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Floodplain forests are flood-dependent ecosystems. They rely on well-timed, periodic floods for the provision of regeneration sites and on tapered flood recession curves for the successful establishment of seedlings. These overbank flood events are described as regeneration flows. Once floodplain forest trees are established, in order to grow they also require adequate, although variable, river stage levels or maintenance flows throughout the year. Regeneration flows are often synonymous with flood flows and only occur periodically. There is a disparity between this need for varied interannual flows over the decadal time frame and the usual annual cycle of flow management currently used by most river management agencies. Maintenance flows are often closer to established minimum flows and much easier to provide by current operational practices.A number of environmental flow methodologies, developed in North America, Australia, and South Africa are described in this review. They include the needs of the floodplain environment in the management and allocation of river flows. In North America, these methodologies have been put into practice in a number of river basins specifically to restore floodplain forest ecosystems. In Australia and South Africa, a series of related holistic approaches have been developed that include the needs of floodplain ecosystems as well as in-channel ecosystems. In most European countries, restoration of floodplain forests takes place at a few localized restoration sites, more often as part of a flood-defense scheme and usually not coordinated with flow allocation decisions throughout the river basin. The potential to apply existing environmental flow methodologies to the management of European floodplain forests is discussed.  相似文献   

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A wildland fire is a serious threat for forest ecosystems in Southern Europe affecting severely and irreversibly regions of significant ecological value as well as human communities. To support decision makers during large-scale forest fire incidents, a multidisciplinary system has been developed that provides rational and quantitative information based on the site-specific circumstances and the possible consequences. The systems architecture consists of several distinct supplementary modules of near real-time satellite monitoring and fire forecast using an integrated framework of satellite Remote Sensing, GIS, and RDBMS technologies equipped with interactive communication capabilities. The system may handle multiple fire ignitions and support decisions regarding dispatching of utilities, equipment, and personnel that would appropriately attack the fire front. The operational system was developed for the region of Penteli Mountain in Attika, Greece, one of the mountain areas in the country most hit by fires. Starting from a real fire incident in August 2000, a scenario is presented to illustrate the effectiveness of the proposed approach.  相似文献   

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西南地区卫星林火监测系统的建立   总被引:2,自引:0,他引:2  
本文对建立GIS支持的NOAA卫星林火监测系统进行了分析.内容包括:监测区GIS的形成;NOAA卫星图像叠加经纬度网格;GIS与NOAA卫星图像的复合.1994年春天,我们对西南林区林火进行了1个多月的实时监测,证明了该系统具有林火分辨率高和定位准确的特点.是一个较为理想的林火监测系统。  相似文献   

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国内关于旅游发展动力机制研究述评   总被引:1,自引:0,他引:1  
旅游发展是一项系统工程,涉及到经济、社会、文化以及发展政策、旅游资源、消费趋势、旅游产品等方面的因素而不断发展.从旅游发展动力机制的角度,着重对我国旅游发展动力机制研究的理论框架、动力机制类型、区域旅游发展动力机制以及相关的案例进行述评,并结合当前我国旅游发展动力机制研究的趋势和重点,对旅游发展动力机制研究进行展望.  相似文献   

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After an initial burst of enthusiasm in the 1990s, community-based forest management (CBFM) is increasingly being viewed with a critical eye. Evidence suggests that many programs have failed to promote their stated objectives of sustainability, efficiency, equity, democratic participation and poverty reduction. A large volume of academic literature now exists on CBFM, examining both the success and failure of such initiatives in a wide variety of countries. Through analysis of key themes, concepts and issues in CBFM, this article provides a review of CBFM initiatives in tropical developing countries for policymakers, practitioners and planners wishing to gain an understanding of this wide-ranging, interdisciplinary academic literature. The article identifies key institutions and incentives that appear to significantly affect the success or failure of CBFM initiatives. In particular, it reports that consideration of institutional and socioeconomic factors along with personal characteristics of key stakeholders such as beliefs, attitudes, financial resources and skills are important determinants of CBFM outcomes. However, local incentive structures also appear to be important. There is increasing recognition in the literature of the need to consider the conditions under which local politicians entrusted with carrying out CBFM initiatives will deem it worthwhile to invest their scarce time and resources on environmental governance.  相似文献   

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Management of public lands occurs today with high levels of scrutiny and controversy. To succeed, managers seek the support, involvement, and endorsement of the public. This study examines trust as an indicator of managerial success and attempts to identify and measure the components that most influence it. A review of trust literature yielded 14 attributes that were hypothesized to contribute to trust, grouped into the three dimensions of Shared Norms and Values, Willingness to Endorse, and Perceived Efficacy. Operationalizing these attributes and dimensions, a telephone survey was administered to a sample of Montana, USA, residents living adjacent to the Bitterroot National Forest (= 1,152). Each of the attributes was measured in the context of federal lands fire and fuel management. Structural equation modeling showed that all 14 attributes were found to be influential contributors to levels of trust. Results suggest that if managers are to maintain or increase levels of public trust, they need to consider each of trust’s attributes as they make social, ecological, and economic resource decisions.  相似文献   

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Regular fuel reduction burning is an important management strategy for reducing the scale and intensity of wildfires in south-west Australian native forests, but the long term effects of this on tree and stand growth are not well understood. Five fire treatments, including application of frequent and infrequent low intensity burns, and 25 years of fire exclusion, were applied to small (4 ha) experimental plots in a low rainfall mixed jarrah (Eucalyptus marginata) and marri (Corymbia calophylla) forest to investigate the effects of these treatments on tree stem diameter growth, stand basal area increment and tree mortality. Mean tree stem growth measured over 20 years was lowest in the long unburnt treatment compared with the burn treatments, although surface soil nutrient levels were generally higher in the unburnt treatment, suggesting these sites may be moisture limited. There was no clear pattern of the effects of the burn treatments, including the number of fires and the interval between fires, on tree stem growth, stand basal area increment, crown health or mortality. These factors were strongly influenced by dominance condition, with dominant and co-dominant trees growing most and suppressed trees growing least and experiencing the highest mortality levels. There was no evidence of deteriorating tree or stand health that could be attributed to either regular low intensity burning or to a long period (25 years) of fire exclusion.  相似文献   

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以1997-2012年《中国林业统计年鉴》的全国森林火灾成灾面积为依据,应用BP神经网络模型对成灾面积进行了预测,对预测方法进行了检验.在此基础上,利用残差提出了修正的BP神经网络模型,并对预测方法进行了改进.研究结果表明,修正的BP神经网络预测精度高于BP神经网络,预测相对误差平均为7.2%,可应用于森林火灾成灾面积的预测.  相似文献   

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姚伟卿 《四川环境》2008,27(5):93-98
从生物学的角度分析了固体有机废弃物堆肥过程中微生物群落的变化,强化堆肥及减少恶臭的生物学途径,简单概述了堆肥过程中提高堆肥质量和效率的主要影响因素(温度、C/N等),最后提出了今后该领域的发展方向。  相似文献   

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Environmental Management - This study investigated the indicators of adaptive capacity along with disturbances in community forest management systems in the East Asian countries, China, Japan and...  相似文献   

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本文首次以上海市“十四五”规划的视角,使用系统动力学方法研究上海市的绿色发展因素。首先确定了由经济、社会、环境、资源四个子系统交叉融合而构成上海市绿色发展系统,再基于系统动力学原理和上海市2012—2019年的数据构建上海市绿色发展模型,响应“十四五”规划在绿色发展方面设立的目标,构建多个未来发展情景并进行指标参数调控,依据各个情景的仿真结果,分析并总结了“十四五”规划背景下上海市的绿色发展特点。研究结果表明,影响绿色发展的关键因素由主到次依次为生态环境建设支出、研发支出、产业结构调整。相比于产业的投资结构调整,上海市对从业人员结构的调整可以高效平衡经济与环境的发展;加快科技创新可以在很大程度上抑制碳排放,从而快速实现上海市的“双碳”目标;针对化学污染物的治理,污染源防治不但十分有效,而且有利于持续性发展,这些措施应是上海市政府的首选。  相似文献   

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New approaches to forest planning are needed to support the transition of European forests to sustainable management. The aim of this study is to review forest planning systems already in place throughout Europe by exploring a set of case-study countries reflecting the main silvicultural schools of Western Europe, including Belgium, Finland, France, Italy, Portugal, and Slovenia.

A literature review and case-study data were used to assess the scale factors (vertical logic) as well as the relationships between forest planning and other environmental/land-use planning sectors (horizontal logic). The influence of EU policy on the development of forest planning is also discussed. As assessed using the vertical logic, the multi-scale and multi-topic planning approaches adopted in the countries studied here are highly heterogeneous. The horizontal logic shows that despite the importance of an inter-sectoral and harmonic relational framework between forest planning and the planning efforts of other sectors such as landscape and urban planning, the various plans are barely consistent with each other across the European countries studied here. Although interest is growing in the multi-functionality of forests, their sustainable management calls for the development of better integrated planning approaches across Europe.  相似文献   


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原子荧光法因其分析灵敏度高、基体干扰少、线性范围宽、操作简便快速,是目前测砷最好的方法之一。但原子荧光法在测定砷过程中存在很多因素影响测定结果的准确度。文章通过实验从载流、还原剂、加入硫脲-抗坏血酸混合液的量和稳定时间及仪器预热时间几方面对影响原子荧光法测定废水中砷的主要因素进行探讨,从而确定最佳工作条件。并通过对相对标准偏差和检出限及标准样品的测定,证明了采用此方法能保证测量结果的准确可靠。  相似文献   

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70年的中国环境立法,总体上分为三个阶段,即起步阶段、发展阶段和进入生态文明新阶段。起步阶段是从1949年10月新中国成立到1978年底党的十一届三中全会召开之前,发展阶段是从1979年到2012年党的十八大召开之前,进入生态文明新阶段是从2012年11月党的十八大召开至今。历史表明,在毛泽东主席和周恩来总理等老一辈党和国家领导人的关心和有关部门的共同努力下,我国的环境立法在新中国成立后已经提到工作日程,并取得一定成绩。党的十八大以来我国的环境法制建设取得历史性进步。在充分肯定成就的基础上,通过反思,发现我国环境立法依然存在立法质量不高、立法体制机制不够合理、实施效果不理想等问题。为此,应当根据习近平生态文明思想和党的十九大、十九届四中全会精神,明确新时代环境立法的指导思想和原则,加快环境法律的立改废释工作,切实提高环境立法质量,补齐生态保护立法的短板,积极推进相关法律的生态化,加强配套环境法规和规章的制定,加快健全完善生态环境保护法律体系,实现环境治理体系与治理能力的现代化。  相似文献   

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本文对四川盆地森林覆盖率的影响因素进行逐步回归分析,结果表明影响森林覆盖率的自然因素是综合的,它包括气候、地貌、土壤等自然条件。其中以7月降水量、地形崎岖度、山地比例、酸性紫色土比例及土地垦殖系数等作为决定四川森林覆盖率变化的最重要因素,这5个因素即可解释盆地森林覆盖率80%以上的变化。  相似文献   

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