Validation of SSiB model over grassland with CHeRES field experiment data in 2001     

SUN Lan  XUE Yongkang 《大气科学进展》2004,21(4):547-556

The Simplified Simple Biosphere model (SSiB) is validated in off-line simulations against field measurements in the summer of 2001 from the China Heavy Rainfall Experiment and Study (CHeRES) over a grassland site located in the lower reaches of the Yangtze River. When initialized and driven by the observed atmospheric forcing, the model reproduced the observed surface heat fluxes and surface skin temperature realistically. The model was also able to well simulate the variation of soil water content. The sensitivity experiments found that the leaf reflectance was the most significant parameter in improving the estimation of surface albedo during both wet and dry periods. This study suggests that the model is capable of simulating the physical processes and of assessing the impact of biophysical parameters that relate to land-atmosphere interactions over the eastern Asian monsoon regions, which is crucial for mesoscale atmospheric models.  相似文献   

Paleoseismic records of large earthquakes on the cross-basin fault in the Ganyanchi pull-apart basin,Haiyuan fault,northeastern Tibetan Plateau     

Yanbao Li  Yongkang Ran  Hu Wang  Fuyao Wu 《Natural Hazards》2014,71(3):1695-1713

Field observations and analog models show that cross-basin faults play a key role in the evolution of pull-apart basins and dominate the distribution of earthquake rupture in basin areas. We studied the long-term history of large earthquakes on a cross-basin fault to reveal its behavior in response to propagating earthquake rupture and gain insight into the evolution of the pull-apart basin. A number of pull-apart basins have developed along the Haiyuan fault in the northeastern Tibetan Plateau, the largest being the Ganyanchi pull-apart basin. The surface rupture associated with the 1920 M 8.5 earthquake shows that a cross-basin fault developed in the basin and that the basin is now going through the late stage of its evolution. We excavated two trenches and drilled four cores across the cross-basin fault in the basin and found abundant evidence of paleoseismic events. Seven events were identified and ¹⁴C-dated. The two youngest events are associated with the historical records of 1092 AD and 1920 AD, respectively. The paleoseismic sequence shows the recurrence of earthquakes characterized by earthquake clusters alternating with a single event. Comparing these with previous paleoseismic results, all the major earthquake events seem to be associated with cascade events that ruptured multi-fault segments, suggesting that only an earthquake of this scale (likely M > 8) can produce obvious surface rupture along the cross-basin fault. We propose that the fault has a long tectonic history, with a series of cascade rupture events that could play an important part in the evolution of the pull-apart basin.  相似文献   

一种基于图像灰度直方图相似度计算的室内定位方法     

王永康  汪云甲  毕京学  曹鸿基 《测绘通报》2018,(4):63-67

近年来,视觉定位由于定位精度高广泛应用于室内定位与导航。然而,室内环境复杂多变,视觉定位在很多场景下无法实现高精度定位,而且多数视觉定位算法耗时和计算复杂度高,不适用于智能手机。为实现基于智能手机的准确高效定位,本文提出了一种基于图像灰度直方图相似度计算的定位方法。该方法分为两个阶段：离线阶段和在线阶段。离线阶段在已知坐标的格网点分别利用智能手机采集图像,提取图像灰度直方图,建立图像灰度直方图图像特征库;在线阶段智能手机在待测点采集图像提取灰度直方图,然后与图像特征库进行相似度计算,选取相似度和最大值的格网作为概略位置,以相似度为权重采用加权均值法得到准确位置。将所提方法和KNN算法进行对比,试验结果表明,该方法的平均定位误差优于0.3 m,与KNN算法相比定位精度提高了40.7%,计算时间优于1.7 s。  相似文献   

Landslides triggered by the 20 April 2013 Lushan,China, Mw 6.6 earthquake from field investigations and preliminary analyses   总被引：2，自引：1，他引：1  

Chong Xu  Xiwei Xu  J. Bruce H. Shyu  Mingxing Gao  Xibin Tan  Yongkang Ran  Wenjun Zheng 《Landslides》2015,12(2):365-385

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大青山山前断裂呼和浩特段晚第四纪古地震活动历史   总被引：8，自引：1，他引：8  

冉勇康  张培震  胡博  郭文生 《中国地震》2002,18(1):15-27

通过沿大青山山前断裂呼和浩特段的奎素、乌兰不浪和青山牧场 3个地点地貌面和探槽组的精细研究 ,揭露出该断裂段距今约 1 9万年以来共发生 7次古地震事件。它们分别发生在距今约 1 875± 0 0 75、1 6 97± 0 0 96、1 4 6 5± 0 0 6 7、1 182± 0 0 6 9、0 94 5± 0 0 2 6、0 6 83±0 0 2 6和 0 4 5 0± 0 0 2 3万年 ,平均重复间隔 2 375± 4 32年。由断层位移量限定法和多探槽校验法判定 ,这一时期该断裂段的古地震活动历史是完整的  相似文献   

1679年三河-平谷8级地震发震断层的古地震及其重复间隔   总被引：17，自引：9，他引：17       下载免费PDF全文

冉勇康  邓起东 《地震地质》1997,19(3):2-201

通过大探槽开挖和断层陡坎分析，揭示出发生于１６７９年８级地震的新夏垫断层自距今约２万ａ以来共发生了４次地震事件。前两次为砂体液化显示的事件；后两次为可见直接断错证据的事件。分析得到的１６７９年地震最大垂直位移为１．７５ｍ，前１６７９年事件为１．４１ｍ，是两次震级非常接近的特征地震。４次事件发生的时间分别为距今约２００００，１３０００，７５００和３１７ａ，平均重复间隔时间为（６５６１±６９１）ａ，显示了准周期重复的特征  相似文献   

钱塘江和信江间的越岭运河试析     

祝示康  王宗涛  赵洛金  王成农  张福祥 《地理研究》1988,7(4):54-63

本文从钱塘江与信江间的沟通与河系网络关系,分析了越岭运河的重要意义.对择选区的自然条件作了评述,并对选择路线和运河型式的不同方案作了比较研究.  相似文献   

海原断裂的古地震及特征地震破裂的分级性讨论   总被引：14，自引：0，他引：14       下载免费PDF全文

冉勇康  邓起东 《第四纪研究》1998,18(3):271-278

海原断裂高湾子地点三维探槽揭露了全新世5次事件的位移量。由老至新走滑位移量分别为：5．6±2．3,1．5±1．1,1．5±1．2,2±1和7±0．5m。古地震对比反映出,晚第四纪以来断裂带发生的14次事件中,仅有2～3次事件为贯穿全断裂的破裂事件,说明古地震并不都具有1920年海原大地震的强度。特征地震和段落存在分级性。破裂分级的现象不是孤立的,但多发生在走滑断裂上。  相似文献   

Sensitivity of a regional climate model to land surface parameterization schemes for East Asian summer monsoon simulation     

Wenkai Li  Weidong Guo  Yongkang Xue  Congbin Fu  Bo Qiu 《Climate Dynamics》2016,47(7-8):2293-2308

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地对空微波遥感温度、水汽廓线的联合求解   总被引：2，自引：0，他引：2  

薛永康  林海 《气象学报》1984,42(4):423-430

本文讨论了地对空微波遥感时5毫米吸收带各通道间的相关性,对各种地对空温度反演方法进行了比较。并应用蒙特卡洛法和统计控制法进行了温度、水汽的联合反演,挑选了最佳反演通道,取得了较为满意的数值结果。  相似文献