Approach of technical decision-making by element flow analysis and Monte-Carlo simulation of municipal solid waste stream

This paper deals with the procedure and methodology which can be used to select the optimal treatment and disposal technology of municipal solid waste （MSW）, and to provide practical and effective technical support to policy-making, on the basis of study on solid waste management status and development trend in China and abroad. Focusing on various treatment and disposal technologies and processes of MSW, this study established a Monte-Carlo mathematical model of cost minimization for MSW handling subjected to environmental constraints. A new method of element stream （such as C, H, O, N, S） analysis in combination with economic stream analysis of MSW was developed. By following the streams of different treatment processes consisting of various techniques from generation, separation, transfer, transport, treatment, recycling and disposal of the wastes, the element constitution as well as its economic distribution in terms of possibility functions was identified. Every technique step was evaluated economically. The Mont-Carlo method was then conducted for model calibration. Sensitivity analysis was also carried out to identify the most sensitive factors. Model calibration indicated that landfill with power generation of landfill gas was economically the optimal technology at the present stage under the condition of more than 58% of C, H, O, N, S going to landfill. Whether or not to generate electricity was the most sensitive factor. If landfilling cost increases, MSW separation treatment was recommended by screening first followed with incinerating partially and composting partially with residue landfilling. The possibility of incineration model selection as the optimal technology was affected by the city scale. For big cities and metropolitans with large MSW generation, possibility for constructing large-scale incineration facilities increases, whereas, for middle and small cities, the effectiveness of incinerating waste decreases.     

陕西入境旅游流外向扩散的数量化分析

在分析旅游流研究现状的基础上,以1999-2009年<中国旅游统计年鉴>、<入境游客抽样调查资料>为主要数据来源,以陕西入境旅游流外向扩散为研究对象,选取陕西入境旅游流外向扩散的15个典型旅游省市,借助SPSS、Excel等统计软件,从流量变化、流入指数等方面对陕西入境旅游流外向扩散进行数量化分析.结果表明,陕西入境旅游流主要流向上海、北京、重庆、四川和广西等经济发达地区或具有垄断性旅游资源的省市.研究结果为各省市入境旅游业区域联合发展,调整旅游产业结构提供依据.     

汶川地震前成都市避难场所应急能力评估

为判断地震避难场所紧急避难能力是否满足居民灾后紧急避难阶段的需求,提出基于L-A模型的避难场所应急能力评估方法。该方法充分考虑紧急避难场所容纳能力、居民空间分布状况、紧急疏散路径因素,采用空间网络分析方法确定避难场所服务范围,将区域未能接纳人数及地震避难场所利用率作为避难场所评估分析的重要因素,并综合运用GIS技术实现评估分析的可视化。最后以成都市现有避难场所布局为例进行分析,结果表明:在震后紧急避难阶段成都中心城区有一定数量的人群未能安全避难且紧急避难场所资源分布不均衡。     

中国资源型城市转型发展的政策演变与效果分析

本文总结了中国20多年来关于资源型城市转型发展政策演变和不同阶段的转型发展重点,并分析了推进资源型城市转型发展的成效。主要结论如下：（1）中国资源型城市转型发展政策近二十年来的发展演化路径,基本遵循了问题导向和目标导向相结合的发展逻辑,经历了从“行政干预”“行政引导”到“综合治理”的变迁,国家角色不再以单一化的行政干预方式出现,而是以国家、市场与社会的复合型关系系统推进政策治理,施策对象逐步扩大,施策领域呈现精细化、专业化的演化特征。综合来看,政策演化大致可分为三个阶段,即解困阶段、分类治理阶段和高质量发展阶段。（2）当前国家已经形成了以资源枯竭城市转型发展、资源富集城市创新发展、独立工矿区改造提升和采煤沉陷区综合治理为重点的“四位一体”的发展政策框架。从解决资源枯竭城市衰退问题入手,重点关注两类特殊困难地区,同时面向未来规避资源富集地区发展路径依赖,构成了全方位的政策引导体系。（3）各资源型城市充分利用当地优势和发展基础,初步形成了特色化的转型发展模式。（4）在新时期资源型城市面临着碳减排任务大、经济增长乏力、特殊地区发展困难等严峻挑战,亟需全力破解重点问题,推进可持续发展进程。     

低碳城市的CO2与PM2.5减排协同效应分析

将基于卫星遥感数据的CO₂与PM_2.5纳入统一研究框架,运用多期双重差分等方法,在城市尺度上分析评估2007～2019年中国低碳城市政策对CO₂减排与PM_2.5污染控制的协同效应及其影响机制.研究发现:低碳城市CO₂与PM_2.5减排的协同效应十分显著,低碳政策使试点城市的CO₂排放量和大气PM_2.5浓度分别下降3.2%和0.74%,且结论在一系列稳健性检验后依然成立.机制分析表明,改善公共交通环境是低碳城市建设实现协同效应的最主要途径.低碳城市政策的协同效应存在地区差异,经济发展水平高、产业结构水平高的城市以及非资源型城市的协同效应更为显著.对此,应充分发挥协同效应,进一步加快低碳城市建设,实现CO₂和PM_2.5等大气污染物协同治理.     

大连北三市土地利用景观格局及其生态环境效应

以大连市北部的县级市瓦房店市、普兰店市和庄河市为研究区,引用2005年土地利用矢量数据,选用生态意义较明确的景观特征指数,对大连北三市土地利用景观格局及其生态环境效应进行比较分析。揭示土地利用景观格局对生态环境的影响。     

环境规制破解资源诅咒的异质效应

基于2013~2018年我国资源型城市的面板数据,采用变系数模型、中介效应模型,分析环境规制对资源诅咒的破解效果以及经由技术、结构、外贸对资源诅咒的破解路径.研究发现,衰退型、再生型资源城市的环境规制有利于破除资源诅咒;提升技术水平是破解资源诅咒的主要方式;成长型资源城市的环境规制不利于技术提升;成熟型资源城市的环境规制呈现促进资源产业占比的趋势;衰退型资源城市的环境规制加剧了资源产业对其他行业的挤出;再生型资源城市的环境规制尚不能通过优化产业与贸易结构实现显著的经济促增效果.     

黄河北徙与北宋城市适应方式探析

黄河变迁史上的第三次大改道导致黄河突发北徙,彻底改变了泛滥区城市的自然和人文环境,是开展复杂人地耦合系统研究的理想区域。利用水平横剖面法、数理统计与GIS手段相结合的方法,探索黄泛城市的数目、时空变化特征和适应性类型。结果表明：（1）黄河7个行河期的决溢泛滥,产生29座受灾城市;（2）受灾城市总体分布广泛,但又相对集中分布在黄河决口所形成的洪积扇顶部附近,地势低洼的冀中平原以及黄、御等河流交汇处;（3）黄泛城市主要呈现出避河患迁城、因河患省并、原址加固防御、直接湮废四种适应性类型,以避河患迁城型居多,占45%;（4）朝廷政策和城市规模是影响城市在黄河突发灾害下的空间分异和适应性举措的重要人文因素。黄泛区受灾城市具有重要的地方性保存和可持续发展演进模式。建议将其纳入“黄河流域生态保护和高质量发展”国家战略,作为讲好黄河故事的重要区域。     

Cocky and climate smart? Climate change mitigation and place-branding in three Swedish towns

Sustainable development has emerged as a distinctive marker of place identity in addition to traditional markers such as buildings and spectacles. Climate change mitigation as a potential place brand, indicating sustainable development, is in focus of this article, comparing such efforts in three Swedish towns. Based on documentary studies and interviews, it demonstrates how one town has been successful in branding itself as “the Greenest City in Europe”, whereas mitigation efforts in two other towns are barely known outside the town halls. In the first case, a combination of material, symbolic, and institutional components has been decisive in establishing a brand with internal and external legitimacy. This case highlights the importance of a dedicated network of influential actors and a potent governance structure visualising the will of a town to make its climate mitigation efforts known. Despite similar material conditions, the two others come short on the symbolic and the institutional dimensions, although they may still have a potential for future success in terms of mitigation both in practice and as a marker of identity.     

Constraints to implementation of sustainability indicator systems in five Asian cities

Contemporary studies on sustainability indicator systems (SISs) typically focus on the technical advancement of indicator construction, on qualitative impacts of indicator programmes and on impacts on governance, decision-making and sustainability as a social construct. Yet, their implementation so far has rarely been addressed, even though monitoring and the use of indicator results fall far behind the number of SISs developed. This study aims at the identification of requirements for the development of and constraints to the implementation of SISs in five Asian cities of developing countries. Interviews with local key actors are held, and a qualitative content analysis is carried out. Findings include evidence on the degree of indicator implementation in the case study cities, a hexagonal model for the classification of requirements and constraints, as well as general conclusions for barriers to the use of SISs.