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951.
分析了天水台数字深井水温资料在陕西石泉ML4.7级地震前的异常特征,发现在震前5天内深井水温发生大幅度的降升变化,呈负脉冲形态,表现为典型的脉冲型前兆异常形态特征。 相似文献
952.
953.
R. Mook 《Pure and Applied Geophysics》1978,117(4):573-582
For the site of the astronomical observatory operated by The University of Tromsø in Skibotn, Northern Norway, the distribution of very small amounts of atmospheric water vapour is estimated from aerological data. For 5 winter months through a period of 11 years, during at least 6 per cent of the time, the precipitable water is likely not to exceed 3.0 mm, i.e. observations at wavelengths as long as 25 and a little short of 1 mm are possible. For a mountain site at 1250 m altitude, the corresponding amount is estimated to be 1.8 mm. The small amounts considered, were observed in the subsidence of tropospheric ridges. The Skibotn site is compared with other sites for infrared measurements in the Subtropics and in the Arctic. 相似文献
954.
Monitoring and evaluation of groundwater quality in drinking water protectorates is of particular interest if the uncontrolled entry of pollutants, for example by infiltrating river water, cannot be excluded. A fluorescence spectroscopic method is presented as possible alternative to the conventional expensive hydrochemical investigations. This method uses the information yielded by synchronous fluorescence spectra. After a Fourier transformation of the original spectra and a following discriminant analysis, the samples can be classified in different groups corresponding to the different types of groundwater. The method was tested in the drinking water protectorate of a waterworks of a German metropolis (Halle, Sachsen-Anhalt). We found a prediction rate of about 90% in the investigated case. 相似文献
955.
对重力学反问题研究中零外部位密度的数学性质及物理意义进行了系统研究和分析.首先从基本定义及条件的描述入手,推演出其数学表示和限制,由此揭示重力学反问题的非适定性形态,进而论及其与非零外部位密度之间的数学关系.由此证明对应于给定外部位的场源函数可以分解成零外部位密度与调和密度的直和.通过对其物理意义的讨论,为地球物理反演非零外部位场源及物理大地测量学构制等效场源提供理论依据. 相似文献
956.
“七五”期间,黄淮海平原农业开发禹城试区,成功地推广了鱼塘-台田生态系统。为挖掘开发潜力及寻求最佳系统模式,本文结合渔业生产环境条件进行鱼塘不同深度的温度分析,认为,在该区的气候条件下,水深一般保持在1.5 ̄2.0m较为适宜。 相似文献
957.
浅地层剖面仪在水域工程勘察中的应用 总被引:7,自引:0,他引:7
扼要介绍了水上浅地层剖面仪的方法技术,列举了该法在浅海,内河和湖泊减种典型环境及相应的地质条件下勘测所得到的剖面记录及地质解释结果,指出了运用该方法所能解决的工程地质问题。 相似文献
958.
The principle of water balance is well known, but its application often causes controversy. One recent debate is the use of the water balance equation to determine the safe yield and sustainable yield. Two extreme opinions exist on natural groundwater recharge. One misconception is that the development of groundwater is considered to be safe if the pumping rate does not exceed the rate of natural recharge. Another is that the sustainable pumping rate has nothing to do with natural recharge, but depends on the increased recharge and decreased discharge (called capture) induced by pumping. The truth is that both the natural recharge and dynamic development of the capture determine the safe yield or sustainable yield of a groundwater basin. This paper clarifies the water budget controversy and uses the water balance equation to critically analyse the concepts of safe yield and sustainable yield. Numerical simulation of a hypothetical case was used to demonstrate the natural groundwater balance, effects of pumping and the dynamic development of the capture. 相似文献
959.
Víctor Leiva Antonio Sanhueza José M. Angulo 《Stochastic Environmental Research and Risk Assessment (SERRA)》2009,23(3):299-307
In this article, we develop a new model based on the Birnbaum-Saunders distribution that results to be both useful and practical
for environmental sciences. The density, distribution and hazard functions, moments and properties of this new model are presented.
A graphical analysis of the density is also provided. Furthermore, we estimate parameters, propose asymptotic inference and
discuss influence diagnostics by using likelihood methods for the new distribution. An illustrative example with real data
related to water quality indicates the adequacy on the new distribution. 相似文献
960.
Water vapour transport of the pre-monsoon period and the general performance of the Indian summer monsoon 总被引:1,自引:0,他引:1
S. N. Bavadekar 《Pure and Applied Geophysics》1982,120(1):67-78
The advective monthly mean transfer of water vapour in the layer below 700 mbar is investigated for India for the years 1962 to 1972 and for the months January to September. The average zonal and meridional components of the transfer of water vapour for India are obtained. They are further averaged for different combinations of the pre-monsoon months from January to May and are correlated with the summer monsoon rainfall. The correlation coefficients for zonal transfer of water vapour are either negative or small positive for different combinations of the months mentioned above. The correlation coefficients for the meridional transfer of water vapour are positive. The maximum value is 0.74 for the March to May combination and is statistically significant at the 1% level.An extensive investigation is, therefore, made for the March to May averages of water vapour transfer for four broad regions of India. The parameters of water vapour transfer for these regions are compared with the threshold values and the prediction category, normal or drought, for the subsequent summer monsoon season is determined for all years. The correlation coefficient between the index of drought, as determined from parameters of water vapour transport and rainfall departure, is statistically significant at the 2% level. 相似文献