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531.
Dušan Polomčić Bojan Hajdin Zoran Stevanović Dragoljub Bajić Katarina Hajdin 《Hydrogeology Journal》2013,21(7):1519-1530
The Vi? Bare groundwater source is used to supply water to the population and industry of Obrenovac, one of the municipalities of Belgrade (the capital of Serbia). It is a typical riverbank filtration site; exploitation is performed through 30 drilled wells and two radial wells located in the meander of the Sava River. The established hydraulic connection between the river and tapped aquifer is so great that the river regime has a dominant influence on the aquifer. As a consequence of this, water-delivery reduction occurs in the dry months (summer–autumn), when the population needs water the most. Based on the data associated with the river’s gauges, precipitation, quantity of pumped water and groundwater-level fluctuation, a simulation of the groundwater regime for non-steady-state flow conditions has been undertaken through a numerical model. To overcome problems of water shortage during the dry season, the possibility of artificial recharge using an infiltration channel, made up of two connected parts, was analyzed. During the dry months, 80 % of the wells receive water partly from the infiltration channel. In this way, possibilities for extracting additional water are created. The application of this concept is discussed. 相似文献
532.
Xiaodong Wu Lin Zhao Tonghua Wu Ji Chen Qiangqiang Pang Erji Du Hongbing Fang Zhiwei Wang Yonghua Zhao Yongjian Ding 《Environmental Earth Sciences》2013,68(3):865-870
A large volume of underground gas in the permafrost region of the Qinghai-Tibetan Plateau has been identified. Although many studies were performed to investigate the soil organic carbon dynamics and Earth degassing in volcanic areas, this is the first report of a large amount of non-volcanic CO2 contained in permafrost. The gas was mostly CO2 (81.76 vol. %) and nitrogen (14.59 vol. %). The gas composition and the evidence from carbon stable isotope values (?23.9 ‰, PDB) suggested that the gases possibly had a deep origin. The gas emissions may be triggered by permafrost degradation, which means mitigation of the barrier effect of permafrost for the gas. In addition, plate tectonic processes may also lead to gas emissions, as the tectonic activity is strong in the area. Therefore, particular attention should be paid to the underground gases in the study of global change and permafrost degradation. 相似文献
533.
Correlation between incompetent beds and slope deformation at Badong town in the Three Gorges reservoir, China 总被引:2,自引:0,他引:2
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. 相似文献
534.
Spatial distribution of surface soil water content under different vegetation types in northwest Guangxi, China 总被引:3,自引:1,他引:2
Wanxia Peng Tongqing Song Fuping Zeng Kelin Wang Hu Du Shiyang Lu 《Environmental Earth Sciences》2013,69(8):2699-2708
Geostatistical and statistical analyses were combined to examine the spatial distribution of soil water content under four vegetation types during the dry season, in the peak-cluster depression in the karst region in northwest Guangxi, southwest China. The soil water content significantly increased from farmland to plantation, secondary forest, and primary forest; whereas the variation coefficients, the sill (C 0+C), and total spatial variance increased, although the range decreased. The spatial distribution of soil water content in the different vegetation types had a high spatial autocorrelation. Different models produced a best fit for the semivariograms of the four vegetation types. Elevation and slope position were the primary factors influencing the spatial distribution of soil water content, with other key factors differing between the four vegetation types. Moreover, even though different specific factors influenced soil water content in the four vegetation types, the correlations and degrees of associations between the soil water content and these various factors differed. Therefore, the corresponding strategies for rational usage and management of water resources should be different for the four vegetation types in this region. 相似文献
535.
536.
In order to monitor the pattern, distribution, and trend of land use/cover change (LUCC) and its impacts on soil erosion, it is highly appropriate to adopt Remote Sensing (RS) data and Geographic Information System (GIS) to analyze, assess, simulate, and predict the spatial and temporal evolution dynamics. In this paper, multi-temporal Landsat TM/ETM+ remotely sensed data are used to generate land cover maps by image classification, and the Cellular Automata Markov (CA_Markov) model is employed to simulate the evolution and trend of landscape pattern change. Furthermore, the Revised Universal Soil Loss Equation (RUSLE) is used to evaluate the situation of soil erosion in the case study mining area. The trend of soil erosion is analyzed according to total/average amount of soil erosion, and the rainfall (R), cover management (C), and support practice (P) factors in RUSLE relevant to soil erosion are determined. The change trends of soil erosion and the relationship between land cover types and soil erosion amount are analyzed. The results demonstrate that the CA_Markov model is suitable to simulate and predict LUCC trends with good efficiency and accuracy, and RUSLE can calculate the total soil erosion effectively. In the study area, there was minimal erosion grade and this is expected to continue to decline in the next few years, according to our prediction results. 相似文献
537.
538.
Kunming basin is a Cenozoic faulted basin under the control of mainly SN-trending active faults. In and around the basin, there are a total of eight major active faults. Seismo-geological survey and fault slip observation show that the SN- and NE-trending active faults are mostly sinistral strike-slip faults, while the NW-trending faults are mostly dextral strike-slip faults. Using stress tensor inversion method with 706 active fault striation data at 22 measurement sites, we determined tectonic stress field of the study area. The result shows that modern tectonic stress field in and around Kunming basin is characterized by NNW-SSE compression, ENE-WSW extension, and strike-slip stress regimes. The maximum principal compressional stress (σ1) is oriented 335o~2o, with an average dip angle of 21°; the minimum (σ3) is oriented 44o~93o, with an average dip angle of 14°, and the intermediate (σ2) has a high, or nearly vertical, dip angle. The inversion result from fault slip data is consistent with the result from focal mechanism solutions. 相似文献
539.
湖南太阳山隆起区断层活动性研究 总被引:1,自引:0,他引:1
湖南省太阳山地区是洞庭湖西缘一个晚新生代时期隆起的低山丘陵区,山体走向为北北东方向,自南向北斜列展布了太阳山低山区和凤凰山低山区,二者之间为北北东向大龙站谷地.通过对该地区现有6条断层活动性的地质调查,获得了位于大龙站谷地东侧的肖伍铺断层断错中更新世晚期,距今12.3±1.O万年地层的地质证据,为中更新世晚期至晚更新世早期有活动的断层,表现为逆冲活动的性质.根据岗市-河袱断层带发育的断层泥及其测年结果可知,该断层可能在中更新世中期有过活动.其余4条断层没有第四纪以来活动的地质地貌表现,属于前第四纪断层.上述研究结果对认识1631年太阳山63/4级地震的发震构造是有意义的. 相似文献
540.
First record of contourites from Lower Devonian Liptrap Formation in southeast Australia 总被引:2,自引:0,他引:2
Typical contourite deposits associated with submarine turbidite fan deposits are recognized for the first time from the Lower Devonian Liptrap Formation at Cape Liatrap, Victoria in southeast Australia. The contourites are well integrated within the turbidite fan deposits and are characterized by thin (5-8 cm), lenticular, well-sorted coarse-grained siltstones to fine-grained sandstones with current-ripples and cross beddings. The palaeocurrent directions of the turbidite fan and contourites are perpendicular to each other, with the former directed generally westward while the latter varying from 165° to 190° southward. In view of the facies types and architecture, we suggest that the turbidite fan was developed at the base of a westward inclined palaeo-slope, at the front of which the contourites were deposited as a result of southward flowing deep-sea contour (geostrophic) currents. The depositional setting inter- preted for the Liptrap Formation thus may provide a provisional model for the Lower Devonian conti- nental slope and abyssal basin environment in the southeastern part of the Melbourne Trough. 相似文献