放射虫等生物群在非史密斯地层研究中的应用--以东昆仑阿尼玛卿混杂岩带为例

造山带混杂岩地层构成的主要特色是造山带大地构造演化各阶段的不同来源、不同时代、不同环境、不同变形变质程度、不同大小的各种构造岩片 (块 )或重叠、或位移、或缺失 ,形成现今统一的混杂物质场 .造山带非史密斯地层方法则通过混杂堆积中的构造岩片四维裂拼复原分析 ,着重了解各构造岩片的原生生成时代、相环境、古大地构造背景和变形变质历程 .根据在东昆仑阿尼玛卿混杂岩带中新发现的放射虫、孢粉、遗迹化石等资料 ,对该混杂岩带的构造岩片 (块 )时态、相态进行了研究 ,为阿尼玛卿造山带的演化历程提供了精细解剖新资料 .     

铅同位素系统剖面化探与隐伏矿深度预测--以云南金平龙脖河铜矿为例

运用铅同位素三维空间拓扑投影特征值V1和V2 进行隐伏矿深度预测的铅同位素系统剖面化探方法使铅同位素化探方法得到了发展 .新建立的隐伏矿深度预测的理论模型在云南金平龙脖河铜矿评价中得到了验证 ,观察到的铅同位素深度变化规律与理论模型吻合得很好 .预测结果表明 ,龙脖河铜矿东矿带隐伏矿主矿体应出现在海拔 - 4 0 0～ - 5 0m左右 ;西矿带隐伏矿深度低于海拔 - 4 0 0m .     

Formation mechanism of carbonate cemented zones adjacent to the top overpressured surface in the central Junggar Basin,NW China

Carbonate cemented zones are normally adjacent to the top overpressured surface in the central Junggar Basin,NW China.Stable carbon and oxygen isotopic compositions and petrological investigations of carbonate cements in the carbonate cemented zones indicate that:(1) carbonate cements are composed dominantly of ferrocalcite,ferroan dolomite,and ankerite;(2) carbonate cements are formed under a high temperature circumstance in the subsurface,and organic fluid migration has an important effect on the formatio...     

Organic carbon fluxes from the upper Yangtze basin: an example of the Longchuanjiang River,China

To investigate the effects of anthropogenic activity, namely, land use change and reservoir construction, on particulate organic carbon (POC) transport, we collected monthly water samples during September 2007 to August 2009 from the Longchuanjiang River to understand seasonal variations in the concentrations of organic carbon species and their sources and the yield of organic and inorganic carbon from the catchment in the Upper Yangtze basin. The contents of riverine POC, total organic carbon and total suspended sediment (TSS) changed synchronously with water discharge, whereas the contents of dissolved organic carbon had a small variation. The POC concentration in the suspended sediment decreased non‐linearly with increasing TSS concentration. Higher molar C/N ratio of particulate organic matter (average 77) revealed that POC was dominated by terrestrially derived organic matter in the high flows and urban wastewaters in the low flows. The TSS transported by this river was 2.7 × 10⁵ t/yr in 2008. The specific fluxes of total organic carbon and dissolved inorganic carbon (DIC) were 5.6 and 6 t/km²/yr, respectively, with more than 90% in the high flow period. A high carbon yield in the catchment of the upper Yangtze was due to human‐induced land use alterations and urban wastes. Consistent with most rivers in the monsoon climate regions, the dissolved organic carbon–POC ratio of the export flux was low (0.41). Twenty‐two percent (0.9 t/km²/yr) of POC out of 4 t/km²/yr was from autochthonous production and 78% (3.1 t/km²/yr) from allochthonous production. The annual sediment load and hence the organic carbon flux have been affected by environmental alterations of physical, chemical and hydrological conditions in the past 50 years, demonstrating the impacts of human disturbances on the global and local carbon cycling. Finally, we addressed that organic carbon flux should be reassessed using adequate samples (i.e. at least two times in low‐flow month, four times in high‐flow month and one time per day during the flood period), daily water discharge and sediment loads and appropriate estimate method. Copyright © 2011 John Wiley & Sons, Ltd.     

Flood frequency under the influence of trends in the Pearl River basin,China: changing patterns,causes and implications

Using a nonstationary flood frequency model, this study investigates the impact of trends on the estimation of flood frequencies and flood magnification factors. Analysis of annual peak streamflow data from 28 hydrological stations across the Pearl River basin, China, shows that: (1) northeast parts of the West and the North River basins are dominated by increasing annual peak streamflow, whereas decreasing trends of annual peak streamflow are prevailing in other regions of the Pearl River basin; (2) trends significantly impact the estimation of flood frequencies. The changing frequency of the same flood magnitude is related to the changing magnitude or significance/insignificance of trends, larger increasing frequency can be detected for stations with significant increasing trends of annual peak streamflow and vice versa, and smaller increasing magnitude for stations with not significant increasing annual peak streamflow, pointing to the critical impact of trends on estimation of flood frequencies; (3) larger‐than‐1 flood magnification factors are observed mainly in the northeast parts of the West River basin and in the North River basin, implying magnifying flood processes in these regions and a higher flood risk in comparison with design flood‐control standards; and (4) changes in hydrological extremes result from the integrated influence of human activities and climate change. Generally, magnifying flood regimes in the northeast Pearl River basin and in the North River basin are mainly the result of intensifying precipitation regime; smaller‐than‐1 flood magnification factors along the mainstream of the West River basin and also in the East River basin are the result of hydrological regulations of water reservoirs. Copyright © 2014 John Wiley & Sons, Ltd.     

中国渤海湾盆地上地壳岩石成分模型(英文)

许多地震属性,比如地震的纵横波速度,泊松比,声波阻抗,都能用来区分不同的岩石类型,利用拉梅阻抗作为进一步的约束来代替声波阻抗能更好的降低结果的非唯一性。我们用这种方法构建了渤海湾地区一条剖面的岩石成分模型。我们简要介绍了区分岩石类型的地震参数,重点在于不同的参数组合对于分辨岩石类型的敏感性。为了与室温常压条件下测得的有代表性的岩石的地震波速度和密度进行对比,我们首先需要做温度和压力的校正。接着,我们需要用已知资料和实验测得的各种岩石样品做对比,来确定研究区的岩石类型。我们收集了渤中凹陷一条剖面的纵波速度资料。该剖面10km深范围内的属于同种岩石类型的不同岩石最终通过地震波速度、泊松比、密度、声波阻抗、以及拉梅阻抗综合约束。     

Delineation of reservoirs using remote sensing and their storage estimate: an example of the Yellow River basin,China

Reservoirs are an integral component of water resources planning and management. Periodic and accurate assessment of the water storage change in reservoirs is an extraordinarily important aspect for better watershed management and water resources development. In view of the shortcomings of conventional approaches in locating reservoirs' spatial location and quantifying their storage, the remote sensing technique has several advantages, either for a single reservoir or for a group of reservoirs. The satellite‐based remote sensing data, encompassing spatial, spectral and temporal attributes, can provide high‐resolution synoptic and repetitive information with short time intervals on a large scale. Using remote sensing images in conjunction with Google Earth and field check of representative reservoirs, the spatial distribution of constructed reservoirs in the Yellow River basin was delineated, and their storage volume and the residence time of the stored water were estimated. The results showed that 2816 reservoirs were extracted from the images, accounting for 89·5% of the registered total. All large‐ and medium‐sized reservoirs were extracted while small reservoirs may not be extracted due to coarse resolution and cloud‐cover shadows. An empirical relationship between the extracted water surface area and the compiled storage capacity of representative reservoirs was developed. The water storage capacity was estimated to be 66·71 km³, about 92·7% of the total storage capacity reported by the authority. Furthermore, the basin was divided into 10 sub‐basins upon which the water's residence time was analysed. The water discharge in the basin has been greatly regulated. The residence time has surged to 3·97 years in recent years, ranking the Yellow River in the top three of the list in terms of residence time and flow regulation among large river systems in the world. It is expected that it will be further extended in future owing to decreasing water discharge and increasing reservoir storage capacity. Copyright © 2011 John Wiley & Sons, Ltd.     

On the usefulness of remote sensing input data for spatially distributed hydrological modelling: case of the Tarim River basin in China

The ecological situation of the Tarim River basin in China seriously declined since the early 1950s, mainly due to a strong increase in water abstraction for irrigation purposes. To restore the ecological system and support sustainable development of the Tarim River basin region in China, more hydrological studies are demanded to properly understand the processes of the watershed and efficiently manage the water resources. Such studies are, however, complicated due to the limited data availability, especially in the mountainous headwater regions of the Tarim River basin. This study investigated the usefulness of remote sensing (RS) data to overcome that lack of data in the spatially distributed hydrological modelling of the basin. Complementary to the conventional station‐based (SB) data, the RS products that are directly used in this study include precipitation, evapotranspiration and leaf area index. They are derived from raw image data of the Chinese Fengyun meteorological satellite and from the Moderate Resolution Imaging Spectroradiometer (MODIS). The MODIS land surface temperature was used to calculate the atmospheric temperature lapse rate to describe the temperature dependency on topographical variations. Moreover, MODIS‐based snow cover images were used to obtain model initial conditions and as validation reference for the snow model component. Comparison of model results based on RS input versus conventional SB input exhibited similar results in terms of high and low river runoff extremes, cumulative runoff volumes in both runoff and snow melting seasons and spatial and temporal variability of snow cover. During summer time, when the snow cover shrinks in the permanent glacier region, it was found that the model resolution influences the model results dramatically, hence, showing the importance of detailed (RS based) spatially distributed input data. Copyright © 2011 John Wiley & Sons, Ltd.     

东营凹陷波动古湖相烃源岩沉积特征

以东营凹陷牛38井为例,研究显示,该井沙河街组沙三段烃源岩的沉积特征具有明显的波动性．宏观上体现为, 构造因素控制湖盆的整体升降和沉积构造旋回,但季节性气候及其它因素的影响使湖盆呈现次级旋回的复合性沉积．微观上表现为纹层的不连续性及生物扰动构造等事件性沉积.古湖面不同幅度的波动和变化导致相对稳定的泥岩沉积的不稳定性,有机质的分布也呈现较显著的非均质性．湖泊的沉积过程影响了微量元素、有机质以及烃源物质的分布,水体较深、盐度较高的沙三段下部多数微量元素含量较高以及B／Ca、Sr／Ba呈现高值;水体较浅、盐度较低的沙三段中部各元素的分布较为稳定,B／Ca、Sr／Ba比值及Sr的含量均显著降低.波动性沉积导致烃源岩呈现明显的优劣性分布,沙三段下部中的有机质富集,为优质烃源岩;沙三段中部的有机质分布较为分散,生排烃的资源潜力有限．     

Sediment flux into the sea as influenced by different source areas in the drainage basin: example of the Yellow River,China

Abstract

The runoff and sediment of large rivers usually come from different source areas, which make different contributions to the sediment flux into the sea. This has been studied with the example of the Yellow River in China, whose suspended sediment flux into the Bohai Sea accounts for 19.4% of the world total. The drainage basin of this river can be divided into four major water and sediment source areas. The sediment flux into the sea is found to be closely related to the water and sediment from the different source areas in the drainage basin and, accordingly, an empirical regression model has been established to express this relationship. According to this model, in each tonne (t) of sediment from the fine sediment producing area (FSA), 0.85 t (for yearly series) and 0.72 t (for event series) can be transported into the sea; in each tonne of sediment from the coarse sediment producing area (CSA), only 0.21 t (for yearly series) and 0.34 t (for event series) can be transported into the sea. Since the 1970s, the Yellow River's sediment flux into the sea has declined markedly and this reduction can be attributed to a great degree to the soil control measures in the fine sediment producing area. Coupling the models of this study to the previously established models for estimating the impacts of soil control measures on water and sediment balance in the Yellow River basin, a quantitative prediction may be made for the change of sediment flux into the sea that might result from climate change and human activities in the future.     

Retrieval of suspended sediment concentrations in large turbid rivers using Landsat ETM+: an example from the Yangtze River,China

Suspended sediment concentration (SSC) is a critical parameter in the study of river sediment transport and water quality variation, but traditional measurement methods are costly and time‐consuming. This paper is focused on presenting a methodology that may be useful in estimating SSC which is of key importance in process geomorphology and hydrology. In previous studies, remote sensing has been applied to estimate the SSC of sea waters as well as low turbid inland waters like lakes, reservoirs and short river reaches visible within a single Landsat satellite image coverage. Rivers, especially highly turbid large rivers, have largely been ignored. The dataset used in this paper includes measured SSC and multi‐temporal Landsat ETM+ images covering most part of the Yangtze River. Using an effective easy‐to‐use atmospheric correction method that does not require in situ atmospheric conditions, retrieved water reflectance of Band 4 was found to be a good SSC indicator within the large SSC range 22–2610 mg l^–1. The newly developed regression relation between SSC and water reflectance of Band 4 appears to be able to provide a relatively accurate SSC estimate directly from Landsat ETM+ images for the Yangtze River from the upper, the middle to the lower reaches. With the relation it is possible to estimate or map out SSC dynamics of large rivers which lack SSC data due to constraints of conventional measurements. Copyright © 2009 John Wiley & Sons, Ltd.     

华北地区遥测地震台网联网：数据共享的有效手段

从数据共享的角度描述了华北地区遥测地震台网联网的基本要求、预期目标、技术途径、总体结构及联网后取得的效益,说明遥测地震台网联网是实现地震观测数据共享的一种有效手段。