塔里木河下游河岸带地下水埋深对生态输水的响应过程

为了解塔里木河下游生态输水量与地下水埋深多年响应变化过程,得出地下水埋深对生态输水的响应变化规律,以塔里木河下游英苏断面为研究区,运用定性与定量分析方法,综合考虑不同输水差异（包括零输水年即2008年、输水极少年即2009年、输水较多年2011年等）,对2000-2015年英苏断面1 050 m范围内地下水埋深数据进行了分析。结果表明：研究断面内地下水埋深在各年份总体呈现比较平稳的递减趋势,年内个别月具有较大的增幅,另外由于冻土消融等因素影响,地下水埋深在2~3月有一定的增幅;离河较近区域的地下水埋深变化对生态输水的响应具有时间同步性,而离河道较远地区的地下水埋深在响应时间上存在滞后性,本研究断面1 050 m范围内地下水埋深响应时间维持在1 a内;经过多年生态输水过程,英苏监测断面距离河道约750 m范围内地下水平均埋深维持在2~6 m范围内,基本达到植物生长所需地下水埋深水平;另外,综合分析研究断面多年输水引起的地下水位响应过程,为获得生态输水过程所带来的最大生态效益,生态输水不仅要保持一定的输水量,还要保持输水年周期的连续性。     

基于生态敏感性和生态系统服务的黑河中游生态功能区划与生态系统管理

生态功能区划是协调生态保护与经济发展的矛盾、实施区域生态系统管理的重要途径。以黑河中游为研究区,基于基础地理信息数据、自然地理数据和土地覆被数据（1986、1995、2000、2010、2011年）,在生态敏感性和生态系统服务重要性分析的基础上,以最小子流域为基本单元,运用二阶聚类法进行生态功能区划;并依据主导生态系统服务对研究区进行分区管理与生态调控。得出结论：（1）黑河中游生态系统类型以荒漠、草地和农田为主,占总面积的90%;森林、水域、城镇与农村居民点零星分布,所占面积不到10%;1986-2010年,农田经历了减少-扩张-再减少的变化,但城镇与农村居民点一直呈现扩张趋势;（2）西北部生态敏感性明显高于东南部,其中极敏感区（约占24%）主要位于张掖-临泽-高台平原北侧、合黎山、祁连山山前戈壁与荒漠、肃南明花区;高度敏感区（约占58%）分布于走廊中部冲洪积平原;（3）各生态系统服务重要性空间分布格局具有一定的相似性,非常重要和极重要综合服务功能区约占3.2%,位于走廊中部的黑河干流缓冲区内;中等和一般重要地区约占20%,分布在山丹和民乐境内祁连山、焉支山、龙首山附近;（4）黑河中游可分为祁连山森林草地生态区、走廊冲洪积平原农田生态区和走廊北部平原灌丛荒漠生态区3个生态区8个生态功能区,依其主导生态系统服务分为生态保育区、生态协调区和生态控制区3类,进而提出了对应的生态系统管理措施。     

基于相对风险模型的土地利用变化生态风险定量评价——以石羊河流域为例

土地利用是否合理是推进国民经济发展的关键,也是生态环境变化的风向标。通过理论研究和实地调研,构建了土地利用生态风险定量评价体系,借助相对风险模型（RRM）对石羊河流域的生态风险及其影响因素进行研究。结果表明：（1）在划分的3个评价单元中,中部绿洲生态保护区在土地利用中面临的生态风险最大,北部盆地防沙治沙区次之,南部山地水源涵养区生态风险最小;（2）在3大风险单元的6类不同风险源中,工程建设对石羊河流域的生态风险影响最大,其次是作物种植和畜牧养殖,且在自然环境相对较好的区域表现得尤为明显。     

Progress in the Research on Benefit-sharing and Ecological Compensation Mechanisms for Transboundary Rivers

Transboundary rivers have important geopolitical and geo-economic connotations, but riparian states of transboundary rivers are often driven by their own rapid population growth and economic development to be-come involved in regional conflicts about the development and use of water resources. Therefore, finding a balance between the need for fair and reasonable development of water resources and the effective protection of environment from an ecological perspective has become a major problem faced by the international community. This paper begins with consideration of international water laws related to transboundary rivers and then reviews advances in the research on benefit-sharing, ecological compensation mechanisms, and adaptive management systems. We believe that existing international water laws form a complete legal system and that more attention needs to be paid to transboundary cooperation and sustainable water resource use. With respect to how transboundary water conflicts are resolved, there is a trend to move away from single water resource allocation (a zero-sum game) to benefit-sharing in order to achieve a win-win situation for riparian states, but there are still some difficulties in transboundary ecological compensation. In China, the central government has paid attention to horizontal ecological compensation between upstream and downstream, offering guidance to promote establishment of inter-province ecological compensation. Based on existing practice, horizontal ecological compensations are still in their infancy, small in scale, supported by a weak legal system, lacking market mechanisms to encourage their use and relying on fiscal transfers as the method of payment. In the future, China will need to intensify its research on legal system development, international cooperation, and benefit-sharing as these impact transboundary water resources. Because government can be seen as a management department with multiple identities (enabler, regulator and buyer), to improve adaptive transboundary ecological compensation mechanisms, government must develop as soon as possible data sharing platforms, standards of water consumption behaviors and intergovernmental policies (or ordinances).     

Ecological-Living-Productive Land Classification System in China

Rapid economic development, industrialization, and urbanization aggravates the tense relationship between human beings and the land. With multiple demands for food security, ecological protection and economic development, frequent conflicts and competition occur between multiple different functional land types. The current land use classification system focuses on the productive and living functions of land, but gives little consideration to ecological functions. This study builds a national Ecological-Living-Productive Land Classification System based on land functions emphasizing the concept and position of ecological land. So-called ecological land uses are types of land use regulating, maintaining and protecting ecological security. The new land classification is more flexible for overall planning purposes and for making arrangements for ecological, living and productive land spaces. The Ecological-Living-Productive Land Classification System includes three levels. The first level has four major types: ecological land, ecological-productive land, productive-ecological land, and living-productive land. The second level subdivides the major types into 15 functional land categories, including major ecological regulation land, common ecological regulation land, and ecological conservation land for ecological lands; pasture land, timber land and aquaculture land for ecological-productive lands; arable land and orchard for productive-ecological lands; and urban built-up area, rural living land, and industrial land for living-productive lands. The third level is based on land cover types. Based on multiple data sources, and using a strategy of zoning and re-classification, we extracted the spatial distribution of ecological-living-productive lands on a national scale. The areas of ecological land, ecological-productive land, productive land, and living-productive land area are 6,037,000 km², 1,353,800 km², 2,001,900 km² and 207,300 km², respectively; accounting for 62.89%, 14.10%, 20.85% and 2.16% of total area, respectively. For the second-level classification, the area of ecological conservation land is the largest, accounting for 20.17% of the total area. Ecological land is located mainly in central and western China. Ecological-productive land is distributed in various areas throughout the country, and productive-ecological land and living-productive land are concentrated in eastern China.     

Study of Ecological Compensation for Paddy Fields: Oriented towards Eco-environmental Restoration

Agricultural land provides not only food and fiber (an important element of food security), but also serves as a non-market commodity with characteristic externalities and public services. However, there are also many negative impacts on environment of the paddy production. Thus, Payments for paddy ecosystem services encourage farmers to engage in ecological or organic agricultural practices and agro-ecological/environmental supply. However, compared with forest, wetland, and pasture, the eco-function and ecosystem services of paddy fields have gotten insufficient attention. It is necessary to establish an eco-compensation mechanism for paddy fields that boosts behavior that protects farms to benefit the ecosystem. Based on a review of eco-compensation for paddy fields, this paper proposes the policy game framework of eco-compensation for paddy fields, which is oriented to ecological restoration. Secondly, this paper introduces methods for determination of compensation standards, including the cost the farmers’ willingness to accept, and the ecological benefits of adopting environmental friendly farming practices. And finally, this paper puts forward policy recommendations for eco-compensation for paddy ecosystems.     

Assessment of Terrestrial Ecosystem Sensitivity and Vulnerability in Tibet

The Tibetan Plateau serves an important shelter function for the ecological security of Asia, and especially China. Here, we proposed and improved indicators and methods for assessing the ecological sensitivity and vulnerability of the terrestrial alpine Plateau ecosystems and assessed the freeze-thaw erosion, land desertification, water-caused soil loss, and land salinization sensitivity, together with ecological vulnerability, from the overall ecological sensitivity, ecological pressure, and elasticity aspects in Tibet. The results indicate that the terrestrial ecosystem of Tibet is quite sensitive to freeze-thaw erosion, land desertification and water-caused soil loss. Extremely and highly sensitive regions account for 9.62% and 83.69%, respectively, of the total area of the Tibet Autonomous Region. Extremely and highly vulnerable areas account for 0.09% and 52.61%, respectively, primarily distributed in the Himalayan and Gangdise mountain regions in west Tibet; the Nyainqentanglha, Tanggula, Hoh Xil, and Kunlun mountain regions; and the northwest and northern regions of the Changtang Plateau. The results will aid the development of customized protection schedules according to different ecological issues in each region.     

Overview of Ecological Restoration Technologies and Evaluation Systems

Ecological degradation is a global problem, and ecological restoration technologies have played and will continue to play an important role in its mitigation. However, the lack of systematic research and evaluations of ecological technologies has thus far affected their effective application in vulnerable ecological regions. This study therefore provides an overview of the main technologies for remediating soil and water erosion, desertification, and rock desertification in China and throughout the world. It addresses key issues and recommends approaches for evaluating ecological restoration technologies. Restoration technology emerged as early as 1800. Over the years such technology has changed from single objective applications to multi-purpose, multi-objective applications employing strategies that take into account ecosystem rehabilitation and integrated ecological and socioeconomic development. Along with this technological evolution, different countries have taken pertinent actions as part of their restoration initiatives. However, key issues remain, including the lack of location-specific restoration technologies and a methodological strategy to assess and prioritize existing technologies. This study proposes a four-level analytical hierarchical framework in conjunction with an indicator system that highlights the establishment and adaptation of associative indicators, while also recommending a three-phase evaluation method (TheMert), targeting TheMert to qualitative (quick and extensive) and quantitative (detailed) evaluations in order to select the most appropriate restoration technologies available. This study can also be used as a basis for understanding the evaluation and prioritization of restoration technologies, while increasing the awareness of decision makers and the public on the role of technology in restoring degraded ecosystems.     

Influence of Ecological Technology Measures on the Annual Sediment Load of the Wuding River

The influence of ecological technology measures on the annual sediment loads of rivers complies with the principles of statistics. In this paper, the annual sediment load of the Wuding River is taken as the dependent variable and the rainfall, rainstorms during the flood period of the Wuding River and areas of ecological technology measures are taken as the independent variables to analyze the influence of ecological technology measures on the annual sediment load of the Wuding River during the years 1956 to 2007. This research uses a stepwise regression method. The result shows that 1) the non-linear regression equation composed of three independent variables including 7-8 monthly rainfalls along the Wuding River, areas of ecological technology measures and maximum daily rainfall along the Wuding River has been calculated and set up; the correlation coefficient is R²=0.857 and the significance level is α=0.001. 2) R²=0.717 is adjusted and the regression equation reveals a change of annual sediment load exceeding 71.7% over 52 years; 3) The standardized regression coefficient for ecological technology measure area has the maximum absolute value of the three independent variables shows maximum influence on the change of annual sediment load; and 4) Because of implementing the ecological technology measures, until to year of 2007, when the 7-8 monthly rainfall and maximum daily rainfall are the maximum values in the research section, the annual sediment load is calculated as 149million ton, which is 36% of the maximum value in the history.     

Numerical simulations of a highway bridge structure employing passive negative stiffness device for seismic protection

A new passive seismic response control device has been developed, fabricated, and tested by the authors and shown to be capable of producing negative stiffness via a purely mechanical mechanism, thus representing a new generation of seismic protection devices. Although the concept of negative stiffness may appear to be a reversal on the desired relationship between the force and displacement in structures (the desired relationship being that the product of restoring force and displacement is nonnegative), when implemented in parallel with a structure having positive stiffness, the combined system appears to have substantially reduced stiffness while remaining stable. Thus, there is an ‘apparent weakening and softening’ of the structure that results in reduced forces and increased displacements (where the weakening and softening is of a non‐damaging nature in that it occurs in a seismic protection device rather than within the structural framing system). Any excessive displacement response can then be limited by incorporating a damping device in parallel with the negative stiffness device. The combination of negative stiffness and passive damping provides a large degree of control over the expected performance of the structure. In this paper, a numerical study is presented on the performance of a seismically isolated highway bridge model that is subjected to various strong earthquake ground motions. The Negative Stiffness Devices (NSDs) are described along with their hysteretic behavior as obtained from a series of cyclic tests wherein the tests were conducted using a modified design of the NSDs (modified for testing within the bridge model). Using the results from the cyclic tests, numerical simulations of the seismic response of the isolated bridge model were conducted for various configurations (with/without negative stiffness devices and/or viscous dampers). The results demonstrate that the addition of negative stiffness devices reduces the base shear substantially, while the deck displacement is limited to acceptable values. This assessment was conducted as part of a NEES (Network for Earthquake Engineering Simulation) project which included shaking table tests of a quarter‐scale highway bridge model. Copyright © 2014 John Wiley & Sons, Ltd.