Evaluating U.S. National Heritage Areas: Theory, Methods, and Application

Like many governmental actors in recent decades, the U.S. National Park Service (NPS) has operated increasingly through partnerships with other state and federal agencies, non-governmental organizations (NGOs), community groups, and private sector corporations. Perhaps the most salient example of this trend toward partnerships is the rapid growth and development of national heritage areas (NHAs). Since the first NHA received congressional designation in 1984, NHAs have become an increasingly popular strategy for protecting and managing landscapes. To date, congressional designation has been granted to 49 NHAs, making them one of the fastest growing initiatives involving the NPS. Despite this growth, no prior research has examined the efficacy or effectiveness of the NHA model. This article introduces the NHA concept, while reviewing the literature on evaluation research and its application to protected area management. We then offer an NHA program theory model for evaluating NHAs. The model was developed using a theory-based, process evaluation approach, along with 90 qualitative interviews conducted at three study sites: Blackstone River Valley National Heritage Corridor, MA-RI (BLAC); Delaware and Lehigh National Heritage Corridor, PA (DELE); and Cane River National Heritage Area, LA (CANE). We conclude by discussing the key challenges and implications associated with developing a long-term research agenda for evaluating NHAs.     

Air pollution control by economic incentives in the U.S.: Policy,problems, and progress

This paper deals with cost-effectiveness of the economic incentive policies of the bubble concept and offset credits relative to the policy of direct regulations of air emissions. The second section discusses single- and multi-plant bubbles, their adoption across regions and industries, the methods used to control emissions and the extent of savings in costs. We conclude that despite the delay resulting from duplication of review of state implementation plans by both the state and the Environmental Protection Agency, the required technological commands, the requirement to model air quality and the restrictions to permit bubbling only in the attainment areas, the policy is progressing successfully and should be encouraged by eliminating the restrictions. The third section analyzes the policy of emission offset credit, trading, and banking which can permit economic growth in nonattainment areas. It reviews the available literature, which deals only with aggregation of offsets across cities instead of individual offset trades. Progress by individual offset trades is analyzed in terms of the number of offsets, their acceptance across regions, the extent of reductions in emissions, and the classification of the offsets into internal and external trades. Comparison of estimated capital costs and prices of individual offsets with direct regulation costs reveals that the former are economical. We conclude that despite the problems of high tradeoff ratios, the short and uncertain life of the emission offset credits and the technological commands, the policy is progressing successfully and should be encouraged further by relaxing restrictions.This paper represents the author's personal views. Neither the Commission nor any member of its staff is in any way responsible for these views.     

Order 636 and the U.S. natural gas industry

An intent of the U.S. Federal Regulatory Commission's Order 636, promulgated in April 1992, was to promote competition and efficiency in the transportation sector of the natural gas industry. Additionally, the Order altered the roles of the traditional players in the industry by increasing not only their options for purchase and sale of natural gas, but also their risks. Increased options have the potential of increasing competition and efficiency, not only in the transportation sector, but also in the distribution sector. This paper examines impacts of Order 636. Using annual, aggregate, U.S. price data, a Wilcox rank sum test is employed to test for statistically significant differences between the pre- and post-636 eras. Results indicate median revenues attributable to the transportation sector have declined since the implementation of Order 636.¹ Although there are naturally a number of factors that may affect transportation revenues, the decline in median price can be attributed, at least in part, to increased competition, increased efficiency, or both. At this level of aggregation the effects can not be segregated. Results also indicate that although decreased costs of transportation have at least partially been passed on to final consumers, local distribution companies have not significantly altered their business practices when dealing with customers.     

中美欧跨区域大气环境监管比较研究及启示

近年来,酸雨、灰霾和光化学烟雾等跨区域大气环境问题日益突出,严重威胁广大人民群众的健康和环境安全。美国和欧盟在跨区域大气环境监管中都取得了丰富的经验。本文通过对中美欧跨区域大气环境监管在组织机制、法律法规、机构建设和监管手段等4个方面比较分析,结合我国国情,试图为我国跨区域大气环境监管的完善提供一些有益的启示。     

Glyphosate and Its Degradation Product AMPA Occur Frequently and Widely in U.S. Soils,Surface Water,Groundwater, and Precipitation

Glyphosate use in the United States increased from less than 5,000 to more than 80,000 metric tons/yr between 1987 and 2007. Glyphosate is popular due to its ease of use on soybean, cotton, and corn crops that are genetically modified to tolerate it, utility in no‐till farming practices, utility in urban areas, and the perception that it has low toxicity and little mobility in the environment. This compilation is the largest and most comprehensive assessment of the environmental occurrence of glyphosate and aminomethylphosphonic acid (AMPA) in the United States conducted to date, summarizing the results of 3,732 water and sediment and 1,018 quality assurance samples collected between 2001 and 2010 from 38 states. Results indicate that glyphosate and AMPA are usually detected together, mobile, and occur widely in the environment. Glyphosate was detected without AMPA in only 2.3% of samples, whereas AMPA was detected without glyphosate in 17.9% of samples. Glyphosate and AMPA were detected frequently in soils and sediment, ditches and drains, precipitation, rivers, and streams; and less frequently in lakes, ponds, and wetlands; soil water; and groundwater. Concentrations of glyphosate were below the levels of concern for humans or wildlife; however, pesticides are often detected in mixtures. Ecosystem effects of chronic low‐level exposures to pesticide mixtures are uncertain. The environmental health risk of low‐level detections of glyphosate, AMPA, and associated adjuvants and mixtures remain to be determined.     

Annual Estimates of Recharge,Quick‐Flow Runoff,and Evapotranspiration for the Contiguous U.S. Using Empirical Regression Equations

This study presents new data‐driven, annual estimates of the division of precipitation into the recharge, quick‐flow runoff, and evapotranspiration (ET) water budget components for 2000‐2013 for the contiguous United States (CONUS). The algorithms used to produce these maps ensure water budget consistency over this broad spatial scale, with contributions from precipitation influx attributed to each component at 800 m resolution. The quick‐flow runoff estimates for the contribution to the rapidly varying portion of the hydrograph are produced using data from 1,434 gaged watersheds, and depend on precipitation, soil saturated hydraulic conductivity, and surficial geology type. Evapotranspiration estimates are produced from a regression using water balance data from 679 gaged watersheds and depend on land cover, temperature, and precipitation. The quick‐flow and ET estimates are combined to calculate recharge as the remainder of precipitation. The ET and recharge estimates are checked against independent field data, and the results show good agreement. Comparisons of recharge estimates with groundwater extraction data show that in 15% of the country, groundwater is being extracted at rates higher than the local recharge. These maps of the internally consistent water budget components of recharge, quick‐flow runoff, and ET, being derived from and tested against data, are expected to provide reliable first‐order estimates of these quantities across the CONUS, even where field measurements are sparse.     

保护臭氧层谈判中的美欧博弈

臭氧层损耗是重要的全球环境问题之一。最早认识到臭氧层危害的美国率先在国内立法控制相关物质,然而另一大经济体——欧共体,在这一方面却行动迟缓。在保护臭氧层的国际谈判中,美欧之间相互妥协,最终达成了对氟氯烃化合物(CFCs)进行限控的《蒙特利尔议定书》。美欧之间的分歧来自国内化工业巨头的影响,国际经济变动影响外交决策。国际环境问题背后隐藏的经济关系与大国的领导作用是影响国际环境合作的主要因素。     

The Ethical Values in the U.S. Agricultural and Food System

Many segments of society have systems of values arising from collective beliefs and motivations. For agriculture, and our food system, increasing production to feed the growing human population clearly is a core value. However, a survey we conducted, together with a previously reported survey, showed that the curricula of most U.S. colleges of agriculture do not offer ethics courses that examine the basis of this core value or include discussion of agriculture’s ethical dilemmas such as misuse of pesticides, not progressing rapidly enough toward sustainability goals, relative lack of involvement in addressing diet-related health issues, and lack of commitment to reducing agriculture’s role as a contributor to global climate change. These surveys provide strong evidence that few students have an opportunity to learn ethical concepts and apply them to issues of importance to the agriculture/food system. We suggest that such issues are both growing societal concerns and serious ethical problems that demand attention if our agricultural/food system is not see its relationship with the public further imperiled. Further, we suggest that there is a need for, indeed an obligation of, the faculty of colleges of agriculture to embrace a thorough analysis and discussion of agriculture’s values and their ethical foundation. We offer our thoughts on why curricula of colleges of agriculture do not provide such opportunities and on the importance of agricultural faculties providing leadership in ethical analysis and discussion.     

Nitrate Concentrations in Springs Flowing into the Lower Flint River Basin,Georgia U.S.A.1

Allums, Stephanie E., Stephen P. Opsahl, Stephen W. Golladay, David W. Hicks, and L. Mike Conner, 2012. Nitrate Concentrations in Springs Flowing Into the Lower Flint River Basin, Georgia U.S.A. Journal of the American Water Resources Association (JAWRA) 48(3): 423-438. DOI: 10.1111/j.1752-1688.2011.00624.x Abstract: Analysis of long-term data from (2001-2009) in four springs that discharge from the Upper Floridan aquifer into the Flint River (southwestern Georgia, United States) indicate aquifer and surface-water susceptibility to nutrient loading. Nitrate-N concentrations ranged from 1.74 to 3.30 mg/l, and exceeded historical levels reported for the Upper Floridan aquifer (0.26-1.52 mg/l). Statistical analyses suggest increasing nitrate-N concentration in groundwater discharging at the springs (n = 146 over eight years) and that nitrate-N concentration is influenced by a dynamic interaction between depth to groundwater (an indicator of regional hydrologic conditions) and land use. A one-time synoptic survey of 10 springs (6 springs in addition to the 4 previously mentioned) using stable isotopes generated δ¹⁵N-NO₃⁻ values (4.8-8.4‰ for rural springs and 7.7-13.4‰ for developed/urban springs) suggesting mixed sources (i.e., fertilizer, animal waste, and soil organic nitrogen) of nitrate-N to rural springs and predominantly animal/human waste to urban springs. These analyses indicate a direct relation between nitrate-N loading since the 1940s and intensification of agricultural and urban land use. This study demonstrates the importance of evaluating long-term impacts of land use on water quality in groundwater springs and in determining how rapidly these changes occur.     

Lake Water Levels and Associated Hydrologic Characteristics in the Conterminous U.S.

Establishing baseline hydrologic characteristics for lakes in the United States (U.S.) is critical to evaluate changes to lake hydrology. We used the U.S. Environmental Protection Agency National Lakes Assessment 2007 and 2012 surveys to assess hydrologic characteristics of a population of ~45,000 lakes in the conterminous U.S. based on probability samples of ~1,000 lakes/yr distributed across nine ecoregions. Lake hydrologic study variables include water‐level drawdown (i.e., vertical decline and horizontal littoral exposure) and two water stable isotope‐derived parameters: evaporation‐to‐inflow (E:I) and water residence time. We present (1) national and regional distributions of the study variables for both natural and man‐made lakes and (2) differences in these characteristics between 2007 and 2012. In 2007, 59% of the population of U.S. lakes had Greater than normal or Excessive drawdown relative to water levels in ecoregional reference lakes with minimal human disturbances; whereas in 2012, only 20% of lakes were significantly drawn down beyond normal ranges. Water isotope‐derived variables did not differ significantly between survey years in contrast to drawdown. Median E:I was 20% indicating that flow‐through processes dominated lake water regimes. For 75% of U.S. lakes, water residence time was less than one year and was longer in natural vs. man‐made lakes. Our study provides baseline ranges to assess local and regional lake hydrologic status and inform management decisions in changing environmental conditions.