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991.
Müsteyde Baduna Koçyiğit Hüseyin Akay Ali Melih Yanmaz 《Arabian Journal of Geosciences》2017,10(15):331
The main goal of this study is to investigate the effect of the size of the subbasins of a watershed on the hydrologic parameters and their spatial variability in an estimation of the hydrologic parameters and hydrograph of a neighbouring ungauged basin. In this paper, Hydrologic Engineering Center-Hydrologic Modelling System (HEC-HMS), a semi-distributed hydrologic model, is used to calibrate and cross-validate two flood events occurred in 1998 and then validate four other flood events occurred in 1991, 1994, 2002, and 2009 in Gokirmak Basin in Western Black Sea Region, Turkey. The basin is divided into seven different subbasins to investigate the effect of watershed partitioning on calibrated hydrologic parameters of each subbasin using the peak-weighted root mean square error method as an objective function and the hydrograph at the outlet of the whole basin. It is found out that as the geometric magnitudes of the subbasins changed, the calibrated values of the hydrologic parameters of those subbasins changed as well. Then, a neighbouring basin, Kocanaz, is considered as an assumed neighbouring ungauged basin to investigate the effect of watershed partitioning of a gauged basin on the estimation of hydrograph of a neighbouring ungauged basin. Hydrologic parameters and direct runoff hydrograph of assumed ungauged neighbouring basin are estimated from the hydrologic parameters of the HEC-HMS calibration results of Gokirmak. Statistical indicators of the simulation results for each basin partitioning were graded with respect to the boundary values of the simulation outputs to find the best alternative. The grading results show that the simulation results with a single basin gave better representation among all other partitioning except two flood events. 相似文献
992.
Faisal Rehman Abdullah M. Alamri Sherif M. El-Hady Hussein M. Harbi Ali H. Atef 《Arabian Journal of Geosciences》2017,10(24):540
A probabilistic approach is used to evaluate the seismic hazard for 12 strategic cities in Saudi Arabia along the eastern coast of Red Sea. The focal depth variations controlled by rheological characteristics are taken into account for hazard calculations, and its creditability is tested through sensitivity analysis for hazard results. This study presents a neo-probabilistic seismic hazard assessment methodology in which the focal depth distribution of earthquakes within seismogenic layer is divided into three depth slices. These depth slices are based upon rheological characteristic of seismogenic layer. The hazard results are obtained using this depth-slice methodology and conventional approach in which uniform distribution of seismicity within seismogenic layer is assumed. The sensitivity analysis culminated in underestimation of hazard values in higher frequencies for uniform distribution of seismicity within seismogenic layer. Foregoing the observations recorded above, it can be concluded that the exploitation of depth-slices biased by the rheology to calculate hazard is relatively preferable in the situations demanding safety measures. 相似文献
993.
Abdelhafid El Alaoui El Fels Ali Bachnou Noureddine Alaa 《Arabian Journal of Geosciences》2017,10(24):554
The Tinitine sub-watershed of Rheraya is renowned for its semiarid climate, irregular supply of water flow, and its historical floods; for these reasons, it is classified as vulnerable areas during a rainfall event. We conducted this study to propose flood prediction models adapted to this risky zone. For this, a hydrological method of flood forecasting rainfall-runoff used to determine a model conforms to the semiarid basin. This model is based on the articulation of the series production and transfer function. The goal of the production function is to determine the portion of the rainfall runoff, which is performed by two approaches that differ in their structures: (1) the first approach is based on the mathematical model of Horton; (2) the second approach is based on the determination of the part of the rain contributes to runoff and obtained by a spatial map of runoff coefficient (GIS). The transfer function is based on the two models of Clark and Nash, rainy efficient routes to the catchment outlet from a unit hydrograph. The characteristic parameters of these models are obtained through the application of mathematical optimization methods such as genetic algorithms. Thereby, the coupling function producing Horton (identified by the parameters: initial infiltration?=?15.03, final infiltration?=?0.3, and phi?=?0.45) and Clark transfer function (identified by the parameters CA?=?0.21 and CB?=?0.79) was given very satisfying results, mainly the low difference between observed and simulated hydrograph and Nash coefficient which is about 85%. This shows the interest of this coupling model in flood forecasting. 相似文献
994.
Arash Adib Milad Mahmoudian Kafshgar Kalaee Mohammad Mahmoudian Shoushtari Keivan Khalili 《Arabian Journal of Geosciences》2017,10(9):208
In this research, the main hydrological characteristics (such as trend, stationarity, and normalization of hydrological data) of the Kasilian watershed are considered from 1970 to 2009. For forecasting of discharge, gene expression programming (GEP) method is applied. Normality and stationarity of time series are necessary for application of GEP method. For this purpose, third edition of Mann-Kendall trend test and skewness test are used for detection of trend and normalization of data, respectively. Also, five methods are applied for detection of stationarity of data. Modified Mann-Kendall trend test and Theil and Sen’s median slope method illustrate that annual and monthly precipitation data have slight decreasing trend, annual and monthly discharge data have insignificant decreasing trend, and annual and monthly temperature data have an increasing trend. Skewness test illustrates that annual, monthly, and daily discharge and precipitation data are not normal. By using logarithm function, skewness is minimized and symmetry of data is improved. After normalization of time series by logarithm function, five methods are applied for testing of stationarity of time series. These methods show that different normalized time series are stationarity and stationarity of time series is improved by elimination of periodic properties of data. For forecasting of daily discharge by GEP method, 85% of data are used for training and 15% of data are used for testing. By using data of 3 days ago, the GEP has the best efficiency. Coefficient of correlation (CC), root mean square error (RMSE), mean absolute error (MAE), and mean absolute relative error (MARE) are 0.9, 0.495 lit/s, 0.288 lit/s, and 0.053, respectively. 相似文献
995.
Geological and Geochemical Investigation of Three Ophiolite‐Hosted Manganese Prospects,Southeast of Birjand,South Khorasan,East of Iran
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Behnaz Barghi Ali Asghar Calagari Mohammad Hossein Zarrinkoub Vartan Simmonds 《Resource Geology》2017,67(4):414-425
The studied ophiolite‐hosted manganese prospects are located in southeast of Birjand, South Khorasan, in the east of Iran. The manganese ores within the ophiolitic sequence in this region occur as small discrete patches, associated with radiolarian chert and shale. Manganese ores in the host rocks are recognizable as three distinct syngenetic, diagenetic, and epigenetic features. The syngenetic manganese ores occurred as bands associated with light‐red radiolarian chert. The diagenetic Mn ores occurred as lenses accompanied by dark‐red to brown radiolarian chert. The epigenetic Mn ores occurred as veins/veinlets within the green radiolarian shale. The major manganese ore minerals are pyrolusite, braunite, bixbyite, ramsdellite, and romanechite showing replacement, colloidal, and brecciated textures. The high mean values of Mn/Fe (15.32) and Si/Al (15.65), and the low mean concentration values of trace elements, such as Cu (85.9 ppm), Ni (249.9 ppm), and Zn (149 ppm), as well as the high concentration values of Si, Fe, Mn, Ba, Zn, Sr, and As in the studied manganese ores furnished sufficient evidence to postulate that the sea‐floor Mn‐rich hydrothermal exhalatives were chiefly responsible for the ore formation, and the hydrogenous processes had negligible role in generation of the ores. The further geological and geochemical evidence also revealed that the ores deposited on the upper parts of the ophiolitic sequence by submarine exhalatives. The intense hydrothermal activities caused leaching of elements such as Mn, Fe, Si, Ba, As and Sr from the basaltic lavas (spilites). After debouching of the sea‐floor exhalatives, these elements entered the sedimentary basin. The redox conditions were responsible for separation of Fe from Mn. 相似文献
996.
997.
Natural Hazards - Ground vibrations induced by the blasting of explosives can cause damage to the slope stability of mines. The important indicators of rock mass such as the geological... 相似文献
998.
Darama Yakup Selek Zeliha Selek Bulent Akgul Mehmet Ali Dagdeviren Murat 《Natural Hazards》2019,97(1):211-227
Natural Hazards - Hasanlar Dam and Hydroelectric Power Plant are located on Küçük Melen Creek in the Western Black Sea Basin of Turkey. The dam was constructed in 1974 to provide... 相似文献
999.
Al-Hemoud Ali Al-Sudairawi Mane Al-Rashidi Mufreh Behbehani Weam Al-Khayat Ahmed 《Natural Hazards》2019,97(1):139-155
Natural Hazards - Boundary layer temperature inversion and mixing heights are important parameters in understanding the atmospheric dispersion of air pollution. Surface and elevated inversions were... 相似文献
1000.
The Hizeh-Jan kaolin deposit(northwest of Varzeghan, East-Azarbaidjan Province, NW Iran) is a product of the alteration of Eocene andesitic rocks. Based on mineralogical examinations, kaolinite, quartz, smectite, pyrophyllite, muscovite-illite, alunite, calcite, diaspore, goethite and hematite are the most abundant mineral phases in this deposit. The geochemical indicators, such as Y/Ho and Zr/Hf, indicate the non-CHARAC(non-Charge-radius control) behavior of these pairs, which are likely to be due to the occurrence of the tetrad effect phenomenon in this deposit. Simultaneous concave and convex shapes in the chondrite-normalized REE distribution patterns are a remarkable feature of the kaolin samples. Bivariate diagrams of the size of the third tetrad effect(T_3) versus geochemical parameters such as Y/Ho, Nb/Ta and Zr/Hf ratios display two distinct populations for the kaolin samples. The first population is characterized by high T_3 values(>0.13), which are near or on the fault zone. The second population is characterized by low T_3 values(<0.13), and are farther from the fault zone. The obtained results from the geochemical data have furnished compelling evidence that fluidrock interaction, overprint of hypogene processes by supergene ones, and structural control, are key controlling factors for the occurrence of tetrad effects in REE distribution patterns in the Hizeh-Jan kaolin deposit. 相似文献