生态足迹与可持续发展初步分析——以北京市、沈阳市、哈尔滨市为例

生态足迹从具体的生物量角度研究自然资本消耗的空间，为核算地区资本利用状况提供框架，进而可判断区域可持续发展状态。文章在简要介绍生态足迹的概念与计算模型基础上，定量研究了北京市、沈阳市、哈尔滨市等三城市2003年－2006年4年间的生态足迹和生态承载力的变化规律和特征。根据计算进行分析，结果表明人类负荷超过其生态容量，生态承载均不能满足生态足迹的需求，社会经济处于一种不同程度不可持续的发展状态。为使城市生态建设可持续的发展提出生态恢复建议及措施。     

基于农业生态地带模型的中国粮食产能动态评估

随着人口增加和人们生活水平的不断提高,我国粮食消费需求将继续呈刚性增长,使得粮食品种和区域结构性矛盾加剧,而粮食产能的动态评估能够让我们加深认识我国粮食供需平衡,对制定适宜于我国经济社会发展同时保障粮食安全的粮食可持续发展战略具有重要意义.论文选取农田生产力作为我国粮食产能的指标,通过改进农业生态地带(AEZ)模型,动态嵌入不同县域水平的管理和投入水平的限制性因子,集成县级截面数据估计投入系数权重,并基于此估算了全国2000-2010年间农田生产力水平.研究发现,2000年以来,我国农田生产力虽年际间存在波动,但总体呈现增长的态势,且区域差异性显著.农田生产力水平存在从沿海到内陆、从南向北及从东向西的递减的梯度,而局部地区农田生产力变化明显,表现出明显的东西分异规律,其次是南北分异规律.而对各个地区农田生产力平均值统计发现,东部沿海地区与南部省份的农田生产力要高于内陆省份,西部地区农田生产力普遍低于东部和中部地区.2000、2005、2010年全国分县统计的粮食产量数据与动态估算结果进行精度验证,其相关系数分别达到0.82、0.76和0.89,实际产量为估算结果的69.4％、73.4％、67.2％,较好的反映了我国农田生产力的基本状况.最后,基于我国农田生产力时空变化规律和局部差异性特征,以及我国经济区水平上的中国农田生产力的变化规律,从耕地数量保障、农业管理和投入水平提高以及适宜的农业区划方面,提出适宜于我国自然环境状况和社会经济发展的农田生产力保障策略,对保障我国的农田生产力的稳定增长方面的规划决策与政策制定具有参考价值.     

Measuring impacts on species with models and metrics of varying ecological and computational complexity

Approaches to assess the impacts of landscape disturbance scenarios on species range from metrics based on patterns of occurrence or habitat to comprehensive models that explicitly include ecological processes. The choice of metrics and models affects how impacts are interpreted and conservation decisions. We explored the impacts of 3 realistic disturbance scenarios on 4 species with different ecological and taxonomic traits. We used progressively more complex models and metrics to evaluate relative impact and rank of scenarios on the species. Models ranged from species distribution models that relied on implicit assumptions about environmental factors and species presence to highly parameterized spatially explicit population models that explicitly included ecological processes and stochasticity. Metrics performed consistently in ranking different scenarios in order of severity primarily when variation in impact was driven by habitat amount. However, they differed in rank for cases where dispersal dynamics were critical in influencing metapopulation persistence. Impacts of scenarios on species with low dispersal ability were better characterized using models that explicitly captured these processes. Metapopulation capacity provided rank orders that most consistently correlated with those from highly parameterized and data-rich models and incorporated information about dispersal with little additional computational and data cost. Our results highlight the importance of explicitly considering species’ ecology, spatial configuration of habitat, and disturbance when choosing indicators of species persistence. We suggest using hybrid approaches that are a mixture of simple and complex models to improve multispecies assessments.     

填埋场渗漏检测高压直流电法等效电路模型的建立

通过对400V、350V、300V高压直流工作电压下小型模拟填埋场实验数据的分析 ,提出了简化的模型等效电路 .由于高密度聚乙烯(HDPE)衬层的存在使得模型具有了整流特性 ,其电容大小将随着衬层面积和供电电压的增加而增加 ;供电电极的接触电阻与大地的电阻率成正比 ,与电极的粗细及入土深度有关 .同时 ,接触电阻主要由电极附近的土壤电阻决定 ,大于10倍电极半径以外的土壤对接触电阻的影响不超过全部电阻的10% ,故降低电极附近土壤的电阻率可有效地降低电极的接触电阻 .     

从水质水量相结合的角度再论黄河的水资源

建立了流域水资源数量与质量联合评价的方法,发展了可利用水资源量的概念和计算方法,以及水资源功能容量和水资源功能亏缺的概念和计算方法,提出了水环境功能容量和功能亏缺的概念和计算方法.根据黄河流域1997—1999年间主要水文站点逐月的水质监测数据、水文数据及各取水口逐月的取水量数据,对黄河流域的水资源进行了水质水量综合评价.结果表明,在1997、1998和1999年,黄河可利用的水资源总量分别为2 5 5 3 9×10 8m3、3 43 41×10 8m3和3 5 5 44×10 8m3,分别占总天然径流量的80 2 % ,78 2 %和82 0 % .黄河水资源功能容量和亏缺在这3年间的平均值分别为42 3 5 0×10 8m3,78 97×10 8m3.对主要污染指标CODMn来说,黄河的水环境功能容量和功能亏缺在这3年间的平均值分别为2 95 71 5 4kg和199 70kg ;对主要污染指标NH+ 4 N来说,平均值分别为3 774 2 6kg和113 0 8kg .因此,与CODMn相比,NH+ 4 N对黄河可利用水资源总量的影响更大.水资源功能容量和水环境功能容量均分别显著大于水资源功能亏缺和水环境功能亏缺,说明在绝大部分情况下,黄河实际的水质要优于达到水资源功能所要求的水质     

Marshaling Adaptive Capacities within an Adaptive Management Framework to Enhance the Resiliency of Wastewater Systems

We assess adaptive capacity and adaptive management as measures of wastewater (WW) system resiliency using data from interviews with WW system managers (hereafter managers) impacted by past storms. Results suggest the most resilient WW systems are those with high adaptive capacities that employ an adaptive management approach to make ongoing adaptation investments over time. Greater amounts of generic adaptive capacities (i.e., skilled staff and good leadership) help smooth both day‐to‐day and emergency operations and provide a foundation for adaptive management. In turn, adaptive management helps managers both build more generic adaptive capacities, and develop and employ greater amounts and diversity of specific adaptive capacities (i.e., soft and/or hard adaptations) that are especially important for enhancing and sustaining resiliency. Adaptive management also enables managers to better understand their system's vulnerabilities, how those vulnerabilities change over time, and what specific actions may reduce those vulnerabilities. Finally, our work suggests WW system resilience critically depends on the capacities of the human systems for building resilience as much as or more so than relying only on physical infrastructure resilience. Our work contributes to filling an important gap in the literature by advancing our understanding of the human dimensions of infrastructure resilience and has practical implications for advancing resilience in the WW sector.     

Regional Study on Economical Supporting Capacity of Land Resources in Shandong Province

Abstract

Taking the land resources of 17 cities in Shandong Province as the basic data, the article studied on the economical supporting capacity of land resources in terms of the effect of land on economy. The author classified 17 cities of Shandong Province into four types according to the economical supporting capacity of land resources by quantitatively estimating the evaluation indices of the total amount of land resources, the potential of urban and other nonagricultural land, and the integrated economical supporting capacity of land resources, etc. The author proposes the questions requiring further study at the end of this article.     

Model Modification and Application on Carrying Capacity of Relative Resources

Abstract

Based on the retrospection of researches on carrying capacity, this article reviewed systematically the research progresses on carrying capacity of relative resources (CCRR). Then the viewpoint was put forward that CCRR is not an appropriate method of appraising the regional sustainability, but a sound way to obtain cognition for coordinating spatial location and flow of population and economy. However, as the most popular computing method of CCRR, the Weighting Linear Sum Model is defective in the random of weight choice and the neglect of matching among different resources. Therefore, this article established the Geometric Model on CCRR based on modifying Weighting Linear Sum Model, which can be used to appraise regions where resources are close matching. Employing the Geometric Model, the article empirically analyzed the population and economic CCRR in Hubei Province from 1978 to 2006. The result indicates that the population in Hubei Province is overloading while the economic carrying capacity is abundant compared to the whole country, and the economic insufficiency restricts the population carrying capacity. In the future, Hubei Province will become one of the core developing zones which are characterized by economic conglomeration.     

土壤对污染物的缓冲性研究进展

本文阐述了土壤对污染物的缓冲特性的概念，研究土壤对污染物缓冲性的目的和意义、历史、现状和前景，为土壤污染与防治提供了一定的理论依据。     

Comparison of Morphodynamic Models for the Lower Yellow River1

Xia, Junqiang, Zhengbing Wang, Yanping Wang, and Xin Yu, 2012. Comparison of Morphodynamic Models for the Lower Yellow River. Journal of the American Water Resources Association (JAWRA) 1‐18. DOI: 10.1111/jawr.12002 Abstract: Significant channel adjustments often occur during flood seasons in the Lower Yellow River (LYR), and it is a challenging work to accurately simulate the morphodynamic processes in the LYR using numerical models. A comparison of two morphodynamic models (Delft3D and 2DLLCDM) for the LYR is presented herein to identify critical improvements for these models. The concepts of these models are first compared with each other. The models were then used to simulate the processes of flood routing, sediment transport, and morphological changes occurring in a braided reach of the LYR. The differences were investigated between the simulated results from these models and corresponding field measurements, and the results indicate that: (1) the hydrodynamic processes calculated by both models agree closely with the measurements if an appropriate Manning’s roughness coefficient is used; (2) the concentrations of suspended load at the downstream boundary calculated by the models agree reasonably with the observed data; and (3) the predicted cross‐sectional profiles obtained from these models do not correspond well with the measurements. Based on these findings, the weak aspects of the models are clarified, and three critical improvements are recommended, including: (1) the development of roughness predictor; (2) the refinement of graded sediment transport capacity formulation; and (3) the consideration of bank erosion module. These improvements need to be implemented in the future.