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1.
Impact of warmer climate on melt and evaporation for the rainfed, snowfed and glacierfed basins in the Himalayan region 总被引：9，自引：0，他引：9
The impact of warmer climate on melt and evaporation was studied for rainfed, snowfed and glacierfed basins located in the western Himalayan region. Hydrological processes were simulated under current climatic conditions using a conceptual hydrological model, which accounts for the rainfall–runoff, evaporation losses, snow and glacier melt. After simulations of daily observed streamflow (R2=0.90) for 6 years, the model was used to study the impact of warmer climate on melt and evaporation. Based on the future projected climatic scenarios in the study region, three temperature scenarios (T+1, T+2 and T+3 °C) were adopted for quantifying the effect of warmer climate. The comparison of the effect of warmer climate on different types of basins indicated that the increase in evaporation was the maximum for snowfed basins. For a T+2 °C scenario, the annual evaporation for the rainfed basins increased by about 12%, whereas for the snowfed basins it increased by about 24%. The high increase of the evaporation losses would reduce the runoff. It was found that under a warmer climate, melt was reduced from snowfed basins, but increased from glacierfed basins. For a T+2 °C scenario, annual melt was reduced by about 18% for the studied snowfed basin, while it increased by about 33% for the glacierfed basin. Thus, impact of warmer climate on the melt from the snowfed and glacierfed basins was opposite to each other. The study suggests that out of three types of basins, snowfed basins are more sensitive in terms of reduction in water availability due to a compound effect of increase in evaporation and decrease in melt. For a complex type of basin, the decrease in melt from seasonal snow may be counterbalanced by increase in melt from glaciers. However, on long-term basis, when the areal extent of glaciers will decrease due to higher melt rate, the water availability from the complex basins will be reduced. 相似文献
2.
前陆盆地是一种较为特殊的沉积盆地,是位于造山带前沿和相邻克拉通之间的沉积盆地,是在板块会聚或碰撞条件下,靠近克拉通(或大陆)一侧形成的盆地.我们通过MT测深结果分析,直观地看到了松辽盆地西缘存在着前陆盆地的电性异常特征.本文通过MT测深结果,结合构造动力学环境、地质构造现象分析,认为松辽盆地西缘可能存在前陆盆地(松辽西前陆盆地).这个前陆盆地的存在,可以合理地解释大杨树盆地与其东部松辽盆地主体深度上的重大差异;可以解释利用传统的断陷盆地无法解释的松辽盆地中“凹中隆”的问题;无疑会对目前的研究理论注入新的内涵,从而更有助于指导松辽盆地及其外围的油气勘探与开发. 相似文献
3.
Most of petroliferous sedimentary basins in China have experienced multiple phases of tectonic evolution and deposition, and are characterized by tectonic and depositional superimposition. The term "superimposed basin" is suggested to describe those basins which consist of two or more simple prototype basins superimposing vertically and/or coalescing laterally. The characteristics of petroliferous superimposed basins are "multiple stages of basin forming and reworking, multiple layers of source rocks, multiple periods of hydrocarbon generation and expulsion, multiple periods of petroleum migration-accumulation-escape". Therefore,applying the wave process analysis method to studying the process of basin formation, hydrocarbon generation, and reservoir formation, and then establishing theory of "petroleum accumulation system" is helpful to enhancing petroleum exploration efficiency in superimposed basins.This paper will, based on case study in the Tarim basin, report the major developments in studying basin formation, hydrocarbon generation and petroleum accumulation. In study of basin formation, (1) geophysical comprehensive profiles reveal that the Tarim plate has been subducted beneath the Tianshan orogenic belt with an interfinger structure and that the deep structure in the eastern section of the Tianshan orogenic belt is different from that in the western section. (2) The vertical variation in debris and geochemical composition reveals the nature and Mesozoic-Cenozoic evolution history of the Kuqa Depression. (3) Field investigation and paleostress reconstruction show that the Kuqa Depression has undergone gravity-driven extension in sedimentary cover when the Tianshan uplifted vertically. In hydrocarbon generation study, new developments include (1) setting environmental index to judge high grade source rocks in marine carbonates, and (2) establishing the lower limit of the organic carbon content for effective carbonate source rocks. In petroleum accumulation study, (1) methods of determining paleopressure and paleotemperature of forming fluid inclusions have been established. (2) The petroleum source analysis has indicated that the crude oil in the Lunnan and Tahe oilfields are derived from the source rocks of the Middle and Upper Ordovician. (3) Three generations of oil inclusions from the Lunnan oilfield have been recognized and dated. 相似文献
4.
The composition of back-arc basin lower crust and upper mantle in the Mariana Trough: A first report 总被引：1，自引：0，他引：1
Robert J. Stern Sherman H. Bloomer Fernando Martinez Toshitsugu Yamazaki T. Mark Harrison 《Island Arc》1996,5(3):354-372
Abstract The Mariana Trough is an active back-arc basin, with the rift propagating northward ahead of spreading. The northern part of the Trough is now rifting, with extension accommodated by combined stretching and igneous intrusion. Deep structural graben are found in a region of low heat flow, and we interpret these to manifest a low-angle normal fault system that defines the extension axis between 19°45' and 21°10'N. A single dredge haul from the deepest (∼5.5 km deep) of these graben recovered a heterogeneous suite of volcanic and plutonic crustal rocks and upper mantle peridotites, providing the first report of the deeper levels of back-arc basin lithosphere. Several lines of evidence indicate that these rocks are similar to typical back-arc basin lithosphere and are not fragments of rifted older arc lithosphere. Hornblende yielded an 40 Ar/39 Ar age of 1.8 ± 0.6 Ma, which is interpreted to approximate the time of crust formation. Harzburgite spinels have moderate Cr# (<40) and coexisting compositions of clinopyroxene (CPX) and plagioclase (PLAB) fall in the field of mid-ocean ridge basalt (MORB) gabbros. Crustal rocks include felsic rocks (70-80% SiO2 ) and plutonic rocks that are rich in amphibole. Chemical compositions of crustal rocks show little evidence for a 'subduction component', and radiogenic isotopic compositions correspond to that expected for back-arc basin crust of the Mariana Trough. These data indicate that mechanical extension in this part of the Mariana Trough involves lithosphere that originally formed magmatically. These unique exposures of back-arc basin lithosphere call for careful study using ROVs and manned submersibles, and consideration as an ocean drilling program (ODP) drilling site. 相似文献
5.
渤海湾盆地构造成因观点剖析 总被引：19，自引：4，他引：15
目前有关渤海湾盆地构造形成机制的解释主要有两种：伸展＋走滑观点和伸展＋拉分观点。这些观点从现有的断层成因模式或应力分析原理出发,强调多种应力方式或多期构造应力场的作用,动力学机制的解释比较复杂。研究表明,盆地边界几何条件（包括裂陷边界几何形态,边界断层的剖面几何形态及性质）和裂陷伸展方向是决定裂陷盆地伸展构造形成特征的关键因素,而砂箱模拟介研究裂陷盆地构造形成过程和机制的重要方法。 相似文献
6.
Poly-phase salt tectonics and hydrocarbon accumulation in Tarim superimposed basin, northwest China 总被引：2，自引：0，他引：2
The purpose of this paper is to discuss the poly-phase salt tectonics and its relation to the hydrocarbon accumulation of the Tarim superimposed basin. Several salt sequences are developed in the Tarim basin, they are: (1) the Mid-Early Cambrian salt sequence, mainly distributed in the west part of the north Tarim uplift and Keping uplift; (2) the Early Carboniferous salt sequence, mainly distributed in the south slope of the north Tarim uplift; (3) the Paleogene salt sequence, mainly distributed in the mid-west part of the Kuqa foreland fold belt and north Tarim uplift; and (4) the Miocene salt sequence, mainly distributed in the east part of the Kuqa foreland fold belt. The salt sequences deposited in the tectonically calm scenario, while the salt layers deformed during the period of intense tectonism. Although the salt sequences are characteristic of plastic flow, the differences of salt deformation styles exist in the different salt sequences because of the different deformation mechanism. It is attractive that the distribution of the large oil-gas fields or pools has a bearing upon the salt sequences and salt structures, such as the Tahe oilfield related to the Lower Carboniferous salt sequence and laterally facies changed mudstone, the Kela No.2 gas field to the Paleogene salt structures, and the Dina gas field to the Miocene salt structures. It is indicated that the large-scale hydrocarbon accumulation is controlled by the poly-phase salt sequences and structures. The deep analysis of the poly-phase salt tectonics is helpful to understanding the characteristics of the structural deformation and oil-gas accumulation of the Tarim basin. 相似文献
7.
南黄海盆地是大型海相中、古生界和陆相中、新生界两期叠合型盆地,本文根据最新地震资料结合钻井资料及与海陆地质资料的对比研究对盆地内地震层序进行了划分,得到了陆相中、新生界盆地基底即中、古生界海相盆地的顶界埋深、三叠系和上二叠统的残留厚度,推断了陆相层基底地层分布,并根据磁力异常资料推测了海相中、古生界盆地结晶基底埋深,推断了海相中、古生界整体残留情况.下三叠统青龙组和上二叠大隆及龙潭组在南黄海盆地南部坳陷及勿南沙隆起广泛存在,而在北部坳陷的分布则狭窄,中部隆起则由于隆起和剥蚀作用导致这两套地层几乎没有残余.对中-古生界海相盆地和中-新生界陆相盆地的基底特征进行了比较,认为海相中、古生界在南黄海地区区域性存在,海相层厚度分布特征受基底起伏控制,同时受到印支板块运动的影响,中部隆起区是海相中、古生界比较稳定的地区.下古生界可能在南黄海盆地广泛分布,但受资料限制,还难以获知其残余地层的特征. 相似文献
8.
本文对柴达木盆地东部新生代盆地结构和构造演化进行了研究.地震剖面揭示柴达木盆地东部新生界分别向南、北盆地边缘变薄和尖灭,盆地北部被欧龙布鲁克山和埃姆尼克山隆起强烈改造.通过对新生代地层厚度横向变化以及地层剖面分析,确定欧北断裂自中新世晚期开始向北逆冲,导致欧龙布鲁克山发生隆升和德令哈凹陷的形成.埃北断裂从上新世开始活动,与欧北断裂同时向北逆冲,导致德令哈凹陷进一步沉降,形成厚度达2600m的狮子沟组.埃南断裂在第四纪开始大规模向南逆冲,不仅造成其北侧的欧龙布鲁克山和埃姆尼克山隆起强烈抬升和向南推覆,而且导致南侧霍布逊凹陷的形成,成为柴达木盆地第四纪沉积中心.早期提出的前陆盆地和背驮式盆地模型显然不能解释柴达木盆地东部新生代构造格架和演化历史.本次研究认为柴达木盆地东部的形成是强烈的水平挤压作用导致地壳发生大规模褶皱的结果,即柴达木盆地东部新生代是一个大规模向斜.该向斜盆地模型很好地解释了新生代地层向盆地边缘减薄以及沉积中心主要位于盆地中部等现象.了解柴达木盆地东部构造发展对了解青藏高原侧向扩展具有重要意义. 相似文献
9.
Some relationships between lithology,basin form and hydrology: a case study from the Thames basin,UK 总被引：1，自引：0，他引：1
The role of lithology in influencing basin form and function is explored empirically by investigating correlations between a range of catchment variables, where the spatial unit of analysis is not surface catchments but lithologically coherent groundwater units. Using the Thames basin, UK, as a case study, nine groundwater units have been identified. Values for 11 hydrological and geomorphological variables, including rainfall, drainage density, Baseflow Index, aquifer porosity, storage coefficient and log‐hydraulic conductivity, aquifer and drainage elevation, river incision, and hypsometric integral have been estimated for each of the groundwater units in the basin, and Pearson correlation coefficients calculated for all pairs of variables. Seven of the correlation coefficients are found to be significant at a confidence level of > 99%. Negative correlations between drainage density and log aquifer hydraulic conductivity, and between drainage density and river incision, and positive correlations between log‐hydraulic conductivity and river incision, log‐hydraulic conductivity and Baseflow Index, and between Baseflow Index and river incision are inferred to have consistent causal explanations. For example, incision of rivers into aquifers leads to relative increases in hydraulic gradients in the vicinity of rivers which, in turn, promotes the development of secondary porosity increasing both aquifer hydraulic conductivity and, hence, Baseflow Index. The implication of this interpretation is that the geomorphological evolution of basins is intimately linked to the evolution of hydraulic conductivity of the underlying aquifers. This is consistent with, and supports the notion of a coupled complexly evolving surface water‐groundwater system. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
10.
对松辽盆地深反射地震资料的分析表明 ,该盆地地壳不仅具有层圈结构 ,而且具有明显的块断构造 ,这些块断的边界是深部热流体的网络通道。以深反射地震资料研究为基础 ,结合区域地震层析成像、火山岩地球化学等对壳幔相互作用的研究成果 ,通过地壳层圈与块断结构、构造变形史以及盆地构造与深部构造之间的关系研究 ,认为松辽盆地的形成过程是 :库拉 -太平洋板块向欧亚大陆之下俯冲作用导致的地幔隆起促使地壳拆沉减薄、地壳“三明治”结构形成 ,同时导致上地壳伸展沉降及其后期的热沉降。正因如此 ,盆地整体凹陷与地幔凸起成镜像关系 ,而断陷与拆离带凸起成偏镜像关系。强烈的壳幔作用是形成松辽盆地大规模沉降的动力学基础 ,也是盆地油气 (包括无机物质 )富集的重要原因 相似文献
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The structural activities took place extensively in the Asia continent during the Cenozoic era owing to the strong continent-to-continent
collision and continuous compression between the India Plate and the Eurasia Plate. Huang Jiqing called such structural activities
Himalayan movement. China’s sedimentary basins developed and took shape mainly during the Himalayan movement period. It is
also the main period for formation and development of the oil and gas reservoirs. Of 366 large and medium-sized oil and gas
fields currently found in China, 212 reservoirs were formed in the Neogene-Quaternary period. The proportion is as high as
68.2%. The oil and gas migration and accumulation in the latest geological period, which were controlled by the times, properties,
styles and strength of the Himalayan movement, took place mainly in eight regions, such as the low uplift area of Bohai Sea,
the onshore faulted sag area of Bohai Bay, anticlinorium zone in Daqing, the foreland fold-and-thrust belt in West China,
the tilted structural zone in West China, the cratonic palaeohigh in the Tarim Basin, the zone of fault and fold belt in the
East Sichuan Basin, and the biological gas zone in the East Qaidam Basin. The oil and gas pool formations in those regions
have their own characteristics. With the great potential and broad prospect, those regions are the main exploration areas
in China in the future. 相似文献
14.
Elisa Armijos Alain Laraque Sonia Barba Luc Bourrel Catalina Ceron Christelle Lagane 《水文科学杂志》2013,58(7):1478-1494
AbstractWater discharge and suspended and dissolved sediment data from three rivers (Napo, Pastaza and Santiago) in the Ecuadorian Amazon basin and a river in the Pacific basin (Esmeraldas) over a 9-year period, are presented. This data set allows us to present: (a) the chemical weathering rates; (b) the erosion rates, calculated from the suspended sediment from the Andean basin; (c) the spatio-temporal variability of the two regions; and (d) the relationship between this variability and the precipitation, topography, lithology and seismic activity of the area. The dissolved solids load from the Esmeraldas basin was 2 × 106 t year-1, whereas for the Napo, Pastaza and Santiago basins, it was 4, 2 and 3 × 106 t year-1, respectively. For stations in the Andean piedmont of Ecuador, the relationship between surface sediment and the total sediment concentration was found to be close to one. This is due to minimal stratification of the suspended sediment in the vertical profile, which is attributed to turbulence and high vertical water speeds. However, during the dry season, when the water speed decreases, sediment stratification appears, but this effect can be neglected in the sediment flux calculations due to low concentration rates. The suspended sediment load in the Pacific basin was 6 × 106 t year-1, and the total for the three Amazon basins was 47 × 106 t year-1. The difference between these contributions of the suspended sediment load is likely due to the tectonic uplift and the seismic and volcanic dynamics that occur on the Amazon side.Editor Z.W. KundzewiczCitation Armijos, E., Laraque, A., Barba, S., Bourrel, L., Ceron, C., Lagane, C., Magat, P., Moquet, J.-S., Pombosa, R., Sondag, F., Vauchel, P., Vera, A., and Guyot, J.L., 2013. Yields of suspended sediment and dissolved solids from the Andean basins of Ecuador. Hydrological Sciences Journal, 58 (7), 1478–1494. 相似文献
15.
In order to achieve the integrated river basin management in the arid and rapid developing region, the Heihe River Basin (HRB) in Northwestern China, one of critical river basins were selected as a representative example, while the Murray–Darling Basin (MDB) in Australia and the Colorado River Basin (CRB) in the USA were selected for comparative analysis in this paper. Firstly, the comparable characters and hydrological contexts of these three watersheds were introduced in this paper. Then, based on comparative studies on the river basin challenges in terms of the drought, intensive irrigation, and rapid industrialization, the hydrological background of the MDB, the CRB and the HRB was presented. Subsequently, the river management strategies were compared in three aspects: water allocation, water organizations, and water act and scientific projects. Finally, we proposed recommendations for integrated river basin management for the HRB: (1) Water allocation strategies should be based on laws and markets on the whole basin; (2) Public participation should be stressed by the channels between governance organizations and local communities; (3) Scientific research should be integrated into river management to understand the interactions between the human and nature. 相似文献
16.
Since the latest Oligocene–earliest Miocene the building of the Sicilian fold and thrust belt has been accompanied by development of a “peripheral” foreland basin system which migrated toward the foreland. In north-western Sicily, the sedimentary record of the foreland basin system migration is represented by a stratigraphic succession made up of several lithostratigraphic units, bounded by regional unconformity surfaces, deposited recording at least four main sedimentary phases, each characterized by the development of different types of syntectonic basins. 相似文献
17.
A comparative analysis of a variety of relationships for prediction of basin lag is performed by applying them to 23 basins located in the same geographical area and characterized by a rather similar vegetative cover. The results of computations indicate that a lag–area relationship with two constant parameters is the best predictor for most basins; under different vegetative covers in the same basin only one parameter should be variable. For a few other basins characterized by an anomalous drainage channel network of low density, such a relationship can lead to unacceptable errors. Thus, there is a need for an additional relationship to overcome this difficulty, but a larger number of anomalous basins would be required for its determination. An alternative procedure, based on the use of the non‐linear kinematic wave, which at least allows singling out the cases where a specific lag–area relationship is not reliable, is proposed. This procedure, therefore, represents a partial but very useful solution to avoid considerable errors in hydrological practice. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
18.
Scattering of elastic waves by an orthotropic basin of arbitrary shape embedded in a half-space is investigated for the sagittal plane motion using an indirect boundary integral equation approach. Steady-state results were obtained for incident plane harmonic pseudo P-, S-, and Rayleigh waves. Detailed convergence analysis of the method is presented. Green's functions are evaluated by using adaptive Newton–Cotes or Filon quadratures. Surface ground motion is presented for semicircular and semielliptical basins with different material properties and various angles of incidence. The results show that surface motion strongly depends upon nature of incident wave, geometry and material properties of the basin, and location of the observation point. Comparison with isotropic basin response demonstrates that anisotropy is very important in amplification of surface ground motion. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
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Scattering of elastic waves by an orthotropic sedimentary basin is investigated for antiplane strain model using an indirect boundary integral equation approach. Both steady state and transient response were obtained for semicircular and semielliptical basins with different material properties. The results indicate that the basin geometry and the impedance contrast between the half-space and the basin have similar effects on the surface ground motion amplification as for the isotropic case. However, the material anisotropy may change significantly the fundamental resonant frequencies of the basin, resulting in different surface displacement amplification patterns. In addition, it was observed that the arrival time of the main disturbance on the surface strongly depends on material anisotropy for different angles of incidence. The results demonstrate that material anisotropy may be very important in explaining surface ground motion amplification for sedimentary basins. © 1998 John Wiley & Sons, Ltd. 相似文献