and agency policy and decisions. Disconnects also occur because of the interaction between the attributes of agencies and the attributes of science, such as their different spatial and temporal scales of interest. After offering examples of these disconnects in post-fire treatment, the paper concludes with recommendations to reduce disconnects by improving monitoring, increasing synthesis of scientific findings, and directing social-science research toward identifying and deepening understanding of these disconnects. 相似文献
在燃气聚乙烯(PE)管道风险评价过程中,为降低风险因素的模糊性、不确定性对评价准确性的影响,在模糊推理的基础上,提出一种基于模糊Petri网(Fuzzy Petri net,FPN)的燃气PE管道风险评价方法。首先对燃气PE管道主要风险因素进行分析,以燃气PE管道事故为顶事件,建立一个包括3个二级指标和16个三级指标的层次化评价指标体系;然后将风险评价指标体系转换为FPN模型,并运用层次分析法(AHP)和熵权法组合求取各评价指标的权重值,既避免了主观赋权的主观性和盲目性,又避免了客观赋权的片面性和机械性;最后根据模糊Petri网模型给出模糊推理算法,并应用模糊推理算法进行燃气PE管道风险评价。实例分析表明:与传统的风险评价方法相比,应用模糊Petri网的燃气PE管道风险评价方法得出的结果更加客观和准确。 相似文献
The characteristics of colloids in urban road runoff with different traffic in Beijing, China, such as concentration, particle size, chemical property, and affinity for heavy metals were determined. The concentration of colloids was high, and an evident first flush effect was found in the runoff of road with heavy traffic. A large portion of colloids were distributed in the range of 1–10 μm. Traffic activity, rainfall intensity, and time of sample collection would not change the size distribution of colloids in the road runoff. The chemical property of colloids in the road runoff would be influenced by the soil erosion nearby green space, causing the content of organic colloids was high. The correlation coefficient between the concentration of colloids in colloidal fractions and the concentration of heavy metals (Cu, Zn, Cd, Pb, Fe, and Mn) in the road runoff with different traffic decreased with the same sequence from 0.02–0.2 μm, 0.2–0.45 μm, 0.45–1 μm, to 1–10 μm, suggesting that the heavy metals had stronger affinity for the colloids with small size. The concentration of Cu, Pb, and Zn exhibited significant correlations with the concentration of organic colloids in the road runoff. More aggregated spherical particles were found in the TEM image of the road runoff with heavy traffic. Zeta potentials and RMV data showed that the colloids with smaller size and the colloids in the road runoff with lighter traffic were much more stable.