唐山地区基岩地震动峰值衰减特征研究

基于搜集的唐山地区的强震记录数据,采用考虑地震动峰值加速度、近距离和震级的三种衰减模型,然后利用数理统计回归的方法对这些模型的结果进行了对比和分析,获得了唐山地区基岩场地峰值加速度衰减关系.并用2012年5月28日的唐山4.8级地震对此衰减关系进行了验证.     

Wood biomass functions for Acacia abyssinica trees and shrubs and implications for provision of ecosystem services in a community managed exclosure in Tigray,Ethiopia

In the Ethiopian highlands, remarkable recovery of vegetation has been achieved using exclosures, protecting vegetation against livestock browsing and firewood harvesting. But these emerging forest resources require tools for sustainable use, implying knowledge on biomass stocks and growth. In this study we developed biomass functions estimating total, stem and branch biomass from diameter at stump height (DSH) and tree height (H) for an 11-year old exclosure in Tigray, Ethiopia. In a systematic grid of 55 plots, DSH and H of all trees and shrubs were recorded. 40 Acacia abyssinica trees were selected for destructive sampling. Allometric relationships using a natural log–log model were established between aboveground biomass, DSH and H. Models with only DSH were found best with R² between 0.95 and 0.98. The functions were 10 fold cross-validated and R²_{_}cv ranged from 0.94 to 0.97, indicating good model performance. The models were found well in range with those of other seasonal forests in East Africa. Total aboveground biomass was estimated 25.4 ton ha⁻¹ with an annual production of 2.3 ton ha⁻¹, allowing sustainable wood fuel use for 4 persons ha⁻¹. The presented predictive functions help to harmonize between ecological and societal objectives and are as such a first step towards an integrated planning tool for exclosures.     

A spatial analysis of the geographic distribution of musculoskeletal and general practice healthcare clinics in Auckland,New Zealand

Despite the high incidence of musculoskeletal health problems in New Zealand, the use of specialised musculoskeletal healthcare providers appears to be limited to a small subsection of society. Analysis of the spatial distribution of musculoskeletal and general practice clinics in Auckland, New Zealand was undertaken to understand the geographical component of the issue of musculoskeletal healthcare accessibility. The locations of all physiotherapy, chiropractic, osteopathic, podiatry, acupuncture and general practitioner (GP) clinics in urban Auckland were mapped and analysed using a combination of spatial statistical tools. Results showed a contrast between the distribution of the predominantly privately-funded musculoskeletal clinics, which appeared clustered in central areas of the city, and predominantly publicly-funded GP clinics, which appeared more evenly spread across the study area. Several physical and social environmental variables appeared to be correlated with clinic location, including clinic proximity to major roads and urban centres, and residential socioeconomic status and ethnicity. This study represents a first step in understanding the underlying causes of the demographic divide between users and non-users of musculoskeletal healthcare. These results may help to inform the development of strategies to improve the accessibility of musculoskeletal healthcare services for people living or working in areas with low provision of musculoskeletal clinics.     

Diversity in Knoxville: An applied perspective

This study contributes to the literature on applied urban geography by examining spatial patterns and processes of changing racial/ethnic diversity within the intra-urban context of Knoxville metropolitan statistical area. Knoxville embraces a diverse economic set up with opportunities in high-tech research and development, manufacturing, tertiary/service-sectors, construction, as well as entertainment industry. This serves well for its continued population growth, including minorities during 1990–2009. This paper explores how the neighborhood-level socioeconomic, demographic, and built-environment characteristics relate to tract-level racial/ethnic diversity, measured by multi-group diversity score and its components. Tools such as isarithmic surface density maps, correlations, principal components and regression analyses are used to examine processes of change. Results indicate that diversity in 1990 associates with negative change whereas diversity in 2000 associates with positive change. Though overall diversity sprawls and increases during 1990–2009, diversity among non-White declines during 2000–2009 and shows spatial confinement. Regressions suggest complicated mosaics of changing neighborhoods, providing evidence of invasion-succession, filtering and resurgence of ethnic-enclaves in specific neighborhoods. Concerning the six counties of the MSA, Knox is the most diverse whereas Union the least, though the share of Hispanics tops in Loudon and Asians in Knox. In terms of strategic planning, findings from this research can be used in creating equitable and sustainable urban communities that can improve the overall well-being of people by reducing racial/ethnic and socio-economic disparities that might occur as undesirable consequences of fast increasing diversity.     

Vibration diagnostics of weak base embankments

In this paper the theoretical background was analyzed for vibration diagnostics method and experience in its application for weak base embankments. General schemes of survey and recommendations on hard...     

基于回归克里格的生态水文无线传感器网络布局优化

在黑河上游八宝河流域建立自动化、时空协同、智能观测的生态水文无线传感器网络,实现分布式的地面观测,对于定量刻画流域尺度时空异质性较强的生态水文要素的动态特征及其不确定性具有重要意义。在观测网设计过程中,节点的空间布局将直接影响到无线传感器网络的观测水平。为准确捕捉流域内关键生态水文要素的时空变异性和场分布,探讨了一种基于回归克里格模型的空间采样布局优化方法,并以地表温度观测网优化为例,应用到八宝河流域生态水文无线传感器网络布局方案设计中。研究结果表明,该优化方法同时考虑了目标变量与环境变量之间的相关关系以及残差在空间上的自相关特征,可以同时优化目标变量的地理空间和属性空间。优化后的无线传感器网络可以较好地捕捉流域内生态水文要素的时空动态特征。     

三种壳口颜色脉红螺（Rapanavenosa）形态学和线粒体16SrRNA与COI基因片段差异比较分析

脉红螺壳口通常有3种颜色：“黑白条纹螺”、“中间螺”和“橙色螺”。本论文对3种壳口颜色的脉红螺分别进行了形态学和mt16SrRNA、COI基因片段序列比较分析。形态学分析结果表明,除厣宽／壳高、厣高／壳高、厣高／体螺层、厣高／壳口长、厣高／壳口宽、厣高／厣宽的形态学特征指数和出肉率不具有显著性差异外,其它形态特征和生物学相关变量具有显著差异,且对湿重的影响效果不同。“黑白条纹螺”壳口长和壳口宽对湿重影响最大,而“中间螺”和“橙色螺”各形态特征对湿重均无显著的直接影响。根据各形态特征均值建立的居群形态聚类图显示,“中间螺”和“橙色螺”形态差异较小,二者与“黑白条纹螺”的形态差异较大。然而基于mt16SrRNA和COI基因片段序列分析结果显示,三种壳口颜色的脉红螺无遗传分化,为同一种。     

Quantification of the effect of forest harvesting versus climate on streamflow cycles and trends in an evergreen broadleaf catchment

ABSTRACT

A new method known as Unobserved Components–Dynamic Harmonic Regression (UC-DHR) was applied to a 39-year record of rainfall and streamflow for three sub-catchments of the Sarukawa Experimental Watershed in southwestern Japan. Some 25% of the timber was harvested from one of the sub-catchments in May–July 1982 and the objective was to quantify the magnitude of this effect relative to the effects of climate cycles (e.g. Southern Oscillation Index). The observed effects of inter-annual climate cycles (i.e. 0.89–1.36 mm/d) were seen to be comparable (i.e. 0.70–1.17 mm/d) to the effects of harvesting 25% of the standing timber. This result underlines the importance of always quantifying the effect of climate on streamflow response when harvesting impacts are studied.

Editor D. Koutsoyiannis; Associate editor T. Okruszko     

Cyclic sedimentation of the Karharbari Formation (Damuda Group), Talchir Gondwana basin, Orissa

The cyclic arrangement of lithofacies of the Karharbari Formation of the Damuda Group from a part of the Talchir Gondwana basin has been examined by statistical techniques. The lithologies have been condensed into five facies states viz. coarse-, medium-, fine-grained sandstones, shale and coal for the convenience of statistical analyses. Markov chain analysis indicates the arrangement of Karharbari lithofacies in form of fining upward cycles. A complete cycle consists of conglomerate or coarse-grained sandstone at the base sequentially succeeded by medium-and fine-grained sandstones, shale and coal at the top. The entropy analysis categorizes the Karharbari cycles into the C-type cyclicity, which is essentially a random sequence of lithologic states. Regression analysis undertaken in the present study indicates the existence of sympathetic relationship between total thickness of strata (net subsidence) and number and average thickness of sedimentary cycle and antipathic relationship between number and average thickness of sedimentary cycle. These observations suggest that cyclic sedimentation of the Karharbari Formation was controlled by autocyclic process by means of lateral migration of streams activated by intrabasinal differential subsidence, which operated within the depositional basin and the channels carrying coarse grade clastic sediments, which make the cycles thicker, tend to be more common in the areas of maximum subsidence. Clastic sediments issued from the laterally migrating rivers interrupted the cyclic sedimentation of the Karharbari Formation in many instances.     

TRMM数据在中国降雨侵蚀力计算中的应用

长时间序列降雨过程资料的获取一直是降雨侵蚀力计算中的一个难题。尝试利用地面实测站点数据分别对TRMM(Tropical Rainfall Measuring Mission)卫星的3B43和3B42数据进行回归建模和订正,并采用订正后的3 h平均降雨强度代替30 min最大降雨强度,同时基于TRMM数据的EI180的降雨侵蚀力算法,计算出了全国南北纬50°范围(TRMM覆盖区)内2013年月、季和年降雨侵蚀力;最后分别计算了省域和区域尺度下的降雨侵蚀力对全国尺度下的结果进行对比验证。结果表明:(1) TRMM降水数据比地面站点观测的降水量略大,但与实测站点数据具有很好的线性回归关系,其季尺度决定系数R²均较高,由此也说明了TRMM数据可以很好地反映全国范围内降雨的季节性变化。(2)利用订正后的TRMM3B42数据计算出研究区内的年均降雨侵蚀力为536.02 MJ·mm·hm^-2·h^-1·a^-1,其降雨侵蚀主要集中在5~8月份。(3) 2013年全国降雨侵蚀变化趋势由东南向西北方向逐渐降低,且沿海省份较内陆省份降雨侵蚀较高。(4)通过对年降雨侵蚀力结果与实测站点降雨量以及订正的TRMM降水数据分析表明,降雨侵蚀力与降水之间存在着紧密的二次非线性关系。(5)通过尺度验证,其中省域尺度验证误差为8.34%,区域尺度误差仅为0.24%,由此说明了TRMM数据在不同尺度下均具有良好的适应性,同时也验证了方法在不同尺度下的有效性。该方法为有效解决土壤侵蚀中降雨强度计算资料缺乏的瓶颈,同时也为降雨侵蚀力的计算提供了一条有效的途径。