农业水资源利用效用评价研究进展   总被引：9，自引：1，他引：8       下载免费PDF全文

雷波  刘钰  许迪  姜文来 《水科学进展》2009,20(5):732-738

效用问题是农业水资源利用的关键和核心.构建科学合理的指标体系评价农业水资源利用效用对于实现农业水资源持续高效利用有着重要的意义.国内外对水资源利用效用评价的理论和方法研究经历了由单一的用水效率评价向以效率和效益有机结合为特征的效用评价的发展历程,其评价尺度也从最初的作物或田间等微观尺度向灌区、流域、国家乃至全球等中观和宏观尺度发展.未来农业水资源利用效用评价研究发展的重点,将集中在建立基于不同尺度水平衡观点上的农业水资源利用效用评价指标体系以及不同尺度指标的尺度效应及转换等方面.  相似文献   

Patterns and Dynamics of Rifting on Passive Continental Margin from Shelf to Slope of the Northern South China Sea:Evidence from 3D Analogue Modeling     

Sun Zhen  Zhou Di  Wu Shimin  Zhong Zhihong  Myra Keep  Jiang Jianqun  Fan Hao 《中国地质大学学报(英文版)》2009,20(1)

Affected by thermal perturbation due to mantle uprising,the rheological structure of the lithosphere could be modified,which could lead to different rifting patterns from shelf to slope in a passive continental margin.From the observed deformation style on the northern South China Sea and analogue modeling experiments,we find that the rift zone located on the shelf is characterized by half grabens or simple grabens controlled mainly by long faults with large vertical offset,supposed to be formed with normal lithasphere extension.On the slope,where the lithosphere is very hot due to mantle upwelling and heating,composite grabens composed of symmetric grabens developed.The boundary and inner faults are all short with small vertical offset.Between the zones with very hot and normal lithosphere,composite half grnbens composed of half grabens or asymmetric grabens formed,whose boundary faults are long with large vertical offset,while the inner faults are relatively short.Along with the thickness decrease of the brittle upper crust due to high temperature,the deformation becomes more sensitive to the shape of a pre-existing weakness zone and shows orientation variation along strike.When there was a bend in the pre-existing weakness zone,and the basal plate was pulled by a clockwise rotating stress,the strongest deformation always occurs along the middle segment and at the transition area from the middle to the eastern segments,which contributes to a hotter lithosphere in the middle segment,where the Baiyun (白云) sag formed.  相似文献   

基于高分辨率层序地层学的大庆长垣南部浅层气分布特征研究   总被引：1，自引：0，他引：1  

刘宗堡  吕延防  杨志  李秋影  李迪 《地层学杂志》2009,33(4)

松辽盆地大庆长垣南部黑帝庙油层具有良好的浅层气开发潜力。应用高分辨率层序地层学原理,通过对各级基准面旋回结构、叠加样式的沉积动力学分析,利用1164口测井曲线和6口井岩芯资料,把松辽盆地大庆长垣南部黑帝庙油层划分为1个长期基准面旋回、4个中期基准面旋回、25个短期基准面旋回,提出了研究区北部为后期构造抬升而缺失的层序地层新格架。短期基准面旋回内储层沉积特征及单砂体展布规律研究表明:黑帝庙油层为松辽盆地北部物源控制的湖盆逐渐萎缩背景下形成的河控缓坡三角洲前缘亚相沉积体系,微相类型以水下分流河道、河口坝和远砂坝为主。依据区域性湖侵成因的9套暗色泥岩盖层把黑帝庙油层垂向上划分为9套储盖组合;生储盖组合特征及动态资料综合分析表明浅层气主要分布于长期旋回下降早期的中期旋回下降晚期或上升早期储层砂体中;单砂体展布规律与气源断层和构造的合理匹配是浅层气富集的主控因素,气藏类型主要为构造—岩性、断层—岩性圈闭,在以上研究的基础上应用气水解释模板在全区预测地质储量,其研究对指导整个松辽盆地北部浅层气勘探与开发具有重要理论意义和实际应用价值。  相似文献   

陕西省数字地震台网与模拟地震台网地震参数比较   总被引：1，自引：1，他引：0  

狄秀玲  王平  张春芳 《地震地磁观测与研究》2004,25(2):39-43

对1998年1月至2001年12月之间,陕西省数字地震台网与模拟地震台网测定的地震参数作了比较,并进行了讨论。  相似文献   

SN 2002cv: a heavily obscured Type Ia supernova     

N. Elias-Rosa  S. Benetti  M. Turatto  E. Cappellaro  S. Valenti  A. A. Arkharov  J. E. Beckman  A. Di Paola  M. Dolci  A. V. Filippenko  R. J. Foley  K. Krisciunas  V. M. Larionov  W. Li  W. P. S. Meikle  A. Pastorello  G. Valentini  W. Hillebrandt 《Monthly notices of the Royal Astronomical Society》2008,384(1):107-122

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河道砂体宽/窄方位三维观测系统地震物理模型分析   总被引：1，自引：0，他引：1  

狄帮让  徐秀仓  魏建新 《应用地球物理》2008,5(4):294-300

The effect of the wide and narrow azimuth 3D observation systems on seismic imaging precision is becoming a hot area for studies of high precision 3D seismic acquisition methods in recent years. In this paper we utilize 3D physical seismic modeling experiments. A 3D channel sand body physical seismic model is constructed and two acquisition systems are designed with wide azimuth （16 lines） and narrow azimuth （8 lines） to model 3D seismic data acquisition and processing seismic work flows. From analysis of migrated time slice data with high quality and small size, we conclude that when the overlying layers are smooth and lateral velocities have little change, both wide and narrow azimuth observation systems in 3D acquisition can be used for obtaining high precision imaging and equivalent resolution of the channel sand body.  相似文献   

Lava-flow hazard on the SE flank of Mt. Etna (Southern Italy)     

G.M. Crisci  G. Iovine  S. Di Gregorio  V. Lupiano 《Journal of Volcanology and Geothermal Research》2008

A method for mapping lava-flow hazard on the SE flank of Mt. Etna (Sicily, Southern Italy) by applying the Cellular Automata model SCIARA_-fv is described, together with employed techniques of calibration and validation through a parallel Genetic Algorithm. The study area is partly urbanised; it has repeatedly been affected by lava flows from flank eruptions in historical time, and shows evidence of a dominant SSE-trending fracture system. Moreover, a dormant deep-seated gravitational deformation, associated with a larger volcano-tectonic phenomenon, affects the whole south-eastern flank of the volcano.  相似文献   

Geophysical investigations of the plumbing system of Stromboli volcano (Aeolian Islands,Italy)     

Mario Mattia  Marco Aloisi  Giuseppe Di Grazia  Salvatore Gambino  Mimmo Palano  Valentina Bruno 《Journal of Volcanology and Geothermal Research》2008

In this work, we report the results of an integrated approach using both seismological and geodetic data provided by the INGV-CT (Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Catania) Stromboli volcano monitoring systems, in order to improve the knowledge of its plumbing system. In particular, we investigated the relationships between the June 1999 seismic swarm, occurring in the area of Stromboli, and the possible activation of the NE–SW oriented volcano-tectonic structure. We analyzed this seismic swarm proposing new locations and a morphological analysis of the waveforms. This approach allowed us to demonstrate that there are relationships between the tectonic activity near Stromboli and the rising of magma. This evidence supports the hypothesis that during the 1999 swarm an intrusive process started from a crustal level where earthquakes were located (about 10–15 km b.s.l.).  相似文献   

The Breccia Museo formation, Campi Flegrei, southern Italy: geochronology, chemostratigraphy and relationship with the Campanian Ignimbrite eruption   总被引：3，自引：1，他引：2  

Lorenzo Fedele  Claudio Scarpati  Marvin Lanphere  Leone Melluso  Vincenzo Morra  Annamaria Perrotta  Gennaro Ricci 《Bulletin of Volcanology》2008,70(10):1189-1219

The Breccia Museo is one of the most debated volcanic formations of the Campi Flegrei volcanic district. The deposit, made up of six distinctive stratigraphic units, has been interpreted by some as the proximal facies of the major caldera-forming Campanian Ignimbrite eruption, and by others as the product of several, more recent, independent and localized events. New geochemical and chemostratigraphical data and Ar–Ar age determinations for several units of the Breccia Museo deposits (~39 ka), correlate well with the Campanian Ignimbrite-forming eruption. The chemical zoning of the Breccia Museo deposits is interpreted here to be a consequence of a three-stage event that tapped a vertically zoned trachytic magma chamber. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

SHRIMP zircon U-Pb dating of the intrusives in the Tongling metallogenic cluster and its dynamic setting   总被引：10，自引：0，他引：10  

GanGuo Wu  Da Zhang  YongJun Di  WenShuan Zang  XiangXin Zhang  Biao Song  ZhongYi Zhang 《中国科学D辑(英文版)》2008,51(7):911-928

This paper selected five typical Mesozoic intrusives from the Tongling metallogenic cluster (Xiaotongguanshan, Fenghuangshan, Xinqiao, Dongguashan, and Shatanjiao plutons), and made a systemic SHRIMP zircon U-Pb dating for the five plutons, which produced an age range of 151.8±2.6- 142.8±1.8 Ma. This work put an accurate constraint on the formation age of the intrusives in the Tongling metallogenic cluster. These age data indicate that magmatic activity reached a peak during Late Jurassic. The intrusive sequence of magma is generally from quartz monzonite (porphyry) through monzonite to granodiorite to quartz monzodiorite to pyroxene monzodiorite to gabbro-diabase. The intrusives of different lithology differed in crystallization age, probably implying the intrusives in the Tongling area underwent an evolutional process of magma, which was closely related to geodynamical setting in the depths of the area. A dynamic model was presented for the origin of the igneous rocks in the study area as follows. The assembly between the Yangtze craton and the North China craton fini- shed at the end of T3, and then the stage of another compressional orogeny began in the Tongling area, i.e., Pacific dynamic system. Along with the subduction of the Izanagi plate underneath the Eurasian plate at J2-J3, NW-trending compression toward the East China continent was produced, and compres- sional deformation also took place, forming NE-trending fold and resulting in thickening of the crust in the Tongling area. High-density eclogite-facies rocks were produced in the low part of the crust, re- sulting in the delamination of mantle lithosphere and lower crust, and upwelling of materials in as- thenosphere. Decompression melting produced basaltic magma, and the materials in lower crust were heated by the underplating of the basaltic magma. Thus, melting of lower crust yielded granitic magma, which intruded along deep and large faults through various geological processes (J3-K1). The SHRIMP U-Pb zircon age of 151.8±2.6-142.8±1.8 Ma for intrusives in the Tongling area suggests that the de- lamination of lithosphere mantle and lower crust at least began at middle-late stage of Late Jurassic, resulting in sharp thinning of lithosphere and intense extension of middle-upper crust. Thus, a lot of decollements were produced between cover and cover, basement and cover, and middle and lower crust. This was structural layering or detachment of lithosphere in the Tongling area. Three concordant ages for old inherited cores of magmatic origin (747-823 Ma) indicated that there were obvious mag- matism in the Tongling area during Neoproterozoic, and a little more of the Neoproterozoic igneous source rocks participated in the formation of Mesozoic intrusives.  相似文献