Episodic Performance and Sensitivity of the Urbanized MM5 (uMM5) to Perturbations in Surface Properties in Houston Texas

We present an application of a fine-resolution, meso-urban meteorological model (urbanized MM5; uMM5) to a multi-day episode in August 2000 in the Houston-Galveston Texas, USA region. The model’s episodic performance and its response to small changes in land-cover and surface physical properties in the area, e.g., scenarios of urban heat island mitigation, are evaluated. The model formulation is reviewed along with its parameterizations, data needs, and fine-resolution geometrical input. Development of scenarios of increased urban albedo and vegetative cover is also discussed. This initial application of the uMM5 to the Houston-Galveston region serves as a basis for future model improvements, evaluation of newer data and parameterization applications, testing more aggressive surface modification scenarios, and performing fine-resolution photochemical modelling. It also provides data for comparison of model results with those from previous studies of this region.     

贵州高原起伏地形下日照时间的时空分布

由于坡度、坡向和地形之间相互遮蔽等局地地形因子的影响, 实际起伏地形下的日照时间与水平面上的日照时间有一定差异。该文建立了一种基于数字高程模型 (DEM) 的起伏地形下日照时间的模拟方法, 计算了起伏地形下贵州高原100 m×100 m分辨率日照时间的时空分布。结果表明:坡度、坡向、地形遮蔽对日照时间的影响较大, 实际起伏地形下日照时间的空间分布具有明显地域特征。1月太阳高度角较低, 坡度、坡向的作用非常明显, 地形遮蔽面积较大, 日照时间的空间差异较多, 日照时间为16~142 h, 最大值约为最小值9倍; 7月太阳高度角较高, 地形遮蔽面积相对较小, 日照时间的空间差异相对较少, 日照时间为133~210 h, 最大值为最小值1.6倍, 但由于7月日照时间相对较多, 局地地形对日照时间影响仍明显。4月、10月日照时间及其变化幅度介于1月和7月之间。     

利用多时相Landsat影像生成白洋淀湖底DEM的研究

该文使用多时相Landsat影像,以白洋淀地区为例,阐述基于中等分辨率的可见光—近红外遥感影像生成具有较高精度数字高程模型的非常规方法。对覆盖同一研究区的不同时相影像分别进行淹没区与非淹没区的分类,提取不同水位高度时的水域边界,并以此为相应水位高度的等高线,对获得的等高线进行插值生成数字高程模型(DEM)。这种由一系列遥感影像提取的水域图生成数字高程模型的方法适用于人为干预较少、地形相对简单的湿地或季节性湖泊,可以弥补该类地区数字高程信息不足或精度不够的缺陷。     

Contrastive Study of the Circular Economy of Coal Resource City Based on Ecological Efficiency and C Model

Being a developing country, the evaluation of Chinese circular economy should have its particular criterion that suits for specific national conditions. With the growth of economy, Chinese environmental loads should be permitted to increase at an appropriate speed. Based on this concept, this paper divides the process of evaluation into two parts which include evaluation of development level and evaluation of development performance. Firstly, this paper sets up a reference system which includes Zaozhuang City of Shandong Province, Jiaozuo City of Henan province, Shizuishan City of Ningxia Hui Autonomous Region and China that is regarded as a region respectively, analyzes the development level of circular economy of coal resource cities based on the evaluation indicator of ecological efficiency, and puts forward the future direction of circular economy of coal resource cities. Secondly, based on C Model of Circular Economy, this paper constructs the measurement model of development performance in which study regions are analyzed in a particular period that is from 2000 to 2020, and evaluates the development performance of circular economy for study regions according to the relationship of growth multiples between economic scale and environmental loads. We can draw several main conclusions: firstly, the development pathways of all four study regions belong to type Ⅱ which resource efficiency is preferred. Secondly, the comprehensive energy consumption efficiencies of coal resource cities were left far behind by China’s average level. Thirdly, the circular economies of all study regions have achieved remarkable progress. Fourthly, the development level of circular economy can be evaluated from two dimensions which consist of horizontal comparison method and vertical comparison method. Fifthly, C model is an appropriate development model that suits for Chinese national conditions and could be selected as an important method to evaluate regional development performance of circular economy.     

少数民族村寨过度商业化个案研究 ——以贵州西江千户苗寨为例

以贵州西江千户苗寨为案例,基于“刺激―机体―反应”分析范式的M-R理论模型,提出影响个体游客商业化感知的外部环境因素和概念模型。通过结构方程模型实证检验影响游客商业化感知的先决变量及各变量间的影响路径,结果表明：旅游空间环境、居民社会形态与旅游产品附属对游客商业化感知具有显著的正相关影响作用,其中,旅游商业环境通过旅游空间环境间接对游客商业化感知产生正向影响作用。在实证分析基础上,从景区管理层面的商业化“刺激―反应”演变过程探讨其驱动机制及利益主体间的关系,认为产权配置不合理及缺乏有效的管理机制是民族村寨类景区过度商业化的根本原因,最后提出调控景区商业化的建议。     

Impact of sample size on geotechnical probabilistic model identification

This paper aims to investigate the impact of sample size on geotechnical probabilistic model identification. First, the copula approach is presented to model the bivariate distribution of geotechnical parameters. Thereafter, the AIC scores are adopted to identify the best-fit marginal distribution and copula. Second, the variation of AIC scores because of small sample size is investigated using simulated data. Finally, the impact of the variation of AIC scores on identification of the best-fit marginal distribution and copula is examined. The minimum sample sizes for geotechnical data are also suggested to obtain a correct identification of the probabilistic models. The results indicate that the AIC scores estimated from a small sample exhibit large variation. The variation of the AIC scores has a significant impact on probabilistic model identification. The marginal distributions and copulas have a low percentage of correct identification when sample size is small. The percentages of correct identification for the marginal distributions and copulas increase with increasing sample size. The correlation coefficient between geotechnical parameters has a much larger impact on probabilistic model identification than the COV of geotechnical parameters. The suggested minimum sample sizes for geotechnical data are useful for guiding practical geotechnical site investigation.     

From Discrete Gravity Survey Data to a High-resolution Gravity Field Representation in the Nordic-Baltic Region

The deduction of a regularly spaced gravity anomaly grid from scattered survey data is studied, addressing mainly two aspects: reduction of gravity to anomalies and subsequent interpolation by various methods. The problem is illustrated in a heterogeneous study area and contrasting test areas including mountains, low terrains, and a marine area. Provided with realistic error estimates, Least Squares Collocation interpolation of Residual Terrain Model anomalies yields the highest quality gravity grid. In most cases, the Bouguer reduction and other interpolation methods tested are equally viable. However, spline-based interpolation should be avoided in marine areas with trackwise survey data.     

溢油扩展、漂移及扩散预测技术研究进展

海上溢油灾害会严重破坏中国近海海洋环境,还会直接危害我国经济发展。因此,开展溢油预测预警技术研究是非常有必要的,能够为海上溢油应急响应提供技术支撑。本文综述了溢油扩展、漂移及扩散数值预测技术的发展过程及相关研究成果,包括溢油扩展模型、溢油漂移与扩散模型、溢油预测预警系统,为未来开展溢油应急工作提供了理论依据和参考。     

Recreational boaters value biodiversity: The case of the California Channel Islands National Marine Sanctuary

Marine ecosystems provide a range of valuable services, some of which come with market prices to quantify value and others for which markets have not set prices. Lacking perfect information, policy makers are at risk of undercounting non-priced values and services, leading to biases in policy decisions in favor of services valued through markets. Furthermore, understanding users’ valuation of specific site attributes, such as marine biodiversity, can contribute to effective policy decisions. This paper presents a non-market valuation of private recreational boaters (PRBs) in the Channel Islands National Marine Sanctuary located in California, USA, using data from an intercept survey conducted in 2006 and 2007. A Random Utility Model is used to estimate PRBs’ daily trip values and the importance of specific site attributes. The average consumer surplus was estimated at $48.62 per trip, with a total non-market value of non-consumptive private recreational boating of $86,325 annually. PRBs show a preference for visiting locations with lower exposure to prevailing winds and greater species richness and abundance, which to the authors’ knowledge is the first time that PRBs have been found to value biological diversity in site choices. Furthermore, this suggests that improved biodiversity and productivity of marine ecosystems contribute to better recreational experiences. The results from this study reveal the importance of including non-market services and stakeholder's preferences into policy decisions.     

Investigation of seismic response of cantilever retaining walls: Limit analysis vs shaking table testing

The earthquake response of cantilever retaining walls is explored by means of theoretical analyses and shaking table testing conducted at University of Bristol (EERC - EQUALS). The theoretical investigations employ both limit analysis and wave-propagation methods, which take into account different aspects of the problem such as inertia, strength, kinematics and compatibility of deformations. The experimental programme encompasses different combinations of retaining wall geometries, soil configurations and input ground motions. The response analysis of the systems at hand aims at shedding light onto salient features of the problem, such as: (1) the magnitude of soil thrust and its point of application; (2) the relative sliding versus rocking of the wall base and the corresponding failure modes; (3) the importance of the interplay between soil stiffness, wall dimensions and excitation characteristics, as affecting the above; (4) the importance of wall dynamics and phase differences between peak stresses and displacements. The results of the experimental investigations are in good agreement with the theoretical models and provide a better understanding on the complex mechanics of the problem.