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Response of remotely sensed Normalized Difference Water Deviation Index to the 2006 Drought of eastern Sichuan Basin

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Science china Earth Sciences 2008年第5期51卷 748-758页

作者： ZHANG WenJiang1, LU QiFeng2, GAO ZhiQiang3 & PENG Jian4 1 School of Water Resource and Hydropower, Sichuan University, Chengdu 610065, china 2 National Satellite meteorological Center, china meteorological administration, beijing 100081, china 3 Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, beijing 100101, china 4 School of Environmental Sciences, Peking University, beijing 100871, china School of Water Resource and Hydropower Sichuan University Chengdu China National Statellite meteorological Center China Meteorological Administration Beijing China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China School of Environmental Sciences Peking University Beijing China

One of the most serious droughts in last century occurred in eastern Sichuan Basin in the summer of 2006 (hereinafter called the Drought). The response of Moderate Resolution Imaging Spectroradiometer (MODIS, boarding on NASA satellites of Terra and Aqua) to the Drought was analyzed in order to reach one practicable monitoring solution for regional soil moisture. Temporal process and spatial extension of the Drought were firstly estimated with ground meteorological and hydrological observations. Then, for the whole region of Sichuan and Chongqing, the remotely sensed Normalized Difference Water In- dex (NDWI) for the summers of 2001―2006 were calculated based on 8-day composite MODIS products, which were further used to construct a new water index (Normalized Difference Water Deviation Index, NDWDI) to examine the sensitivity of remote sensing in the Drought. The study showed that the NDWDI is more sensitive to regional drought than other absolute-soil-moisture-based indices. With the new index, the study extracted the spatial-temporal characteristics of the 2006 Drought, and explored its developing and withdrawing processes, which agreed with related statistics. Compared with ground method of drought observation, the NDWDI-based remote sensing solution of this paper is more pref- erable and practicable in that the local soil properties of water consumption and supply are implicitly taken into account, and the spatial representativity limit of ground observation is circumvented to a degree as satellite remotely senses the earth surface in a way of two-dimensional pixel matrix. So, the NDWDI-based method can be used to monitor regional soil water stress situation more practically and efficiently.

关键词： Sichuan Basin drought Normalized Difference Water Deviation Index response of remote sensing regional scale

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Some characteristics of the atmosphere during an adiabatic process

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Progress in Natural Science:Materials International 2006年第6期16卷 644-648页

作者： GAO Li, LI Jianping and REN Hongli (LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, beijing 100029, china Graduate School of Chinese Academy of Sciences, beijing 100049, china National Climate Center, Laboratory of Climate Studies, china meteorological administration, beijing 100081, china) LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Graduate School of Chinese Academy of Sciences Beijing 100049 China National Climate Center Laboratory of Climatic Studies China Meterological Administration Beijing 100081 China

Some important characteristics of the atmosphere during an adiabatic process are investigated, which include the invariability of atmospheric entropy range and local surface potential temperature, the conservation of the atmospheric mass intervened between any isentropic surface and the ground, and the isentropic surface intersecting with the ground. The analysis shows that the atmospheric reference state (ARS) for investigation on available potential energy (APE) should be defined objectively as the state which could be approached from the existing atmosphere by adiabatic adjustment, and be related to initial atmospheric state before adjustment. For the initial atmosphere state at any time, its corresponding ARS is different from the one at another time. Based on the above-mentioned conclusions, the reference state proposed by Lorenz cannot be obtained physically, so a new conception, the conditional minimum total potential energy, is put forward in order to objectively investigate atmospheric APE.

关键词： available potential energy adiabatic isentropic surface atmospheric reference state conditional minimum total potential energy.

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The tectonic settings and seismogenic tectonics of the M5.7 Jiujiang earthquake in 2005,Jiangxi Province,china

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Science china Earth Sciences 2008年第5期51卷 640-653页

作者： LI ChuanYou1, ZENG XinFu2 & ZHANG JianXi3 1 Institute of Geology, china Earthquake administration, beijing 100029, china 2 Jiangxi Earthquake administration, Nanchang 330039, china 3 beijing Earthquake administration, beijing 100080, china Institute of Geology China Earthquake Administration Beijing China Jiangxi Earthquake administration Nanchang China beijing Earthquake administration Beijing China

The M5.7 Jiujiang earthquake in 2005 was a mid-strong one, stronger than expected to occur in the region. This paper discusses the neo-tectonic settings of this earthquake, and it is thought that the earthquake region is located in the transitional belt, a potential area inducing weak to moderately strong earthquakes, between two large different tectonic units. The results of the reconnaissance work and on-the-spot investigation after earthquake indicate that the occurrence of the M5.7 Jiujiang earth- quake is closely related with the NE-trending fault on the western margin of Ruichang Basin. From its controlling to the landforms and Quaternary depositions, geological profiles, ESR dating, etc., the ac- tivity of the Dingjiashan-Langjunshan fault bounding the basin is discussed. It suggests that this fault displays an active one in Middle Pleistocene by the outcrop. Based on the activity of the fault, and the direction and location of the ground fissures, the isoseismal lines and the nodal plane of the focal mechanism solution, it is inferred that the Dingjiashan-Langjunshan fault is the seismogenic tectonics of the M5.7 Jiujiang earthquake, and the intersection point between this fault and the active NW ones is the possible origin of location of this earthquake. Our study shows that this earthquake is not an event exceeding expectation, and that the active and invisible characteristics of the causative fault are typical in the eastern area of china.

关键词： Jiujiang earthquake tectonic settings Dingjiashan-Langjunshan fault activity seismogenic tectonics

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A preliminary study on seismic design criteria of offshore platforms in Bohai Sea of china

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Earthquake Engineering and Engineering Vibration 2010年第2期9卷 223-231页

作者： Peng Yanju1,Lu Yuejun1,Yan Jiaquan2,Tang Rongyu1,Wang Junqin3 and Li Jiagang3 1. Institute of Crustal Dynamics,china Earthquake administration,beijing 100085,china 2. Institute of Geophysics,china Earthquake administration,beijing 100081,china 3. beijing Research Center of china National Offshore Oil Corp.,beijing 100027,china Institute of Crustal Dynamics China Earthquake Administration Beijing China Institute of Geophysics China Earthquake Administration Beijing China beijing Research Center of china National Offshore Oil Corp. Beijing China

This paper analyzes the seismicity in Bohai Sea,introducing a shape factor K to characterize the seismic risk distribution in sub-regions of the sea. Based on the seismic design ground motions for 46 platforms located in the Bohai Sea,a statistical analysis was performed for different peak ground acceleration (PGA) ratios at two different probability levels. In accordance with the two-stage design method,a scheme of two seismic design levels is proposed,and two seismic design objectives are established respectively for the strength level earthquake and the ductility level earthquake. By analogy with and comparison to the Chinese seismic design code for buildings,it is proposed that the probability level for the strength level earthquake and ductility level earthquake have a return period of 200 and 1000 - 2500 years,respectively. The validity of these proposed values is discussed. Finally,the PGAs corresponding to these two probability levels are calculated for different sub-regions of the Bohai Sea.

关键词： fixed offshore platform seismic design level seismic design objective return period Bohai Sea

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Evolution of terraces Ⅰ–Ⅲ along the Anning River, western Sichuan, based on pollen records and terrace structure

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Science china Earth Sciences 2011年第1期54卷 127-135页

作者： CHENG JianWu1,2 1 Institute of Geology, china Earthquake administration, beijing 100039, china 2 Earthquake administration of Gansu Province, Lanzhou 730000, china Institute of Geology China Earthquake Administration Beijing China Earthquake administration of Gansu Province Lanzhou China

This study reconstructs the long-term evolution of river terraces over large spatial scales along the Anning River, western Sichuan, and identifies external factors controlling terrace formation. Pollen record analysis and terrace structure indicate that formation of the middle section of terraces I-III resulted from the interaction of changing climates and uplift of the margins of the Qinghai-Tibet Plateau. The relative influence of climate and uplift in terrace formation changes in different periods. The terraces reveal multiple, gradual uplift events on the eastern Qinghai-Tibet Plateau, which is of great significance for determining uplift mechanisms across the entire plateau.

关键词： Anning River in western Sichuan terrace formation pollen paleoclimate

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The April 14th, 2010 Yushu earthquake, a devastating earthquake with foreshocks

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Science china Earth Sciences 2010年第6期53卷 791-793页

作者： NI SiDao1, WANG WeiTao2 & LI Li3 1 School of Earth and Space Sciences, University of Science and Technology of china, Hefei 230026, china 2 Institute of Geophysics, china Earthquake administration, beijing 100081, china 3 National Earthquake Infrastructure Service, china Earthquake administration, beijing 100036, china School of Earth and Space Sciences University of Science and Technology of China Hefei China Institute of Geophysics China Earthquake Administration Beijing China National Earthquake Infrastructure Service China Earthquake Administration Beijing China

In the early morning of April 14th, 2010, a strong earth- quake (Ms7.1, http://***; Mw6.9, http://neic. ***) occurred in Yushu district, Qinghai Province, china. More than 2000 lives were lost and over 100000 injured,

关键词： Figure Yushu earthquake a devastating earthquake with foreshocks The April 14th 2010 very than

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Numerous experiments for the impact of warming climate on the phenology and grain yield of winter wheat

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Journal of Environmental Sciences 1990年第4期2卷 11-17页

作者： Zhao Siqiang and ZhangYu The Academy of Metorological Science,State Meteorlogical administration,beijing 100081,china

Based on the environmental and crop data at Zhenjiang City, in Jiangsu Province, middle east of china, the growing process of winter wheat was simulated by CERES-Wheat model assuming the daily average temperature is 1℃ to 2℃ higher than at the present, which are mostly possible for the change of climate because of enrichment of greenhouse gases in the atmosphere. The simulation results show that warming climate can promote development rate and shorten phenological stages of wheat, and the grain yield will be higher than present. Its impact on the kernel weight and grains per square meter were different for the plantings of various sowing dates. The results of this study suggest that substantial changes in agricultural production and management practices are needed to respond to the climatic changes expected to take place in china.

关键词： greenhouse gases warming climate winter wheat climatic change phenology.

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Evaluation of a 3dVAR system for the South china Sea

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Progress in Natural Science:Materials International 2008年第5期18卷 547-554页

作者： Xianjun Xiao a,b, Dongxiao Wang a, Changxiang Yan c, Jiang Zhu c a LED, South china Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, china b NCC, china meteorological administration, beijing 100081, china c Institute of Atmospheric Physics, Chinese Academy of Sciences, beijing 100029, china LED South China Sea Institute of Oceanology Chinese Academy of Sciences Guangzhou 510301 China NCC China Meteorological Administration Beijing 100081 China Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

The authors evaluate a three-dimensional variational (3dVAR) system for the South china Sea (SCS) in this study. The assimilation method applied in the system takes into consideration error correlation along each ground track and uses recursive lter for optimiza- tion. Data from three R/V cruises during the spring and summer of 1998 and the summer of 2000 are used to evaluate the system. The root-mean-square error and bias are reduced signi cantly and when the altimeter data are assimilated, the distribution of the error is much closer to the Gaussian distribution. Precipitation and river discharge in the southwestern SCS are reproduced, and the variability of sea surface height is e ciently transferred to the subsurface. The 3dVAR system performs well for each of the three cruises, suggesting that it is steady for routine usage.

关键词： South china Sea Three-dimensional variational data assimilation Recursive lter

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Responses of soil respiration in non-growing seasons to environmental factors in a maize agroecosystem,Northeast china

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Chinese Science Bulletin 2010年第24期55卷 2723-2730页

作者： LI RongPing1,2,3, ZHOU GuangSheng1,4 & WANG Yu1,3 1 State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, beijing 100093, china 2 Institute of Atmospheric Environment, china meteorological administration, Shenyang 110016, china 3 Graduate University of Chinese Academy of Sciences, beijing 100049, china 4 Chinese Academy of meteorological Sciences, beijing 100081, china State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing China Institute of Atmospheric Environment China Meteorological Administration Shenyang China Graduate University of Chinese Academy of Sciences Beijing China Chinese Academy of meteorological Sciences Beijing China

Based on continuous three-year measurements (from 2004 to 2007) of eddy covariance and related environmental factors, environmental controls on variation in soil respiration (Rs) during non-growing season were explored in a maize agroecosystem in Northeast china. Our results indicated that during non-growing seasons, daily Rs was 1.08-4.08 g CO2 m-2 d-1, and the lowest occurred in late November. The average Rs of non-growing season was 456.06 ± 20.01 g CO2 m-2, accounting for 11% of the gross primary production (GPP) of the growing season. Additionally, at monthly scale, the lowest value of Rs appeared in January or February. From the beginning to the end of non-growing season, daily Rs tended to decrease first, and then increase to the highest. There was a significant quadratic curve relationship between Rs and soil temperature at 10 cm depth when soil temperature was more than 0°C (P2.7%-11.8%. Rs in non-growing season can account for 22.4% of Rs in growing season, indicating that it plays a critical role in assessing the carbon budget in maize agroecosystem, Northeast china.

关键词：中国东北地区农田生态系统生长季节土壤呼吸环境因素玉米土壤含水量反应

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Thermal Activation Analyses of Dynamic FractureToughness of High Strength Low Alloy Steels

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Journal of Materials Science & Technology 2001年第2期17卷 215-218页

作者： Cunjian LI and Shaohua LI Welding Research Department, Central Iron & Steel Research Institute, beijing 100081, china Yuqing DENG State administration of Metallurgical Industry, beijing 100711, china Dept. of Welding Res. Central Iron and Steel Res. Inst. Beijing 100081 China

A formula is derived for determining the influence of temperature and loading rate on dynamic fracture toughness of a high strength low alloy steel (HQ785C) from thermal activation analysis of the experimental results of three-point bend specimens as well as introducing an Arrhenius formula. It is shown that the results obtained by the given formula are in good agreement with the experimental ones in the thermal activation region. The present method is also valuable to describe the relationship between dynamic fracture toughness and temperature and loading rate of other high strength low alloy steels.

关键词： test GB Thermal Activation Analyses of Dynamic FractureToughness of High Strength Low Alloy Steels

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