基于震源-河谷波场数值模拟的坝址地震动参数确定方法   总被引：3，自引：0，他引：3       下载免费PDF全文

贺春晖  王进廷  张楚汉 《地球物理学报》2017,60(2):585-592

针对目前高坝坝址地震动参数确定方法的一些不足,本文尝试了一种基于地震学理论的坝址区三维地震动场生成方法.基本思路是将地震学和工程学结合,针对设定地震,建立震源-传播介质-坝址峡谷场地数值模型,通过超大规模的数值计算,模拟地震波从发震断层破裂开始到坝址场地的物理传播过程,生成坝址区的三维地震动参数.与传统基于衰减关系的地震动参数确定方法相比,这一方法可以考虑震源机制、传播介质和坝址峡谷场地效应等三大要素的影响.对于特定的坝址,可以生成符合实际地质构造、区域岩体动力特性以及坝址峡谷地质地形条件的地震动荷载分布,具有针对性,为重大高坝枢纽工程遭遇极端地震荷载作用时的抗震安全性提供了一种新的分析手段.  相似文献   

丹江口水库上游梯级开发后产漂流性卵鱼类早期资源及其演变   总被引：1，自引：1，他引：0  

雷欢  谢文星  黄道明  谢山  唐会元  陈金生  杨钟  常秀岭  陈锋 《湖泊科学》2018,30(5):1319-1331

2014年对丹江口水库上游四大家鱼等产漂流性卵鱼类进行早期资源的现状调查,结果表明丹江口水库上游现有产漂流性卵鱼类共14种,以银鮈、蛇鮈、花斑副沙鳅、、蒙古鲌等鱼类为主,四大家鱼卵64粒,仅占卵数的1.02%.与1977年、1993年历史调查的产漂流性卵鱼类早期资源数据相比,产卵场数量减少6处,产卵场的规模和位置发生显著变化.丹江口水库上游产漂流性卵鱼类产卵总量下降明显,从1977年的近1745.86亿粒(尾)下降到2014年的455502.76万粒(尾);其中四大家鱼卵苗径流量下降幅度最为显著,从171.27亿粒(尾)下降到4295.22万粒(尾),四大家鱼卵苗径流量占鱼类卵苗总径流量的比例也从9.81%下降到了0.94%以下.  相似文献   

污染场地健康风险评价的实例研究   总被引：35，自引：1，他引：34  

谌宏伟  陈鸿汉  刘菲  何江涛  沈照理  孙静 《地学前缘》2006,13(1):230-235

以常州市A厂有机污染调查为依据,采用篇中讨论的污染场地健康风险评价方法综合评价由土壤、空气、地下水污染带来的人群健康风险。综合分析表明,场地目标污染物为4种苯系物,可能对人体产生肝肾病变、鼻上皮组织恶化和运动协调能力降低等非致癌效应;污染物暴露途径主要有3条,分别暴露于厂区人群和饮用厂区下游民井井水的居民。评价结果显示,厂区人群同时遭受皮肤接触污染土壤和呼吸污染空气带来的非致癌危害。4种污染物的多途径同种污染物累计非致癌危害指数分别为甲苯,2·82×10-2;乙苯,4·94×10-2;间对二甲苯,1·21×10-7;异丙苯,1·05×10-7。两途径多污染物非致癌总危害指数分别为4·26×10-5和7·76×10-2,非致癌综合危害指数为7·76×10-2;厂区下游居民饮用遭受污染的地下水,其多污染物非致癌总危害指数为1·55×10-5。各危害指数均小于1,非致癌健康风险较小。  相似文献   

Using synthetic flow duration curves for rainfall–runoff model calibration at ungauged sites     

P.‐S. Yu  T.‐C. Yang 《水文研究》2000,14(1):117-133

The primary objective of the study is to propose a strategy for rainfall–runoff model calibration at ungauged sites. This strategy comprises two main components: (1) development of the regional analysis method to synthesize the flow duration curves at ungauged sites; and (2) utilization of the synthetic flow duration curves for model calibration. Since the regional analysis method can synthesize the flow duration curves at ungauged sites, the continuous rainfall–runoff model coupled with a global optimization method were applied in southern Taiwan using the synthetic flow duration curve as an objective for model calibration. The results reveal that the regional flow duration curve and the strategy for model calibration at ungauged sites have good performances in the study area. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   

Continuous daily hydrograph simulation using duration curves of a precipitation index     

V. Yu. Smakhtin  B. Masse 《水文研究》2000,14(6):1083-1100

The paper describes a parsimonious approach for generating continuous daily stream‐flow time‐series from observed daily rainfall data in a catchment. The key characteristic in the method is a duration curve. It is used to convert the daily rainfall information from source rain gauges into a continuous daily hydrograph at the destination river site. For each source rain gauge a time‐series of rainfall related ‘current precipitation index’ is generated and its duration curve is established. The current precipitation index reflects the current catchment wetness and is defined as a continuous function of precipitation, which accumulates on rainy days and exponentially decays during the periods of no rainfall. The process of rainfall‐to‐runoff conversion is based on the assumption that daily current precipitation index values at rainfall site(s) in a catchment and the destination site's daily flows correspond to similar probabilities on their respective duration curves. The method is tested in several small catchments in South Africa. The method is designed primarily for application at ungauged sites in data‐poor regions where the use of more complex and information consuming techniques of data generation may not be justified. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   

虚拟站点在黑河流域降水模拟中的应用     

左琪琳  赵娜  段红梅 《地球信息科学学报》2019,21(8):1218-1226

降水作为气候系统的关键因素,也是影响区域植被生长以及生态变化规律的重要因子。本文针对黑河流域气象站点分布稀疏情况,采用信息熵及半变异函数理论构建该流域虚拟气象站点,并结合部分已有站点对整个流域降水进行插值模拟。信息熵可以计算每个站点降水值所包含的信息,通过联合熵以及条件熵来依次选取所含信息量多的站点,同时结合半变异函数模型来观察各站点之间的空间相关性,以此构建最优站点数据集。利用1991-2003年该流域15个气象台站的年平均降水量作为基础数据,考虑高程、坡度、坡向对降水的影响,对降水进行相关性分析,建立回归方程反演虚拟站点降水值。最后,采用协同克里金（Co-Kriging）与具有漂移的克里金（KED）方法对该流域进行插值,对比插值精度。结果表明,增加虚拟站点有效提高了降水插值精度,在该情况下使用KED方法插值结果与观测值最接近。  相似文献   

Broad band filter colours and optical depth of the G and L impact sites of comet shoemaker-levy 9     

M. A. Al Saud  A. A. Malawi  H. M. Basurah  Y. M. Al-Mleaky 《Earth, Moon, and Planets》1996,75(3):147-155

The crash of comet Shoemaker-Levy 9 fragments with Jupiter was observed at Aziziah Observatory, Hail, in Saudi Arabia. Three different observational methods (CCD photometric, spectroscopic, and photoelectric photometric) were used. The observations began on the 13th of July and ended on the 23 of July 1994. The CCD photometric results of the impact of fragmentsG andL are presented here, showing clearly the dark clouds resulted from those impacts. The measurements of the Titanium Oxide (TiO) absorption depth of impactsG andL showed an increase compared to the absorption depth of undisturbed regions, which indicates an increase in the TiO abundance. The increase in the colour reddening towards shorter wavelength found inG andL impacts indicate a composition of small size dust particles. Based on observations obtained at Aziziah Observatory, Saudi Arabia.  相似文献