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381.
结合多参考自适应噪声对消和小波模极大值去噪理论,研究了新疆独山子台跨断层垂直形变观测数据的干扰因素及消除方法,结果表明:利用气象温度数据和断层两盘温差数据作为两个噪声参考输入进行自适应噪声对消,可有效消除信号中的年周期变化;利用小波模极大值去噪方法,可以抑制信号中的高频白噪声成分,使信号畸变更加明显.仿真结果及实际应用均验证了此方法的有效性与实用性,消除干扰后的垂直形变数据与台站100 km范围内4级以上地震有较好的对应性,反映了独山子台对周边地区4级以上地震的映震能力.  相似文献   
382.
秦巴山区地质灾害成因及预报预警   总被引:3,自引:0,他引:3  
利用1955~2007年地质灾害与降水资料以及加密乡镇人工监测站、乡镇自动气象站、水文降水资料,分析秦巴山区地质灾害特点、形成机制、灾害发生与降水强度和降水持续时间的关系,用数理统计方法研究地质灾害不同易发区的临界降水指标,并结合气象部门现行精细化气象预报预警业务流程,研制了秦巴山区地质灾害精细化预报预警思路和制作流程,建成了自动运行的地质灾害预报预警业务系统。2008年应用取得较好的预报效果。  相似文献   
383.
Abstract

Conducting research on coupled social-ecological systems (SESs) presents inherent challenges, such as coordination across disparate disciplines or integrating across multiple scales and levels of governance. To overcome these common challenges, we propose that structuring the research design itself according to SES principles provides for integrative execution of SES science. First, starting with pilot work, human and natural science researchers should work as a team to identify and access multi-level entry points (i.e. points of direct engagement) within the system, relative to the spatiotemporal scales under investigation. Second, teams should implement an adaptive process that begins with the proposed research design and uses shared experiences from pilot work to refine protocols prior to subsequent data collection. We provide examples of multi-level and multi-scale entry points, and show that adaptive management of research design through coordinated iteration allows for better research integration and applicable outcomes.  相似文献   
384.
A submerged body that moves near a free surface needs to keep its attitude and position to accomplish its missions, which are required to validate the performance of a designed controller before sea trial. Hydrodynamic maneuvering coefficients are generally obtained by experiments or computational fluid dynamics, but these coefficients suffer from uncertainty. Environmental loads such as wave excitation, current, and suction forces act on the submerged body when it moves near the free surface. Therefore, a controller for the submerged body should be robust to parameter uncertainty and environmental loads. In this paper, six-degree-of-freedom equations of motion for the submerged body are constructed. An adaptive control method based on the neural network and proportional–integral–derivative controller is used for the depth controller. Simulations are performed under various depth and environmental conditions, and the results show the effectiveness of the designed controller.  相似文献   
385.
To respond to climate impact, poor agricultural households in less developed regions rely on different types of assets that define their overall adaptive capacity (AC). However not all assets build capacity equally. In this study we argue that building AC requires a combination of interventions that address not only climate-related risks (specific capacity) but also the structural deficits (e.g., lack of income, education, health, political power) (generic capacity) that shape vulnerability. Focusing on rainfed agriculture in NE Brazil, we investigate how households leverage and combine generic and specific capacities to reduce vulnerability. Particularly we explore: 1) the relative importance of different kinds of capacity in shaping vulnerability on these households and 2) how the level of generic capacities (particularly as a result of Brazil’s anti-poverty program Bolsa Família) influences the adoption of specific ones. We find that both kinds of capacity matter, as relatively higher levels of generic capacity (in terms of income in general, and climate-neutral income specifically) are associated with higher levels of specific capacity (irrigation). In addition we find that while Bolsa Família has been positive in increasing income, it has not been sufficient to manage the risk of food insecurity during drought events, suggesting a 'poverty trap' in which families are constantly coping with drought but failing to overcome the conditions that make them vulnerable. Our findings indicate that in order to decrease climate vulnerability of poor agricultural households, development interventions, such as anti-poverty programs, have to go beyond cash transfer and should incorporate risk management policies that enhance synergies between generic and specific capacities.  相似文献   
386.
Semi-arid landscapes in the western Mediterranean have been used for millennia, resulting in large-scale transformations and widespread degradation. In some instances, these degraded environments have been unable to recover spontaneously, and ambitious restoration programs have been launched over the last decades to improve landscape conditions. Ecological restoration may speed up succession, promote more complex communities and increase their functionality. But uncertainty in the definition of restoration objectives, failure to identify most efficient practices and, particularly, socio-economic and cultural constrains may compromise future actions. Here, we review recent advances in the restoration of semi-arid vegetation cover in the Iberian southeast, discuss future challenges and suggest two key steps towards increasing the consistency and efficiency of restoration programs: emphasis on ecosystem services, and implementation of participative and adaptive management practices.  相似文献   
387.
卢丽君  张继贤  王腾 《测绘学报》2011,40(4):459-463
为满足在坡度陡、高差大的复杂地形地区高精度DEM制图的需要,在传统的雷达干涉测量技术的基础上,通过引入外部DEM,建立外部DEM模拟相位和干涉解缠相位的对应关系,构建多维线性模型,进行线性回归分析,去除误差相位趋势;同时根据引入的外部DEM估计高程的误差范围,进行高程点的滤波,达到精化DEM的目的,形成最终的DEM产品。该方法已经应用于高分辨雷达影像(COSMO数据)在云南德钦地区DEM地形图的制作,通过GPS数据的验证,其精度达到了国家1∶50 000 DEM制图要求。  相似文献   
388.
随着城市的扩大,泉州市在完成新一轮精度较好的GPS/水准网布测与数据处理的基础上,通过收集、整理泉州市及周边地区陆地重力测量资料、国内外先进的地球重力场模型,采用先进的(似)大地水准面确定理论与方法,完成了泉州市规划区精度优于3 cm的似大地水准面的确定工作.  相似文献   
389.
Multi-level, networked participation is a vital component in building social–ecological resilience and the capacity to adapt to environmental change. This paper outlines the ways in which multi-level participation contributes to adaptive capacity and, in so doing, takes a step toward articulating a theory of participation based on resilience thinking. We use a case study of Gabra pastoralist communities of northern Kenya to illustrate how multi-level participation may lead to increasing adaptive capacity, above and beyond existing pastoralist adaptations. The findings suggest that adaptive capacity is systemic—that is to say, it is a property of the social–ecological system, including especially the network of institutional linkages that characterizes that system, as much as it is a property of particular actors within the system. We argue that there are three key elements of meaningful multi-level participation: an institutional environment in which the various levels of institutions are linked, inclusivity in decision-making at these various levels, and deliberation. These three features can work together to create meaningful multi-level participation, to facilitate the co-production of knowledge and to build adaptive capacity.  相似文献   
390.
Illegal, unregulated and unreported (IUU) fishing is a challenging form of non-compliance in many marine ecosystems. IUU fishing has attracted substantial political attention in the Southern Ocean, where a series of crises created windows of opportunity for change. A crises-response framework was used for examining these dynamics between 1995 and 2009. Crises were defined in relation to their perceived threat, decision time and surprise. Published material was combined with the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLRs) expert interviews, to evaluate changing perceptions of IUU fishing and corresponding actions. A first crisis led to an increased use of informal shortcuts and a concentration of power. A second crisis created windows of opportunities for policy entrepreneurs and stimulated policy innovation. A third crisis led to the implementation of existing contingency plans. These responses were consistent with predictions from the crisis-response framework used. The series of crises threatened the credibility of CCAMLR and changed the incentives for engaging in coalitions, which led to the development of both management and enforcement approaches to compliance. State and non-state actors became increasingly involved in developing these diverse compliance mechanisms, thereby actively contributing to the adaptive capacity of CCAMLR. Synergies between fisheries industry, environmental conservation, and state sovereignty interests were effectively utilized. Individual actors, organizations and countries providing leadership had strong incentives for doing so. Trust and reputation was important for the compliance mechanisms leading to a substantial reduction of IUU fishing.  相似文献   
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