RS AND GIS-BASED FOREST FIRE RISK ZONE MAPPING IN DA HINGGAN MOUNTAINS     

YIN Hai-wei  KONG Fan-hua    LI Xiu-zhen 《中国地理科学(英文版)》2004,14(3):251-257

1INTRODUCTIONForests are one of the major natural resources that per-form important environmental and recreational func-tions (COSTANZA and GROOT, 1997). It is well known that forests can absorb atmospheric carbon, maintain a certain degree of humidity in atmosphere, regulate rainfall, moderate temperature, and restrain soil erosion, etc. (AURELIA, 2003). So, the health of a forest in any given area is a very important indicator of the ecological conditions. But fire is the great…  相似文献   

STUDY ON THE FREQUENCY AND PRINCIPLE OF FLOOD CATASTROPHE IN THE CHANGJIANG DELTA AND ITS NEIGHBORING REGIONS IN THE LAST 2000 YEARS     

ZHANG Sheng  ZHU Cheng  ZHANG Qiang 《中国地理科学(英文版)》2001,11(2):137-143

1 INTRODUCTION The Changjiang (Yangtze) Delta and its neighboring regions mentioned in this article is located in the lower reaches of the Changjiang River, whose north, east, south and west adjacent places are Xingtongyang Canal, Huanghai Sea, East China Sea, Qiantang River, Hangzhou Bay and Nanjing, Zhenjiang respectively. These regions belong to Jiangsu Province, Zhejiang Province and Shanghai City in administrative division, being one of the economic developed regions. The …  相似文献   

Formation Pressure Evaluation Method for Single Well     

WANG Yachun 《东北亚地学研究》2002,(2)

Ｔｈｅｆｏｒｍａｔｉｏｎｐｒｅｓｓｕｒｅｅｖａｌｕａｔｉｏｎｉｓｐｌａｙｉｎｇｖｅｒｙｉｍｐｏｒｔａｎｔｒｏｌｅｉｎｏｉｌａｎｄｇａｓｅｘｐｌｏｒａｔｉｏｎａｎｄｄｅｖｅｌｏｐ ｍｅｎｔ .Ｉｔｃａｎｐｒｏｖｉｄｅｖｅｒｙｉｍｐｏｒｔａｎｔｉｎｆｏｒｍａｔｉ  相似文献   

Advances in the Marine Photochemistry of Some Important Transition Metal Elements   总被引：1，自引：0，他引：1  

YANG Guipeng )  *  ZHAO Xuekun )  QI Jialin ) ) College of Chemistry  Chemical Engineering  Ocean University of China  Qingdao  P..R.China ) Shandong Import  Export Commodity Inspection Bureau  Qingdao  P..R.China 《中国海洋大学学报(英文版)》2003,2(1):79-84

1　Introduction　Historically ,thestudyoflightintheoceanshasbeeninvolvedprimarilyintwothemes :therolelightplaysinmarinelivesanditskeycontrolofprimaryproductivity .Consequently ,thephotochemicalinter actionofsunlightwithseawaterconstituentsandtheresultingenvironmentalconsequenceshasbecomeanimportantstudythemeinthefieldofmarinesciences .Currently ,investigationsinmarine photochemistrymainlyinclude (1)examinationofthenatureandre activityofthechromophoresfoundinthedissolvedor ganicmatterinseawater…  相似文献   

STUDY ON THE SUSTAINABLE DEVELOPMENT OF WETLAND RESOURCES IN THE USSURI /WUSULI RIVER BASIN     

LIU Hong yu  LU Xian guo  WANG Chang ke 《中国地理科学(英文版)》2000,10(3):270-275

1 INTRODUCTION The Ussuri / Wusuli River watershed is located in the southeast part of Heilongjiang Province of China, which joins remote regions of Russia. The watershed consists of approximately 26 000 000 ha, which is about two thirds of the watershed ecosystem in Russia, one  third in China. The Ussuri River forms part of the border between Russia and China, the shared border stretches more than 1100 km. Khanka/Xingkai Lake lies within both China and Russia. Its total area …  相似文献   

NORMALIZED DIFFERENCE SNOW INDEX SIMULATION FOR SNOW-COVER MAPPING IN FOREST BY GEOSAIL MODEL     

CAO Yun-gang    LIU Chuang 《中国地理科学(英文版)》2006,16(2):171-175

1INTRODUCTION Snow is an important component of the Earth's surface. Up to 50×106km2(34%) ofthe Earth's land surface is sea- sonally snow-covered (VIKHAMAR and SOLBERG, 2002).Comparedtootherlandcovers,snowcoverextent varies dramatically on very short time scales (hours- months). Its presence affects physical, chemical and bio- logical processes at many spatial scales and has impor- tant social impacts. At the global scale, its high albedo strongly influences the Earth's radiation …  相似文献   

Meridional Variation of the 1955-2003 Sea Level Anomalies in the Tropical Pacific Ocean Associated with El Nio Events     

FANG Mingqiang)  )  and QU Liqin)  )) Ocean Remote Sensing Institute  Ocean University of China  Qingdao  P. R. China ) The Key Laboratory of Ocean Remote Sensing  Ministry of Education  P. R. China 《中国海洋大学学报(英文版)》2007,(4)

The Sea Level Anomaly-Torque (SLAT, relative to a reference location in the Pacific Ocean), which means the total torque of the gravity forces of sea waters with depths equal to the Sea Level Anomaly (SLA) in the tropical Pacific Ocean, is defined in this study. The time series of the SLAT from merged altimeter data (1993-2003) had a great meridional variation during the 1997-1998 El Nio event. By using historical upper layer temperature data (1955-2003) for the tropical Pacific Ocean, the tempera- ture-based SLAT is also calculated and the meridional variation can be found in the historical El Nio events (1955-2003), which suggests that the meridional shifts of the sea level anomaly are also intrinsic oscillating modes of the El Nio cycles like the zonal shifts.  相似文献   

Refractive Focusing of Interstellar Clouds and Intraday Polarization Angle Swings     

T.P.Krichbaum  A.Witzel  J.A.Zensus 《中国天文和天体物理学报》2007,7(2):215-223

Intraday variations of compact extragalactic radio sources in flux density and po- larization are generally interpreted in terms of refractive scintillation from the continuous interstellar medium of our Galaxy. However, continuous polarization angle swings of～180° (for example, the one observed in the QSO 0917 624) could not be interpreted in this way. Qian et al. have shown that the polarization angle swing observed in the QSO 1150 812 can be explained in terms of focusing-defocusing effect by an interstellar cloud, which occults two closely-placed polarized components. Here we further show that the polarization angle swing event observed in the QSO 0917 624 can also be explained in this way. We also found evidence for the cloud eclipsing a non-polarized (core) component during a short period out- side the swing. A particular (and specific) plasma-lens model is proposed to model-fit the polarization swing event of 0917 624. Some physical parameters related to the plasma-lens and the source components are estimated. The brightness temperatures of the two lensed components are estimated to be ～1.6×1013 K. Thus bulk relativistic motion with a Lorentz factor less than ～20 may be sufficient to avoid the inverse - Compton catastrophe.  相似文献   

双星演化与大样本恒星演化     

韩占文  Eggleton P P  Tout C A  Webbink R F 《天文学进展》2001,19(2):242-245

主要介绍了大样本恒星演化所面临的困难，为解决困难所做的努力及对未来的展望。  相似文献   

The Characteristics of Putaohua Reservoir and Development Strategies in Xujiaweizi Baxin Oilfield     

GUO Qingxia 《东北亚地学研究》2002,(1)

With the using of new full 3-D interpretative technology, the carefully interpretation of the micro ?amplitude structures and faults by the reprocessed 3-D seismic data in IES (Interactive Exploration System) interpretative system of Sun workstation is obtained. Because of the application of the well - advanced predictive technique for reservoir lithological changes, the predictive accuracy rate of drilling for 31 wells drilled in 1996 achieved 100% and the economic and social benefits are desirable.  相似文献