Fine-scale measurements of fog-droplet concentrations: a preliminary assessment

Measurements of warm fog-droplet concentrations carried out in a site in Mexico were analyzed with the purpose of identifying inhomogeneous sections of clouds. The site, located in the Sierra Madre Oriental of eastern Mexico, is characterized by frequent fog events throughout the year, sometimes accompanied with drizzle. Fog droplet concentrations and size spectra were obtained with a Forward Scattering Spectrometer Probe mounted on a ground-based, instrumented van for in-motion operation. The sampling technique, along with the data retrieval scheme used, allows one to investigate fine-scale microphysical structure of fog and to identify droplet concentration zones in cloud segments over spatial resolutions from hundreds of meters to tens of centimeters. The results show that a broadening of the droplet spectra towards larger sizes occurs in zones of decreased droplet concentration. This provides new information regarding fog microstructure at scales where important droplet growth occurs by condensation and coagulation. It is concluded that detailed knowledge of droplet spectra variations along fog transects provide further information for the characterization of cloud inhomogeneities.     

Large-scale urban functional zone mapping by integrating remote sensing images and open social data

ABSTRACT

Urban functional zones (UFZs) are important for urban sustainability and urban planning and management, but UFZ maps are rarely available and up-to-date in developing countries due to frequent economic and human activities and rapid changes in UFZs. Current methods have focused on mapping UFZs in a small area with either remote sensing images or open social data, but large-scale UFZ mapping integrating these two types of data is still not be applied. In this study, a novel approach to mapping large-scale UFZs by integrating remote sensing images (RSIs) and open social data is proposed. First, a context-enabled image segmentation method is improved to generate UFZ units by incorporating road vectors. Second, the segmented UFZs are classified by coupling Latent Dirichlet Allocation (LDA) and Support Vector Machine (SVM). In the classification framework, physical features from RSIs and social attributes from POI (Point of Interest) data are integrated. A case study of Beijing was performed to evaluate the proposed method, and an overall accuracy of 85.9% was achieved. The experimental results demonstrate that the presented method can provide fine-grained UFZs, and the fusion strategy of RSIs and POI data can distinguish urban functions accurately. The proposed method appears to be promising and practical for large-scale UFZ mapping.     

Quantitative estimates of interplate coupling inferred from outer rise earthquakes

Interplate coupling plays an important role in the seismogenesis of great interplate earthquakes at subduction zones. The spatial and temporal variations of such coupling control the patterns of subduction zone seismicity. We calculate stresses in the outer rise based on a model of oceanic plate bending and coupling at the interplate contact, to quantitatively estimate the degree of interplate coupling for the Tonga, New Hebrides, Kurile, Kamchatka, and Marianas subduction zones. Depths and focal mechanisms of outer rise earthquakes are used to constrain the stress models. We perform waveform modeling of body waves from the GDSN network to obtain reliable focal depth estimates for 24 outer rise earthquakes. A propagator matrix technique is used to calculate outer rise stresses in a bending 2-D elastic plate floating on a weak mantle. The modeling of normal and tangential loads simulates the total vertical and shear forces acting on the subducting plate. We estimate the interplate coupling by searching for an optimal tangential load at the plate interface that causes the corresponding stress regime within the plate to best fit the earthquake mechanisms in depth and location.We find the estimated mean tangential load over 125–200 km width ranging between 166 and 671 bars for Tonga, the New Hebrides, the Kuriles, and Kamchatka. This magnitude of the coupling stress is generally compatible with the predicted shear stress at the plate contact from thermal-mechanical plate models byMolnar andEngland (1990), andVan den Buekel andWortel (1988). The estimated tectonic coupling,F _tc , is on the order of 10¹²–10¹³ N/m for all the subduction zones.F _tc for Tonga and New Hebrides is about twice as high as in the Kurile and Kamchatka arcs. The corresponding earthquake coupling forceF _ec appears to be 1–10% of the tectonic coupling from our estimates. There seems to be no definitive correlation of the degree of seismic coupling with the estimated tectonic coupling. We find that outer rise earthquakes in the Marianas can be modeled using zero tangential load.     

Sex offenders,housing and spatial restriction zones

Sex offenders are currently a major focus of crime control policies at the local, regional, state and federal levels throughout the United States. In part, the perceived threat of offender recidivism has motivated legislators to launch stringent community notification programs and to establish spatial restriction zones (SRZs) around schools, daycare facilities and public parks. The purpose of these restriction zones is to help protect children and minimize their exposure to convicted sex offenders living in the community. In addition to the concern that the implementation of SRZs dramatically reduces viable housing options for registered sex offenders, there are concerns that offenders will be forced to reside in socially disorganized areas that may encourage recidivism. The purpose of this paper is to explore the demographic and socioeconomic differences between areas inside and outside SRZs. Implications of these results for sex offender policies are discussed.

Seismic hazard in mega city Kolkata, India

The damages caused by recent earthquakes in India have been a wake up call for people to take proper mitigation measures, especially the major cities that lie in the high seismic hazard zones. Kolkata City, with thick sediment deposit (∼12 km), one of the earliest cities of India, is an area of great concern as it lies over the Bengal Basin and lies at the boundary of the seismic zones III and IV of the zonation map of India. Kolkata has been affected by the 1897 Shillong earthquake, the 1906 Calcutta earthquake, and the 1964 Calcutta earthquake. An analysis on the maximum magnitude and b-value for Kolkata City region is carried out after the preparation of earthquake catalog from various sources. Based on the tectonic set-up and seismicity of the region, five seismic zones are delineated, which can pose a threat to Kolkata in the event of an earthquake. They are broadly classified as Zone 1: Arakan-Yoma Zone (AYZ), Zone 2: Himalayan Zone (HZ), Zone 3: Shillong Plateau Zone (SPZ), Zone 4: Bay of Bengal Zone (BBZ), and Zone 5: Shield Zone (SZ). The maximum magnitude (m _max) for Zones 1, 2, 3, 4, and 5 are 8.30 ± 0.51, 9.09 ± 0.58, 9.20 ± 0.51, 6.62 ± 0.43 and 6.61 ± 0.43, respectively. A probability of 10% exceedance value in 50 years is used for each zone. The probabilities of occurrences of earthquakes of different magnitudes for return periods of 50 and 100 years are computed for the five seismic zones. The Peak Ground Acceleration (PGA) obtained for Kolkata City varies from 0.34 to 0.10 g.     

中国工业用地出让价格空间格局及影响因素

在财政分权和地方竞争的制度背景下,地方政府为了吸引更多企业投资,往往采取过量供应工业用地、压低工业用地价格的手段,直接导致了中国工业用地利用效率低下,甚至资源严重浪费等问题。合理调控工业用地供应规模及价格,发挥市场机制对工业用地出让价格的主导作用,是促进工业用地集约高效利用的重要途径。本文以工业用地出让价格为研究对象,利用2009、2011、2013、2015、2017年全国工业用地出让数据,采用分层模型,结合宏观和微观尺度,实证分析了中国工业用地出让价格的空间格局及关键影响因素。实证研究发现：① 我国不同区域的工业地价差异较大,政府的干预能力显著影响城市工业用地的出让价格,在控制其他影响因素下,干预能力越强,工业用地出让价格越低;② 宗地层面的因素中,距离城市中心或水源越近、交通通达度越好,工业用地的出让价格越高;③ 城市层面的因素中,人口数量越多,经济发展水平越高,工业用地的出让价格越高。本研究首次将分层模型引入实证计量方法,同时验证了影响工业用地出让价格的宏观与微观因素,是对现有工业用地出让价格研究文献的补充与延伸。     

2000-2010年新疆陆地生态系统变化格局与分析

本文以Landsat TM/ETM+数据和HJ-1卫星CCD数据,系统分析了2000-2010年新疆地区陆地生态系统变化。10年间,新疆地区建设用地、农田和湿地生态系统迅速扩张,分别增加了30.5%、26.7%和10.2%;草地与灌丛生态系统则大量减少,分别减少了2.4%和5.1%;冰川积雪减少也较为明显,减少了1.6%;荒漠和森林生态系统变化较小。生态系统变化热点区域主要分布在传统绿洲区,尤其是天山南北麓的绿洲区。水利设施改善与灌溉节水技术进步,以及国家西部开发战略导致灌草地被大量开垦为农田,人口增长则是建设用地增加的主因;全球气候变暖使冰川积雪减少明显,20世纪60年代至今面积减少了16.7%~32.5%,导致山区湿地生态系统增加;国家生态环境保护工程则有效地遏制了林地与荒漠生态系统的恶化趋势。山地水源涵养区除了要严格控制森林砍伐外,还要严格禁止灌草的开垦,控制绿洲农田的增加和重视生态过渡带的保护,并加强全球气候变化对新疆水资源影响的研究,以制定相关对策。     

全球主要俯冲带处板块运动与地震各向异性及应力场的相关性讨论

在全球板块的很多地方,包括俯冲带、大洋中脊、甚至大陆板块的内部等,地震各向异性都与板块绝对运动图像存在一定的相关性,或者与板内应力场的优势取向一致。本文统计分析了全球9个包含主要俯冲带的板块边界内板块运动与地震各向异性及应力场的相关性,结果表明,板块的绝对或相对运动控制着板块边界的地震各向异性和应力场特征,尤其是板块的相对运动,在板块边界带处的影响十分明显;从计算结果还可以看出,板块的相对运动方向与地震各向异性及应力场的相关性要好于板块绝对运动。在包含俯冲带的板块边界处,由于俯冲机理的复杂性和控制因素的多样性,使得俯冲带处两者的相关性较为复杂,不同深度来源的各向异性表现出不同特征,且应力状态受多种因素的控制。     

限制开发区域农户薪柴消费的影响因素分析——以云南省怒江州为例

本文以位于国家限制开发区域的云南省怒江州为例,利用654份农户调查问卷和logistic回归模型对农户薪柴消费的影响因素进行了实证分析。研究结果表明,农户薪柴消费与家庭总人口、是否外出打工、所在行政村是否在自然保护区、所在行政村海拔是否大于2000米、所在行政村到县城的距离正相关,与上年现金支出、是否有现金补贴、住房条件负相关。在保持其他变量不变的前提下,所在行政村海拔大于2000米的农户使用薪柴的概率比海拔在2000米以下的农户高64.70%;在自然保护区的农户消费薪柴的概率是自然保护区外农户的3.26倍;所在行政村到最近县城的距离每增加1公里,农户使用薪柴的概率增加6.12%;对农户进行现金补贴会使薪柴消费概率下降38.39%。在此基础上,对限制开发区域的环保政策、财政政策、人口政策、产业政策、投资政策提出了有针对性的调整建议。     

Seismic isolation foundations with effective attenuation zones

In this paper, a new configuration of seismic isolation foundation containing several concrete layers and some rubber blocks is proposed. The concrete layers and the rubber blocks are placed periodically to form a periodic foundation. To study the isolation ability of this new configuration of periodic foundation, an equivalent analytical model is established. For practical applications, two very useful formulas are obtained. Using these formulas, the low bound frequency and the width of the first attenuation zone can be directly approximated without the calculation of dispersion structure. This new configuration of seismic isolation foundation enjoys the first attenuation zone between 2.15 Hz and 15.01 Hz, which means that the components of seismic waves with frequencies from 2.15 Hz to 15.01 Hz cannot propagate upward in the foundation. To illustrate the efficiency of this seismic isolation foundation, the seismic responses of a 6-story frame with three different foundations are simulated. Numerical simulations show that the seismic responses of the structure with the periodic foundation are greatly attenuated as compared with those of the structure with no isolation base or with traditional rubber bearings.