应用土柱试验求解地下含水介质弥散系数

污染物质在地下含水介质中的运移,除受渗透系数等水文地质条件的制约外,还受到含水介质弥散系数的控制。污染物的扩散,首先是从包气带开始进行的,浑河冲洪积扇地包气带主要岩性是亚粘土及亚砂土,因此,计算出浑河冲洪积扇包气带的弥散系数,对于认识污染物的运移能力是一项必要的工作。本文利用室内动态土柱装置,模拟包气带岩性环境,以0.05 mol/L的NaCl溶液作为示踪剂,经长时间监测,运用弥散系数计算公式进行求参。计算结果是包气带以亚粘土为主要岩性的弥散系数为0.005 71 m2/d,亚砂土的弥散系数为0.012 47 m2/d。     

延边八家子镇上南沟“大理岩”地质地球化学特征及地质意义

传统观点认为,延边八家子镇上南沟"大理岩"为碳酸盐岩地层经过区域变质作用形成。通过详细的野外和镜下观察,发现该"大理岩"并不发育层理等典型沉积岩的特征,而主要呈岩株和岩墙产出,与围岩新东村岩组片岩、片麻岩呈港湾状侵入式接触;且其中发育大量围岩捕虏体,"大理岩"局部还发育有冷凝边;除上南沟"大理岩"外,在上南沟及周边地区并没有碳酸盐岩地层的发育。分析显示,上南沟"大理岩"具有与火成碳酸岩相似的微量元素和稀土元素组成特征,C、O同位素组成处于火成碳酸岩受低温蚀变的演化趋势之内。因此,初步认为延边八家子上南沟"大理岩"并不是由碳酸盐岩地层经区域变质作用形成,其成因可能存在以下2种解释:一种是上南沟"大理岩"为火成碳酸岩,很可能是华北克拉通破坏事件在北缘的响应;另一种可能是大规模富含CO2流体运移的产物,是大规模流体运移成矿的典型范例。     

A spectral mixture model analysis of the Kuroshio variability and the water exchange between the Kuroshio and the East China Sea

For understanding more about the water exchange between the Kuroshio and the East China Sea,We studied the variability of the Kuroshio in the East China Sea(ECS) in the period of 1991 to 2008 using a three-dimensional circulation model,and calculated Kuroshio onshore volume transport in the ECS at the minimum of 0.48 Sv(1 Sv ;106 m3/s) in summer and the maximum of 1.69 Sv in winter.Based on the data of WOA05 and NCEP,The modeled result indicates that the Kuroshio transport east of Taiwan Island decreased since 2000.Lateral movements tended to be stronger at two ends of the Kuroshio in the ECS than that of the middle segment.In addition,we applied a spectral mixture model(SMM) to determine the exchange zone between the Kuroshio and the shelf water of the ECS.The result reveals a significantly negative correlation(coefficient of-0.78) between the area of exchange zone and the Kuroshio onshore transport at 200 m isobath in the ECS.This conclusion brings a new view for the water exchange between the Kuroshio and the East China Sea.Additional to annual and semi-annual signals,intra-seasonal signal of probably the Pacific origin may trigger the events of Kuroshio intrusion and exchange in the ECS.     

零次差分CHAMP卫星简动力定轨和SLR轨道验证

采用零次差分简化动力法对CHAMP卫星GPS相位观测资料进行精密轨道计算,并将计算结果与CHAMP快速轨道进行比对.结果表明X,Y、Z方向差值均方根为0.061 m,0.060 m与0.066 m,精度达到了厘米级;同时利用全球人卫激光观测数据对所求轨道进行验证,表明其精度优于20 cm.     

D-InSAR-based landslide location and monitoring at Wudongde hydropower reservoir in China

Differential synthetic aperture radar interferometry (D-InSAR) has become a useful technique for monitoring ground movement. The technique enables the analysis of very small ground movements in continuous, large areas and has the advantages of high accuracy, high resolution, all-weather adaptability, low cost, and inaccessible area coverage. Thus, D-InSAR has been widely used in the investigation of geologic hazards, such as subsidence, landslide, earthquake, and volcanic activity. In this paper, D-InSAR is used to locate and monitor landslide movement in the wide area of Wudongde Hydropower Reservoir in Jinsha River, China. Five SAR acquisitions are obtained by using the phased array-type L-band synthetic aperture radar sensor of the Advanced Land Observing Satellite. Detailed moving displacement maps in two time periods are derived by using the D-InSAR technique, and potentially moving landslide areas, as well as landslide hazard areas, are then located. The L1R-6 landslide, which is in active state, is investigated in detail. The deforming tendency obtained via D-InSAR is consistent with that obtained via global positioning system (GPS) monitoring. Error analysis of the D-InSAR results is also conducted. Finally, the grid function interpolation method of error reduction, which combines D-InSAR and GPS, is proposed to reduce the single-point error in D-InSAR monitoring and is further verified by the considerable improvement in the accuracy of L1R-6 landslide monitoring.     

Correlation between incompetent beds and slope deformation at Badong town in the Three Gorges reservoir, China

Badong town is a new immigration area in the Three Gorges reservoir, China, which is built on many giant deep-seated landslides. In this region, the slope deformation is very severe and it is strongly correlated with the incompetent beds, which are distributed widely in the rock mass. In this paper, two giant deep-seated translational rock landslides used as study cases are Huangtupo landslide and Zhaoshuling landslide. Firstly, the composition materials, structures and deformation characteristics of the two landslides are analyzed. Then, the position, structure, mineral composition and the formation mechanism of the incompetent beds are studied in detail. Finally, based on the comparison of the position, mineral and structure between incompetent beds and sliding zones of the landslides, the correlations between incompetent beds and giant landslide are discussed. The results indicate that 13 large incompetent beds exist in the middle Triassic Badong Formation strata, which can be divided into three types as weak interlayers, crushed beds and groundwater corrosion zones. The dominant minerals in the incompetent beds are illite, chlorite, quartz and calcite. The contents of the clay minerals in different positions are quite distinct, and the maximum difference of clay content exceeds 70 %. In addition, it is found that the contents of minerals in incompetent beds are similar to the slide zones of the landslides. The initial deformation of slopes normally developed along the incompetent beds, which induced subsequent shear displacement easily. Under the effect of gravity, the deep slip zones were generated mainly along the incompetent beds and the failure mode evolved from creep to integral slide gradually. The results can provide an important reference for the mechanism analysis and prevention of landslides in Badong town.     

Investigation of NDVI in relation to the growth phases of beech leaves in forest

The main objective of the science of phenology is to identify the time of the occurrence of conspicuous periodic phenomena in plants under the impact of climatic factors. The study of phonologic phenomena through visual observations and terrestrial studies and temperature registration using a thermo hydrometer in different altitudinal levels and using the satellite data of IRS1C/1D LISSIII in twelve 1-ha plots in pure beech stands in the altitudinal range of 500 to 1,200 m above the sea level from April to December was carried out in such a way that for each month, one image of sensor was allocated. The produced vegetation indices were matched with terrestrial observations of the phenology periods in each month in the beech plots. The results show that the increase of the altitude above the sea level functions like latitude and its most remarkable impact is the decreasing of the temperature and the shortening of growing season. The terrestrial observations carried out in the plots show that a sudden increase in the temperature leads to the faster growth and emergence of the leaves. The produced correlation coefficient between the temperature and the emergence of the leaves was (p?=?0.01) r?=?0.87. Moreover, the end of fall in the studied region has a direct and significant relation with temperature. The amount of correlation coefficient between the temperature and end of fall in the studied region is equal to (p?=?0.01) r?=?0.91. Normalized difference vegetation index (NDVI) is more related to the growth and nurturing of the leaves. The amount of NDVI during the growth of the leaves, completion of the leaves, and fall of the leaves is equal to 0.35, 0.6, and 0.25, respectively.     

An analysis of vegetation indices in relation to tree species diversity using by satellite data in the northern forests of Iran

Vegetation indices have been introduced for analyzing and assessing the status of quantitative and qualitative characteristics of vegetation using satellite images. However, choosing the best indices to be used in forest biodiversity and vegetation is one of the important problems faced by the users. The purpose of this research is to evaluate six vegetation indices in the analysis of tree species diversity in the northern forests of Iran. The present research uses LISS III sensor data from IRS-P6 satellite. Geometric rectification of images was performed using ground control points, and Chavez model was used for atmospheric correction of the data. The six spectral vegetation indices included NDVI, IPVI, Ashburn Vegetation Index (AVI), TVI, TTVI, and RVI. Shannon–Wiener species diversity index was used to analyze diversity, and the value of the index was calculated in each sample plot. Then, the spectral values of each sample plot were extracted from different bands. The best subset regression was used to analyze the relationship between species diversity and the related bands. The results obtained from the regression showed that polynomial equations under scrutiny as independent variables can assess tree and shrub species diversity better than other bands and compounds used (R ²?=?0.47). The obtained results also indicated a higher capacity in the case of the AVI index for estimating tree species diversity in the under study area.     

用多元回归分析从试井求得的平均渗透系数提取单层参数信息的方法

本文提供一种从试井求得的平均渗透系数回算每个单层渗透系数的方法。井的试验,无论是为供水、排水或工程建设目的的常规试井,还是为热田开发目的的专门性地热试井,其首要任务是确定含水层或热储层的各项参数,其中最主要者为地层的渗透系数K。     

Numerical investigation of the control factors driving Zhe-Min Coastal Current

During the northeast monsoon season, Zhe-Min Coastal Current(ZMCC) travels along the Chinese mainland coast and carries fresh, cold, and eutrophic water. ZMCC is significantly important for the hydrodynamic processes and marine ecosystems along its path. Thus, this bottom-trapped plume deserves to be further discussed in terms of the major driving factor, for which different opinions exist. For this purpose, in this study, a high resolution Semi-implicit Cross-scale Hydroscience Integrated Syste...