Collaborative Modeling to Evaluate Water Management Scenarios in the Rio Grande Basin

This article describes the collaborative modeling process and the resulting water resources planning model developed to evaluate water management scenarios in the transboundary Rio Grande basin. The Rio Grande is a severely water stressed basin that faces numerous management challenges as it crosses numerous jurisdictional boundaries. A collaborative process was undertaken to identify and model water management scenarios to improve water supply for stakeholders, the environment, and international obligations of water delivery from Mexico to the United States. A transparent and open process of data collection, model building, and scenario development was completed by a project steering committee composed of university, nongovernmental, and governmental experts from both countries. The outcome of the process was a planning model described in this article, with data and operations that were agreed on by water planning officials in each country. Water management scenarios were created from stakeholder input and were modeled and evaluated for effectiveness with the planning model.     

IMPROVED ENERGY AND MATERIAL EFFICIENCY USING NEW TOOLS FOR GLOBAL OPTIMISATION OF RESIDUE MATERIAL FLOWS

Residue materials generated in the metallurgical industry have gained an increasing importance, both from the points of view of energy and material supply. A joint process integration model for the integrated steel plant system is developed and used in this paper. It takes into account both residue materials and energy recirculation for the system. The potential for increased recirculation and the effect on the system from an environmental point of view is presented, and implementations and practical experiences are discussed. The model developed can serve as a benchmark for different steelmaking operations and constitute a basis for the continuous work involved in material, energy, environment or economic analyses for the steel production system.     

A typology of time‐scale mismatches and behavioral interventions to diagnose and solve conservation problems

Ecological systems often operate on time scales significantly longer or shorter than the time scales typical of human decision making, which causes substantial difficulty for conservation and management in socioecological systems. For example, invasive species may move faster than humans can diagnose problems and initiate solutions, and climate systems may exhibit long‐term inertia and short‐term fluctuations that obscure learning about the efficacy of management efforts in many ecological systems. We adopted a management‐decision framework that distinguishes decision makers within public institutions from individual actors within the social system, calls attention to the ways socioecological systems respond to decision makers’ actions, and notes institutional learning that accrues from observing these responses. We used this framework, along with insights from bedeviling conservation problems, to create a typology that identifies problematic time‐scale mismatches occurring between individual decision makers in public institutions and between individual actors in the social or ecological system. We also considered solutions that involve modifying human perception and behavior at the individual level as a means of resolving these problematic mismatches. The potential solutions are derived from the behavioral economics and psychology literature on temporal challenges in decision making, such as the human tendency to discount future outcomes at irrationally high rates. These solutions range from framing environmental decisions to enhance the salience of long‐term consequences, to using structured decision processes that make time scales of actions and consequences more explicit, to structural solutions aimed at altering the consequences of short‐sighted behavior to make it less appealing. Additional application of these tools and long‐term evaluation measures that assess not just behavioral changes but also associated changes in ecological systems are needed.     

Using Genetic Profiles of African Forest Elephants to Infer Population Structure,Movements, and Habitat Use in a Conservation and Development Landscape in Gabon

Conservation of wide‐ranging species, such as the African forest elephant (Loxodonta cyclotis), depends on fully protected areas and multiple‐use areas (MUA) that provide habitat connectivity. In the Gamba Complex of Protected Areas in Gabon, which includes 2 national parks separated by a MUA containing energy and forestry concessions, we studied forest elephants to evaluate the importance of the MUA to wide‐ranging species. We extracted DNA from elephant dung samples and used genetic information to identify over 500 individuals in the MUA and the parks. We then examined patterns of nuclear microsatellites and mitochondrial control‐region sequences to infer population structure, movement patterns, and habitat use by age and sex. Population structure was weak but significant, and differentiation was more pronounced during the wet season. Within the MUA, males were more strongly associated with open habitats, such as wetlands and savannas, than females during the dry season. Many of the movements detected within and between seasons involved the wetlands and bordering lagoons. Our results suggest that the MUA provides year‐round habitat for some elephants and additional habitat for others whose primary range is in the parks. With the continuing loss of roadless wilderness areas in Central Africa, well‐managed MUAs will likely be important to the conservation of wide‐ranging species. Utilización de Perfiles Genéticos de Elefantes Africanos para Inferir su Estructura Poblacional, Movimientos y Uso del Hábitat en un Paisaje con Conservación y Desarrollo en Gabón Resumenfgs     

Cost-effective mitigation strategies to reduce bycatch threats to cetaceans identified using return-on-investment analysis

Globally, fisheries bycatch threatens the survival of many whale and dolphin species. Strategies for reducing bycatch can be expensive. Management is inclined to prioritize investment in actions that are inexpensive, but these may not be the most effective. We used an economic tool, return-on-investment, to identify cost-effective measures to reduce cetacean bycatch in the trawl, net, and line fisheries of Australia. We examined 3 management actions: spatial closures, acoustic deterrents, and gear modifications. We compared an approach for which the primary goal was to reduce the cost of bycatch reduction to fisheries with an approach that aims solely to protect whale and dolphin species. Based on cost-effectiveness and at a fine spatial resolution, we identified the management strategies across Australia that most effectively abated dolphin and whale bycatch. Although trawl-net modifications were the cheapest strategy overall, there were many locations where spatial closures were the most cost-effective solution, despite their high costs to fisheries, due to their effectiveness in reducing all fisheries interactions. Our method can be used to delineate strategies to reduce bycatch threats to mobile marine species across diverse fisheries at relevant spatial scales to improve conservation outcomes.     

Effects of using arsenic–iron sludge wastes in brick making

The arsenic–iron sludge generated in most of the treatment systems around the world is discharged into the nearest watercourse, which leads to accumulative rise of arsenic and iron concentrations in water. In this study, attempts were made to use the arsenic–iron sludge in making bricks and to analyze the corresponding effects on brick properties. The water treatment plant sludge is extremely close to brick clay in chemical composition. So, the sludge could be a potential substitute for brick clay. This study involved the addition of sludge with ratios 3%, 6%, 9% and 12% of the total weight of sludge–clay mixture. The physical and chemical properties of the produced bricks were then determined and evaluated and compared to control brick made entirely from clay. Results of different tests indicated that the sludge proportion and firing temperature were the two key factors in determining the quality of bricks. The compressive strength of 3%, 6%, 9% and 12% sludge containing brick samples were found to be 14.1 MPa, 15.1 MPa, 9.4 MPa and 7.1 MPa, respectively. These results indicate that the compressive strength of prepared bricks initially increased and then decreased with the increase of sludge proportion. Leaching characteristics of burnt bricks were determined with the variation of pH at a constant temperature. The optimum amount of sludge that could be mixed with clay to produce good bonding of clay–sludge bricks was found to be 6% (safely maximum) by weight.     

Combustion features under different center of heat release of a diesel engine using dimethyl carbonate/diesel blend

Experiments were performed in a single cylinder common-rail diesel engine that adopts a low temperature premixed charge compression ignition (PCCI) mode. Combustion features of dimethyl carbonate (DMC)-diesel blends under various centers of heat release (COHRs) were revealed in details. With retarding of COHR, all the peaks of pressure and pressure rise rate and bulk gas temperature are postponed and declined in sequence. Normally, the crank angle of peak pressure is quite close to the COHR, while the peak of bulk gas temperature appears about 7°CA after COHR as a rule. The prolongation can be demonstrated at every stage of combustion such as q₁₀ and q₉₀ with the COHR being put backward. In addition, the heat release of diesel is completely slower than that of D10 fuel at various stages. Unfortunately, retarding of COHR implies a declining thermal efficiency of engines as well as a higher cyclic variation in general. Nevertheless, D10 blend has higher thermal efficiency than diesel thanks to high oxygen content of DMC and low boiling point that prompts better fuel atomization and complete combustion. Meanwhile, the cyclical variation of D10 is greater than diesel fuel owing to the low heat value, high latent heat of vaporization, and poor flammability of DMC. As a total, a comprehensive understanding of PCCI combustion features under different COHRs can be conducive to conducting effective management of combustion process and manipulating the subsequent emission performance to a favorable level.     

小麦籽粒镉含量影响因素Meta分析和决策树分析

快速的城市化、工业化和农业集约化造成了严重的土壤问题,如土壤酸化和镉污染等,严重威胁着中国的粮食安全和人体健康.小麦是中国第二大粮食作物,对镉有较强的积累能力.探明小麦籽粒镉含量的影响因素对保障小麦安全生产至关重要.然而,目前对小麦籽粒镉含量的影响因素还缺乏全面和定量的分析.对近10年发表的56篇相关论文进行Meta分析和决策树分析,结果表明,土壤样点中镉含量超过农用地土壤污染风险筛选值的比例为52.6%,小麦籽粒镉含量超过食品安全国家标准(0.10 mg·kg^-1,GB 2762-2017)的比例为64.1%.土壤理化性质中,pH、有机质、有效磷和土壤全镉含量是影响小麦籽粒镉含量的重要因素.土壤的pH≤5.5和5.5-1≤土壤有机质含量<30 g·kg^-1时,小麦籽粒镉含量超标率最高,为61.0%.农田土壤的pH≥7.1且全镉含量<1.60 mg·kg^-1时有利于小麦安全生产.不同小麦品种籽粒镉含量...     

实施环境-水文-生态-经济协同管理战略,保护和修复长江湖泊群生态环境

长江中下游浅水湖泊群具有十分重要的生态服务功能。然而,该湖群正面临江湖阻隔和富营养化等严重威胁。近年来,湖泊生态环境的保护和修复越来越受到重视,但治理效果不甚明显。其根本原因是:对由流域诸多胁迫导致的湖泊问题缺乏系统全面的认识,导致头痛医头、脚痛医脚。为此,本文提出应对长江湖群实施环境-水文-生态-经济协同管理战略,即在湖泊及其流域实施环境工程以控制入湖污染,实施生态水文工程以恢复自然水文体制,实施生态修复工程以增强生物自净能力,制定水环境经济制度以建立湖泊保护修复的激励和约束机制,构建生态健康评价体系以实施适应性管理,前提是责任主体明确。