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51.
Sedimentological and biostratigraphic analysis of Campanian–Maastrichtian reduced series of the J. Serj permitted to characterize two episodes of submarine erosion. The first is pre-Upper Maastrichtian (Rosita contusa zone), the second is pre-Upper Palaeocene (Morozovella velascoensis zone). Thus, two type-1 boundary surfaces are distinguished. These surfaces limit three stratigraphic intervals in apparent continuity. Syn-sedimentary tectonic activity is attested by gravity deposits or processes (conglomerates, slumps). To cite this article: A. Amri et al., C. R. Geoscience 337 (2005). 相似文献
52.
Ahmed Mohamed Youssef 《Natural Resources Research》2008,17(4):215-226
Recently, both the Egyptian government and private sector have been interested in developing low desert zone areas. The low
desert zones are located between the recent Nile flood plain and the limestone plateau, from the east and west sides, and
represent an important source of aggregate materials. The development of these areas, however, will reduce the supply of aggregate
materials so that new sources must be identified. This study describes several processing methods, applied to a Landsat Enhanced
Thematic Mapper Plus image of 2001, to develop a reliable method to map the aggregate materials. By using different enhancement
techniques with the help of a supervised classification method, it was found that decorrelation stretch and principal component
analysis are the most suitable methods to discriminate between different types of aggregates, as well as to isolate these
aggregates from the surrounding materials. Field and laboratory investigations indicated that two types of aggregates were
recognized, confirming the remote sensing findings. 相似文献
53.
A priori testing of sparse adaptive polynomial chaos expansions using an ocean general circulation model database 总被引:1,自引:0,他引:1
Justin Winokur Patrick Conrad Ihab Sraj Omar Knio Ashwanth Srinivasan W. Carlisle Thacker Youssef Marzouk Mohamed Iskandarani 《Computational Geosciences》2013,17(6):899-911
This work explores the implementation of an adaptive strategy to design sparse ensembles of oceanic simulations suitable for constructing polynomial chaos surrogates. We use a recently developed pseudo-spectral algorithm that is based on a direct application of the Smolyak sparse grid formula and that allows the use of arbitrary admissible sparse grids. The adaptive algorithm is tested using an existing simulation database of the oceanic response to Hurricane Ivan in the Gulf of Mexico. The a priori tests demonstrate that sparse and adaptive pseudo-spectral constructions lead to substantial savings over isotropic sparse sampling in the present setting. 相似文献
54.
The present study aims mainly to delineate and outline the regional subsurface structural and tectonic framework of the buried basement rocks of Abu El Gharadig Basin, Northern Western Desert, Egypt. The potential field data (Bouguer gravity and total intensity aeromagnetic maps) carried out in the Abu El Gharadig Basin had been analyzed together with other geophysical and geological studies. The execution of this study is initiated by transformation of the total intensity aeromagnetic data to the reduced to pole (RTP) magnetic map. This is followed by applying several transformation techniques and various filtering processes through qualitative and quantitative analyses on both of the gravity and magnetic data. These techniques include the qualitative interpretation of gravity, total intensity magnetic and RTP magnetic maps. Regional–residual separation is carried out using the power spectrum. Also, the analytic signal and second vertical derivative techniques are applied to delineate the hidden anomalies. Aeromagnetic anomalies in the area reflect significant features on the basement tectonics, on the deep-seated structures and on the shallow-seated ones. Major faults and intrusions in the area are indicated to be mainly along the NE–SW, NW–SE, ENE–WSW and E–W directions. The Bouguer gravity map indicates major basement fracturing, as well as variations in the sedimentary basins and ridges and subsequent tectonic disturbances. The most obvious anomalous trends on the gravity map, based on their frequencies and amplitudes, are along the NE–SW, ENE–WSW, E–W and NW–SE trends. The main of Abu EL Gharadig Basin depositional center does not show sharp variations, because of the homogeneity of the marine rocks and the great basement depths. 相似文献
55.
Ahmed Mohamed Youssef Hamid Reza Pourghasemi Zohre Sadat Pourtaghi Mohamed M. Al-Katheeri 《Landslides》2016,13(5):839-856
The purpose of the current study is to produce landslide susceptibility maps using different data mining models. Four modeling techniques, namely random forest (RF), boosted regression tree (BRT), classification and regression tree (CART), and general linear (GLM) are used, and their results are compared for landslides susceptibility mapping at the Wadi Tayyah Basin, Asir Region, Saudi Arabia. Landslide locations were identified and mapped from the interpretation of different data types, including high-resolution satellite images, topographic maps, historical records, and extensive field surveys. In total, 125 landslide locations were mapped using ArcGIS 10.2, and the locations were divided into two groups; training (70 %) and validating (25 %), respectively. Eleven layers of landslide-conditioning factors were prepared, including slope aspect, altitude, distance from faults, lithology, plan curvature, profile curvature, rainfall, distance from streams, distance from roads, slope angle, and land use. The relationships between the landslide-conditioning factors and the landslide inventory map were calculated using the mentioned 32 models (RF, BRT, CART, and generalized additive (GAM)). The models’ results were compared with landslide locations, which were not used during the models’ training. The receiver operating characteristics (ROC), including the area under the curve (AUC), was used to assess the accuracy of the models. The success (training data) and prediction (validation data) rate curves were calculated. The results showed that the AUC for success rates are 0.783 (78.3 %), 0.958 (95.8 %), 0.816 (81.6 %), and 0.821 (82.1 %) for RF, BRT, CART, and GLM models, respectively. The prediction rates are 0.812 (81.2 %), 0.856 (85.6 %), 0.862 (86.2 %), and 0.769 (76.9 %) for RF, BRT, CART, and GLM models, respectively. Subsequently, landslide susceptibility maps were divided into four classes, including low, moderate, high, and very high susceptibility. The results revealed that the RF, BRT, CART, and GLM models produced reasonable accuracy in landslide susceptibility mapping. The outcome maps would be useful for general planned development activities in the future, such as choosing new urban areas and infrastructural activities, as well as for environmental protection. 相似文献
56.
Ahmed M. Youssef Biswajeet Pradhan Elhami Tarabees 《Arabian Journal of Geosciences》2011,4(3-4):463-473
Urban, industrial, and tourist developments are considered of high priority in Egypt. In the current research, the site suitability investigation for rating the different environmental, geological, and geotechnical conditions facing civil engineering projects were assessed using a geographic information system (GIS) multi-criteria approach. The study area is one of the most promising areas for urban and touristic as well as industrial developments in Egypt, which is located on the NW coast of the Gulf of Suez. This area may face several geo-environmental problems that will limit its suitability for civil projects. Weighted GIS model, which integrates different types of data sources, such as land use/cover, geological, geomorphological, geophysical, environmental, remote sensing, and field data, can be achieved to create a site suitability map. In this paper, an analytical hierarchy process approach has been used to develop the weighted model for different factors. As a result of this study, areas of potential geotechnical and geo-environmental hazards that could impact the design and construction of civil projects were identified. Therefore, changes can be made early in the design process before significant design efforts are being invested. 相似文献
57.
Modeling disruptions causing domino effects in urban guided transport systems faced by flood hazards
Gonzva Michaël Barroca Bruno Gautier Pierre-Étienne Diab Youssef 《Natural Hazards》2017,89(1):183-200
Coastal cities are more vulnerable to floods due to the joint impact of rainfall and tide level. Quantitative risk assessment of disaster-causing factors is critical to urban flood management. This paper presents an integrated method to quantify the hazard degree of disaster-causing factors, rainfall and tide level, and to investigate the optimal management of flooding risk in different disaster-causing factor areas. First, an urban flood inundation model is used to simulate inundated extents in different drainage districts. Then, formulas are put forward to calculate the hazard degree of rainfall and tide level based on inundated extents in different combinations of rainfall and tide level. According to the hazard degree, the main disaster-causing factor could be identified in each drainage district. Finally, the optimal management of flooding risk in different disaster-causing factor areas is selected by disaster reduction analysis and cost–benefit analysis. Furthermore, the coastal city, Haikou of China, is taken as a case study. The results indicate that the hazard degree increases with the increasing distance between the drainage district and the Qiongzhou Strait or the Nandu River in the eastern of Haikou. Heavy rain is the main disaster-causing factor in inland areas, while high tide level is the main disaster-causing factor in island areas. For the area whose main disaster-causing factor is heavy rain, water storage projects could effectively reduce flooding. Meanwhile, pumps are economical choices for the area where tide level is the main disaster-causing factor. The results can provide reference for drainage planning in other coastal areas. 相似文献
58.
Coupling of remote sensing data aided with field investigations for geological hazards assessment in Jazan area,Kingdom of Saudi Arabia 总被引:3,自引:2,他引:3
Ahmed M. Youssef Biswajeet Pradhan Abdullah A. Sabtan Hassan M. El-Harbi 《Environmental Earth Sciences》2012,65(1):119-130
The city of Jazan is situated on the eastern flank of the Read Sea and considered as one of the fastest growing cities in
the Kingdom of Saudi Arabia. This zone attracts a lot of investors for various development projects. Recently, many new projects
have been implemented and constructed in this region including new urban areas, infrastructures, and industrial projects.
However, historically this area has been challenged from different types of geological hazards. These geological hazards are
catastrophic events that can cause human injury, loss of life, and economic devastation. The current study is aimed at evaluating
the different types of geological hazards in Jazan city. This study is based on interpretation of satellite data such as LANDSAT
and QuickBird images, existing geological maps, and physiographical characteristics with the help of field and laboratory
analyses. The results of the analysis indicate that there exist various types of geological hazards in the study area mostly
related to the natural factors which include (1) Sabkha soil; (2) Salt dome; (3) Loess soil; and (4) Sand dune/drift. Further,
the findings of this study revealed that, most of these geological hazards have a severe impact on the ongoing development
activities in Jazan area. 相似文献
59.
Youssef Brouziyne Aziz Abouabdillah Rachid Bouabid Lahcen Benaabidate Ons Oueslati 《Arabian Journal of Geosciences》2017,10(19):427
Being a laborious approach, manual calibration of hydrologic model in a semi-arid context requires in-depth knowledge of the watershed and as much as possible field input data to obtain reliable simulations. In this study, manual calibration and relative sensitivity analysis approaches of the SWAT model (Soil and Water Assessment Tool) were applied for water balance in a 1993 km2 watershed (on the R’dom river) located in North-western Morocco. The watershed is located in a semi-arid area dominated by agro-forestry activities. The objectives of this study were (i) to perform a local sensitivity analysis of the SWAT model taking into consideration the watershed characteristics and (ii) to implement a detailed methodology of manual calibration and validation of the model in a semi-arid context. Sensitivity analysis has been carried out on 12 different SWAT input parameters, and has revealed that 4 input parameters only were the most influential ones on flow components of the R’dom watershed. Model manual calibration was conducted along 2006 and 2007 by comparing measured and predicted monthly and daily discharges and taking Nash-Sutcliffe coefficient (NSE), determination coefficient (R 2), and percent bias (PBIAS) as goodness-of-fit indicators. Validation has been performed by the same approach through 2008 and 2009 period. All final NSE values were above 0.5, R 2 values exceeded 0.7, and PBIAS lower than 25% demonstrating satisfactory model performances over the study watershed conditions. The SWAT model set-up with measured input data, manually calibrated and validated, reflects well the real hydrologic processes occurring in the R’dom watershed and can be used to assess current and future conditions and to evaluate alternative management practices. 相似文献
60.
A. M. Youssef A. M. Hassan A. A. A. El-Haddad 《Journal of the Indian Society of Remote Sensing》2009,37(3):377-393
Different outcropping sedimentary rock units, ranging in age from Paleozoic to Miocene, can provide significant information
to understand the development of tectono-sedimentary evolution of the Sidri — Feiran area, southwestern Sinai Peninsula. The
aim of this research is to test the ability of Landsat ETM+ imagery for differentiating and mapping these units with the help
of Shuttle Radar Topography Mission (SRTM) and field investigations. For this purpose, true and false colour composite images,
image enhancement techniques (Principle Component Analysis and Minimum Noise Fraction), and 3D perspective views were applied
to the data and the geological-photo interpretations were carried out. 相似文献