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451.
Forest and land fires in Southeast Asia have many social, economic, and environmental impacts. Tropical peatland fires affect global carbon dynamics, and haze from peat fires has serious negative impacts on the regional economy and human health. To mitigate these fire-related problems, forest and land management agencies require an early warning system to assist them in implementing fire prevention and management plans before fire problems begin. Fire Danger Rating Systems (FDRS) were developed for Indonesia and Malaysia to provide early warning of the potential for serious fire and haze events. In particular, they identify time periods when fires can readily start and spread to become uncontrolled fires and time periods when smoke from smouldering fires will cause an unacceptably high level of haze. The FDRS were developed by adapting components of the Canadian Forest Fire Danger Rating System, including the Canadian Forest Fire Weather Index (FWI) System and the Canadian Forest Fire Behavior Prediction (FBP) System, to local vegetation, climate, and fire regime conditions. A smoke potential indicator was developed using the Drought Code (DC) of the FWI System. Historical air quality analysis showed that the occurrence of severe haze events increased substantially when DC was above 400. An ignition potential indicator was developed using the Fine Fuel Moisture Code (FFMC) of the FWI System. Historical hot spot analysis, grass moisture, and grass ignition studies showed that fire occurrence and the ability for grass fires to start and spread dramatically increased when FFMC > 82. The Initial Spread Index (ISI) of the FWI System was used to develop a difficulty of control indicator for grassland fires, a fuel type that can exhibit high rates of spread and fire intensity. This ISI-based indicator was developed using the grass fuel model of the FBP System, along with a standard grass fuel load and curing level estimated from previous Indonesian studies. Very high fire intensity is expected in grasslands when ISI ≥ 6. To provide early warning, the FDRS identifies classes of increasing fire danger as the FFMC, DC, and ISI approach these key threshold values. The Indonesian FDRS is now operated nationally at the Indonesian Meteorological and Geophysical Agency. The Malaysian Meteorological Service operates the Malaysian FDRS and displays regional outputs for the Association of Southeast Asian Nations. The FDRS are being used by forestry, agriculture, environment, and fire and rescue agencies to develop and implement fire prevention, detection, and suppression plans.  相似文献   
452.
One of the social phenomena that have arisen in Indonesia in the post-Reformasi period (mid-1998) is the increase in land tenure conflicts between local communities and tree plantation companies, and between local communities and the forestry department. Land tenure conflicts often trigger forest and land fires, which is both a symptom and a cause of increasing conflict over tenure and use rights. If the tenure issue is not appropriately addressed, it will continue to result in unwanted fires and forest degradation, related smoke and gas emissions, and environmental and economic losses. A recent study in Sumatra revealed that, in many cases, (1) tenure conflicts between companies and communities, resulting from past government policies and practices, often trigger forest and land fires because of frustrations by the communities of being unable to have their claims heard in a fair and transparent judicial system; and (2) even with the use of military force, forest policy and management has largely failed to protect forest resources when local communities were not involved. The nature of the partnership between communities and companies in land use development is also an important factor in influencing the incidence and control of fire.  相似文献   
453.
Environmental accounts bring together economic and environmental information in a common framework to measure the contribution of the environment to the economy and the impact of the economy on the environment. They enable governments to set priorities, monitor economic policies more precisely, enact more effective environmental regulations and resource management strategies, and design more efficient market instruments for environmental policies. This article uses examples from the regional environmental accounting programme in southern Africa to demonstrate the usefulness of environmental accounts to policy-making and natural resource management. The examples address the contribution of natural capital endowments (minerals and fisheries) to sustainable development in Botswana and Namibia; the economic importance of non-market forest goods and services in South Africa; and the socio-economic impact of current water allocation and pricing policies in Botswana, Namibia and South Africa. While there are many additional policy applications, these few provide a powerful argument for the use of environmental accounts in all countries.  相似文献   
454.
我国历经6年的林权制度改革作为促进林业发展的根本措施,正在不断深化并已经取得很大成就。但同时也应看到其对生态环境具有一定影响(正面和负面影响)。如果国家在实施林业制度改革之前或实施初期对其可能带来的生态环境影响进行预先的评估,有利于最大程度地减少其负面影响和扩大其正面影响,将有助于决策者做出科学决策。因此开展林权改革环境影响理论与实践研究成为当务之急,是进一步开展好林权制度改革后续的配套政策措施研究的重要内容,是保障林权改革相关政策顺利实施的重要保障。为此建议:第一,国家相关部门要高度关注林权制度改革过程中对生态环境的影响;第二,应尽快深入开展林权改革环境影响评价理论与实践研究;第三,把林权改革作为重点领域开展政策环境影响评价试点,为在规划环评基础上进一步实施政策环评制度提供技术支撑,为修改《环评法》和政策环评作好技术储备,为促进林业绿色发展保驾护航。  相似文献   
455.
Abstract:  Ecosystem management was formally adopted over a decade ago by many U.S. natural resource agencies, including the Forest Service and the Bureau of Land Management. This approach calls for management based on stakeholder collaboration; interagency cooperation; integration of scientific, social, and economic information; preservation of ecological processes; and adaptive management. Results of previous studies indicate differences in the extent to which particular components of ecosystem management would be implemented within the U.S. Forest Service and the Bureau of Land Management and suggest a number of barriers thought to impede implementation. Drawing on survey and interview data from agency personnel and stakeholders, we compared levels of ecosystem-management implementation in the Forest Service and Bureau of Land Management and identified the most important barriers to implementation. Agency personnel perceived similarly high levels of implementation on many ecosystem-management components, whereas stakeholders perceived lower levels. Agencies were most challenged by implementation of preservation of ecological processes, adaptive management, and integration of social and economic information, whereas the most significant barriers to implementation were political, cultural, and legal.  相似文献   
456.
Quantifying dispersal is crucial both for understanding ecological population dynamics, and for gaining insight into factors that affect the genetic structure of populations. The role of dispersal becomes pronounced in highly fragmented landscapes inhabited by spatially structured populations. We consider a landscape consisting of a set of habitat patches surrounded by unsuitable matrix, and model dispersal by assuming that the individuals follow a random walk with parameters that may be specific to the habitat type. We allow for spatial variation in patch quality, and account for edge-mediated behavior, the latter meaning that the individuals bias their movement towards the patches when close to an edge between a patch and the matrix. We employ a diffusion approximation of the random walk model to derive analytical expressions for various characteristics of the dispersal process. For example, we derive formulae for the time that an individual is expected to spend in its current patch i, and for the time that it will spend in the matrix, both conditional on the individual hitting next a given patch j before hitting any of the other patches or dying. The analytical formulae are based on the assumptions that the landscape is infinitely large, that the patches are circularly shaped, and that the patches are small compared to interpatch distances. We evaluate the effect of these assumptions by comparing the analytical results to numerical results in a real patch network that violates all of the three assumptions. We then consider a landscape that fulfills the assumptions, and show that in this case the analytical results are in a very good agreement with the numerical results. The results obtained here allow the construction of computationally efficient dispersal models that can be used as components of metapopulation models.  相似文献   
457.
The scientific community, forest managers, environmental organizations, carbon-offset trading systems and policy-makers require tools to account for forest carbon stocks and carbon stock changes. In this paper we describe updates to the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3) implemented over the past years. This model of carbon-dynamics implements a Tier 3 approach of the Intergovernmental Panel on Climate Change (IPCC) Good Practice Guidance for reporting on carbon stocks and carbon stock changes resulting from Land Use, Land-use Change and Forestry (LULUCF). The CBM-CFS3 is a generic modelling framework that can be applied at the stand, landscape and national levels. The model provides a spatially referenced, hierarchical system for integrating datasets originating from different forest inventory and monitoring programs and includes a structure that allows for tracking of land areas by different land-use and land-use change classes. Ecosystem pools in CBM-CFS3 can be easily mapped to IPCC-defined pools and validated against field measurements. The model uses sophisticated algorithms for converting volume to biomass and explicitly simulates individual annual disturbance events (natural and anthropogenic). Several important scientific updates have been made to improve the representation of ecosystem structure and processes from previous versions of CBM-CFS. These include: (1) an expanded representation of dead organic matter and soil carbon, particularly standing dead trees, and a new algorithm for initializing these pools prior to simulation, (2) a change in the input data requirement for simulating growth from biomass to readily available merchantable volume curves, and new algorithms for converting volume to biomass, (3) improved prediction of belowground biomass, and (4) improved parameters for soil organic matter decay, fire, insect disturbances, and forest management. In addition, an operational-scale version of CBM-CFS3 is freely available and includes tools to import data in standard formats, including the output of several timber supply models that are commonly used in Canada. Although developed for Canadian forests, the flexible nature of the model has enabled it to be adapted for use in several other countries.  相似文献   
458.
The forest succession model FORDYN is developed based on TREEDEV model. TREEDEV is a process-based tree growth model, that calculates tree growth based on carbon and nitrogen balance, and is calculated using on the photo-production of leaves, respiration, nitrogen content of all organisms and that in soil, and other losses due to respiration, litter and renewal of stems, branches, leaves and roots. In the FORDYN model succession is divided into three phases called early, middle and late succession, and the transition between these three succession phases is distinguished by a difference in leaf area index. As a verification of the model we used the characteristics and available data of a monsoon evergreen broad-leaved forest in Dinghushan Biosphere Reserve (DHS-BR). The model was validated with natural forest data. In addition, a sensitivity analysis was performed in which 30 independent variables were varied and analyzed in connection with their influence on 16 dependent variables describing forest conditions. The simulation results describe the changes in total biomass, carbon and nitrogen change in plant–litter–soil system of an undisturbed monsoon evergreen broad-leaved forest during succession. We compared these findings with simulation in which different logging management strategies were used. The results show that having a longer logging cycle, delaying the first logging time and a smaller logging fraction the scenario can contribute to a sustainable forest development, while still having a positive economic yield.  相似文献   
459.
This study investigates the changes in soil microbial populations as vegetational succession progress from abandoned farmland to climax forest in the Ziwuling Forest, which is located in the northern part of the Loess Plateau, China. Different organic C and total extractable N between the fumigated and non-fumigated soils were assumed to be released from soil microorganisms. Soil microbial C was calculated using Kec = 0.38 and microbial N was calculated using Ken = 0.45. The released P was converted to microbial biomass P using Kep = 0.40. Soil bacteria, fungi, and actinomycetes increased as the vegetational succession progressed. Microbial C was of the highest amount in farmland. Microbial C, N, and P generally increased from abandoned land to climax community. The results indicated significant (P < 0.05) diversities of soil microbial biomass under different vegetation. There was a significant correlation between microbial biomass and soil nutrients. Knowledge about soil microbial populations is important for forecasting vegetational succession and determining the ecological condition of the environment.  相似文献   
460.
The concept of the renewal property is extended to processes indexed by a multidimensional time parameter. The definition given includes not only partial sum processes, but also Poisson processes and many other point processes whose jump points are not totally ordered. Various properties of renewal processes are discussed. Renewal processes are proposed as a basis for modelling the spread of a forest fire under a prevailing wind.
B. Gail IvanoffEmail:
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