Application of back-propagation networks in debris flow prediction   总被引：6，自引：0，他引：6  

Tung-Chueng Chang  Ru-Jen Chao   《Engineering Geology》2006,85(3-4):270-280

Debris flows have caused serious loss of human lives and a lot of damage to properties in Taiwan over the past decades. Moreover, debris flows have brought massive mud causing water pollution in reservoirs and resulted in water shortage for daily life locally and affected agricultural irrigation and industrial usages seriously. A number of methods for prediction of debris flows have been studied. However, the successful prediction ratio of debris flows cannot always maintain a stable and reliable level. The objective of this study is to present a stable and reliable analytical model for occurrence predictions of debris flows. This study proposes an Artificial Neural Networks (ANN) model that was constructed by seven significant factors using back-propagation (BP) algorithm. These seven factors include (1) length of creek, (2) average slope, (3) effective watershed area, (4) shape coefficient, (5) median size of soil grain, (6) effective cumulative rainfall, and (7) effective rainfall intensity. A total of 178 potential cases of debris flows collected in eastern Taiwan were fed into the ANN model for training and testing. The average ratio of successful prediction reaching 93.82% demonstrates that the presented ANN model with seven significant factors can provide a stable and reliable result for the prediction of debris flows in hazard mitigation and guarding systems.  相似文献   

Damage Survey of Water Supply Systems and Fragility Curve of PVC Water Pipelines in the Chi–Chi Taiwan Earthquake     

Ban-Jwu Shih  Che-Hao Chang 《Natural Hazards》2006,37(1-2):71-85

Substantial damage to water supply systems, including water delivery pipelines, water treatment plants, reservoirs, and water storage tanks, was reported after the 1999 Chi–Chi Taiwan Earthquake. This paper first summarizes the damage survey and then presents the results of seismic fragility analysis for underground pipelines. Construction blueprints of the water delivery pipelines and repair work orders of 11 townships and cities in the disastrous area were digitized into a Geographical Information System (GIS) for analysis and assessment. With the aid of the GIS system, we found that PVC pipes made up 86% of water delivery pipelines while steel, cast iron, ductile iron, PE and others took the rest. Therefore, this paper focuses on the fragility analysis of PVC pipes. Three different methods were applied to derive the fragility relations between the PVC water pipes having nominal diameters (approximately inner diameters) greater than or equal to 65 mm and earthquake intensity parameters such as peak ground acceleration and peak ground velocity. The results were then examined with those of other countries. The discrepancy between our results and the empirical equation used by HAZUS, an earthquake loss estimation software developed by the Federal Emergency Management Agency was not significant.  相似文献   

青藏高原北缘昆仑-羊湖地区构造演化特征     

戴传固  李硕  边申武 《贵州地质》2006,23(1):1-4

昆仑—羊湖地区位于青藏高原北缘昆仑山脉中段之南侧,区內发育古生代以来地层和几克里阔勒蛇绿岩、阿克苏库勒蛇绿岩、奥依亚依拉克花岗岩带、昆仑花岗岩带,经历了祁秦昆(原特提斯)洋的形成和发展阶段；南昆仑洋的形成和发展阶段；金沙江(古特提斯)洋的形成和发展阶段、陆內造山及隆升阶段。  相似文献   

贵州东部石英脉型金矿地质特征和成矿作用   总被引：7，自引：3，他引：7  

王尚彦  张立新  陶平  戴传固  况顺达  王敏 《贵州地质》2006,23(1):36-43

贵州东部以晚元古代地层为容矿地层的金矿,主要是石英脉型金矿。它们主要分布在从江地区、天柱—锦屏—黎平地区和梵净山地区。前2者处于南华褶皱带西缘,后者处于南华褶皱带与扬子陆块的过渡带。矿体分布在断裂(带)和背斜核部。共伴生矿物为石英、黄铁矿、毒砂、闪锌矿、方铅矿、黝铜矿,黄铜矿,辉锑矿、绿泥石等。矿化蚀变以硅化、黄铁矿化、毒砂化、绿泥石化为主。形成温度主要集中在100℃～350℃,是中低温热液矿床,呈现100～150℃和200～300℃两个区段。金有来源于围岩的、也有来源于深部岩浆的；流体有来源于地层和深部的,也有大气降水的混入。金矿的形成是多时代多阶段形成的：雪峰期提供原始物质；加里东期是一次主要成矿期；燕山时期也是一个重要的金矿形成时期,不但形成新金矿,还改造加里东期形成的金矿  相似文献   

Early Estimation of Seismic Hazard for Strong Earthquakes in Taiwan   总被引：1，自引：0，他引：1  

Wen-Yu Jean  Yu-Wen Chang  Kuo-Liang Wen  Chin-Hsiung Loh 《Natural Hazards》2006,37(1-2):39-53

A shakemap system providing rapid estimates of strong ground shaking could be useful for emergency response providers in a damaging earthquake. A hybrid procedure, which combines site-dependent ground motion prediction models and the limited observations of the Real-Time Digital stream output system (RTD system operated by Central Weather Bureau, CWB), was set up to provide a high-resolution shakemap in a near-real-time manner after damaging earthquakes in Taiwan. One of the main factors that affect the result of ground motion prediction analysis is the existence of site effects. The purpose of this paper is to investigate the local site effects and their influence in the ground shaking and then establish an early estimation procedure of potential hazard for damaging earthquakes. Based on the attenuation law, the site effects of each TSMIP station are discussed in terms of a bias function that is site and intensity-level dependent function. The standard deviation of the site-dependent ground motion prediction model can be significantly reduced. The nonlinear behavior of ground soil is automatically taken into account in the intensity-level dependent bias function. Both the PGA and the spectral acceleration are studied in this study. Based on the RTD data, event correctors are calculated and applied to precisely estimate the shakemap of damaging earthquakes for emergency response.  相似文献   

全数字摄影测量系统DEM生产的质量控制     

戴腾  童忠富  祁信舒  陈春华 《地理空间信息》2005,3(1):51-52,56

目前,数字高程模型(DEM)在理论研究和实践应用方面都有了很大的进展,已在测绘、地质、农业、工程、建筑、军事、导航等多个领域得到了广泛应用,因此高效快捷地生产高精度的DEM是十分必要和迫切的。全数字摄影测量系统DEM生产方案是解决这一问题的有效途径,文章针对该系统的特点,提出了加强质量控制的策略和方法,并阐述了对一些实践问题的解决。  相似文献   

地震波混合阶褶积算法模拟   总被引：6，自引：0，他引：6  

戴志阳  孙建国  查显杰 《物探化探计算技术》2005,27(2):111-114

基于正反傅立叶变换,提出了地震波模拟的混合阶褶积算法。该方法原理简单、易于实现,结合了有限差分与伪谱法的优点,具有较高的精度和计算效率,适用于地震波场的正演计算,同时还给出了二维地震波场的理论计算实例。计算结果表明,此算法模拟结果正确、精度高、速度快、能适应较为复杂地质模型,并且易于推广到各向异性介质中去。  相似文献   

邯峰矿区古构造应力场与构造演化     

曹代勇占文峰  张军杨森丛  张路锁刘太福 常明华 《中国煤田地质》2005,17(5):1-3

采用共轭剪节理应力反演方法,恢复了邯郸-峰峰矿区晚古生代以来的3期古构造应力场,进而探讨了煤田构造的演化历史,将其分为4大阶段：①中生代早期近NS向挤压,煤系后期改造初动期;②中生代晚期SE-NW向挤压,奠定煤田构造格架的基础;③中生代末至古近纪NW-SE向拉张,煤田构造格架定型;④新近纪以来近东西向拉张,煤田构造的现代活动.  相似文献   

甘肃北山造山带红石山地区正εNd(t)值花岗质岩石的成因及地质意义   总被引：8，自引：0，他引：8  

刘明强王建军  代文军党引业 《地质通报》2005,24(9):831-836

在1：5万红岭幅等3幅区域地质调查中，对晚古生代中酸性侵入岩和火山岩的Sm—Nd同位素研究表明，这些不同时代、不同类型的岩石，均表现出高的正εNd（t）值和较低的TDM值，而且变化范围很小，揭示该区花岗质岩石的源岩同位素成分均一，且主要来源于地幔。正εNd（t）值花岗质岩石的存在，可能对研究大陆地壳生长具有重要意义。  相似文献   

葛洲坝水利枢纽运行后泥沙冲淤变化分析   总被引：2，自引：1，他引：2       下载免费PDF全文

戴会超  何文社  袁杰  曹叔尤 《水科学进展》2005,16(5):691-695

对葛洲坝水利枢纽及其运行情况和河段特性进行了介绍。分析认为葛洲坝水利枢纽运行前后的入库水沙特性基本一致。探讨了库区冲淤变化特点、淤积量及其分布,冲淤过程及达到冲淤平衡的时间。对坝下游河床的冲淤过程、冲淤量、达到冲淤平衡的时间以及河床粗化,河底高程历年变化及同流量水位降低的原因、降低量及变化过程进行了分析总结。研究结果可为进一步探讨三峡水利枢纽与葛洲坝水利枢纽联合调度运用后水库泥沙淤积变化规律提供参考。  相似文献