Evaluation of leachate composition by multivariate data analysis (MVDA)

Landfills generate emissions in the form of gas and leachate. The emissions are often measured within monitoring programmes. It is likely that the requirements of such monitoring programmes can be extended in the future, particularly in light of the increased interest in specific organic substances. Multivariate data analyses (MVDA) have been used to evaluate the possibility of predicting the content of specific organic substances from more common analyses. The results indicate that this is possible for a specific leachate. MVDA can also be used to reduce the number of analyses performed within existing monitoring programmes while retaining information about all the variables formerly included in the programmes.     

A GIS/Simulation Framework for Assessing Change in Water Yield over Large Spatial Scales

Recent legislation to initiate vegetation management in the Central Sierra hydrologic region of California includes a focus on corresponding changes in water yield. This served as the impetus for developing a combined geographic information system (GIS) and simulation assessment framework. Using the existing vegetation density condition, together with proposed rules for thinning to reduce fire risk, a set of simulation model inputs were generated for examining the impact of the thinning scenario on water yield. The approach allows results to be expressed as the mean and standard deviation of change in water yield for each 1-km² map cell that is thinned. Values for groups of cells are aggregated for typical watershed units using area-weighted averaging. Wet, dry, and average precipitation years were simulated over a large region. Where snow plays an important role in hydrologic processes, the simulated change in water yield was less than 0.5% of expected annual runoff for a typical watershed. Such small changes would be undetectable in the field using conventional stream flow analysis. These results suggest that use of water yield increases to help justify forest-thinning activities or offset their cost will be difficult.     

Evaluation of a Collaborative Model: A Case Study Analysis of Watershed Planning in theIntermountain West

Collaborative planning processes have become increasingly popular for addressing environmental planning issues, resulting in a number of conceptual models for collaboration. A model proposed by Selin and Chavez suggests that collaboration emerges from a series of antecedents and then proceeds sequentially through problem-setting, direction-setting, implementation, and monitoring and evaluation phases. This paper summarizes an empirical study to evaluate if the Selin and Chavez model encompasses the range of factors important for the establishment and operation of collaboration in watershed planning from the perspective of the planning coordinator. Analysis of three case studies of watershed based planning efforts in the Intermountain West suggests the model realistically describes some of the fundamental collaborative elements in watershed planning. Particularly important factors include the involvement of stakeholders in data collection and analysis and the establishment of measurable objectives. Informal face-to-face dialog and watershed field tours were considered critical for identifying issues and establishing trust among stakeholders. Group organizational structure also seems to play a key role in facilitating collaboration. From this analysis, suggestions for refining the model are proposed.     

废钻井液固化实验研究

利用经实验筛选的固化剂配方对废钻井液进行了固化处理的室内配方研究。结果表明,经该固化剂配方处理后的固结材料在水中浸泡5d后的浸出液在色度、化学需氧量、pH值、石油类、悬浮物含量和重金属含量等指标方面可达到国家《污水综合排放标准》(GB8978-1996)中的二级标准。     

用配合饲料饲喂乌梢蛇的试验研究

试验选用的乌梢蛇均为亚成蛇，平均体重291．79g。试验分2组进行，试验期45d。对照组用活饵投喂，处理组全程均用配合饲料人工填喂。活饵为泽蛙，人工饵料用鱼肉、明胶、添加剂等配成（粒度规格1—1．5cm^3）。各组饲养条件相同，试验结束时逐组逐个测量体重、体长、尾长，并计算存活率。试验结果表明，人工饵料组的增重、体长、尾长好于对照组，但人工饵料组的存活率低于对照组。     

Storage of CO2 in saline aquifers: Effects of gravity, viscous, and capillary forces on amount and timing of trapping

CO₂ can be effectively immobilized during CO₂ injection into saline aquifers by residual trapping – also known as capillary trapping – a process resulting from capillary snap-off of isolated CO₂ bubbles. Simulations of CO₂ injection were performed to investigate the interplay of viscous and gravity forces and capillary trapping of CO₂. Results of those simulations show that gas injection processes in which gravitational forces are weak compared to viscous forces (low gravity number N_gv) trap significantly more CO₂ than do flows with strong gravitational forces relative to the viscous forces (high N_gv). The results also indicate that over a wide range of gravity numbers (N_gv), significant fractions of the trapping of CO₂ can occur relatively quickly. The amount of CO₂ that is trapped after injection ceases is demonstrated to correlate with N_gv. For some simulated displacements, effects of capillary pressure and aquifer dip angle on the amount and the rate of trapping are reported. Trapping increases when effects of capillary pressure and aquifer inclination are included in the model. Finally we show that injection schemes such as alternating injection of brine and CO₂ or brine injection after CO₂ injection can also enhance the trapping behavior.     

工艺过程危险有害因素辨识的研究

鉴于化工企业工艺过程的特殊性,笔者建议其危险、有害因素的辨识可以在直观经验分析法和系统安全分析法的基础上,结合危险和可操作性研究(HAZOP)的思想来进行辨识。笔者尝试性地给出了相关术语的说明、介绍辨识方法和操作程序,并分别从生产过程(包括化学反应、化工操作单元和物料输送)和工艺设备、装置角度,对其中的所包含的具体内容进行剖析,最后以电解过程举例说明,该方法可用于化工企业进行危险性因素辨识。     

A narrative perspective on institutional work in environmental governance – insights from a beach nourishment case study in Sweden

Institutional work offers a promising lens for understanding institutional change, focusing on the efforts of actors in creating, maintaining or disrupting institutions. In this paper, we explore the capacity of a narrative approach to provide insights on institutional work, using a case study from the coast of Sweden. We identify four narratives that compete in the policy discourse regarding erosion and beach nourishment in the coastal province of Scania. The narratives reveal that actors hold different beliefs concerning the magnitude of the erosion problem, the division of responsibilities and the suitability of sand nourishment as a coastal protection measure. The narrative competition is considered reflective of past institutional discussions and ongoing institutional work in coastal management in Scania, confirming that narratives are used as sense-making and meaning-giving devices in institutional discussions.     

Multiresource simulation for wildland management

The model presented here is a simulation of the watershed of the Little South Fork of the Cache la Poudre River system located in the Front Range of the Rocky Mountains of Colorado. This simulation model, TERRA, provides information of resource interactions, ecosystem processes, and harvest ramifications for this watershed. The information is generated through sets of difference equations to represent process flows. The model has a modular design that separates the ecologic processes—weather conditions, hydrologic functions, forage and timber production, wildlife and domestic population dynamics, recreation use, and management activities—from the simulation planning overhead—updating, plotting, and printing.The model is designed such that the output is readily usable information for an allocation model and the decision-making process. This is accomplished by allowing different levels of specified management activities as input and producing responses and output on a per unit land area basis.This simulation is a useful research tool for estimating parameter and variable values and levels of management-resource interaction. Lack of a pertinent field data base inhibits the model from actually being used as a management tool in the planning process.Submitted for publication as Paper No. 1217 in the Journal Series of the Agricultural Experiment Station, University of Florida.     

Simulation modeling and resource management

Simulation models are becoming increasingly important as tools for synthesizing and applying information in almost all aspects of land management. They are particulary valuable for predicting and comparing outcomes of alternative decisions and assumptions. Models also permit managers to consider and integrate the potential influences of a large number of variables.