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81.
The seismic hazard in the Sannio-Matese area has been worked out by a modification of the McGuire (1976) computing programme, taking into account the influence of nine potential seismic source zones.The method uses truncated-quadratic intensity-frequency distribution and azimuth-dependent intensity attenuation derived from isoseismal maps for each of the seismogenetic sources. A new modification has been introduced to take into account different decay of the intensity in the near (to VIII degree) and far (from VIII degree) field.Different assumptions about maximum possible intensities and truncation of intensity-frequency laws are used to evaluate the effects of the uncertainties on the computed hazard at high intensities. Intensities associated with different level of annual probability are computed for five test sites in the considered area. Maps displaying the expected intensity for a mean return period of 500 years (pa 0.002) are presented and compared with observed intensities.Presented at the XXIst General Assembly of the European Seismological Commission, Symposium on Methods of Seismic Hazard Assessment in Europe, Sofia, 23–27 August 1988. 相似文献
82.
David M. Livingstone Dieter M. Imboden 《Aquatic Sciences - Research Across Boundaries》1989,51(4):351-369
The mean heat budget of Lake Aegeri, Switzerland, is 950 MJ·m–2, comparable to that of neighbouring lakes. The annual variation in the net heat flux can be adequately described using a six-term heat balance equation based on 12 years of monthly mean meteorological and surface temperature data. Although the magnitude of the net heat flux is dominated by the radiative terms of the equation, the one-month backward shift of the net flux and total heat content extrema from the solstices and equinoxes respectively is due to the phase shift of the non-radiative with respect to the radiative terms. A linear approximation was used to express the net heat flux in terms of a heat exchange coefficient and an equilibrium temperature. The former varies from 17 to 28 W·m–2·K–1 in the course of a year; fluctuations in the latter are found to depend mainly on fluctuations in cloud cover and relative humidity, whilst the effect of fluctuations in air temperature and wind speed is slight. 相似文献
83.
西太平洋赤道海域的热量平衡 总被引:1,自引:0,他引:1
本文利用1986年11月中国科学院实验3号考察船在西太平洋赤道海域(0°~5°N,130°~150°E)考察所获得的29天辐射资料和同期取得的温、压、湿、风和探空等资料,计算了这一海域11月份的热量平衡各量值和整层气柱的加热量。结果表明:该海域是一个强热源区,其上空大气也是一个强热源区。 相似文献
84.
Norikazu Matsuoka 《地球表面变化过程与地形》1994,19(5):423-435
Rock temperatures were monitored for a year at two alpine rockwalls in the Akaishi Range, Japan, where permafrost is absent. Diurnal frost and thaw penetration depths were evaluated from subsurface isotherms drawn on the basis of the temperature records at 0, 10 and 40 cm depths. The surface of the rockwalls experienced more than 100 diurnal freeze-thaw cycles, most of which accompanied a frost or thaw penetration shallower than 50 cm, and several long duration cycles with deeper frost or thaw penetration. Theoretical frost and thaw depths were also calculated by incorporating the surface freezing indices into the modified Berggren equation, the results from which were then compared with the actual values. The modified Berggren equation provided values that showed a strong correlation with observed depths, despite somewhat underestimating the actual values. Using the modified Berggren equation, the seasonal frost depth in the observed winter was estimated to be about 4·5 m. The frost and thaw depths are considered to give the maximum estimation of the depth to which frost-induced cracking can propagate in the bedrock. 相似文献
85.
内蒙古奈曼麦田生长期的微气象变化 总被引:2,自引:1,他引:2
采用波文比热量平衡法分析了内蒙古奈曼麦田生长不同阶段的微气象变化。结果表明:(1)麦田反射率随小麦生长趋于旺盛而减小;(2)随着小麦的生长,净辐射及其与太阳总辐射的比值增大;(3)白天净辐射主要用于潜热交换;夜里净辐射主要由潜热交换与土壤热交换补给;(4)波文比白天小,早晨和夜里大。 相似文献
86.
87.
不同补给源的水,其水质、水温存在差异。根据质量和热量守恒原理,通过对不同补给水源进行长期观察,可确定矿坑水的补给源及其比例。作者推导出了存在二种和三种补给水源情况下各补给水源所占比例的计算公式,并应用到湖南洞口县的石下江煤矿,取得了良好效果。 相似文献
88.
TROPICAL ATMOSPHERIC NONLINEAR STEADY RESPONSE SOLUTION UNDER EFFECTS OF PAIRED HEAT SOURCES OF CONTRASTING NATURE 下载免费PDF全文
Based on steady semi-geostrophic model equations,analysis is carried out of the linear and nonlinearmodification/response of the tropical atmosphere to the forcing of ideal paired heat sources of contrasting nature.Re-suits show that the linear part is dominant in the steady response but the nonlinear modification is quite noticable in theneighborhood of the heat source and between the paired sources,and the barotropic mode and second baroclinic modeplay a different role in the modification,with the barotropic(second baroclinic)mode modification depending largely onthe Rossby wave self-interaction(the magnitude due to the Kelvin-Rossby wave interaction)between the pairedsources. 相似文献
89.
90.