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61.
First-generation compensation plans (CPs) for Dutch highway projects have been evaluated with respect to implementation of the compensation principle (1993), which aims to counterbalance the adverse ecological impacts of large-scale development projects. Decision-making on the seven projects took place between 1993 and 1995. Specifically, we considered: (a) the processes employed to prepare and implement the compensation plans; (b) the methods used to identify, plan, and execute the compensation measures; and (c) the results yielded by these methods. We conclude that the CPs were prepared fairly uniformly, particularly in terms of the processes and methodologies used to derive compensation measures. Five of the seven CPs had become operational by 2001 and initial experience is now being gained on land acquisition and transfer of compensation sites to nature conservation trusts. Further progress of CPs is likely to be seriously hampered by growing demand for land for development in general and associated increases in real estate prices. Several problems are addressed and recommendations made with respect to: (a) developing a legal basis for the compensation principle; (b) the relationship with re-allotment projects; (c) estimation of compensation costs; (d) an annual bias of CP budgets to account for rising costs; (e) contingency measures; and (f) criteria for CP (ex-post) evaluation.  相似文献   
62.
We have developed a modeling framework to support grid-based simulation of ecosystems at multiple spatial scales, the Ecological Component Library for Parallel Spatial Simulation (ECLPSS). ECLPSS helps ecologists to build robust spatially explicit simulations of ecological processes by providing a growing library of reusable interchangeable components and automating many modeling tasks. To build a model, a user selects components from the library, and then writes new components as needed. Some of these components represent specific ecological processes, such as how environmental factors influence the growth of individual trees. Other components provide simulation support such as reading and writing files in various formats to allow inter-operability with other software. The framework manages components and variables, the order of operations, and spatial interactions. The framework provides only simulation support; it does not include ecological functions or assumptions. This separation allows biologists to build models without becoming computer scientists, while computer scientists can improve the framework without becoming ecologists. The framework is designed to operate on multiple platforms and be used across networks via a World Wide Web-based user interface. ECLPSS is designed for use with both single processor computers for small models, and multiple processors in order to simulate large regions with complex interactions among many individuals or ecological compartments. To test Version 1.0 of ECLPSS, we created a model to evaluate the effect of tropospheric ozone on forest ecosystem dynamics. This model is a reduced-form version of two existing models: , which represents an individual tree, and , which represents forest stand growth and succession. This model demonstrates key features of ECLPSS, such as the ability to examine the effects of cell size and model structure on model predictions.  相似文献   
63.
Water Network Synthesis Using Mutation-Enhanced Particle Swarm Optimization   总被引:2,自引:0,他引:2  
Different techniques for the synthesis of industrial water reuse/recycle networks have been developed in recent process integration research. These tools range from graphical pinch analysis approaches to mathematical programming models. The latter have the advantage of being flexible enough to incorporate various water network constraints, but in many cases these are often non-linear, thus making the identification of global optima difficult. Recent work has demonstrated the effectiveness of metaheuristic algorithms such as particle swarm optimization (PSO), for finding good solutions these problems. This work describes the use of a modified PSO for solving mixed integer non-linear programming (MINLP) models for water network synthesis. By incorporating a mutation operator for the binary variables in the model, the algorithm is able to escape sub-optimal network topologies and proceed towards better solutions than can be found with ordinary PSO. Two case studies involving water recycle/reuse are used to demonstrate the new design methodology.  相似文献   
64.
Over recent decades Auckland, New Zealand, metropolitan area has vastly expanded as a result of rapid population growth and low-density housing developments. In order to manage the uncontrolled low-density urban sprawl, Auckland Council proposed a compact city model through promoting higher density housing developments. In order to understand the implications of this transition on future residential water demand, this study first evaluated water consumption in three major housing types in Auckland including single houses, low-rise and high-rise apartments. Using the geographic information system, the water consumption information, estimated from a large sample of 60,000 dwellings across Auckland, was subsequently integrated with the Proposed Auckland Unitary Plan outlining the future housing composition over different areas in Auckland. Through developing different growth scenarios, the study showed that the housing transition from single houses to more intensified multi-unit houses cannot considerably affect the average per capita water consumption in Auckland.  相似文献   
65.
针对突发性水污染事件的突发性、复杂性与潜在的次生衍生危害等特点,设计并开发了面向突发性水污染事件的三维可视化系统。对建设三维可视化系统的需求进行了分析,提出了系统的四层体系结构,基于三维地理信息系统World Wind组件,采用三维可视化环境建模、海量数据缓存机制以及基础地理信息集成等信息技术,开发了系统的基本应用与高级应用,将系统应用到2005年发生在松花江流域的突发性水污染事件中。实例表明:所设计的三维可视化系统具有集成性、可扩展性和较好三维表现力等特点,支持海量数据与复杂应用的集成与三维展示,为突发性水污染事件的空间模拟和决策支持提供支撑。  相似文献   
66.
水环境监测信息集成、共享与决策支持平台构建   总被引:1,自引:0,他引:1  
以水环境监测数据可靠传输交换与集成、信息规范化处理分析、高效共享与决策支持为应用主线,对水环境监测信息集成、共享与决策支持平台的建设目标、总体架构、主要功能进行了研究,设计了平台的总体架构及主要功能,以实现涉水部门水环境信息的采集、传输、交换、存储、分析、发布、共享、展现等,为环境管理与决策人员、为公众、为各级(国家级流域级省级地市级县级)环境监测业务人员提供信息支撑。  相似文献   
67.
The work highlights the difficulties of using standard sampling and statistical techniques to investigate regional phenomena and presents an integrated approach combining small-scale sampling with broad-scale observations to provide input into a modeling exercise. It is suggested that such approaches are vital if landscape- and regional-scale processes are to be understood and managed. The way in which the problem is perceived (holistically or piecemeal) affects the way treatments are designed and their effectiveness: past approaches have failed to integrate the various scales and processes involved. Effective solutions require an integrated holistic response.  相似文献   
68.
空间功能识别是确定国土空间规划空间开发保护格局的关键环节,理论和实践意义重大。基于土地利用和地表覆盖现状、精细化DEM、地形单元等基础地理信息,水、生态、环境、灾害等专题数据,社会统计数据等多元信息,利用空间分析、多元统计、计量模型、基于规则的分类模型等技术方法,从多元信息综合集成和自动分类识别的角度,研究构建了一套市县国土空间规划空间主导功能识别的关键技术与方法,并对榆林市域进行空间功能分区。研究表明:本文方法有效将地理实体单元、功能评价指标综合于统一的地域单元,保证了空间功能分类识别的准确性;通过自动分类算法建模,实现空间功能识别的自动化,提高了国土空间规划的客观性和工作效率。  相似文献   
69.
酒泉地区城镇类型较多,城镇体系中的许多关系需要统筹协调,本文侧重从城镇的规模和空间关系分析,城乡一体化和区一发展,基础产业和环境建设等三个角度,探讨了区域城市可持续发展问题。  相似文献   
70.
通过对生物倍增工艺处理市政污水的沿程污染物降解规律的考察表明,工艺对有机物的去除效果显著,COD和BOD5出水分别为47.80 mg/L和19.80 mg/L;氨氮去除率可达100%。发现厌氧区提前发生反硝化并一定程度上影响系统除磷效果;通过对各主要影响因素进行分析,认为低碳源的进水条件是影响系统同步脱氮除磷效果的关键因素;提出在进水口直接添加碳源以及分点进水的碳源分配+辅助化学除磷的方式可强化氮磷去除效果。  相似文献   
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