The reversible process concept applied to the environmental management of large river systems

The wetland ecosystems occurring within alluvial floodplains change rapidly. Within the ecological successions, the life span of pioneer and transient stages may be measured in several years or decades depending on the respective influences of allogenic (water dynamics, erosion, and deposition) and autogenic developmental processes (population dynamics, eutrophication, and terrestrialization). This article emphasizes the mechanisms that are responsible for the ecosystem changes and their importance to environmental management. Two case studies exemplify reversible and irreversible successional processes in reference to different spatial and temporal scales. On the scale of the former channels, the standing-water ecosystems with low homeostasis may recover their previous status after human action on the allogenic processes. On the scale of a whole reach of the floodplain, erosion and deposition appear as reversible processes that regenerate the ecological successions. The concepts of stability and reversibility are discussed in relation to different spatiotemporal referential frameworks and different levels of integration. The reversible process concept is also considered with reference to the energy inputs into the involved subsystems. To estimate the probability of ecosystem regeneration or the cost of restoration, a concept of degrees of reversibility is proposed.     

A conceptual model for assessing ecological risk to water quality function of bottomland hardwood forests

Ecological risk assessment provides a methodology for evaluating the threats to ecosystem function associated with environmental perturbations or stressors. This report documents the development of a conceptual model for assessing the ecological risk to the water quality function (WQF) of bottomland hardwood riparian ecosystems (BHRE) in the Tifton-Vidalia upland (TVU) ecoregion of Georgia. Previus research has demonstrated that mature BHRE are essential to maintaining water quality in this portion of the coastal plain. The WQF of these ecosystems is considered an assessment endpoit—an ecosystem function or set of functions that society chooses to value as evidenced by laws, regulations, or common usage. Stressors operate on ecosystems at risk through an exposure scenario to produce ecological effects that are linked to loss of the desired function or assessment end point. The WQF of BHRE is at risk because of the ecological and environmental quality effects of a suite of chemical, physical, and biological stressors. The stressors are related to nonpoint source pollution from adjacent land uses, especially agriculture; the conversion of BHRE to other land uses; and the encroachment of domestic animals into BHRE. Potential chemical, physical, and biological stressors to BHRE are identified, and the methodology for evaluating appropriate exposure scenarios is discussed. Field-scale and watershed-scale measurement end points of most use in assessing the effects of stressors on the WQF are identified and discussed. The product of this study is a conceptual model of how risks to the WQF of BHRE are produced and how the risk and associated uncertainties can be quantified.     

灾害生态学问题研究

灾害生态学是从生态进化的角度上研究灾害问题，其目的在于通过对生态灾害的界定，生态灾害成因分析，来寻求防止或减轻生态灾害的有效途径．文章从灾害与生态进化的关系入手，阐述了研究灾害生态学问题的重要意义，提出了当前灾害生态学研究的主要问题，为灾害生态学的研究提供了一条新的思路。     

生态系统评价:问题分析与研究展望

生态系统评价是当前生态学研究中的一个热点和难点，它能够为区域生态系统健康检测、优良生态系统类型筛选、土地利用格局合理配置以及生态服务功能优化提供宝贵的参考和决策依据。论述了生态系统评价的相关内容、研究的尺度问题以及目前相配套的研究方法，分析了其中存在的诸多问题，简明指出了今后的工作重点和努力方向，并展望了生态系统评价的未来走向。认为今后综合性的生态系统评价以及与此相配套的评价方法需要得到大力加强和研发，同时生态系统评价应该和区域水土流失治理、生态安全和可持续发展等重大问题紧密结合。     

山东省海河流域污染状况及减排对策

水环境恶化已成为山东省海河流域经济社会可持续发展的一大隐忧，整个流域1480km的河长中，已有85％受到污染。从加强排污口规范化整治、设置科学化的监测考核断面、环境监督日常化、建立严格的地方政府考核机制等四个方面，科学地提出了完成减排任务应该采取的对策。     

Modification of ecological footprint evaluation method to include non-renewable resource consumption using thermodynamic approach

This study is to modify the ecological footprint methodology by incorporating non-renewable or abiotic resources as an additional category. The use of abiotic resources can be quantified as global hectare by using thermodynamic approaches. A detailed case study on various countries including Australia, Belgium, Brazil, Canada, Japan, USA, and Vietnam shows the advantage of using the new modified ecological footprint (EF) as an indicator for sustainable development. The modified EF includes not only biotic resources, but also the abiotic resources. The case study indicates that the modified EF differs from the traditional EF up to 123% in the case of Belgium, and 90% in the case of Australia. For developing countries such as Brazil and Vietnam, the differences are relatively smaller (21% for Brazil and 9.4% for Vietnam). The estimated total ecological footprint of the world using the new method implies more serious problems associated with over consumption than using results from the original ecological footprint method.     

安徽省国家地质公园建设问题及对策探讨

安徽省地质资源丰富,地质遗迹众多,2002年至今共有7处地质遗迹被评定为国家地质公园。简要介绍了地质公园建设的意义以及安徽省7处国家地质公园的基本情况,分析了安徽国家地质公园建设过程中存在的问题,并提出了相应的对策。     

Soil Moisture Data Assimilation Using Support Vector Machines and Ensemble Kalman Filter1

Abstract: A hybrid data assimilation (DA) methodology that combines two state‐of‐the‐art techniques, support vector machines (SVMs) and ensemble Kalman filter (EnKF), is applied for soil moisture DA in this work. The SVM methodology provides a statistically sound and robust approach to solving the inverse problem, and thus to building statistical models. EnKF is an extension of the Kalman Filter (KF), a well‐known tool in prediction updating. In the present research, ground measurements were used to build a SVM‐type soil moisture predictor. Subsequent observations and their statistics were assimilated to update predictions from the SVM model by coupling it with EnKF. In this way, both model predictions and ground data, as well as their statistics, are fused thus minimizing the prediction error and making the predictions and observations statistically consistent. The results are shown for two approaches; one in which update is done at every time step and the other which assumes that data is only available at alternate time steps (in window of 10 time steps) and hence update is performed at those occasions. The SVM‐EnKF coupling is shown to improve soil moisture forecasts in an example using data from the Soil Climate Analysis Network site at Ames, Iowa.     

小流域生态经济的实践与探索

我国的小流域治理工作已经开展了几十年，在治理水土流失方面取得了一定的成效。如何巩固已取得的成绩，实现小流域的可持续发展引起了广泛关注。本文通过阐述生态经济的概念，指出小流域生态经济系统存在的问题，并结合小流域的特点探讨了在小流域建设生态经济的途径。     

学校突发事件应急管理存在的问题及解决对策研究

阐述学校突发事件的定义,针对目前学校安全的严峻形势和现状,分析了学校突发事件应急管理的重要性。基于应急管理理论,剖析我国学校突发事件特点。通过对学校安全应急管理体制系统的分析,指出存在的主要问题,进而提出可行性对策:必须构建统一的学校安全应急管理体制、建立健全应急管理机构、充分发挥各级政府效能,完善应急预警。最后,提出加强学校突发事件的应急管理,有必要建立学校安全应急指挥决策系统;完善我国学校安全法律法规与标准体系;必须建立一个科学、系统、全面的学校安全应急管理体制。