河南省经济发展的国土空间评价分区研究

优化国土开发格局是国土规划的核心任务,合理的区划方案是国土开发利用的基础。基于可持续发展理论,结合河南省国土资源属性的多功能性,从社会、经济、资源和生态环境入手建立国土多功能利用评价指标体系,通过模糊聚类分析法将河南省18个地级市分成4种类型区,并采用熵权法对各类型区进行功能评价。结果表明：重点发展功能区的各项功能评价值均居于首位;农业发展功能区的农业生产功能价值最高,其余各项功能相对较弱;综合发展区功能区的各项功能均不突出;生态优先功能区的经济、社会和资源功能受生态环境功能的影响最明显。通过对比分析,验证了构建的指标评价体系和分区方法基本可行,表明区划方案可对省级国土规划的编制和国土资源的可持续利用提供技术支撑。     

Influence of thermal stratification on the surfacing and clustering of floaters in free surface turbulence

The dispersion of floaters, small organic particles lighter than water, on the free surface of an open turbulent channel flow subject to thermal stratification is studied by Direct Numerical Simulation (DNS) of turbulence and Lagrangian Particle Tracking (LPT). Constant heat flux is maintained at the free surface of the channel, the bottom wall is adiabatic and the turbulent flow is driven by a pressure gradient. This archetypal flow setup mimics an environmentally plausible situation which can be found in terrestrial water bodies. The free surface turbulence characteristic of such flows has a strong influence on the distribution of the floaters: the objective of this work is to study the effect of different regimes of stable stratification on the surface distribution of floaters. The distribution of the floaters can possibly influence the transfer of chemical species across the water/atmosphere interface. Our results show that the modification of turbulence due to the thermal stratification strongly influences the settling velocity of floaters in the bulk of the flow. At the surface, stratification effects are also observed on the clustering of the floaters: the filamentary patterns of floaters observed in unstratified turbulence are progressively lost as thermal stratification increases, and the distribution of the floaters remains roughly two-dimensional.     

银川地区M_L4级地震活动特征研究

1970年以来银川地区ML4级地震在时间上丛集发生,分别从主震震前小震与震后余震分布特征、余震序列参数计算和震源机制解的角度,研究了以上地震的活动特征。结果显示:每次地震的发生均具有一定的独立性;可计算余震参数的地震序列为非前兆震群,这一点与实际相符;震源机制解显示几次地震的发震断层主要属于银川隐伏断裂,并可能与该断裂附近的一系列次级断裂有关。分析认为几次地震的发生可能是局部应力调整的结果,与未来该区域是否发生大震关系不大,同时可以推测未来该区域依旧可能发生类似震级的有感地震。     

东营市城区第四纪松散堆积物工程建筑适宜性评价

从工程地质角度,以东营城区0～50m的土体为研究对象,分析了土体的工程地质特征,采用专家类聚法,对一般工业民用建筑和高层重型建筑物场地的工程建筑适宜性做出了评价并进行了区域划分,对东营城区将来的工程建设规划具有重要的指导意义。     

基于时间序列聚类方法分析北京出租车出行量的时空特征

受城市资源配置、区域功能分化的影响,城市中居民的出行往往呈现出特定的模式和规律,而这种出行模式的背后反映出城市的功能结构。城市车辆GPS导航的广泛使用,以及车辆轨迹数据的大量获取,为分析城市居民出行模式及理解城市功能结构提供了数据支撑。本文以道路分割城市得到的地块为研究单元,利用北京市一个月的出租车轨迹数据,对北京居民的出行模式及城市功能格局进行分析。在轨迹数据分析中,本文从轨迹数据中提取每个地块的出行量时间序列信息,然后采用结合时间序列距离度量和时间序列自身相关性的聚类方法,对出行量时间序列数据进行聚类分析,从而研究乘客出行的时空分布特征,最后结合北京市POI数据,探讨了不同区域乘客出行规律和区域功能类型的相互关系。结果表明,出租车出行量时间序列模式在工作日和周末间存在明显差异。此外,工作日的2个出行高峰与通常的通勤早晚高峰不同。由出行量所得的区域聚类结构,除具有重要交通枢纽功能的地块外,总体上以市中心为圆心大致呈同心圆分布,且距离市中心越远出行量越小。研究结果对于分析北京市居民出行行为、辅助城市交通规划具有一定的意义。     

General multidimensional cloud model and its application on spatial clustering in Zhanjiang, Guangdong

Traditional spatial clustering methods have the disadvantage of “hardware division”, and can not describe the physical characteristics of spatial entity effectively. In view of the above, this paper sets forth a general multi-dimensional cloud model, which describes the characteristics of spatial objects more reasonably according to the idea of non-homogeneous and non-symmetry. Based on infrastructures’ classification and demarcation in Zhanjiang, a detailed interpretation of clustering results is made from the spatial distribution of membership degree of clustering, the comparative study of Fuzzy C-means and a coupled analysis of residential land prices. General multi-dimensional cloud model reflects the integrated characteristics of spatial objects better, reveals the spatial distribution of potential information, and realizes spatial division more accurately in complex circumstances. However, due to the complexity of spatial interactions between geographical entities, the generation of cloud model is a specific and challenging task.     

模糊聚类在不良地质洞段红外探水中的应用

在玉昆铁路柿花树隧道不良地质发育的洞段进行红外探水工作期间,常用的分析方法有时无法预判掌子面前方是否存在隐伏水体或含水构造。为了提高红外探水短距离预报的准确率,用模糊聚类法将掌子面测点场强的数据分类,根据开挖传递的地质信息,研究模糊聚类结果的变化规律、突水风险与岩体破碎程度之间的关系。实践证明,模糊聚类法和常用分析方法的结合,使红外探水取得了较好的预判效果。     

Evidence for evolution in the clustering of quasars

We discuss the changes in the amplitude of the correlation function of quasar clustering with the redshift. Using the new Hewitt-Burbidge QSO catalogue, we find from a statistical analysis of the quasar pairs that the positive results of quasar clustering are mainly contributed by low-redshift quasars. There is an obvious change in the quasar distribution at z = 2. There is no clustering for z > 2. The difference in clustering is not due to any selection effect on the brightness. The evidence is that quasar clustering evolved with cosmological time.     

Self-organized Fractal Seismicity and b Value of Aftershocks of the 2001 Bhuj Earthquake in Kutch (India)

— The devastating intraplate earthquake of M_w 7.7 of 26 January, 2001 took place along the south-dipping reverse fault in the lower crust ( 23 km) of Kutch, Gujarat, India, obliterating some 14,000 people. The aftershock activity has ensued for three years. We analyzed 997 aftershocks of M 3.0 to study the b value and fractal correlation dimensions in time and space. The b value is found to be 0.8 ± 0.03 from the Gutenberg-Richter relation and 0.76 ± 0.02 from the maximum-likelihood, suggesting a typical value for the intraplate region. The spatial correlation is 1.71 ± 0.02, indicating that events are approaching a two-dimensional region. Further, the temporal correlation dimension is estimated to be 0.78 ± 0.02, confirming the structure is mono-fractal in time domain. The depth section of b value shows a peak at 15–35 km depth range coinciding with the maximum occurrence of aftershocks ( 47%), which is inferred as a fluid-filled highly fractured rock matrix with fractures of high density. It will be important to note that tomographic results also suggest a low Vp, low Vs and a large Poissons ratio for the same depth range, further confirming this inference. Additionally, we have studied the variation of D₂^s and b value with time. During the first two months of aftershock activity the results show a marked negative correlation between spatial correlation dimension D₂ (large) and b value (low), indicating the predominance of large events associated with weak clustering. The negative correlation means the stress release along faults of a larger surface area. After two months the fractal dimension (D₂^s) and b value suggests a positive correlation implying more numerous smaller shocks with stress release along faults of a smaller surface area. This would indicate a reduced probability of large magnitude earthquakes due to fragmentation of the fault zone.Acknowledgement. The authors thank Dr. V.P. Dimri, Director, NGRI for his encouragement and kind permission to publish this work. The Department of Science and Technology, New Delhi supported this study.