Climate Change Impacts on Local Flood Risks in the U.S. Northeast: A Case Study on the Connecticut and Merrimack River Basins

This study investigates the potential impacts of climate change on future flows in the main stem of the Connecticut and Merrimack rivers within Massachusetts. The study applies two common climate projections based on (Representative Concentration Pathways), RCP 4.5 and RCP 8.5 and downscaled gridded climate projections from 14 global climate models (GCMs) to estimate the 100‐year, 24‐h extreme precipitation events for two future time‐periods: near‐term (2021–2060) and far‐term (2060–2099). 100‐year 24‐h precipitation events at near‐ and far‐term are compared to GCM‐driven historical extreme precipitation events during a base period (1960–1999) and results for RCP 8.5 scenario show average increases between 25%–50% during the near‐term compared to the base period and increases of over 50% during the far‐term. Streamflow conditions are generated with a distributed hydrological model where downscaled climate projections are used as inputs. For the near‐term, the medians of the GCMs using the RCP 4.5 and RCP 8.5 suggest 2.9%–8.1% increases in the 100‐year, 24‐h flow event in the Connecticut and an increase of 9.9%–13.7% in the Merrimack River. For the far‐term, the medians of the GCMs using the RCP 4.5 and RCP 8.5 suggest a 9.0%–14.1% increase in the Connecticut and 15.8%–20.6% for the Merrimack River. Ultimately, the results presented here can be used as a guidance for the long‐term management of infrastructures on the Connecticut and Merrimack River floodplains.     

应对气候变化与生态环境保护协同政策研究

应对气候变化与生态环境保护协同是实现碳达峰目标和碳中和愿景、构建现代气候治理体系和治理能力的重要举措,构建实施协同政策十分关键,是统筹推进应对气候变化与生态环境保护的根本支撑。本文分析了应对气候变化与生态环境保护的协同关系,评估了应对气候变化与生态环境保护协同政策现状,分析了存在的主要问题,提出了协同政策的推进思路框架、重点方向、实施保障以及实施路线图。     

气候变暖对冻结期黑土碳氮循环关键过程及指标的影响

冬季土壤碳氮循环是全球生物地球化学循环的重要组成部分,对气候变暖的响应极为敏感.为更好地了解气候变暖对冻结期黑土碳氮动态的影响,本试验采用红外辐射仪模拟土壤增温,并进行了两种不同水平的增温研究（W1和W2）.结果表明,在冻结期（2019年11月至翌年1月）,与对照处理（C）相比,模拟增温使表层土壤温度（0 cm土壤温度）分别上升1.54℃（W1）和4.10℃（W2）,并显著增加了土壤含水量,这很可能是由于积雪融化造成的.两种增温水平均降低了积雪覆盖厚度、土壤冻结深度、土壤有机碳（SOC）含量及活性有机碳（LC）含量.而冻结期增温对黑土氮循环关键过程及指标的影响则相对更复杂,随着增温幅度的提升,硝态氮（NO₃^--N）含量显著降低、全氮（TN）含量及净氮硝化速率明显增加,而铵态氮（NH₄⁺-N）、总无机氮（TIN）含量及净氮矿化速率则显著地呈现出先增加后降低的趋势.气候变暖将给冻结期黑土带来更为温暖湿润的环境,并且由此引起的土壤碳氮含量及转化过程的变化将会对随后生长季植物和微生物群落的结构组成、生产力及碳氮循环等过程产生深远的影响.这为研究冻结期东北黑土碳氮循环机制提供了一定的科学依据.     

Greening the structural change process: ranking sustainability of countries in climate change

This paper proposes an analytical toolkit to measure the sustainability of industrialization across countries. Drawing from a methodology developed to analyze economic development as a process of modernization, it ranks countries on the basis of the emissions they produce and their stage of development. The proposed index penalizes environmental pressures taking into account the modernization level of a country. The paper also proposes an assessment of the environmental performance of countries at the same level of modernization. It introduces the notion of policy space as the difference between the best and worst environmental performer at a given level of modernization. An important finding of the paper is that the magnitude of the policy space is not homogenous across different levels of income and environmental targets.     

A sustainability index for small island developing states

This paper proposes a novel approach to measuring the progress of small island developing states (SIDS) towards sustainable development (SD) as set by the UN Sustainable Development Goals 2030. Currently, these goals do not provide adequate guidance on how countries might measure their progress towards sustainability. We use these goals and a subset of their targets to develop an index with concrete targets, through the use of pertinent sustainability indicators, that SIDS should aim to achieve a sustainable society. In addition to the three categorical pillars of SD (social, economic and environmental), we included the category Climate Change and Disaster Management (incorporating Disaster Risk Reduction). The basis of our decision is that the UN and the Intergovernmental Panel on Climate Change have both recognized the vulnerability of SIDS to both environmental hazards. Our index scores a total 70 individual indicators for the four categories to track the progress of a SIDS towards a sustainable society. Using the Caribbean nation, Republic of Trinidad and Tobago, as our SIDS case study, we report the average of the scores for each category to illustrate its progress towards sustainability. Overall Trinidad and Tobago is slowly progressing towards a more sustainably developed society. Our results show that the nation is only moderately successful regarding progress in three traditional pillars of SD, social, economic and environmental. However, Trinidad and Tobago scores poorly in the Climate Change and Disaster Management category and needs to improve in this area especially due to its vulnerability.     

Trees and rural households’ adaptation to local environmental change in the central highlands of Ethiopia

This study assesses the role of trees in adaptation strategies of rural households to local environmental change in the central highlands of Ethiopia. Change in tree cover was assessed by producing Land Use and Land Cover (LULC) maps using satellite remote sensing images, and household survey was conducted to generate socioeconomic data. The results show that tree cover has increased over the last 30 years, mostly in the form of eucalyptus woodlots around homesteads. Eucalyptus reportedly helps households pass through livelihood shocks and provide protection against negative effects of climate change and variability. Despite some concerns on the part of local agricultural experts that planting eucalyptus may affect future food production, farmers are converting their croplands into eucalyptus woodlots. We conclude that land use planning and proper allocation of land resource is important to improve local livelihoods while also supporting adaptation of communities to local environmental change in general and climate change in particular.     

COVID-19疫情期间成都市地面臭氧污染特征及气象成因分析

受COVID-19疫情影响,我国各地采取了一系列封锁管控措施,由此导致大气污染物排放强度降低.本文以成都市为例,分析了2020年上半年的气象条件和大气污染浓度特征,并重点对臭氧浓度变化及同期对比结果进行了细致分析.结果表明：①与2019年同期相比,除O₃外的5种污染物（NO₂、CO、SO₂、PM₁₀、PM_2.5）浓度均降低,降幅分别为13.60%、8.96%、6.30%、4.56%、1.80%,而O₃浓度却异常升高,升幅最大值分别出现在2月（35.1%）和5月（36.1%）.②2020年上半年,O₃浓度高值出现时间较2015—2019年提前,气象条件较有利于臭氧的生成.100 hPa和500 hPa位势高度为正距平,气温、日照时数较往年升高,相对湿度和降水量下降,以静小风为主.③2020年4月25日—5月6日臭氧污染持续时间长,主要是由于复工复产导致臭氧前体物排放增加,以及稳定的天气形势,使成都长时间处于高温（>30℃）、低湿（40%~60%）、静小风（1.3 m·s^-1）等不利扩散的气象条件下.气团后向轨迹和污染潜在源区表明研究区受到来自成都偏东一带及川南地区高污染气团短距离输送的影响.     

莆田地区一次臭氧污染过程分析

利用2018年7月28日—8月5日莆田地区4个环境监测站臭氧逐小时浓度观测资料、莆田国家气象站逐小时资料、莆田地区风廓线雷达站逐小时资料对7月29日—8月4日的臭氧污染过程进行分析.结果表明,除7月30日臭氧最大浓度为193 μg·m^-3外,其余日期莆田市监测站的臭氧浓度小时最大值均超过200 μg·m^-3.本次污染过程在气象条件上臭氧浓度与温度呈正相关,与湿度呈负相关,臭氧浓度与两者的相关系数绝对值均大于0.77.边界层上的偏西风和西南风在此次过程中表现出有利于本地区臭氧污染的形成和维持.结合污染物排放资料和后向轨迹分析表明,污染主要成因以外来源输送为主,后向轨迹经过漳州、泉州排放区,本地区排放对污染的贡献较少.莆田市监测站的NO_x与O₃浓度呈正相关的特殊现象是海陆风和山谷风配合地形造成的O₃和NO_x共同堆积和扩散所导致的.     

沿岸用地状况对中小河道沉水植物定居光照强度的影响

河道沿岸用地状况对水环境质量和水生态系统健康产生重要影响,水体光衰减特征对沉水植物定居生长具有重要意义.通过以建设闲置区、居住商业区、非居住商业区等不同沿岸用地状况中小河道为研究对象,分析了上海市130个中小河道调查区段的水环境和水下光环境指标.结果表明,上海市中小河道调查区段水体光衰减系数（K_d（PAR））的分布范围为1.243~7.592 m^-1,河道沿岸不同用地状况对K_d（PAR）具有较大影响,建设闲置区显著大于非居住商业区和居住商业区.总固体悬浮物是导致上海市中小河道水体光衰减的主要因素,但不同沿岸用地状况之间引起水体光衰减的主导因子存在差异：因处在建设开发阶段或表土裸露状态,建设闲置区的水体光衰减主导因子为总固体悬浮物,而非居住商业区、居住商业区的水体K_d（PAR）则受到总固体悬浮物、有机污染和营养盐等共同影响.总体上,总磷和叶绿素a随总固体悬浮物浓度增加表现为先增加后降低趋势.沉水植物定居光环境的最大水深Z_macrophytes分布范围为0.462~2.821 m,结合中小河道水深判定水下光照强度不足严重制约沉水植物恢复,并且浊度与K_d（PAR）的相关性显著.建设闲置区、居住商业区、非居住商业区等沿岸用地状况水体浊度与K_d（PAR）的相关系数分别为0.785、0.738、0.646,可作为判定沉水植物定植光照强度及适宜生长区的易操作定量指标.     

冠状病毒气溶胶传播及环境影响因素

当前,新型冠状病毒肺炎正在全球大范围流行,严重影响了人类健康和生产生活.目前已明确的新型冠状病毒的传播途径包括飞沫传播和接触传播,一些传播感染事件的研究间接证明新型冠状病毒可以通过空气传播,然而对于新型冠状病毒通过气溶胶传播机制的认识仍然不足,其对疾病传播的相对贡献等还在研究和论证中.本文分析了引起重症急性呼吸综合征、中东呼吸综合征和新型冠状病毒肺炎的不同冠状病毒通过气溶胶传播的研究结果,评述了病毒气溶胶的产生机制、病毒气溶胶的空气动力学特征、冠状病毒在气溶胶中的存活规律及环境因素的影响、以及冠状病毒在室内外环境气溶胶中的赋存和传播情况,探讨了当前对于明确新型冠状病毒的气溶胶传播研究的不足以及跨学科研究的展望.