地下水的MIMO系统和参数识别方法

根据含水系统的输入输出特性,用时间差分方法逼近,可以获得较高精度的预报模型,无需得知含水系统的内部结构,建模统一。本文提出MIMO系统参数的三种识别方法:1.参数和阶的逐步回归一次识别法;2.半递推识别法;3.逐步回归定参数定阶后递推识别法。     

Regular multigraphs and their application to the Monte Carlo evaluation of moments of non-linear functions of Gaussian random variables

This paper expands on the multigraph method for expressing moments of non-linear functions of Gaussian random variables. In particular, it includes a list of regular multigraphs that is needed for the computation of some of these moments. The multigraph method is then used to evaluate numerically the moments of non-Gaussian self-similar processes. These self-similar processes are of interest in various applications and the numerical value of their marginal moments yield qualitative information about the behavior of the probability tails of their marginal distributions.     

87Sr/86Sr-Untersuchungen an Grundwässern des Berliner Urstromtales

From a sector within an extended Tertiary basin 21 groundwater samples as well as 3 rock samples of a Zechslein diapir were analysed for ⁸⁷Sr/⁸⁶Sr-ralio. As a tendency the isotope ratio of the dissolved strontium is decreasing with increasing depth and strontium content. Furthermore, strontium content and salinity are correlated. With two exceptions the isotope data are in the range between about 0.7080 and 0.7100. Significant differences in the strontium isotope composition were found between the Zechstein salts and the typical groundwaters. This shows, that the Zechstein diapir can not be the source of the higher salinity in parts of the groundwater system. The results are discussed.     

Umweltisotope Zur Stüzung Eines Hydrogeologischen Konzepts im Mygdonias-Becken,Halbinsel Chalkidiki (Griechenland)

Abstract

Recharge areas in hard rocks of the margin of the Mygdonias-Basin (Greece) with the origin of thermal waters (max. 50°C) are assumed. Environmental isotopes, ³H, D, ¹⁸O. ¹³C, ³⁴S are supporting a concept of recharging normal temperated water along the northern margin of the basin, especially in the cross-area of tectonic faults.     

Isotopic composition of atmospheric moisture from pan water evaporation measurements

A continuous and reliable time series data of the stable isotopic composition of atmospheric moisture is an important requirement for the wider applicability of isotope mass balance methods in atmospheric and water balance studies. This requires routine sampling of atmospheric moisture by an appropriate technique and analysis of moisture for its isotopic composition. We have, therefore, used a much simpler method based on an isotope mass balance approach to derive the isotopic composition of atmospheric moisture using a class-A drying evaporation pan. We have carried out the study by collecting water samples from a class-A drying evaporation pan and also by collecting atmospheric moisture using the cryogenic trap method at the National Institute of Hydrology, Roorkee, India, during a pre-monsoon period. We compared the isotopic composition of atmospheric moisture obtained by using the class-A drying evaporation pan method with the cryogenic trap method. The results obtained from the evaporation pan water compare well with the cryogenic based method. Thus, the study establishes a cost-effective means of maintaining time series data of the isotopic composition of atmospheric moisture at meteorological observatories. The conclusions drawn in the present study are based on experiments conducted at Roorkee, India, and may be examined at other regions for its general applicability.     

USGS48 Puerto Rico precipitation – a new isotopic reference material for δ2H and δ18O measurements of water

A new secondary isotopic reference material has been prepared from Puerto Rico precipitation, which was filtered, homogenised, loaded into glass ampoules, sealed with a torch, autoclaved to eliminate biological activity, and calibrated by dual-inlet isotope-ratio mass spectrometry. This isotopic reference material, designated as USGS48, is intended to be one of two isotopic reference waters for daily normalisation of stable hydrogen (δ²H) and stable oxygen (δ¹⁸O) isotopic analysis of water with a mass spectrometer or a laser absorption spectrometer. The δ²H and δ¹⁸O values of this reference water are?2.0±0.4 and?2.224±0.012 ‰, respectively, relative to Vienna Standard Mean Ocean Water on scales normalised such that the δ²H and δ¹⁸O values of Standard Light Antarctic Precipitation reference water are?428 and?55.5 ‰, respectively. Each uncertainty is an estimated expanded uncertainty (U=2u_c) about the reference value that provides an interval that has about a 95 % probability of encompassing the true value. This isotopic reference water is available by the case of 144 glass ampoules containing 5 mL of water in each ampoule.     

水文预报不确定性的研究进展与展望

本文归纳了水文预报不确定性的来源与分类,综述了国内外对水文预报不确定性的研究进展以及相关文献、方法与模型,展望了水文预报不确定性研究的发展前景.水文预报的不确定性始终存在,并制约防洪调度决策的正确性,水文预报结果应该描述为概率的而不是确定的形式,概率水文预报实现了预报与决策的耦合.     

水库水情自动测报系统研究

对盘石头水库水情自动测报系统的建设方案进行了研究，并分析了系统可靠性，为实现水库安全运行及优化调度、获得最佳的防洪效益提供理论依据。     

水文测报系统的结构化分层、互连及通信协议的探讨

从计算机网络技术的角度，对水文测报系统的体系结构进行了分析和探讨，内容包括：水文测报系统结构化分层；通信协议的讨论；各层次网络的互连．     

Natural and anthropogenic variations in the Po river waters (northern Italy): insights from a multi-isotope approach

Po is the main Italian river and the δ¹⁸O and δ²H of its water reveal a similarity between the current meteoric fingerprint and that of the past represented by groundwater. As concerns the hydrochemisty, the Ca–HCO₃ facies remained constant over the last 50 year, and only nitrate significantly increased from less than 1?mg/L to more than 10?mg/L in the 1980s, and then attenuated to a value of 9?mg/L. Coherently, δ¹³C_DIC and δ³⁴S_SO4 are compatible with the weathering of the lithologies outcropping in the basin, while extremely variable δ¹⁵N_NO3 indicates contribution from pollutants released by urban, agricultural and zootechnical activities. This suggests that although the origin of the main constituents of the Po river water is geogenic, anthropogenic contributions are locally significant. Noteworthy, the associated aquifers have the same nitrogen isotopic signature of the Po river, but are characterized by significantly higher NO^– ₃ concentration. This implies that aquifers’ pollution is not ascribed to inflow of current river water, and that the attenuation of the nitrogen load recorded in the river is not occurring in the aquifers, due to their longer water residence time and delayed recovery from anthropogenic contamination.