Time series forecasting of river flow using an integrated approach of wavelet multi-resolution analysis and evolutionary data-driven models. A case study: Sebaou River (Algeria)     

Mousaab Zakhrouf  Hamid Bouchelkia  Madani Stamboul  Sungwon Kim  Salim Heddam 《自然地理学》2018,39(6):506-522

The complexity of hydrological processes and lack of data for modeling require the use of specific tools for non-linear natural phenomenon. In this paper, an effort has been made to develop a conjunction model – wavelet transformation, data-driven models, and genetic algorithm (GA) – for forecasting the daily flow of a river in northern Algeria using the time series of runoff. This catchment has a semi-arid climate and strong variability in runoff. The original time series was decomposed into multi-frequency time series by wavelet transform algorithm and used as inputs to artificial neural networks (ANN) and adaptive neuro-fuzzy inference system (ANFIS) models. Several factors must be optimized to determine the best model structures. Wavelet-based data-driven models using a GA are designed to optimize model structure. The performances of wavelet-based data-driven models (i.e. WANFIS and WANN) were superior to those of conventional models. WANFIS (RMSE = 12.15 m³/s, EC = 87.32%, R = .934) and WANN (RMSE = 15.73 m³/s, EC = 78.83%, R = .888) models improved the performances of ANFIS (RMSE = 23.13 m³/s, EC = 54.11%, R = .748) and ANN (RMSE = 22.43 m³/s, EC = 56.90%, R = .755) during the test period.  相似文献   

Analyse multi-échelle par ondelettes des contacts géologiques : application à la carte gravimétrique du Maroc nord-oriental     

Driss Khattach  Hamid Mraoui  Driss Sbibih  Touria Chennouf 《Comptes Rendus Geoscience》2006,338(8):521-526

The multiscale wavelet analysis has been applied to the gravity data from northeastern Morocco to map the major geological contacts, such us faults. Hence, the faults affecting the survey area were outlined with their importance level and dip direction. Seismic data confirm these results and testify the efficiency of this method, particularly in studying structure of plains. The structural map established is a very useful document in the planning of natural resources investigations (i.e. water, mines) to be undertaken in the area of study. To cite this article: D. Khattach et al., C. R. Geoscience 338 (2006).  相似文献   

An investigation on the Eocene Pushtasar basaltic lava in relation to Moghan Aulacogene     

Homayoon?MohammadihaEmail author  Mansour?Mostafazadeh  Neda?Gholami 《Arabian Journal of Geosciences》2015,8(5):2879-2887

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Monitoring of dust storm and estimation of aerosol concentration in the Middle East using remotely sensed images     

Taheri Shahraiyni  Hamid  Karimi  Khadijeh  Habibi Nokhandan  Majid  Hafezi Moghadas  Naser 《Arabian Journal of Geosciences》2015,8(4):2095-2110

Arabian Journal of Geosciences - Dust storms are one of the major environmental disasters in the arid regions of Middle East, occurring in very high frequency. As a result, monitoring dust storms...  相似文献   

Application of analytical hierarchy process,frequency ratio,and certainty factor models for groundwater potential mapping using GIS   总被引：4，自引：1，他引：3  

Yousef Razandi  Hamid Reza Pourghasemi  Najmeh Samani Neisani  Omid Rahmati 《Earth Science Informatics》2015,8(4):867-883

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Snow water equivalent prediction using Bayesian data assimilation methods   总被引：1，自引：0，他引：1  

Marc Leisenring  Hamid Moradkhani 《Stochastic Environmental Research and Risk Assessment (SERRA)》2011,25(2):253-270

Using the U.S. National Weather Service’s SNOW-17 model, this study compares common sequential data assimilation methods, the ensemble Kalman filter (EnKF), the ensemble square root filter (EnSRF), and four variants of the particle filter (PF), to predict seasonal snow water equivalent (SWE) within a small watershed near Lake Tahoe, California. In addition to SWE estimation, the various data assimilation methods are used to estimate five of the most sensitive parameters of SNOW-17 by allowing them to evolve with the dynamical system. Unlike Kalman filters, particle filters do not require Gaussian assumptions for the posterior distribution of the state variables. However, the likelihood function used to scale particle weights is often assumed to be Gaussian. This study evaluates the use of an empirical cumulative distribution function (ECDF) based on the Kaplan–Meier survival probability method to compute particle weights. These weights are then used in different particle filter resampling schemes. Detailed analyses are conducted for synthetic and real data assimilation and an assessment of the procedures is made. The results suggest that the particle filter, especially the empirical likelihood variant, is superior to the ensemble Kalman filter based methods for predicting model states, as well as model parameters.  相似文献   

Timing of juvenile arc crust formation and evolution in the Sapat Complex (Kohistan–Pakistan)     

Pierre Bouilhol  Urs Schaltegger  Massimo Chiaradia  Maria Ovtcharova  Andreas Stracke  Jean-Pierre Burg  Hamid Dawood 《Chemical Geology》2011,280(3-4):243-256

The combination of age determination and geochemical tracers allows understanding the source evolution during magmatism. We studied the Sapat Complex, in the exhumed Cretaceous Kohistan Paleo-Island Arc, to reconstruct the formation of the juvenile lower arc crust and the evolution of the mantle source during arc magmatism. High precision ID-TIMS U/Pb dating on zircon, shows that a protracted period of magmatic accretion formed the Sapat Complex between 105 and 99 Ma. Since continued melt percolation processes that formed the lower crust obscured the original bulk rock Nd–Pb–Sr isotopic composition, we rely on the Hf isotopic composition of zircons of different ages to unravel the source evolution. Nd and Pb bulk isotopic compositions coupled with Hf isotopic composition on zircons allow reconstructing a geodynamical scenario for the Sapat Complex, and the Cretaceous history of the Arc. We suggest that trenchward migration of the hot mantle source at 105 Ma explains the small heterogeneous εHf signal between + 14 and + 16. This heterogeneity vanished within ca. 2 million years, and the εHf of the source evolved from + 16 to + 14 at 99 Ma. Integrated to the Kohistan Cretaceous history, which has a baseline of εHf ≈ 14, these data pinpoint two geodynamical events, with slab retreat and the formation of the Sapat Complex followed by splitting of the Kohistan island arc at 85 Ma.  相似文献   

Specification and prediction of nickel mobilization using artificial intelligence methods   总被引：1，自引：0，他引：1  

Raoof Gholami  Mansour Ziaii  Faramarz Doulati Ardejani  Shahoo Maleki 《Central European Journal of Geosciences》2011,3(4):375-384

Groundwater and soil pollution from pyrite oxidation, acid mine drainage generation, and release and transport of toxic metals are common environmental problems associated with the mining industry. Nickel is one toxic metal considered to be a key pollutant in some mining setting; to date, its formation mechanism has not yet been fully evaluated. The goals of this study are 1) to describe the process of nickel mobilization in waste dumps by introducing a novel conceptual model, and 2) to predict nickel concentration using two algorithms, namely the support vector machine (SVM) and the general regression neural network (GRNN). The results obtained from this study have shown that considerable amount of nickel concentration can be arrived into the water flow system during the oxidation of pyrite and subsequent Acid Drainage (AMD) generation. It was concluded that pyrite, water, and oxygen are the most important factors for nickel pollution generation while pH condition, SO₄, HCO₃, TDS, EC, Mg, Fe, Zn, and Cu are measured quantities playing significant role in nickel mobilization. SVM and GRNN have predicted nickel concentration with a high degree of accuracy. Hence, SVM and GRNN can be considered as appropriate tools for environmental risk assessment.  相似文献   

Time evolution of nonplanar electron acoustic shock waves in a plasma with superthermal electrons     

Hamid Reza Pakzad  Kurosh Javidan  Mouloud Tribeche 《Astrophysics and Space Science》2014,352(1):185-191

The propagation of cylindrical and spherical electron acoustic (EA) shock waves in unmagnetized plasmas consisting of cold fluid electrons, hot electrons obeying a superthermal distribution and stationary ions, has been investigated. The standard reductive perturbation method (RPM) has been employed to derive the cylindrical/spherical Korteweg-de-Vries-Burger (KdVB) equation which governs the dynamics of the EA shock structures. The effects of nonplanar geometry, plasma kinematic viscosity and electron suprathermality on the temporal evolution of the cylindrical and spherical EA shock waves are numerically examined.  相似文献   

Effect of q-nonextensive distribution of electrons on dust-ion acoustic solitons     

Hamid Reza Pakzad 《Astrophysics and Space Science》2014,353(2):551-557

Properties of dust-ion acoustic solitary waves (DIASWs) in dusty plasmas composed of nonextensive electrons, cold fluid ions and stationary dust particles are investigated. The possibility of soliton formation and the effect of nonextensivity of the electron distribution on the soliton characters are studied using the pseudo-potential method. Regions of parameters in which a solitary wave can be propagated in the plasma is analyzed too. It is found that the solitary excitations strongly depend on the electron-ion density ratio (μ), Mach numbers (M) as well as the nonextensive parameter (q). It is shown that the domain of allowed Mach numbers depends drastically on the plasma parameters and especially on the electron nonextensivity. It is found that beyond a threshold value of the nonextensive parameter (q), dust-ion acoustic solitons are admitted.  相似文献