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996.
高铁沿线施工期间引起地面沉降的因素错综复杂、相互影响,本文提出通过对沉降区域地下水位、孔隙水压力等进行分层观测,根据分层观测得到地下水位变化、孔隙水压力变化等数据,并采用回归分析法构建了沉降区域地面沉降与诸影响因子的关联模型,通过对郑徐客运专线开封段进行的地面沉降监测量与同时采用二等精密水准测量得到的监测点沉降量进行对比分析,结果表明本方法的有效性和可靠性。 相似文献
997.
比较了3种基于GNSS空间信号进行时差监测的方法,其中,单站精密单点定位(PPP)时差监测法依赖于卫星轨道和钟差的精度,高精度PPP一般采用事后处理的方法;网解时差监测法受卫星轨道误差的影响较小,且不受卫星钟差误差的影响,因此能够用于高精度时差实时监测。为分析不同方法时差监测的差异,在距离不同的时间实验室之间进行了时差试验,试验中将外接相同原子钟的两个测站的时差用于评定时差监测的精度,而相距2000 km的测站用于验证高精度实时时差监测的精度。结果表明:①实时网解与事后PPP时差监测的精度相当,达到了0.16 ns;②采用PPP方法,是否固定站坐标时差结果差异的RMS为0.04 ns;③采用实时网解的方法,对于相隔数千千米的测站实时时差监测,其与PPP后处理结果的差异约为0.14 ns。 相似文献
998.
《Geoforum》2017
Agri-environmental policies and planning influence agricultural landscape management, and thus the capacity to deliver landscape services and to contribute to rural viability. Numerous models and frameworks have been developed to improve comprehension of the mechanisms and interrelationships between policies, landscape and socio-economic values and benefits. As social-ecological systems, landscapes are closely depending from the socio-institutional and territorial context of the specific rural locality. The paper proposes an enhanced framework for assessing these mechanisms by acknowledging the critical role of the regional macro-environment. A literature review and the revisiting of evidence from eight European case studies are applied to establish a comprehensive understanding and exemplification of the links between the policies, landscape, ecosystem services and value flows. Results highlight the need for integrative, inter- and transdisciplinary research approaches. Efficient landscape policies require enhanced regional embeddedness and targeting, acknowledgement of user demands and the capability of regional community and governance structures for policy implementation and natural capital valorisation. 相似文献
999.
《Geoforum》2017
Climate change increases the complexity and uncertainty of regional natural resource management (NRM), calling into question the appropriateness of linear knowledge-transfer approaches. In this paper we reflect on knowledge practices among a partnership of researchers and NRM planners, under a federal program of NRM investment intended to ‘deliver information’ to regional NRM planners to support planning for climate change. We unpack ‘container’ and ‘conduit’ metaphors of linear, one-way communication invoked by the starting conditions, and explore whether more relational ways of communicating were achieved. A key theme emerged early in the research that NRM planners felt overwhelmed by the sheer volume of information available and discouraged by the irrelevance of much of it to their climate change planning. Our research-practice collaboration unfolded in this context and through ongoing face-to-face and virtual engagement over a period of two years. The collaborative approach featured joint identification of priority activities, co-design of planning approaches, and the iterative co-development of an online ‘information portal’, which acted as a boundary object. We report the emergence of a ‘knowing system’, resulting from these efforts to foster relationships and co-produce boundary objects in a particular geographic context. Our findings highlight the potential benefits of investing in the capacity of researchers and NRM practitioners to engage in collaborative research partnerships premised on the emergence of knowing systems. 相似文献
1000.
In this study, soil volumetric water content and temperature variations are analyzed in an embankment constructed at Héricourt in France. A fully coupled hydro-thermal soil model is developed allowing two dimensional analysis. With meteorological data, soil surface heat flux and water flux boundary conditions are estimated considering soil-atmosphere interaction. Comparisons between measurements and simulations reveal the relevance of the proposed approach, in particular in terms of suitable boundary conditions and soil parameters. Both field monitoring and numerical modeling indicate that the influence depth of soil-atmosphere interaction is limited for volumetric water content, but it is much greater for temperature. 相似文献