综合考虑减排效益的污染物总量分配方法研究

如何在目标总量控制和容量总量控制间找到契合点,使总量控制既体现环境改善需求,又能促进环保基础设施建设和经济调控目标的实现成为当前的研究重点。基于目标总量控制,探索一种综合考虑减排效益的污染物总量分配方法,构建了以人口、GDP、水资源量、水环境容量和环保投资作为评价指标的环境基尼系数最小化模型,并将其应用于内蒙古自治区COD总量的优化分配。结果表明,与初始分配相比,优化分配后的环境基尼系数总和下降了0.85%,优化后的分配方案更公平、合理。在优化分配过程中,各评价指标间互相制约,较好提高了最终分配结果的科学性和可操作性。     

湖北省畜禽养殖污染现状及总量控制

通过畜禽产排污系数以及2011年湖北省的统计数据,估算出湖北省2011年畜禽养殖业畜禽粪便总量及COD、氮、磷的产生量,分析了污染物对环境污染的情况,并对湖北省畜禽养殖的环境容量和污染风险进行了初步评估。结果表明,2011年湖北省畜禽的粪便总量为8 479.8万t,主要分布在襄阳市、黄冈市、孝感市。全省粪便耕地负荷为16.2 t/hm~2/a,警报值为0.54,分级级数为II,对环境构成污染的威胁为"稍有"。全省氮、磷的耕地负荷分别为157.9 kg/hm~2/a、24.5 kg/hm~2/a,其中,鄂州市、黄冈市均超过欧盟限量标准(氮170 kg/hm~2/a、磷35 kg/hm~2/a)。2011年湖北省的实际养殖总量分别为7 868.5万头猪当量(N)、9 725.3万头猪当量(P),都超过畜禽50%环境容量(为4 599.4万头猪当量(N),7 161.1万头猪当量(P)。除了荆州市外,其他大部分地区的实际养殖数量都超过50%环境容量,这些地区应该严格控制畜禽的养殖数量并同时做好污染物消减措施。     

Production disruption management for R/M integrated supply chain using system dynamics methodology

The impacts of production disruption in Remanufacturing/Manufacturing (R/M) integrated supply chain on the sales and the methods of production disruption management were studied. A system dynamics model for the R/M integrated supply chain with production disruption was improved by system dynamics methodology. The numerical examples were shown to illustrate the simulation results. The impacts of different recovery times of production disruption on the sales were presented. In order to mitigate the disruption risks and ensure the sales at the needed sales ratio, the methods for setting multi-echelon inventory levels before the occurring of the production disruption and the methods for making back-up plans after the production disruption occurs were given.     

Impact of incorporating customer preference in sustainable remanufacturing of commercial returns

This paper investigates optimum production parameters for a reverse supply chain for manufacturing of primary products and remanufacturing of commercial returns (products returned by customers for refund or exchange). The market for the product consists of two categories, the primary and remanufactured products. The demands for these markets are independent and considered to be random variables following a normal distribution function. The approach presented in this work differs from many previously published works because the acceptability of products varies among customers. The interaction between the designed quality and variable customers’ preferences determines the likelihood of a product being returned. Two major decision variables targeted in this study are the production cycle time and the targeted quality for production of parts used in the product. Through an analytical formulation and numerical examples, a relationship between the total profit of the system and the two decision variables is developed and optimised. The analysis demonstrates that the total profit of the hybrid system could be increased significantly by targeting the optimum targeted (not necessarily the highest) values for quality of parts and the optimum cycle length. And this objective could be accomplished with significant gain with respect to sustainability and waste reduction.     

基于海外耕地投资的中国粮食供给安全研究

海外耕地投资是中国企业走出去,参与国际投资合作,获取耕地资源的重要手段。海外耕地投资能够通过国际合作和粮食进口,增加中国粮食供给,对国内粮食市场产生重大影响。基于柯布道格拉斯生产函数模型,对粮食播种面积、粮食成灾面积、农业机械总动力、农村用电量、粮食生产劳动力人数、有效灌溉面积、农业产品生产价格指数、农膜施用量、化肥施用折纯量、农药施用量等10个因素进行模型参数筛选,拟合中国粮食总产量关于粮食产量影响因子的函数关系,测算中国国内粮食生产总量;同时通过时间序列数据拟合出口粮、工业用粮、饲粮、种子粮以及粮食损耗的函数模型,测算中国国内粮食需求总量;在此基础上,通过情景分析法模拟不同情景下,中国在海外生产的粮食进入中国市场的比例,并以此作为影响中国粮食总产量的因子之一,构建关于中国粮食总供给的函数模型,分别测算不同情境中海外耕地投资生产的粮食对中国粮食供给安全的影响程度。研究结果表明,悲观情景和一般情境中,海外耕地投资生产的粮食对中国粮食安全的影响并不显著,乐观情境中中国海外耕地投资对中国粮食安全产生显著影响。进一步研究表明,当海外耕地投资粮食进口率超过75.3%时,海外耕地投资会对中国粮食供给安全产生显著影响。研究结论和建议:目前中国海外耕地投资对中国粮食安全的影响并不显著;中国的海外耕地投资能够直接或间接增加中国粮食供给,并且供给量显著提高,存在提高中国粮食供给率,保障国家粮食安全的巨大潜力,决策部门需要重视海外耕地投资,引导海外耕地投资良性发展。     

基于海洋生态产品的海岛旅游绿色发展经济激励额度评估

海洋生态系统为人类提供了环境友好型海产品、可持续海洋原材料、可持续基因资源、生态旅游产品、海景观房地产等海洋生态标签生态产品和减缓温室效应产品、净化环境要素产品、灾害控制产品等海洋关键环境要素生态产品。本文以海洋生态产品理论为基础,将海岛旅游绿色发展含义界定为旅游目的地环境友好型海产品的生产与消费,旅游目的地海洋生态系统与森林生态系统持续稳定地提供核心生态系统服务和旅游业低碳排放;并运用海洋渔业生态标签制度(MFELS)、生态系统服务付费(PES)和市场替换法(MRM),以山东省长岛县为案例地,以问卷调查和访谈调查获取的数据为基础,对海岛旅游绿色发展经济激励额度进行了评估。结果表明:(1)运用MFELS可获得0.207 0×10~8元/a的经济激励资金,其中山东省短途客源地游客、京津冀晋豫中途客源地游客和其他省市区长途客源地游客平均每人次分别承担13.26元、17.57元和17.56元;(2)运用PES可获得0.673 6×10~8元/a的经济激励资金,其中短途游客、中途游客和长途游客平均每人次分别承担43.44元、57.89元和54.42元;(3)运用MRM可获得0.154 1×10~8元/a的经济激励资金,其中各类游客平均每人次分别承担0.00元、14.59元和34.58元;(4)运用MFELS、PES和MRM可获得1.034 7×10~8元/a的经济激励资金,其中各类游客平均每人次分别承担56.70元、90.05元和106.56元。研究建议:各客源地游客承担海岛旅游绿色发展经济激励资金应考虑区域的差异性特征。     

A Comparison of Three Federal Datasets for Thermoelectric Water Withdrawals in the United States for 2010

Historically, thermoelectric water withdrawal has been estimated by the Energy Information Administration (EIA) and the U.S. Geological Survey's (USGS) water‐use compilations. Recently, the USGS developed models for estimating withdrawal at thermoelectric plants to provide estimates independent from plant operator‐reported withdrawal data. This article compares three federal datasets of thermoelectric withdrawals for the United States in 2010: one based on the USGS water‐use compilation, another based on EIA data, and the third based on USGS model‐estimated data. The withdrawal data varied widely. Many plants had three different withdrawal values, and for approximately 54% of the plants the largest withdrawal value was twice the smallest, or larger. The causes of discrepancies among withdrawal estimates included definitional differences, definitional noise, and various nondefinitional causes. The uncertainty in national totals can be characterized by the range among the three datasets, from 5,640 m³/s (129 billion gallons per day [bgd]) to 6,954 m³/s (158 bgd), or by the aggregate difference between the smallest and largest values at each plant, from 4,014 m³/s (92 bgd) to 8,590 m³/s (196 bgd). When used to assess the accuracy of reported values, the USGS model estimates identify plants that need to be reviewed.     

The changing face of the Mary Valley: considering the fairness,sustainability and resilience of the agricultural system in a peri-urban setting

Agricultural systems around the world are being severely impacted by changing climate, extreme weather events, urbanisation and neo-liberal (free market) policies. Yet, there are currently few studies on the experiences of those affected by these compounding pressures captured at the local scale. Experiences of adaptive responses – along with recommendations for transformations of the agricultural systems provided by those working in local-level settings – have also not been captured. Yet, such responses provide valuable insights into what can be done, and what needs to be done, to bring about a more equitable and sustainable food system. In this paper, we draw upon the opinions and experiences of those involved in food production and distribution in the historically abundant, peri-urban, region of the Mary Valley, Queensland, Australia. Underpinning the practical and strategic recommendations made by participants is a need for supermarket and government policies to appropriately reflect the immense value of small-scale farmers in sustaining rural communities and enhancing the resilience and sustainability of Australia’s food security. Importantly, our participants in this case study location reiterate that the impacts of climate change are manageable if the farming business is able to generate enough profit to absorb the costs of preparation and recovery from disasters.     

Reconciling food and bioenergy feedstock supply in emerging economies: Evidence from Jiangsu Province in China

This study takes the perspective of emerging economies as an independent group to answer the question of how to reconcile food supply and bioenergy feedstock provision, a critical topic in bioenergy research. While much of the literature has covered this issue, the role of emerging economies has rarely been explored. Due to their transitional status in the world economy, solutions from this group can facilitate the diffusion of modern bioenergy from industrialized countries to least developed ones. This paper uses Jiangsu Province in China as a case study to analyze its local practice on the reconciliation between food and bioenergy. Local experience reveals that the key is the use of cellulosic biomass, whose sources are straws of food crops on arable lands and energy crops on reclaimed mudflats. To ensure a sustainable provision of cellulosic biomass, it is necessary to involve the entire bioenergy supply chain consisting of smallholder farmers, haulers and bioenergy plant operators. For the management of the supply chain, we compare two options, “Multiple to Multiple” and “Multiple to One”, where the second option is more adequate to shape a long-term stable relationship between biomass suppliers and consumers and thus facilitate the introduction of energy crops.     

A City Wide Assessment of the Financial Benefits of Rainwater Harvesting in Mexico City

We assess the potential financial benefits of rooftop rainwater harvesting (RWH) in Mexico City from the perspective of property owners and entrepreneurs. A bottom‐up approach was followed by evaluating RWH at individual buildings and aggregating the results to a borough/city level. We consider sector‐specific water demands, potable and nonpotable uses, and user‐specific water tariffs. We find that RWH is economically most beneficial for nondomestic users rather than for small domestic users, who are often the target of RWH interventions. Based on a net present value analysis, a potable RWH system is not favored for most domestic users under the current subsidized municipal water tariff structure. Our analysis only considers capital and maintenance expenses, and not other benefits related to increased access to water and reliability, or social benefits from a switch to a RWH system. If the initial capital expense for RWH is partly financed by transferring the water subsidy to an entrepreneur, then RWH becomes financially attractive for a wide range of domestic users. To improve water access in Mexico City, RWH is attractive in the most marginalized boroughs where water use is currently lower and precipitation is higher. For domestic users relying on trucked water, RWH can have great financial benefits. Our approach provides quantitative data with high spatial specificity, highlighting the places and types of users that would benefit most from RWH.