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1.
深基坑开挖引起的周边地表变形预测是一个复杂非线性问题,引起地表沉降的影响因素很多,各因素之间呈高度的非线性关系。传统的基坑用边地表沉降变形预测方法存在着一定的局限性,其预测精度有待提高,而人工神经网络是一种多元非线性动力学系统,可以灵活方便地对多成因的复杂未知系统进行高度建模,实现全面考虑各种主要影响因素的深基坑周边地表沉降变形预测。本文介绍了误差反向传播(BP)网络模型的结构、学习过程及其算法的改进,径向基函数(RBF)网络模型的结构及其学习过程;分析了影响深基坑开挖周边土体沉降变形的主要影响因素;以25个基坑工程的地表沉降实测资料为训练样本,建立了11个输入影响因素的BP神经网络模型和RBF神经网络模型,通过对样本的学习训练过程及对5个检验样本的预测精度,说明了人工神经网络用于预测基坑周边地表沉降的可行性和准确性。  相似文献   
2.
The implementation of sustainable development may seem a simple concept when written on paper. However to carry-out long term actions put forward by the Agenda 21 (AG21) at the local level represents one of the main challenges as municipal governments in general do not have the capacity to effectively implement the process. Regional environmental assessment (REA) has shown to be effective in supporting decision-making not only to correct environmental problems due to past unsustainable social-economic developments but also help local governments to implement sustainable actions. However this requires long-term investments of AG21 plans and projects. The allocation of regular and consistent financial resources is one of the main ingredients for the sustainable development process. But traditional plans and projects financed by national and/or international funds may not be sustainable in the long-term because they become dependent on external funding. Research demonstrate that innovative economic instruments such as ecotaxes represent a feasible alternative to sponsor local sustainability because taxes are collected permanently by the government and could be invested in continuous actions. Ecotaxes experiences have provided important reference to structure a municipal incentive model (MIM) to sponsor AG21’s environmental plans and projects on a long-term (permanent) basis. However sustainable development cannot be solely through economic investments. A comprehensive municipal environmental management scheme (MEMS) has been established to support the incentive model. The scheme seeks not only to improve local institutional framework but also incentive continuous participation of local stakeholders at all levels of society. Participatory events and the provision of incentives (educational and financial) are key to motivate society to protect the environment and support actively the sustainable development process as emphasised in the RIO-92 Conference.  相似文献   
3.
交通建设项目施工期环境监理探讨   总被引:6,自引:0,他引:6  
探讨交通建设项目施工期环境监理方法,提出环境监理的目的、意义、程序,内容和工作方法。  相似文献   
4.
叙述了思茅目前开展景观影响评价的情况和意义,提出了景观影响评价的基本概念、步骤、内容和方法,介绍了一种较为简便、实用的用于景观影响评价的定量方法。  相似文献   
5.
We studied the Noel KempffMercado Climate Action Project (NKMCAP),Bolivia, to assess whether forestprotection carbon (C) projects cansignificantly benefit local people. Wehypothesized that forest protection canonly securely deliver C if significantstakeholders are meaningfully andtransparently involved, traditional orcustomary rights are recognized and theirloss compensated for, and there are directlinkages between conservation anddevelopment objective. Our researchfocused on 53 members of the communities ofFlorida, Porvenir and Piso Firme and 36secondary stakeholders. In each of thevillages we held half-day meetings withcommunity leaders, complemented bysemi-structured one-hour interviews with 5,10, and 7 families, representing 20%, 10%and 8% of each community. The long-termimpact of the NKMCAP on the localcommunities may well be positive. However,in the short run, certain sections of thelocal communities are financially poorer. Forest protection projects clearly have thepotential to sequester C, protectbiodiversity and simultaneously contributeto sustainable rural development, but ifthey really are to improve rurallivelihoods, they must be designed andimplemented carefully and participatively.  相似文献   
6.
The Lawrence Berkeley National Laboratory (Berkeley Lab) and the Center for Sustainable Development in the Americas (CSDA) conducted technical studies and organized two training workshops to develop capacity in Central America for the evaluation of climate change projects. This paper describes the results of two baseline case studies conducted for these workshops, one for the power sector and one for the cement industry, that were devised to illustrate certain approaches to baseline setting. Multiproject baseline emission rates (BERs) for the main Guatemalan electricity grid were calculated from 2001 data. In recent years, the Guatemalan power sector has experienced rapid growth; thus, a sufficient number of new plants have been built to estimate viable BERs. We found that BERs for baseload plants offsetting additional baseload capacity ranged from 0.702 kgCO2/kWh (using a weighted average stringency) to 0.507 kgCO2/kWh (using a 10th percentile stringency), while the baseline for plants offsetting load-following capacity is lower at 0.567 kgCO2/kWh. For power displaced from existing load-following plants, the rate is higher, 0.735 kgCO2/kWh, as a result of the age of some plants used for meeting peak loads and the infrequency of their use. The approved consolidated methodology for the Clean Development Mechanism yields a single rate of 0.753 kgCO2/kWh. Due to the relatively small number of cement plants in the region and the regional nature of the cement market, all of Central America was chosen as the geographic boundary for setting cement industry BERs. Unfortunately, actual operations and output data were unobtainable for most of the plants in the region, and many data were estimated. Cement industry BERs ranged from 205 kgCO2 to 225 kgCO2 per metric ton of cement.  相似文献   
7.
以煤矿建设项目对土地资源影响的特点和规律为基础,满足该类项目环境影响评价要求为指导,以陕西省黄陵建庄矿区建北矿井及选煤厂新建项目为例,介绍西部煤矿建设项目土地资源影响量化评价的方法与思路,是西部煤矿项目土地资源影响评价深化的一种研究,有利于协调煤炭资源开发与土地资源保护问题.  相似文献   
8.
城镇市政设施投资项目环境影响后评价探讨   总被引:1,自引:0,他引:1  
城镇市政设施是城镇经济和社会发展的载体,加强其环境影响后评价工作,能为其决策者提供系统、全面、科学的信息反馈,对于促进城镇社会经济与自然环境的持续、协调、稳定发展,具有十分重要的现实意义.在对城镇市政设施投资项目环境影响后评价的概念进行界定的基础上,对城镇市政设施投资项目环境影响后评价的意义及工作程序进行了阐释,并结合城镇市政设施投资项目的具体特点,对其环境影响后评价的内容从大气、水体、噪声、土壤、固体废弃物和生态等六个方面进行了研究探讨.  相似文献   
9.
张利民  邹敏 《环境科技》2002,15(4):26-27
目前国内部分省市已陆续开展建设工程环境监理的试点工作,并取得一些好的经验。本文通过分析开展第三方环境监理工作的必要性和国内几家试点工作的进展情况,提出了在江苏省开展建设工程第三方环境监理工作的对策。  相似文献   
10.
This study aims at describing, analyzing and evaluating the relation between management styles and process dynamics of a complex planning process confronted with unexpected dynamics. The development of an aquatic disposal site for dredged contaminated sediments in Oslo was managed by a project management style focused on timely and cost-effective implementation. Coupling the remediation project with another infrastructural project and the actual construction of the site led to unexpected dynamics in terms of resistance and controversy. Project management had difficulties in adjusting its style accordingly, resulting in even more delay and resistance. Managing complex planning projects requires a style suitable to the characteristics of the project and the capability of adjusting it to changing circumstances. The paper concludes with some explanations why it is difficult to change management styles in complex planning and implementation processes and complexity-embracing approaches to deal with this.  相似文献   
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