Featured Collection Introduction: Connectivity of Streams and Wetlands to Downstream Waters

Connectivity is a fundamental but highly dynamic property of watersheds. Variability in the types and degrees of aquatic ecosystem connectivity presents challenges for researchers and managers seeking to accurately quantify its effects on critical hydrologic, biogeochemical, and biological processes. However, protecting natural gradients of connectivity is key to protecting the range of ecosystem services that aquatic ecosystems provide. In this featured collection, we review the available evidence on connections and functions by which streams and wetlands affect the integrity of downstream waters such as large rivers, lakes, reservoirs, and estuaries. The reviews in this collection focus on the types of waters whose protections under the U.S. Clean Water Act have been called into question by U.S. Supreme Court cases. We synthesize 40+ years of research on longitudinal, lateral, and vertical fluxes of energy, material, and biota between aquatic ecosystems included within the Act's frame of reference. Many questions about the roles of streams and wetlands in sustaining downstream water integrity can be answered from currently available literature, and emerging research is rapidly closing data gaps with exciting new insights into aquatic connectivity and function at local, watershed, and regional scales. Synthesis of foundational and emerging research is needed to support science‐based efforts to provide safe, reliable sources of fresh water for present and future generations.     

Numerical analysis of the effects of fluctuations of discharge capacity on transient flow field in gas well relief line

Transient gas flow in relief line is computed to determine the effects of fluctuations of discharge capacity on flow field. Based on the theories of computational fluid dynamics and aerodynamics, the solution and the analysis were carried out using finite volume CFD solver FLUENT 13.0. Flow fields in seven working conditions were simulated in the numerical investigation and their results were compared. The results showed that the fluctuations of discharge capacity, including extent and period, exert obvious effects on transient gas flow field in relief line. The larger the fluctuation extent and the shorter the fluctuation period, the more significant is the effect. The application method of simulation results is provided to guide the laying and fixing of pipelines, which is verified by filed measurement.     

The dynamic response of pressure relief valves in vapor or gas service. Part II: Experimental investigation

An experimental testing program designed to evaluate the opening stability characteristics of direct acting pressure relief valves (PRV) in gas/vapor service is described. Three different valve sizes from each of three different manufacturers were tested at two different set pressures to determine their opening characteristics (disk lift vs. time). The valves were tested with several different lengths of inlet piping as well as with and without discharge piping to determine the conditions under which unstable operation (chatter) would occur. Part I of this program described a mathematical model for predicting the dynamic response of PRV's, and the data described in this test program were used to evaluate the accuracy of the model, as described in Part III of this study to follow.     

环境救济法的体系——由四川藏区农村环境公害问题引出

以四川藏区农村的环境公害问题为引入对象,结合先进国家和地区的农村生态环境法制管理救济机制和应对机制,从现行相关程序法和实体法的法理角度,初步阐释适合我国农村生态环境法制实现的救济处理机制和救济途径,从而在一定程序上构建起我国的环境救济法体系。     

A community-based approach to low-income residential energy efficiency participation barriers

Financial barriers are often cited as the principle impediment to the adoption of energy efficiency measures. Since 1976, the US Department of Energy's Weatherisation Assistance Programme (WAP) has provided state block grants for no-cost, low-income energy efficiency retrofits. Yet, millions of low-income American households lack affordable, reliable, and efficient energy access. The American Recovery and Reinvestment Act of 2009 boosted WAP's annual appropriation from $230 million to $5 billion, requiring states to explore innovate approaches to quickly increasing programme participation. Community-based energy programmes have shown success for overcoming various barriers and increasing participation in the adoption of energy technologies. This case study explores a community-based approach to scaling WAP-funded energy efficiency retrofits in a cluster of five urban, low-income, majority African-American neighbourhoods, known as the Green Impact Zone (GIZ), in Kansas City, Missouri. Findings from interviews with GIZ stakeholders suggest that local context is important to how energy efficiency participation barriers manifest. The targeted, community-based approach to WAP created institutional capabilities for increased recognition of participation challenges and facilitated opportunities for alternative solutions that may otherwise have been overlooked under the standard self-referral implementation of WAP. Lastly, effective implementation of WAP required policy workarounds that recognised the unique characteristics and needs of the target community.     

日本第四次修订《食品、农业和农村基本法》及启示

日本政府2015年推出了《食品、农业和农村基本法》的第四次修订,以保证粮食供应和食品安全;推动集约化农业经营,保障农业收入稳定;推动农产品出口和农业技术创新;改善补贴政策,稳定农村人口作为下一阶段日本兴农政策的核心内容。我国农业发展面临许多与日本相似的问题,如农业经营规模小、效率低,务农收入低、人口显著减少等。在我国城镇化和农村劳动力老年化加速的背景下,分析和借鉴日本最新的兴农政策,提出对我国农业政策的若干启示:1以我国近期最新颁布的《食品安全法》和农药残留、化肥实施等国家标准的落实、健全为法制保障基础,推进农业标准化生产和规范化经营管理、建立食品生产全程可追溯机制、加强省县乡三级农产品和食品监测检验能力建设,以尽快提升我国食品安全水平;以培育需求和引导兴趣、技术支持、市场协助建设为手段,激励农户和消费者自主投入生态农业发展。2重点完善国家层面的发展战略统筹和政治、经贸、投资谈判支持,依靠政府的强力支持推动已起步的"一带一路"食品与农业投资发展势头,以壮大我国农产食品出口和农业海外发展。3近期以加强土地流转监管法律政策和财政金融配套扶持政策的建设为主,使支持力度集中于土地实际经营者,以有效提升新型规模化农业经营主体的数量和质量。4将农业补贴由集中于农业生产补贴向兼顾农户收入保障和生态保护、农业发展转移,将农户收入保障形式由财政补贴向保险保障转变,以求农业补贴和保险更高效、长久地兼顾农户收入保障和支持引领农业发展。     

Timber harvest calculations on a National Forest: A case study

Harvest calculations determine sawtimber flows from public lands and are closely scruntinized by a wide spectrum of forest users. This study examines the reliability of harvest calculations on a single national forest in New Mexico Forest Service determinations of an array of variables were reviewed and evaluated. The study revealed a lack of precision in Forest Service adherence to self-imposed procedural standards governing the calculation process. Timber sales have taken place on lands where such standards prohibit harvesting and these lands have been included in annual harvest calculations. Assumptions required by a mathematical model used by the Forest Service in calculating the harvest were not followed in the subsequent implementation of the harvest level. These factors suggest that the Forest Service could have significantly over-stated annual harvest rate for the first decade. Opportunities exist to improve the calculation, and benefits realized may greatly exceed additional costs of implementation     

SPATIAL ECONOMICS OF TARGETING MANURE POLICY1

ABSTRACT: Increasing specialization separates animal production from cropland, complicating manure management. To assist policy targeting efforts, we highlight areas where on-farm use of manure may be problematic. Matching confined animal production with land, on the farm- rather than at the county-level, gives our analysis an advantage over previous studies in avoiding aggregation problems. With manure-based water quality problems, data aggregated to the county level may fail to convey the heterogeneity of animal production across regions and animal types. Aggregation bias blurs the distinction between areas with specialized animal production and those that merely have numerous animals. We estimate bias from using county aggregates, show its distribution spatially and by animal sector, and link it to concentration. Ongoing vertical integration in agriculture likely alters in-county variability in facility scale and scope, and may influence decisions about which data we should gather and use.     

Ecosystem Management across Ownerships: the Potential for Collision with Antitrust Laws

Abstract:  Cross-boundary ecosystem management is increasingly being advocated to address large-scale ecological issues on forested landscapes. Such management requires information about the age, composition, and distribution of trees and other vegetation in addition to the ability to coordinate management over large areas. In the United States, the forest industry owns and manages a large quantity of biologically productive forest land, and these forests are crucial to the success of regional ecosystem planning. Antitrust laws, such as the Sherman Antitrust Act of 1890, limit the industry's ability to participate in regional ecosystem planning because they restrict the ability of competing firms to coordinate activities and share information. Because antitrust courts do not consider the intentions of violators, achieving conservation or other public policy goals, even when working with government agencies, is not a sufficient defense. Therefore, the real and perceived threat of antitrust litigation is a disincentive to the forest industry's participation in large-scale ecosystem management. Potential solutions to this problem include state immunity statutes and third-party data aggregation.     

Connectivity of Streams and Wetlands to Downstream Waters: An Integrated Systems Framework

Interest in connectivity has increased in the aquatic sciences, partly because of its relevance to the Clean Water Act. This paper has two objectives: (1) provide a framework to understand hydrological, chemical, and biological connectivity, focusing on how headwater streams and wetlands connect to and contribute to rivers; and (2) briefly review methods to quantify hydrological and chemical connectivity. Streams and wetlands affect river structure and function by altering material and biological fluxes to the river; this depends on two factors: (1) functions within streams and wetlands that affect material fluxes; and (2) connectivity (or isolation) from streams and wetlands to rivers that allows (or prevents) material transport between systems. Connectivity can be described in terms of frequency, magnitude, duration, timing, and rate of change. It results from physical characteristics of a system, e.g., climate, soils, geology, topography, and the spatial distribution of aquatic components. Biological connectivity is also affected by traits and behavior of the biota. Connectivity can be altered by human impacts, often in complex ways. Because of variability in these factors, connectivity is not constant but varies over time and space. Connectivity can be quantified with field‐based methods, modeling, and remote sensing. Further studies using these methods are needed to classify and quantify connectivity of aquatic ecosystems and to understand how impacts affect connectivity.