循环经济发展评价的生态效率测算模型及应用

生态效率是基于可持续发展的思想,鉴于循环经济发展和实际环境的需求,通过构建循环经济发展评价的生态效率测算模型,针对循环经济中资源和环境2个重要方面,选择实例进行模型的应用。所选择研究对象经过测算,生态效率在"十一五"期间呈现波动上升,在5年时间增长了1.1倍,但仍处于末端治理为主的循环经济发展阶段,较为客观地反映了当地循环经济的发展轨迹。通过相关分析和说明,为循环经济发展评价提供生态效率分析这一方案选择。     

Performance of CH4MOD wetland for the case study of different regions of natural Chinese wetland

Reliable national estimates of CH₄ emissions from natural wetlands depend on model validation based on site observations. We therefore evaluated the performance of the CH4MOD_wetland model in simulating CH₄ emissions from 11 representative wetland sites in five regions of China. Model performance analysis showed that this method effectively simulates differences in the CH₄ fluxes between different sites and regions. The model efficiency for estimating the daily CH₄ fluxes in the northeastern China (NE), Inner Mongolia and northwestern China (NW), the North China plain and the Middle-Lower Yangtze Plain (E) and the Qinghai Tibetan Plateau (SW) was 0.51, 0.20, 0.52 and 0.65, respectively. The efficiency for estimating the annual mean CH₄ fluxes in southern China (S) was 0.99. Systematic negative deviation between the simulated and observed CH₄ emissions existed in all regions, especially in the NW region, which had a mean deviation (RMD) value of − 36.7%. On the national scale, the root mean square error (RMSE), the RMD, the model efficiency (EF) between the simulated and observed seasonal values were 28.7%, − 7.8% and 0.93, respectively. The CH₄ emissions showed the highest sensitivity to air temperature in the NE and SW regions, and to water table depth in the E region. Based on the sensitivity analysis, future climate warming and wetting are likely to increase the wetland CH₄ emissions at different levels in all regions of China.     

The separation of reinforced cementitious composites with a stream-line cutting tool

The paper provides a model for the cutting of reinforced concrete members with stream-line cutting tools. The model is an extended version of the energy model originally developed by Momber and Kovacevic (1995) for hydro-abrasive machining. The model allows the stepwise calculation of the energy absorbed during the cutting of the two parts of the compound - steel bar and matrix material. Hydro-abrasive cutting tests on different cementitious composites are performed in order to verify the numerical results. It is shown that the cutting process can be subdivided into four cutting stages whose locations depended on the energy locally available at the erosion site.     

Methodology for Developing Flood Rule Curves Conditioned on El Niño‐Southern Oscillation Classification1

Lee, Se‐Yeun, Alan F. Hamlet, Carolyn J. Fitzgerald, and Stephen J. Burges, 2011. Methodology for Developing Flood Rule Curves Conditioned on El Niño‐Southern Oscillation Classification. Journal of the American Water Resources Association (JAWRA) 47(1):81‐92. DOI: 10.1111/j.1752‐1688.2010.00490.x Abstract: Regional climate varies on interannual and decadal time scales that in turn affect annual streamflows, flood risks, and reservoir storage deficits in mid‐summer. However, these variable elements of the climate system are generally not included in water resources operating policies that attempt to preserve a balance between flood risk and other water resources system objectives. A methodology for incorporating El Niño‐Southern Oscillation (ENSO) information in designing flood control curves is investigated. An optimization‐simulation procedure is used to develop a set of ENSO‐conditioned flood control rule curves that relate streamflow forecasts to flood control evacuation requirements. ENSO‐conditioned simulated flood risk and storage deficits under current operating policy are used to calibrate a unique objective function for each ENSO classification. Using a case study for the Columbia River Basin, we demonstrate that ENSO‐conditioned flood control curves constructed using the optimization‐simulation procedure consistently reduce storage deficits at a number of interrelated projects without increasing flood risk. For the Columbia Basin, the overall improvements in reservoir operations are relatively modest, and (in isolation) might not motivate a restructuring of flood control operations. However, the technique is widely applicable to a wide range of water resources systems and/or different climate indices.     

Stochastic gravity models for modeling lake invasions

Freshwater aquatic systems in North America are being invaded by many different species, ranging from fish, mollusks, cladocerans to various bacteria and viruses. These invasions have serious ecological and economic impacts. Human activities such as recreational boating are an important pathway for dispersal. Gravity models are used to quantify the dispersal effect of human activity. Gravity models currently used in ecology are deterministic. This paper proposes the use of stochastic gravity models in ecology, which provides new capabilities both in model building and in potential model applications. These models allow us to use standard statistical inference tools such as maximum likelihood estimation and model selection based on information criteria. To facilitate prediction, we use only those covariates that are easily available from common data sources and can be forecasted in future. This is important for forecasting the spread of invasive species in geographical and temporal domain. The proposed model is portable, that is it can be used for estimating relative boater traffic and hence relative propagule pressure for the lakes not covered by current boater surveys. This makes our results broadly applicable to various invasion prediction and management models.     

崇明东滩沿海湿地生态系统健康评价

以生态系统健康及压力-状态-响应（PSR）模型作为研究方法，根据沿海湿地生态系统的特点，建立一套沿海湿地生态系统适用的健康评价指标体系。以现有研究数据和统计资料为基础，对长江口崇明东滩湿地进行单因子和综合评价，分别计算其健康度、压力综合指数和响应综合指数。揭示崇明东滩湿地的生态系统健康状况以及形成原因，并提出保护对策和可持续利用的相关建议。研究结果表明：①崇明东滩湿地生态系统的健康度、压力综合指数和响应综合指数分别为0．72、0．64和0．79，总体上仍处于一个较为健康的状态；②崇明东滩湿地生态系统目前的主要压力并不直接来源于土地围垦，而是来源于水环境污染和外来生物入侵。     

唐山市灾害源分布、综合成灾模型及对策管理程序框图

本文对编制唐山市灾害源分布、综合成灾模型及对策管理程序的功能和总框图给予了简要说明,并结合唐山市各种灾害的情况阐述了该程序建立各部分的子框图的重要性和关键技术。     

Ecosystem Manipulation Experimentation as a Means of Testing a Biogeochemical Model

2 concentration, and global or regional temperature change. Such model projections are frequently used as the basis or justification for public policy decisions and legislation. A substantial need has therefore arisen to test and substantiate the veracity of mathematical model projections. Unfortunately, environmental models can never be truly validated because natural systems are never closed and model solutions are always nonunique. Partial model confirmation is possible, however, and entails demonstration of agreement between prediction and observation. Experimental ecosystem manipulation provides one of the best, and in many cases only, available basis for model confirmation. The use and potential misuse of data from experimental ecosystem manipulations for model testing is explored using examples drawn from the application of an acid–base chemistry model, MAGIC. As model projections provide an increasingly important basis for public policy decisions, and as both the scientific questions and the models become increasingly complex, it will become critical to provide data from a suite of well-designed ecosystem manipulation experiments in order to evaluate the quality and uncertainty of those model projections and the models upon which they are based.