The temporal and spatial relationship between NDVI and climatological parameters in Colorado

1 Introduction In recent years, many researchers have demonstrated that there are essential and evident correlations between NDVI and climatological parameters (temperature and precipitation). The analysis of correlation between climate forces and time-integrated NDVI over US Northern and Central Great Plains suggested that spatial and temporal variation of precipitation and potential evapotranspiration and growing degree days in growing season are the most important control on grassland…     

河南宝泉抽水蓄能电站近场区断裂活动特征及对兴建电站的稳定性评价

本文通过野外调查和人工地震反射剖面法对河南宝泉抽水蓄能电站近场区内的断裂进行了详细的研究,结果表明近场区内的断裂活动在晚更新世以来均已停止,断裂活动将不会影响该电站的稳定性。     

用相关函数优化法计算离散线性水文模型参数

借助于日降雨和出流资料系列,采用相关函数优化方法确定离散线性水文模型参数是一种新的方法.文中选用4个流域8年日降雨和径流资料系列来检验相关函数优化法(6年作为率定期,2年作为验证期),所得结果与常规最小二乘法计算的结果进行比较表明:新方法计算精度比常规最小二乘法计算的精度有所提高,常规最小二乘法仅是相关函数优化法的一种特例.     

Hydrocarbons in sediments of a chronically contaminated bay: the challenge of source assignment

Aliphatic hydrocarbons and 39 PAH (parental and alkylated homologs) determined in ca. 100 sediment samples from the Guanabara Bay, Rio de Janeiro, were evaluated for source discrimination using new approaches. Concentrations of total PAH were in the range of 96-135,000 μg kg(-1) similar to other coastal urbanized embayment. Traditional diagnostic ratios were not as efficient PAH source indicators, e.g. biomass combustion was assigned as the major source of the pyrolytic PAH although the hydrographic basin is highly industrialized and urbanized. It is proved petrogenic imprint cannot be detected if only the 16 USEPA PAH are determined. The high production in the eutrophic system is not apparent in the aliphatic fraction dominated by land derived n-alkanes due to the effectiveness of microbial degradation. The present work demonstrates the complexity of hydrocarbon forensics when applied to chronically contaminated environments.     

GSTARS computer models and their applications, part I： theoretical development

GSTARS is a series of computer models developed by the U.S. Bureau of Reclamation for alluvial river and reservoir sedimentation studies while the authors were employed by that agency. The first version of GSTARS was released in 1986 using Fortran IV for mainframe computers. GSTARS 2.0 was released in 1998 for personal computer application with most of the code in the original GSTARS revised, improved, and expanded using Fortran IV/77. GSTARS 2.1 is an improved and revised GSTARS 2.0 with graphical user interface. The unique features of all GSTARS models are the conjunctive use of the stream tube concept and of the minimum stream power theory. The application of minimum stream power theory allows the determination of optimum channel geometry with variable channel width and cross-sectional shape. The use of the stream tube concept enables the simulation of river hydraulics using one-dimensional numerical solutions to obtain a semi-two- dimensional presentation of the hydraulic conditions along and across an alluvial channel. According to the stream tube concept, no water or sediment particles can cross the walls of stream tubes, which is valid for many natural rivers. At and near sharp bends, however, sediment particles may cross the boundaries of stream tubes. GSTARS3, based on FORTRAN 90/95, addresses this phenomenon and further expands the capabilities of GSTARS 2.1 for cohesive and non-cohesive sediment transport in rivers and reservoirs. This paper presents the concepts, methods, and techniques used to develop the GSTARS series of computer models, especially GSTARS3.     

瑞典废料地质处理的不同地下设施

1 国际合作现在全世界将近有500座核电站在运转。它们产生一些放射性垃圾,其中大多数长效放射性元素需要与人类环境隔离,安全储存成千上万年。在大多数国家,在地下深部岩石中的储存被认为是安全的,然而,其稳定的地质条件和低渗透性结构(如图1)的场地位置是放射性垃圾地下深部储存的必须满足的安全前提。