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Ruzinoor Che Mat Abdul Rashid Mohamed Shariff Biswajeet Pradhan Ahmad Rodzi Mahmud Mohd Shafry Mohd Rahim 《Arabian Journal of Geosciences》2013,6(12):4881-4889
The objective of this paper is to discuss the effectiveness of visualizing online 3D terrain draped with different satellite imageries. The topographic data of the study area were obtained from the contour maps of Universiti Putra Malaysia, Selangor, Malaysia. The high resolution satellite imageries used in this project involving QUICKBIRD (0.6 m resolution), IKONOS (1 m resolution), and SPOT5 (5 m resolution). R2V software was used for editing the contour data, whereas Arc GIS was used for overlaying the imageries over the 3D terrain data. Then the data were exported into Virtual Reality Markup Language to compare the effectiveness of different satellite imageries based on the data file size, imageries size, number of images tile, loading time during office hours (from 8 a.m. to 5 p.m.) and out of office hours (after 5 p.m.), frame rate per second, and visualization quality. The results revealed that IKONOS satellite imageries are better for an effective online 3D terrain visualization utilizing GIS data even though it has lower resolution compared to QUICKBIRD. 相似文献
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This paper demonstrates the use of moderate resolution imaging spectro-radiometer (MODIS) data for fish forecasting mapping of seasonal spatial distribution of sea surface salinity (SSS), temperature (SST) and chlorophyll-a in the ocean waters off the coast of Semporna, Malaysia. Multi-linear regression analysis was performed to estimate SSS and the Brown and Minnet algorithm was used for the SST. The extracted parameters were validated using in situ measurement taken with Hydro-Lab equipment. The extracted parameters from MODIS images reveal the signature values which establish the relationships between these parameters, and thus delineating the potential fish zonation (PFZ) map. These developed models will help for accurate monitoring of large coverage areas at low cost and within short period of time. Furthermore, such models will allow the prediction of the total fish catch in different seasons, thus contributing to fish industry management and marketing. This research recommends the use of PFZ map for mass scale fish harvesting in short time for larger areas. Finally, the research has developed a potential fish zone model amalgamating all the above parameters. The PFZ mapping was carried out off the coast of Semporna, Sabah as there were sufficient fish catch data for accuracy assessment. The R was computed as 0.93 and the higher fish catch areas have coincided very well with the higher PFZ values, meaning the tool is ready for use for operational near real-time fish forecasting. 相似文献
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Mahfuzur Rahman Chen Ningsheng Golam Iftekhar Mahmud Md Monirul Islam Hamid Reza Pourghasemi Hilal Ahmad Jules Maurice Habumugisha Rana Muhammad Ali Washakh Mehtab Alam Enlong Liu Zheng Han Huayong Ni Tian Shufeng Ashraf Dewan 《地学前缘(英文版)》2021,12(6):16-35
Bangladesh experiences frequent hydro-climatic disasters such as flooding.These disasters are believed to be associated with land use changes and climate variability.However,identifying the factors that lead to flooding is challenging.This study mapped flood susceptibility in the northeast region of Bangladesh using Bayesian regularization back propagation(BRBP)neural network,classification and regression trees(CART),a statistical model(STM)using the evidence belief function(EBF),and their ensemble models(EMs)for three time periods(2000,2014,and 2017).The accuracy of machine learning algorithms(MLAs),STM,and EMs were assessed by considering the area under the curve-receiver operating char-acteristic(AUC-ROC).Evaluation of the accuracy levels of the aforementioned algorithms revealed that EM4(BRBP-CART-EBF)outperformed(AUC＞90％)standalone and other ensemble models for the three time periods analyzed.Furthermore,this study investigated the relationships among land cover change(LCC),population growth(PG),road density(RD),and relative change of flooding(RCF)areas for the per-iod between 2000 and 2017.The results showed that areas with very high susceptibility to flooding increased by 19.72％between 2000 and 2017,while the PG rate increased by 51.68％over the same period.The Pearson correlation coefficient for RCF and RD was calculated to be 0.496.These findings highlight the significant association between floods and causative factors.The study findings could be valuable to policymakers and resource managers as they can lead to improvements in flood management and reduction in flood damage and risks. 相似文献
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Mahmud Sultan Sumana Ferdausi Mahojabin Mohsin Md Khan Md. Hasinur Rahaman 《Natural Hazards》2022,111(2):1863-1884
Natural Hazards - The knowledge of the climate pattern for a particular region is important for taking appropriate actions to alleviate the impact of climate change. It is also equally important... 相似文献
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Determinants of farmers’ choice of adaptation methods to climate change in the Nile Basin of Ethiopia 总被引：6，自引：0，他引：6
Temesgen Tadesse Deressa Rashid M. Hassan Claudia Ringler Tekie Alemu Mahmud Yesuf 《Global Environmental Change》2009,19(2):248-255
This study identifies the major methods used by farmers to adapt to climate change in the Nile Basin of Ethiopia, the factors that affect their choice of method, and the barriers to adaptation. The methods identified include use of different crop varieties, tree planting, soil conservation, early and late planting, and irrigation. Results from the discrete choice model employed indicate that the level of education, gender, age, and wealth of the head of household; access to extension and credit; information on climate, social capital, agroecological settings, and temperature all influence farmers’ choices. The main barriers include lack of information on adaptation methods and financial constraints. 相似文献
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Andrea PATZER Jochen SCHLÜTER Ludolf SCHULTZ Mahmud TARKIAN Dolores H. HILL William V. BOYNTON 《Meteoritics & planetary science》2004,39(9):1555-1575
Abstract— We report new petrographic and chemical data for the equilibrated EL chondrite Grein 002, including the occurrence of osbornite, metallic copper, abundant taenite, and abundant diopside. As inferred from low Si concentrations in kamacite, the presence of ferroan alabandite, textural deformation, chemical equilibration of mafic silicates, and a subsolar noble gas component, we concur with Grein 002's previous classification as an EL4‐5 chondrite. Furthermore, the existence of pockets consisting of relatively coarse, euhedral enstatite crystals protruding large patches of Fe‐Ni alloys suggests to us that this EL4‐5 chondrite has been locally melted. We suspect impact induced shock to have triggered the formation of the melt pockets. Mineralogical evidence indicates that the localized melting of metal and adjacent enstatite must have happened relatively late in the meteorite's history. The deformation of chondrules, equilibration of mafic silicates, and generation of normal zoning in Fe, Zn‐sulfides took place during thermal alteration before the melting event. Following parent body metamorphism, daubreelite was exsolved from troilite in response to a period of slow cooling at subsolidus temperatures. Exsolution of schreibersite from the coarse metal patches probably occurred during a similar period of slow cooling subsequent to the event that induced the formation of the melt pockets. Overall shock features other than localized melting correspond to stage S2 and were likely established by the final impact that excavated the Grein 002 meteoroid. 相似文献
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Due to the population growth and continuous migration of people from rural areas to urban areas, it is important to identify the suitable locations for future development in order to find suitable sites for various kinds of facilities such as schools, hospital and fire stations for new and existing urban areas. Site suitability modelling is a complex process involving various kinds of objectives and issues. Such a complex process includes spatial analysis, use of several decision support tools such as high-spatial resolution remotely sensed data, geographical information system (GIS) and multi criteria analysis (MCA) such as analytical hierarchy process (AHP), and in some cases, prediction techniques like cellular automata (CA) or artificial neural networks (ANN). This paper presents a comparison between the results of AHP and the ordinary least square (OLS) evaluation model, based on various criteria, to select suitable sites for new hospitals in Qazvin city, Iran. Based on the obtained results, proximity to populated areas (0.3) and distance to air polluted areas (0.23–0.26) were the two highest important criteria with high weight value. The results show that these two techniques not only have similarity in size (in m2) for each suitability class but they also have similarity in spatial distribution of each class in the entire study area. Based on calculations of both techniques, 1–2%, 25%, 40–43%, 16–20% and 14% of study areas are assigned as ‘not suitable', ‘less suitable', ‘moderately suitable', ‘suitable' and ‘most suitable' areas for construction of new hospitals. Results revealed that a 75% similarity was found in the distribution of suitability classes in Qazvin city using both techniques. Nineteen per cent (19%) of the study area are assigned as ‘suitable' and ‘most suitable' by both methods, so these areas can be considered as safe or secure areas for clinical purposes. Moreover, almost all (99.8%) suitable areas are located in district 3, because of its higher population, less numbers of existing hospitals and large numbers of barren land plots of acceptable size. 相似文献
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Precious-metal distribution and fluid-inclusion petrography of the Elatsite porphyry copper deposit,Bulgaria 总被引：4，自引：2，他引：2
Mahmud?TarkianEmail author Ulf?Hünken Margarita?Tokmakchieva Kamen?Bogdanov 《Mineralium Deposita》2003,38(3):261-281
The Elatsite porphyry copper deposit occurs in an island-arc setting hosted by Late Cretaceous monzonitic-monzodioritic porphyry stocks which were emplaced into Precambrian-Cambrian phyllites. Trace element data of the Late Cretaceous intrusive rocks suggest that they are I-type volcanic arc granitoids. Two main ore mineral assemblages are distinguished: (1) magnetite-bornite-chalcopyrite, and (2) chalcopyrite-pyrite. The first one is linked to potassic-propylitic, and the second to phyllic-argillic alteration. Minor ore minerals are hematite, molybdenite, sphalerite, pyrrhotite, marcasite, hessite, and solid solutions of linnaeite-siegenite-carrollite, tetrahedrite-tennantite, clausthalite-galena, gold-electrum and merenskyite-moncheite. Precious-metal contents are relatively high throughout the deposit but Au, Pd and Pt are concentrated more strongly in the magnetite-bornite-chalcopyrite assemblage. Average grades of Au, Ag, Pd and Pt calculated for the 0.33% Cu ore body are 0.96, 0.19, 0.007 and 0.002 g/t respectively. Analyses of flotation concentrates revealed 25.6% Cu, and Ag, Au, Pd and Pt contents of 33.0, 13.6, 0.72 and 0.15 g/t respectively. The copper mineralisation at Elatsite took place at pressures of 120 to 300 bar, corresponding to depths of formation of 1 to 3 km under hydrostatic conditions. The precious metals were probably transported jointly as chloride complexes in highly saline magmatic-hydrothermal solutions. The fluids had temperatures of 340 to >700 °C and salinities of 28 to 64% NaCl, and mixed with meteoric water. 相似文献