垃圾发电的技术进展和产业前景

我国目前各城市居民日均产生垃圾0．8～1．2公斤不等,我国城市垃圾年产生量约为1．5亿吨,而且还在以每年8％～10％的增长率增长。全国累计垃圾堆存量已经达到60多亿吨,侵占土地面积超过5万公顷,已有200多个城市陷入垃圾包围之中。根据我国环境部预测,2010年我国城市垃圾年产量将为1．52亿吨,2015年和2020年将达到2．1亿吨。虽然我国的垃圾发电刚刚起步,     

长江经济带典型锌冶炼园区不同固废处置模式生态效率研究

我国铜铅锌有色冶炼固废种类多、存量大,富含多种环境毒害元素如镉铬汞砷等,而目前固废末端处置方式单一,对其所含的大量铜铅锌银镍等有价金属组分也未能有效分离,固废污染防控与高效资源化利用问题突出,已成为制约产业绿色可持续发展的关键因素。以长江经济带典型铜铅锌综合冶炼基地为例,设置直接处理(情景1)、内部循环(情景2)和协同利用(情景3)三种锌冶炼固废处置情景模式,结合物质投入产出法、层次分析法与熵值法,构建资源能耗、环境风险、物质循环与经济效益的多维生态效率指标核算方法体系,对三种情景模式开展生态效率综合评估分析。结果表明,情景3因加强了锌冶炼固废在铜、铅冶炼系统间的协同转化,其生态效率综合评价指数最高,为0.2246,较情景1和情景2分别高出313.6%和25.5%;从资源能耗角度来看,情景2单位产品能耗最高,达0.3086;而从物质循环和经济效益角度来看,情景3固废综合利用率最高,达97.6%,铜铅锌三种有价金属回收率达97.2%,利润总额达48131.3万元;但在环境风险方面,尽管情景3固废中重金属污染排放减少1470.4 t/a,但废气中铅砷镉汞等重金属污染排放却比情景1增加了3倍...     

黄河流域国土空间碳中和度研究——以内蒙古段为例

基于全球气候治理背景以及黄河流域在我国生态文明建设中的重要地位,以黄河流域内蒙古段为例,通过情景分析法,建立改进的IPAT模型和集成生态圈模拟器IBIS,预测不同情景下2018-2060年研究区碳排放变化趋势和达峰情况,并结合对碳汇水平的模拟分析2060年碳中和实现进程。结果显示①在基准情景、节能情景、低碳情景和粗放情景下,黄河流域内蒙古段将分别于2040年、2035年、2030年和2050年实现碳达峰,峰值碳排放量分别为12209万t、11213万t、9784万t和17635万t;②在IPCC RCP2.6和RCP6.0气候变化情景下,黄河流域内蒙古段的陆地生态系统整体分别呈现出碳汇和碳源的不同效应,净初级生产力分别为1533万t和-506万t;③综合能源消费碳排放和碳汇水平,在RCP2.6气候情景下,若碳排放选取基准、节能、低碳和粗放情景,则2060年黄河流域内蒙古段分别可实现碳中和进程的18.42%、22.37%、34.46%和9.90%;在RCP6.0气候情景下,由于研究区陆地生态系统呈现出碳源效应,因此难以对碳中和进程的推进做出贡献。可见,对于黄河流域内蒙古段而言,需要科学制订碳达峰、碳中和目标实现时间,未来要更进一步保护重要碳汇生态系统,提升固碳增汇能力;调整能源消费结构,增加可再生能源发展规划指标;构建碳排放权交易市场,促进碳指标流动;制定土地利用碳排放标准,优化国土空间格局。     

广州市固体废物管理与处置现状及对策

分析广州市工业固体废物、危险废物、生活垃圾、余泥渣土等管理与处置现状,揭示广州市现有固体废物管理处置存在的主要问题,并提出对策建议。分析表明,近年广州市工业固体废物年产生量呈上升趋势,工业固体废物排放量有所回升;1999年危险废物实现零排放,医疗垃圾的集中处置率达100%;居民生活垃圾清运处置率达100%。生活垃圾分类收集率为26%,加快了垃圾填埋场的改造和建设;余泥渣土的管理逐步规范化,市区余泥渣土排放工地申领排放证率保持100%。存在问题包括管理上欠长远规划、处置技术落后、二次污染、资源回收率低、资金匮乏等,尤其缺乏对危险废物、废旧电池的集中处置机构。     

住区形态变迁与居民通勤能源消费的关系

快速城市化和城市扩张引发了住区形态的变迁,但形态变迁与居民通勤能源消费关系还不明确,如何通过城市的可持续公共管理政策来控制城市住区形态变迁过程下通勤能源消费及其温室气体排放有着重要意义.以厦门为例,通过土地利用与交通耦合模型TRANUS的情景分析研究了住区形态的变迁对人口、工作以及土地消费空间分布的影响,进而分析了不同情景下通勤能源消费和温室气体排放的水平.结果表明: 基准情景下交通出行早高峰能源消费总量为54.35 tce,CO₂排放为119.12 t;住区形态变迁情景下,通勤能耗和CO₂排放同比基准情景均增加12%;通过适当的土地利用、交通和经济政策的实施,通勤能源消费与CO₂排放同比基准情景减少7%,说明城市公共政策能够有效地控制住区形态变迁背景下通勤能源消费和温室气体排放的增长.     

厦门海湾型城市发展累积生态效应动态评价

港湾地区的快速城市化使港湾湿地生态系统及其生产功能和服务功能发生急剧改变并在时间和空间上产生累积效应。以具有典型意义的厦门港湾湿地为研究对象，采用系统动力学方法，定性分析系统因子因果反馈关系，筛选港湾湿地水动力环境、水质环境、生物生态环境、地形地貌、景观环境作为厦门海湾型城市发展的累积生态效应指示因子。通过调整模型的相关政策变量及组合，仿真模拟了不同发展策略下厦门港湾湿地的累积生态效应，并结合灰色评估模型对累积生态效应进行量化，得出不同发展策略的累积生态效应指数，并对模型进行了模型验证与敏感性分析。设计三大未来发展情景，即基准情景（BS）、发展规划情景（S1）、生态城市发展情景（S2）。模型模拟结果表明：基准情景下2020年厦门城市发展对港湾湿地的累积生态效应指数为0.61;发展规划情景下对港湾湿地的累积生态效应指数为0.37;生态城市发展情景下对港湾湿地的累积生态效应指数为0.30，相对基准情景下可减少累积生态效应50%，建议厦门市按照海湾型生态城市模式进行发展。     

城市住区形态时空模拟——以厦门岛为例

住区形态变迁受到人口迁移、住区满意度和低碳城市发展政策等因素的限制,常用的土地利用模型难以有效表征这一相互制约关系,使得这方面的研究仍然相对不足。通过耦合SD模型和CLUE-S模型,充分发挥了2个模型在宏观情景模拟和微观土地分配上的优势,模拟了住区、人口、住区碳足迹等制约因素的相互关系,为住区形态变迁时空模拟提供了一种有效的方法。以厦门岛为例,根据研究区历史统计数据、问卷调查数据构建了住区形态变迁SD模型,模拟了基准情景、紧凑情景和低碳情景3种不同发展情景下各类住区类型的用地需求,结合CLUE-S模型预测了3种情景下2009年—2020年各类住区类型的用地范围。结果表明,基准年住区类型Ⅰ、Ⅱ、Ⅲ三者占地面积比例为1∶1.18∶0.83,基准情景下2018年住区类型Ⅲ将成为主要的住区类型。低碳发展和紧凑发展是惯性发展的两种极端情况,体现在总住区面积、人均住宅面积和人均碳足迹大小的变化,但是对厦门岛总人口数量的影响并不大。根据目前厦门的发展趋势,低碳发展情景与紧凑发展情景相结合可能更靠近现实。在空间分布上,住区类型Ⅰ未来不再新建;住区类型Ⅱ遵循现状继续发展的惯性较大;住区类型Ⅲ分布在征地成本相对较低的区域。模型模拟结果能够为住区用地规划、住区发展对策建议提供有效的技术支撑。     

基于土地利用模拟预测模型分析的城市绿色空间发展多情景模拟及建设时序研究——以湛江市中心城区为例

城市绿色空间是未来中国城镇战略发展的重要生态空间载体。城市中心城区的绿色空间生态系统服务价值可作为未来城市生态空间规划的重要依据。生态服务系统之间的权衡或协同关系可通过不同土地利用方式和利用强度表征显现。通过对湛江市中心城区绿色空间应用土地利用模拟预测(PLUS)模型进行自然发展情景与国土空间规划情景双情景下2035年土地利用变化模拟,采用当量因子法及热点分析对生态系统服务价值及其高低值在空间上的聚集程度进行分析,与人类活动强度空间分布进行叠置,得出国土空间规划政策下湛江市中心城区城市绿色空间发展优先级分区,优先化解建设用地与绿色空间发展矛盾,为规划政策提供空间政策的量化数据基础,为其可行性实施、时序安排及预期结果提供数据支撑与建议。结果表明：(1)规划政策情景与自然发展情景未来土地利用模拟结果相比,耕地、林地增多,整体水域得到有效保护,建设用地蔓延受到抑制。(2)生态系统服务价值在2035年规划政策情景>2020年实际情景>2035年自然发展情景,分别约为12.22亿元、11.89亿元、10.53亿元,规划政策情境下生态系统服务价值总量较自然发展情景下提升约1.69亿元,...     

基于SWAT模型的乌鲁木齐河上游土地利用和气候变化对径流的影响

选用SWAT分布式水文模型,定量分析了乌鲁木齐河流域土地利用与气候变化对径流的影响,采用情景分析方法设置3类情景,对变化环境下的流域径流进行了预测。以R~2、NSE和PBIAS等3个参数评价了模拟的拟合度,不确定性。结果表明:1)在模型校准期和验证期R~2分别为0.89和0.75,NSE分别为0.84和0.74,PBIAS在18%—23%范围内,说明SWAT模型在乌鲁木齐河上游径流模拟中具有较好的适用性;2)综合型情景模拟分析得出,研究区气候变化对径流的影响强度大于土地利用变化的影响强度。土地利用和气候共同引起流域年均径流量减少1.41 m~3/s,土地利用变化引起年均径流量减少0.04 m~3/s,气候变化引起年均径流量减少1.37 m~3/s;3)极端土地利用情景模拟分析得出,草地情景的年均径流增加0.1 m~3/s,林地情景的年均径流量减少0.58 m~3/s;4)气候变化情景模拟分析得出,流域径流量与降水变化呈正相关关系,与气温变化呈负相关关系。降水量增加10%和20%时,年均径流量增加3.05 m~3/s和4.02 m~3/s。当降水量减少10%和20%时,年均径流量减少0.93 m~3/s和2.25 m~3/s。气温升高1℃和2℃时,年均径流量减少2.71 m~3/s和3.02 m~3/s。在气候变化环境下,需要重视降水和气温的预测,应通过优化土地结构来减缓气候变化的水文效应。     

生命周期评价方法在城市生活垃圾管理中的应用研究述评

结合城市生活垃圾管理系统特征,系统归纳基于生命周期评价(Life cycle assessment,LCA)方法的城市生活垃圾管理模型的发展现状,并对LCA方法在城市生活垃圾管理中的实践以及在我国开展城市生活垃圾管理LCA研究的应用前景进行评述。分析表明,LCA是城市生活垃圾管理领域的重要工具之一,基于LCA方法的城市生活垃圾管理模型在全生命周期环境影响评价与识别、处置工艺选择与改进、可持续生活垃圾管理决策支持等方面具有十分重要的应用价值。中国在本地化生活垃圾管理系统LCA模型开发、清单数据库和评价指标体系构建以及与其他研究方法集成等方面面临挑战。     

A bottom-up modeling of metabolism of the residential building system in China toward 2050

This study predicted the metabolic process of the residential building system in China toward 2050 by addressing the detailed provincial patterns and urban–rural disparity and the characterizing metabolisms of building materials in detail. The results show that after a rapid growth during 1980–1990, the in-use stocks of residential buildings in China are expected to slow down in around 2030, reaching 75 billion m² in 2050. Urban regions will account for 80% of total stocks, and provinces in the eastern and southern coastal areas will have the largest share. As demolition lags construction, the end-of-life residential buildings will continue to grow steadily with huge urban–rural and provincial differences, reaching 1.4 billion m² by 2050. Regarding the metabolism of building materials, the inflow of most materials will decrease after 2030, while the outflow will increase steadily toward inflow. Based on the recycling outlook of construction and demolition waste and the corresponding environmental benefit, it is indicated that under the Chinese government's ambitious planning and vigorous promotion, prior to the middle of the century, the building system has the potential to transition to a sustainable future that meets residents’ housing needs with a remarkable decreasing input of raw materials thereby notably decreasing pressures on the environment, which will significantly benefit the goal of carbon neutrality in China.     

Dynamic Material Flow Analysis for Strategic Construction and Demolition Waste Management in Beijing

Of all materials extracted from the earth's crust, the construction sector uses 50%, producing huge amounts of construction and demolition waste (CDW). In Beijing, presently 35 million metric tons per year (megatonnes/year [Mt/yr]) of CDW are generated. This amount is expected to grow significantly when the first round of mass buildings erected in the 1990s starts to be demolished. In this study, a dynamic material flow analysis (MFA) is conducted for Beijing's urban housing system, with the demand for the stock of housing floor area taken as the driver. The subsequent effects on construction and demolition flows of housing floor area and the concurrent consumption and waste streams of concrete are investigated for Beijing from 1949 and projected through 2050. The per capita floor area (PCFA) is a key factor shaping the material stock of housing. Observations in Beijing, the Netherlands, and Norway indicate that PCFA has a strong correlation with the local gross domestic product (GDP). The lifetime of dwellings is one of the most important variables influencing future CDW generation. Three scenarios, representing the current trend extension, high GDP growth, and lengthening the lifetime of dwellings, are analyzed. The simulation results show that CDW will rise, unavoidably. A higher growth rate of GDP and the consequent PCFA will worsen the situation in the distant future. Prolonging the lifetime of dwellings can postpone the arrival of the peak CDW. From a systematic view, recycling is highly recommended for long‐term sustainable CDW management.     

Life-cycle assessment and cost analysis of residential buildings in South East of Turkey: part 2—a case study

Purpose

Residential buildings play an important role in consumption of energy resources. About 40 % of all primary energy is used in buildings all over the world. This paper is the second part of the study on the life-cycle energy (LCEA), emissions (LCCO₂A) and cost (LCCA) assessment of two residential buildings constructed in urban and rural areas.

Methods

In the first part, the methodology, formulations and procedure for such a comprehensive analysis are provided, while this paper provides an application of the methodology that considers two actual buildings located in Gaziantep, Turkey. The proposed model focused on building construction, operation and demolition phases to estimate energy use, carbon emissions and costs per square meter over a 50-year lifespan. The optimum thickness of insulation used to reduce energy consumption and emissions per square meter is determined.

Results and discussion

It is found that the operating phase is dominant in both urban and rural residential buildings and contributes 87–85 % of the primary energy requirements and 88–82 % of CO₂ emissions, respectively. Life-cycle greenhouse gas emissions were 5.8 and 3.9 tons CO₂ eqv. for BT1 and BT2, respectively. It is calculated that the life-cycle energy consumption and CO₂ emissions of the residential buildings can be reduced by up to 22.8 and 23.4 %, respectively, by using a proper insulation material for the external walls. The life-cycle cost, consisting of mortgage, energy, maintenance, service and demolition payments are calculated to be 7.28 and 1.72 million USD for BT1 and BT2, respectively.

Conclusions

Building envelope developments, such as better wall insulation, provide noteworthy potential energy savings and contribute to the reductions from cooling and space heating. Therefore, primary strategies and technologies needed for efficient buildings include optimal insulation of external walls. The economic insulation thickness of the residential buildings in Gaziantep is determined to be 80 mm by using a life-cycle cost analysis. The results show that because of the differences in building structures and living standards, life-cycle energy intensity and CO₂ emissions in urban residential buildings are 29 and 25 % higher than in rural conditions.

     

LCA of concrete and steel building frames

The effects on the external environment of seven concrete and steel building frames representative of present-day building technology in Sweden were analysed using LCA methodology. Objects of the study included frame construction and supplementary materials. Several-storey offices and dwellings were studied. The functional unit was defined as one average m² of floor area during the lifetime of the building. Inventory data were elaborated for concrete and steel production, the building site, service life, demolition and final disposal. Parameters included were raw material use, energy use, emissions to air, emissions to water and waste generation. The inventory results were presented and evaluated as such, in addition to an interpretation by using three quantitative impact assessment methods. Parameters that weighed heavily were use of fossil fuels, CO₂, electricity, SO_x ² NO_x ² alloy materials and waste, depending on what assessment method was used. Over the life cycle, building production from cradle to gate accounted for about the same contribution to total environmental loads as maintenance and replacement of heat losses through external walls during service life, whereas demolition and final disposal accounted for a considerably lower contribution.     

Spatial analysis of urban material stock with clustering algorithms: A Northern European case study

A large share of construction material stock (MS) accumulates in urban built environments. To attain a more sustainable use of resources, knowledge about the spatial distribution of urban MS is needed. In this article, an innovative spatial analysis approach to urban MS is proposed. Within this scope, MS indicators are defined at neighborhood level and clustered with k‐mean algorithms. The MS is estimated bottom‐up with (a) material‐intensity coefficients and (b) spatial data for three built environment components: buildings, road transportation, and pipes, using seven material categories. The city of Gothenburg, Sweden is used as a case study. Moreover, being the first case study in Northern Europe, the results are explored through various aspects (material composition, age distribution, material density), and, finally, contrasted on a per capita basis with other studies worldwide. The stock is estimated at circa 84 million metric tons. Buildings account for 73% of the stock, road transport 26%, and pipes 1%. Mineral‐binding materials take the largest share of the stock, followed by aggregates, brick, asphalt, steel, and wood. Per capita, the MS is estimated at 153 metric tons; 62 metric tons are residential, which, in an international context, is a medium estimate. Denser neighborhoods with a mix of nonresidential and residential buildings have a lower proportion of MS in roads and pipes than low‐density single‐family residential neighborhoods. Furthermore, single‐family residential neighborhoods cluster in mixed‐age classes and show the largest content of wood. Multifamily buildings cluster in three distinct age classes, and each represent a specific material composition of brick, mineral binding, and steel. Future work should focus on megacities and contrasting multiple urban areas and, methodologically, should concentrate on algorithms, MS indicators, and spatial divisions of urban stock.     

Two Challenges for U.S. Irrigation Due to Climate Change: Increasing Irrigated Area in Wet States and Increasing Irrigation Rates in Dry States

Agricultural irrigation practices will likely be affected by climate change. In this paper, we use a statistical model relating observed water use by U.S. producers to the moisture deficit, and then use this statistical model to project climate changes impact on both the fraction of agricultural land irrigated and the irrigation rate (m³ha⁻¹). Data on water withdrawals for US states (1985–2005) show that both quantities are highly positively correlated with moisture deficit (precipitation – PET). If current trends hold, climate change would increase agricultural demand for irrigation in 2090 by 4.5–21.9 million ha (B1 scenario demand: 4.5–8.7 million ha, A2 scenario demand: 9.1–21.9 million ha). Much of this new irrigated area would occur in states that currently have a wet climate and a small fraction of their agricultural land currently irrigated, posing a challenge to policymakers in states with less experience with strict regulation of agriculture water use. Moreover, most of this expansion will occur in states where current agricultural production has relatively low market value per hectare, which may make installation of irrigation uneconomical without significant changes in crops or practices by producers. Without significant increases in irrigation efficiency, climate change would also increase the average irrigation rate from 7,963 to 8,400–10,415 m³ha⁻¹ (B1 rate: 8,400–9,145 m³ha⁻¹, A2 rate: 9,380–10,415 m³ha⁻¹). The irrigation rate will increase the most in states that already have dry climates and large irrigation rates, posing a challenge for water supply systems in these states. Accounting for both the increase in irrigated area and irrigation rate, total withdrawals might increase by 47.7–283.4 billion m³ (B1 withdrawal: 47.7–106.0 billion m³, A2 withdrawal: 117.4–283.4 billion m³). Increases in irrigation water-use efficiency, particularly by reducing the prevalence of surface irrigation, could eliminate the increase in total irrigation withdrawals in many states.     

Economic values and dominant providers of key ecosystem services of wetlands in Beijing,China

This study estimates the economic values of and the dominant contributors to five key ecosystem services of wetlands in Beijing, by using the wetland inventory data in 2014 and economic valuation methods. Results indicate that the 51,434 ha of wetlands in Beijing annually provide 2.07 billion m³ of flood regulation, 944.01 million m³ of water provision, 42,154 tons of chemical oxygen demand (COD) purification, 3.03 PJ of heat absorption, and 9587 ha of habitat. Their economic values are estimated to be 15.89 billion RMB, 1.19 billion RMB, 169 million RMB, 421 million RMB, and 1.08 billion RMB in 2014 (RMB: Chinese currency, US$1 = RMB 6.14), respectively. The total values of five key wetland ecosystem services reach 18.76 billion RMB. In addition, the reservoir and river wetlands in Miyun, Yanqing, Fangshan, Huairou, and Mentougou Districts contribute 78% of key ecosystem services, whereas the urban wetlands in Xicheng, Dongcheng, Haidian, Chaoyang, and Tongzhou Districts more conveniently serve densely local people, hence they should be given particular attentions. In this paper, we develop the valuation methods of wetland ecosystem services, and recommend diversified strategies, regulations, and programs to protect the remaining wetlands in Beijing. This work can also provide a reference for the valuating of wetland ecosystem services for other urban-rural areas.     

城市建筑群三维空间布局评价与优化——以厦门岛滨海地带为例

随着城市化进程的快速推进,城市建设带来了土地资源紧张,使得越来越多的城市向着高层化、立体化、智能化方向发展;城市建筑群三维空间的最优布局是城市集约化发展的基础条件。针对现阶段的城市建筑群三维空间布局存在一些不足,构建城市建筑群三维空间布局的评估方法体系。以厦门岛滨海地带为研究区,基于多源、多空间分辨率遥感影像数据,从建筑景观、热环境和视觉效果3个角度评价厦门岛滨海地带三维空间格局的现状;并总结城市三维空间布局优化发展模式;从建筑景观、热环境和视觉效果这三个角度提出了厦门岛滨海地带城市建筑三维空间的布局优化建议。三维空间布局评价的结果表明：（1）从建筑景观角度,不同功能建筑群与容积率关系：商业区容积率最高,其次是商品房居住区,文教区占地面积广且建筑密度低,民房居住区的容积率是最低的但其建筑密度高;（2）从热环境角度,考虑温度因素,建筑群建筑密度过大、建筑层数过多都会造成温度较高;（3）从视觉效果角度,研究区具有宽广的视觉空间和宽阔海面,与以山体为背景的天际线形成了鲜明的对比。此外,提出优化低层建筑和合理布局中高层建筑的建筑容积率,设计建筑形态多样化和优化天际线前景、中景和背景的层次布局,可提高厦门岛的城市建筑群三维空间布局。本研究可为厦门岛滨海地带的城市建筑群三维空间布局优化提供基础数据支持与技术支撑,为城市土地资源规划等政府部门提供决策支持,对城市建筑群三维空间的合理利用和景观优化具有重要意义;也为我国其他城市的可持续发展研究提供新的科学理论依据和参考借鉴。     

Tracking Construction Material over Space and Time: Prospective and Geo‐referenced Modeling of Building Stocks and Construction Material Flows

Construction material plays an increasingly important role in the environmental impacts of buildings. In order to investigate impacts of materials on a building level, we present a bottom‐up building stock model that uses three‐dimensional and geo‐referenced building data to determine volumetric information of material stocks in Swiss residential buildings. We used a probabilistic modeling approach to calculate future material flows for the individual buildings. We investigated six scenarios with different assumptions concerning per‐capita floor area, building stock turnover, and construction material. The Swiss building stock will undergo important structural changes by 2035. While this will lead to a reduced number in new constructions, material flows will increase. Total material inflow decreases by almost half while outflows double. In 2055, the total amount of material in‐ and outflows are almost equal, which represents an important opportunity to close construction material cycles. Total environmental impacts due to production and disposal of construction material remain relatively stable over time. The cumulated impact is slightly reduced for the wood‐based scenario. The scenario with more insulation material leads to slightly higher material‐related emissions. An increase in per‐capita floor area or material turnover will lead to a considerable increase in impacts. The new modeling approach overcomes the limitations of previous bottom‐up building models and allows for investigating building material flows and stocks in space and time. This supports the development of tailored strategies to reduce the material footprint and environmental impacts of buildings and settlements.