Characterizing Rainwater Harvesting Performance and Demonstrating Stormwater Management Benefits in the Humid Southeast USA

Rainwater harvesting (RWH) has traditionally been implemented in areas with (semi) arid climates or limited access to potable water supplies; however, recent droughts in the humid southeastern United States have led to increased implementation of RWH systems. The objectives of this study were twofold: (1) present usage characteristics and performance results for four RWH systems installed in humid North Carolina (NC) as compared with systems located in arid/semiarid regions and (2) identify system benefits and modifications that could help improve the performance of RWH systems installed in humid regions of the world. For this study four RWH systems were installed in NC. Their usage was monitored for at least one year and compared with similar studies. Results revealed that dedicated water uses and usage characteristics for RWH systems in NC differed from those previously reported in the literature. Two of the systems studied met 100 and 61% of the potable water demand with designated uses of animal kennel flushing and greenhouse irrigation, respectively. The designated uses yielding the greatest potable water replacement were often seasonal or periodic, thus necessitating the need for identifying and implementing secondary objectives for these systems, namely, stormwater management. Otherwise, the expense and effort required to implement RWH systems in humid areas will most likely preclude their use.     

北京森林BVOCs排放现状及动态变化特征分析

以北京地区森林植被为研究对象,基于森林资源清查蓄积资料和逐小时气象数据,采用光温影响模型对2000~2020年北京森林BVOCs排放量进行估算,并分析其对空气质量的影响.结果显示,2020年北京森林BVOCs排放量为39.57×10⁹g C,异戊二烯、单萜烯和OVOCs分别占72.19%、17.48%和10.32%,杨树、栎树等阔叶树是主要的异戊二烯排放源,油松等针叶树是主要的单萜烯排放源.2000~2020年森林BVOCs排放量从20.30×10⁹g C/a增加到39.57×10⁹g C/a,年平均增长率4.75%;BVOCs排放量的变化表现出明显阶段性特征,2000~2010年增长缓慢,2010~2020年出现大幅上升.20年间异戊二烯所占比重呈下降趋势,单萜烯和OVOCs所占比重则呈上升趋势;杨树对BVOCs排放量的贡献逐渐降低,栎树和其他阔叶树的贡献明显增加,北京新增森林更加注重物种多样化.2000~2020年,BVOCs的O₃生成潜势从181.76×10⁹g增加到331.07×10⁹g,异戊二烯占92.70%,是主要的贡献者;SOA生成潜势从1.11×10⁹g增加到2.65×10⁹g,单萜烯和异戊二烯分别占75.40%和24.60%.O₃生成潜势最大的树种是杨树,SOA生成潜势最大的树种是油松.森林BVOCs排放在夏季对O₃污染的贡献最大,未来绿化中应考虑优化树种组成.     

Allee Effect and the Uncertainty of Population Recovery

Recovery of depleted populations is fundamentally important for conservation biology and sustainable resource harvesting. At low abundance, population growth rate, a primary determinant of population recovery, is generally assumed to be relatively fast because competition is low (i.e., negative density dependence). But population growth can be limited in small populations by an Allee effect. This is particularly relevant for collapsed populations or species that have not recovered despite large reductions in, or elimination of, threats. We investigated how an Allee effect can influence the dynamics of recovery. We used Atlantic cod (Gadus morhua) as the study organism and an empirically quantified Allee effect for the species to parameterize our simulations. We simulated recovery through an individual‐based mechanistic simulation model and then compared recovery among scenarios incorporating an Allee effect, negative density dependence, and an intermediate scenario. Although an Allee effect significantly slowed recovery, such that population increase could be negligible even after 100 years or more, it also made the time required for biomass rebuilding much less predictable. Our finding that an Allee effect greatly increased the uncertainty in recovery time frames provides an empirically based explanation for why the removal of threat does not always result in the recovery of depleted populations or species. El Efecto Allee y la Incertidumbre de la Recuperación de Poblaciones     

典型集雨人饮地区窖水微生物群落多样性及差异解析

为阐释我国典型集雨饮水地区窖水水质自然变化机制,应用16S rRNA基因-Illumina Mi Seq高通量测序技术,对以庭院为组织单元、不同类型集流面和水窖组合模式构建的集雨水源地水体中微生物群落及功能多样性差异进行了研究,表明窖水微生物群落结构及其功能存在显著的差异,造成这种差异的主要因素是窖水内部环境因子、外部环境因子等的异质性.窖水微生物群落结构多样性差异呈现大量的稀有种和少数常见优势种的分布模式,不同类型集流面和水窖组合模式构建的集雨水源地水体中含有不同的显著差异性微生物类群;微生物群落功能多样性差异体现在:编码新陈代谢功能的基因序列与其他功能基因序列相比具有显著的优势性,氨基酸、碳水化物、能量、脂类、辅助因子和维生素、萜类和酮类化合物、核苷酸、多糖的合成与代谢、外来物质的降解与代谢是构成新陈代谢功能的主要基因序列类群,表明窖水中存在大量、具有相对特定生态功能的微生物进行着诸多活跃的与新陈代谢相关活动.研究认为混凝土集流面与混凝土水窖组合模式用于收集和贮存雨水,水质更好、更安全.研究结果加深了对窖水微生物群落结构和多样性的认识,为开展集雨窖水水源地优选及改善窖水水质提供了借鉴.     

声环境影响评价新导则应用研究

从新导则中的评价类别的确定、评价等级的划分、各评价等级的基本要求对比、声环境保护标准和噪声影响评价量的选用等方面分析了环评中理解和执行声环境影响评价新导则和声环境保护新标准中出现的问题,提出了相应的解决方法,以期促进正确合理地应用新导则和新标准,对做好声环境影响评价工作具有指导意义。     

Optimisation of rainwater tank design from large roofs: A case study in Melbourne, Australia

Rainwater tanks for larger roof areas need optimisation of tank size, which is often not carried out before installation of these tanks. This paper presents a case study of rainwater tank evaluation and design for large roof areas, located in Melbourne, Australia, based on observed daily rainfall data representing three different climatic regimes (i.e. dry average, and wet years). With the aim of developing a comprehensive Decision Support Tool for the performance analysis and design of rainwater tanks, a simple spreadsheet based daily water balance model is developed using daily rainfall data, contributing roof area, rainfall loss factor, available storage volume, tank overflow and irrigation water demand. In this case study, two (185 m³ and 110 m³) underground rainwater tanks are considered. Using the developed model, effectiveness of each tank under different climatic scenarios are assessed. The analysis shows that both the tanks are quite effective in wet and average years, however less effective in dry years. A payback period analysis of the tanks is preformed which reveals that the total construction cost of the tanks can be recovered within 15-21 years time depending on tank size, climatic conditions and future water price increase rates. For the tanks, a relationship between water price increase rates and payback periods is developed. The study highlights the need for detailed optimisation and financial analysis for large rainwater tanks to maximise the benefits.     

新导则下天然气输气管道项目大气环境影响评价

文章按照HJ 2.2—2018《环境影响评价技术导则大气环境》要求,以某天然气输气管道项目为实例,对大气环境影响评价工作进行了梳理。首先利用AERSCREEN模型估算出各主要污染物的最大浓度占标率P_max,并以此判定评价等级和评价范围;其次进行环境质量现状调查、污染源调查及污染物排放量核算;最后提出环境监测计划。     

Assessing the impact of the U.S. Endangered Species Act recovery planning guidelines on managing threats for listed species

The Endangered Species Act (ESA) of the United States was enacted in 1973 to prevent the extinction of species. Recovery plans, required by 1988 amendments to the ESA, play an important role in organizing these efforts to protect and recover species. To improve the use of science in the recovery planning process, the Society for Conservation Biology (SCB) commissioned an independent review of endangered species recovery planning in 1999. From these findings, the SCB made key recommendations for how management agencies could improve the recovery planning process, after which the U.S. Fish and Wildlife Service and the National Marine Fisheries Service redrafted their recovery planning guidelines. One important recommendation called for recovery plans to make threats a primary focus, including organizing and prioritizing recovery tasks for threat abatement. We sought to determine the extent to which results from the SCB study were incorporated into these new guidelines and whether the SCB recommendations regarding threats manifested in recovery plans written under the new guidelines. Recovery planning guidelines generally incorporated the SCB recommendations, including those for managing threats. However, although recent recovery plans have improved in their treatment of threats, many fail to adequately incorporate threat monitoring. This failure suggests that developing clear guidelines for monitoring should be an important priority in improving ESA recovery planning.     

Incorporating bioavailability into management limits for copper in sediments contaminated by antifouling paint used in aquaculture

Although now well embedded within many risk-based sediment quality guideline (SQG) frameworks, contaminant bioavailability is still often overlooked in assessment and management of contaminated sediments. To optimise management limits for metal contaminated sediments, we assess the appropriateness of a range methods for modifying SQGs based on bioavailability considerations. The impairment of reproduction of the amphipod, Melita plumulosa, and harpacticoid copepod, Nitocra spinipes, was assessed for sediments contaminated with copper from antifouling paint, located below aquaculture cages. The measurement of dilute acid-extractable copper (AE-Cu) was found to provide the most useful means for monitoring the risks posed by sediment copper and setting management limits. Acid-volatile sulfide was found to be ineffective as a SQG-modifying factor as these organisms live mostly at the more oxidised sediment water interface. SQGs normalised to %-silt/organic carbon were effective, but the benefits gained were too small to justify this approach. The effectiveness of SQGs based on AE-Cu was attributed to a small portion of the total copper being present in potentially bioavailable forms (typically <10% of the total). Much of the non-bioavailable form of copper was likely present as paint flakes in the form of copper (I) oxide, the active ingredient of the antifoulant formulation. While the concentrations of paint-associated copper are very high in some sediments, as the transformation of this form of copper to AE-Cu appears slow, monitoring and management limits should assess the more bioavailable AE-Cu forms, and further efforts be made to limit the release of paint particles into the environment.