External threats and internal management: the hydrologic regulation of the Everglades,Florida, USA

The ecological character of seasonal marshes is determined in large part by the pattern of water level fluctuation. As a result, the ecological health of a wetland reserve can be controlled by hydrologic regulation external to its boundaries. As an example, the Everglades marsh of Everglades National Park in Florida, USA, has been severely effected by management of the inflow of surface water. The Everglades occupies most of the interior of southern Florida, but only the lower 6% of the original marsh is contained in Everglades National Park. Shallow surface water reservoirs north of the park enclose 3600 km² of Everglades. Their levee system confines surface water flow into the park to several structures. Historically this water flowed across the entire core of the natural drainage. Flows into the park have been on a congressionally mandated schedule of minimum deliveries that is supplemented by additional water released into the park in amounts determined solely by upstream water management needs. My research, aimed at evaluating the effects of water conditions, has shown that this regulatory system has adversely affected reproductive success, community structure, and population sizes of sensitive species whose population stability is tied to natural water level fluctuations. These adverse effects were caused by water levels that for over a decade have been maintained at unseasonably high levels. Mathematically deterministic models of water level effects can provide management options based on biologial criteria. Park managers must incorporate understanding gained from such models into internal management decisions. Modifications of water control structures and alternative policies for managing the distribution and amount of surface water flow into the park appear attainable, can improve biological conditions in the park, and need not be adverse to neighboring external interests. Thus far biological changes are severe, and to a large extent irreversible. Ecologically sensitive management of an external threat under constraints imposed by history and setting can better maintain some semblance of ecological processes in the Everglades. If management decisions do not reflect such understanding of ecological processes, further ecological deterioration will result.     

SEARCHING THE WATER RESOURCES LITERATURE: INDEXING/ABSTRACTING COVERAGE FOR LEADING WATER RESOURCES JOURNALS1

ABSTRACT: The Water Resources Scientific Information Center (WRSIC) provides comprehensive indexing/abstracting for the water resources literature. To determine in one objective way the coverage of this information service from a user's point of view, an extensive sampling of the journal literature was used to determine extent to which 10 leading water resources journals are indexed and abstracted by the system. Coverage is so high that some users will want to change toward greater use of the system.     

Taxonomic Considerations in Listing Subspecies Under the U.S. Endangered Species Act

Abstract:  The U.S. Endangered Species Act (ESA) allows listing of subspecies and other groupings below the rank of species. This provides the U.S. Fish and Wildlife Service and the National Marine Fisheries Service with a means to target the most critical unit in need of conservation. Although roughly one-quarter of listed taxa are subspecies, these management agencies are hindered by uncertainties about taxonomic standards during listing or delisting activities. In a review of taxonomic publications and societies, we found few subspecies lists and none that stated standardized criteria for determining subspecific taxa. Lack of criteria is attributed to a centuries-old debate over species and subspecies concepts. Nevertheless, the critical need to resolve this debate for ESA listings led us to propose that minimal biological criteria to define disjunct subspecies (legally or taxonomically) should include the discreteness and significance criteria of distinct population segments (as defined under the ESA). Our subspecies criteria are in stark contrast to that proposed by supporters of the phylogenetic species concept and provide a clear distinction between species and subspecies. Efforts to eliminate or reduce ambiguity associated with subspecies-level classifications will assist with ESA listing decisions. Thus, we urge professional taxonomic societies to publish and periodically update peer-reviewed species and subspecies lists. This effort must be paralleled throughout the world for efficient taxonomic conservation to take place.     

Vertical profiles of biogenic volatile organic compounds as observed online at a tower in Beijing

Vertical profiles of isoprene and monoterpenes were measured by a proton transfer reaction-time of flight-mass spectrometry (PTR-ToF-MS) at heights of 3, 15, 32, 64, and 102 m above the ground on the Institute of Atmospheric Physics (IAP) tower in central Beijing during the winter of 2016 and the summer of 2017. Isoprene mixing ratios were larger in summer due to much stronger local emissions whereas monoterpenes were lower in summer due largely to their consumption by much higher levels of ozone. Isoprene mixing ratios were the highest at the 32 m in summer (1.64 ± 0.66 ppbV) and at 15 m in winter (1.41 ± 0.64 ppbV) with decreasing concentrations to the ground and to the 102 m, indicating emission from the tree canopy of the surrounding parks. Monoterpene mixing ratios were the highest at the 3 m height in both the winter (0.71 ± 0.42 ppbV) and summer (0.16 ± 0.10 ppbV) with a gradual decreasing trend to 102 m, indicting an emission from near the ground level. The lowest isoprene and monoterpene mixing ratios all occurred at 102 m, which were 0.71 ± 0.42 ppbV (winter) and 1.35 ± 0.51 ppbV (summer) for isoprene, and 0.42 ± 0.22 ppbV (winter) and 0.07 ± 0.06 ppbV (summer) for monoterpenes. Isoprene in the summer and monoterpenes in the winter, as observed at the five heights, showed significant mutual correlations. In the winter monoterpenes were positively correlated with combustion tracers CO and acetonitrile at 3 m, suggesting possible anthropogenic sources.     

The potential application of red mud and soil mixture as additive to the surface layer of a landfill cover system

Red mud, the by-product of aluminum production, has been regarded as a problematic residue all over the world. Its storage involves risks as evidenced by the Ajka red mud spill,an accident in Hungary where the slurry broke free, flooding the surrounding areas. As an immediate remediation measure more than 5 cm thick red mud layer was removed from the flooded soil surface. The removed red mud and soil mixture(RMSM) was transferred into the reservoirs for storage. In this paper the application of RMSM is evaluated in a field study aiming at re-utilizing waste, decreasing cost of waste disposal and providing a value-added product. The purpose was to investigate the applicability of RMSM as surface layer component of landfill cover systems. The field study was carried out in two steps: in lysimeters and in field plots. The RMSM was mixed at ratios ranging between 0 and 50% w/w with low quality subsoil(LQS) originally used as surface layer of an interim landfill cover. The characteristics of the LQS + RMSM mixtures compared to the subsoil(LQS) and the RMSM were determined by physical–chemical, biological and ecotoxicological methods. The addition of RMSM to the subsoil(LQS) at up to 20% did not result any ecotoxic effect, but it increased the water holding capacity. In addition, the microbial substrate utilization became about triple of subsoil(LQS) after 10 months. According to our results the RMSM mixed into subsoil(LQS) at20% w/w dose may be applied as surface layer of landfill cover systems.     

秦皇岛市生态农业模式分析

本文根据秦皇岛市的地理条件,气候资源和土壤资源,分析了该地区的农业生产总环境和自然经济条件,提出了因地制宜,合理利用各地的自然资源,建立科学合理又相近相趋的生态农业模式和实施方案。     

Optimal retrofit of water conservation networks

This paper presents a new general mathematical programming model for the optimal retrofit of material conservation networks considering recycle, reuse and regeneration schemes (notice that most of the previously reported methods only have considered the synthesis case, and nowadays it is very important to have strategies for the retrofit of water networks because several existing water network are functioned under suboptimal conditions because these were synthesized using inefficient approaches or because the process and environmental constraints have changed). The model considers the reconfiguration of existing networks to satisfy stricter process and environmental constraints considering the repiping for the network, the reuse of the existing treatment units, the modification for the capacity and performance of the existing units and the installation of new treatment units to reduce the overall operating cost through the reduction of the use of fresh sources. The objective function accounts for the minimization of the total annual cost associated to the retrofit process. This retrofit process involves simultaneously economic (because the reduction of the fresh sources costs) and environmental (because the reduction of the waste streams discharged to the environment and with a better quality) improvements. The applicability of the proposed model is proved through a set of example problems addressed, where no numerical complications were observed. In addition, the proposed approach is general and it can be applied to any specific case with the information required.     

Cleaner red mud residue production at an alumina plant by applying experimental design techniques in the filtration stage

Red mud is a residue obtained by the Bayer process during alumina production, and its disposal is an environmental problem due to its caustic nature, metal and radionuclide content and alkalinity. The present study analyzed five different filtration factors with two levels each in order to improve filtration and, thus, reduce the caustic content of this residue. This study was conducted at the Alumina do Norte do Brasil S.A (ALUNORTE) alumina plant, located in Pará, Brazil, in one of the six filters at the plant. Results show that the condensate is the primary factor in caustic red mud concentrations, followed by dilution, rotation and level of the basin filter. The interactions between dilution and the level of the basin filter were considered significant, as was the interaction amongst the three effects: dilution, level of the basin filter and vacuum. The model adjustment regarding the filtration process allows for the production of a final red mud product with lower caustic concentrations, resulting in economic advantages due to higher caustic recovery in filtration and lower caustic concentration in the red mud residue, which leads to an environmentally safer residue.     

我国资源环境审计研究

从分析我国全面开展资源环境审计的重要性人手,进而剖析了我国资源环境审计的发展状况和存在的现实问题,最后对我国全面深入开展资源环境审计提出了建议。