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101.
NARX neural network approach for the monthly prediction of groundwater levels in Sylhet Sadar,Bangladesh
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Abdullah Al Jami Meher Uddin Himel Khairul Hasan Shilpy Rani Basak Ayesha Ferdous Mita 《地下水科学与工程》2020,8(2):118-126
Groundwater is important for managing the water supply in agricultural countries like Bangladesh. Therefore, the ability to predict the changes of groundwater level is necessary for jointly planning the uses of groundwater resources. In this study, a new nonlinear autoregressive with exogenous inputs(NARX) network has been applied to simulate monthly groundwater levels in a well of Sylhet Sadar at a local scale. The Levenberg-Marquardt(LM) and Bayesian Regularization(BR) algorithms were used to train the NARX network, and the results were compared to determine the best architecture for predicting monthly groundwater levels over time. The comparison between LM and BR showed that NARX-BR has advantages over predicting monthly levels based on the Mean Squared Error(MSE), coefficient of determination(R~2), and Nash-Sutcliffe coefficient of efficiency(NSE). The results show that BR is the most accurate method for predicting groundwater levels with an error of ± 0.35 m. This method is applied to the management of irrigation water source, which provides important information for the prediction of local groundwater fluctuation at local level during a short period. 相似文献
102.
AITinghua 《地球空间信息科学学报》2003,6(3):56-61
In land-use data general-ization, the removal of insignificant parcel with small size is the most fre-quently used operator. Traditionally for the generalization method, the small parcel is assigned completely to one of its neighbors. This study tries to improve the generalization by sepa-rating the insignificant parcel into parts around the weighted skeleton and assigning these parts to different neighbors. The distribution of the weighted skeleton depends on the com-patibility between the removed object and its neighbor, which considers not only topological relationship but also distance relationship and semantic sim-ilarity. This process is based on the Delaunay triangulation model. This paper gives the detailed geometric al-gorithms for this operation. 相似文献
103.
COM技术在地球化学数据处理系统中的应用 总被引:1,自引:1,他引:0
区域地球化学信息作为反映矿产资源区域特性的重要指标,在区域矿产资源评价中占有重要的地位,为了有效利用该指标,这就要求研究实用可行的数据处理系统来更好地对地球化学数据进行处理,随着数据处理方法的不断完善和地矿信息化工作的不断提高,要求处理系统本身具有可重用性,可扩展性,高效性等特点,而组件对象模型(COM)技术提供了一种如何建立可重用、可扩展组件,以及如何通过组件高效率地构筑应用程序的一个规范,使得软件系统以组件方式集成成为可能,作者在COM技术内涵基础上,结合地球化学数据处理系统目前存在的若干问题,探讨了COM组件技术在地球化学数据处理系统中的应用,并对数据处理组件进行了分析设计。 相似文献
104.
105.
The Kidd Creek Cu---Zn sulphide mine is located near Timmins, Ontario. Mill tailings are thickened and deposited as a thickened slurry in a circular, conical-shaped pile with an area of approximately 1200 ha. Deposition of tailings as a thickened slurry results in a relatively uniform grain-size distribution and hydraulic conductivity, and a thick tension-saturated zone above the water table. The tailings are drained by numerous small, ephemeral stream channels, which have developed in a radial pattern. During storms, water from these streams collects in catchment ponds where it is held before treatment. The contribution of tailings pore water to the run off is of interest because of the potential for discharge of pore water containing high concentrations of Fe(II)-acidity, metals and SO4 to the stream. Hydraulic head measurements, measurements of water-table elevation and groundwater flow modelling were conducted to determine the mechanisms responsible for tailings pore water entering the surface streams. Chemical hydrograph separation of storm run off in one of these streams, during three rainfall events, using Na and Cl as conservative tracers, indicates that the integrated tailings pore water fraction makes up between less than 1 % and 20% of the total hydrograph. This range is less than the maximum fraction of tailings pore water of 22–65% reported for run off from a conventional tailings deposit. At this site, preferential flow through permeable fractures may be the dominant mechanism causing discharge of tailings pore water to storm run off. Estimates of the mass of Fe(II) that discharges to the surface run off from the pore water range up to 2800 mg s−1 during a moderate intensity, long duration rainfall event. The greatest potential for discharge of significant masses of solutes derived from the pore water exists during long duration rainfall events, when the water table rises to the surface over large areas of the tailings impoundment. 相似文献
106.
BassamFAIBassam 《中国地质大学学报(英文版)》2003,14(1):52-58
Landsat TM digital spectral data of Lancang-Jinghong area (Yunnan Province) has been used for the purpose of geological interpretation. To meet this object, different image processing tech-niques including selected band color composites, principal component analysis and IHS decorrelation stretching are used to improve the discrimination of different lithologicai and structural features in the area. It was found that IHS decorrelation stretching images obtained from the transformation of false color composite 741 (in red, green and blue) provided the best results based on the original data. By combining the characteristics of images produced by different approaches and other canonically trans-formed images with available geological data and surface observations, the geological interpretation could be done with satisfactory degree of accuracy. 相似文献
107.
BassamFAIBassam 《中国地质大学学报(英文版)》2003,14(3):283-292
Gengma region, Sanjiang district is known to have some large-scale gold deposits. GIS predictive model for hydroghermal gold potential was carried out in this region using weights of evidence modeling technique. Datasets used include large-scale hydroghermal gold deposit records, geological, geophysical and remote sensing imagery. Based on the geological and mineral characteristics of areas with known gold occurrences in Sanjiang, several geological features were thought to be indicative of areas with potential for the occurrence of hydroghtermal gold deposits. Indicative features were extracted from geoexploration datasets for use as input in the predictive model. The features include host rock lithology, geologic structures, wallrock alteration and associated (volcanic-plutonic) igneous rocks. To determine which of the indicative geological features are important spatial predictors of area with potential for gold deposits, spatial analysis was done through the modeling method. The input maps were buffered and the optimum distance of spatial association for each geological feature was determined by calculating the contrast and studentized contrast. Five feature maps were converted to binary predictor patterns and used as evidential layers for predictive modeling. The binary patterns were integrated in two combinations, each of which consists of four patterns in order to avoid over prediction due to the effect of duplicate features in the two structural evidences. The two produced potential maps define almost similar favorable zones. Areas of intersections between these zones in the two potential maps placed the highest predictive favorable zones in the region. 相似文献
108.
Adsorption of dimethoate and 2,4-D on Jordan Valley soils and their environmental impacts 总被引:1,自引:0,他引:1
M. Al Kuisi 《Environmental Geology》2002,42(6):666-671
The adsorption process of dimethoate and 2,4-dichloro-phenoxy acetic acid (2,4-D) on Jordan Valley soils from aqueous solution at 25 °C has been studied. The adsorption isotherms may be classified as L-type of the Giles classification. The Kads values (Freundlich equation) vary between 1.01 (JV5) and 10.36 (JV7) for dimethoate insecticide and between 4.41 (JV5) and 14.87 (JV7) for 2,4-D herbicide, depending on the soil type. The adsorption of 2,4-D herbicide on soils in the study area is about threefold higher than that of dimethoate insecticide. The adsorption process of dimethoate and 2,4-D pesticides seem to be primarily controlled by the organic matter content of the soils and the clay content (most especially montmorillonite). 相似文献
109.
Sedimentologic study of carbonated sediments of the Rmah-I member (Coniacian–Santonian) of Jabal Abtar, central southern Palmyrides (Central Syria), uncovers phosphatic levels, associated with marine vertebrate remains, that give evidence of an early episode of the Senonian phosphatogenesis in the Palmyrides. Sedimentary sequence analysis reveals a gradual marine transgression during the Senonian. Phosphatic sedimentation occurred in a shallow neritic marine environment almost connected with the open sea. Condensed sedimentation could have contributed to the phosphatogenesis. To cite this article: A.K. Al Maleh, N. Bardet, C. R. Geoscience 335 (2003). 相似文献
110.
Field examples of fault-related folds were observed in the south-western margin of the Sirt basin, south-central Libya. Single or paired (conjugate) monoclines, drape synclines, special drag faults can be put in a geometric and evolutionary model, which describes the propagation of basement faults to overlying sediments. At the first stage of evolution the propagating normal or oblique-slip faults show segmentation along-dip direction. Fault segments are separated by continuous, moderately to strongly bended horizons, which show different degrees of diagenesis than surrounding intervals. Fault-related folding and faulting was coeval with lithification of certain carbonate levels. Their gradual cementation increased the rigidity of layers promoting discrete faulting and breaching of fault-related folds. However, folding can be maintained up to the extent when layer dip approaches the dip of the propagating fault zone. This type of deformation can be characteristic for sequences consisted of lithified carbonates sandwiched between thicker marl/shale intervals. 相似文献