Extreme water levels along the central Red Sea coast of Saudi Arabia: processes and frequency analysis     

Antony  Charls  Langodan  Sabique  Dasari  Hari Prasad  Knio  Omar  Hoteit  Ibrahim 《Natural Hazards》2021,105(2):1797-1814

Natural Hazards - Knowledge about extreme water levels is essential for efficient planning and design of coastal infrastructure. This study uses a high-resolution (~?60 m) coupled...  相似文献   

First Telescope of the Russian–Cuban Observatory     

Bisikalo  D. V.  Sachkov  M. E.  Ibrahimov  M. A.  Savanov  I. S.  Nalivkin  M. A.  Naroenkov  S. A.  Fateeva  A. M.  Shugarov  A. S.  Mata  Rudy Montero  Pons  Omar Rodriguez  Rodriguez Uratsuka  Marta R. 《Astronomy Reports》2022,66(1):38-41

Astronomy Reports - Beginning of operation of the first Russian–Cuban Observatory telescope, a wide-field 20-cm robotic telescope installed at the observational site optical station in...  相似文献   

Quantifying uncertainties in fault slip distribution during the Tōhoku tsunami using polynomial chaos     

Ihab Sraj  Kyle T. Mandli  Omar M. Knio  Clint N. Dawson  Ibrahim Hoteit 《Ocean Dynamics》2017,67(12):1535-1551

An efficient method for inferring Manning’s n coefficients using water surface elevation data was presented in Sraj et al. (Ocean Modell 83:82–97 2014a) focusing on a test case based on data collected during the Tōhoku earthquake and tsunami. Polynomial chaos (PC) expansions were used to build an inexpensive surrogate for the numerical model GeoClaw, which were then used to perform a sensitivity analysis in addition to the inversion. In this paper, a new analysis is performed with the goal of inferring the fault slip distribution of the Tōhoku earthquake using a similar problem setup. The same approach to constructing the PC surrogate did not lead to a converging expansion; however, an alternative approach based on basis pursuit denoising was found to be suitable. Our result shows that the fault slip distribution can be inferred using water surface elevation data whereas the inferred values minimize the error between observations and the numerical model. The numerical approach and the resulting inversion are presented in this work.  相似文献   

PITCHER PLANTS RECORDED FROM BRIS FOREST IN JAMBU BONGKOK, KUALA TRENGGANU, MALAYSIA     

Jumaat H Adam　Nurulhuda Edy Muslim　Abdul Halim Hashim　Abd Rahim Othman　Hafiza Abd Hamid　Gire Kibe Gopir　Lydia M Pilik　Ramlan Omar　Muhammad Barzani Qasim　Jumat Salimon　Sahibin Abd Rahim 　Marlia Mohd Hanafiah 《湿地科学》2005,3(3):183-189

1INTRODUCTION NepentheswhichareknownlocallyinPeninsular Malaysiaasperiukkerabelongtoamonogenericfami lyNepenthaceae.Atpresent,atotalofninespecies(excludingnaturalhybrids)arerecordedfromPenin sularMalaysia.Ofthese,fourspeciesareendemic,whilsttheotherfivespeciesarefoundoutsidethepen insula.Thespeciescanarbitrarilybeclassifiedinto thelowlandspeciesandthehighlandspecies(Clarke,2002;Shivas,1984;Kurata,1976).Threespeciesarefoundinthehighlandhabitatscom monlyatanelevationofabove1000mforaboves…  相似文献   

Flow Estimation in a Basin by Using a Hydrological Model: Application to the Basin of Wadi Djendjen (Jijel,North-East Algeria)     

Abdelmadjid Boufekane  Omar Saighi 《Water Resources》2018,45(4):523-531

The aim of this study was to transform the rain into flow in the basin of Wadi Djendjen by using a simulation model in absence of the continuous measurements of the flow. The obtained results indicated and confirmed the strong adaptability of this model with varied hydroclimatic situations. The validation process showed an interesting result, which lead to conclude that the model is well calibrated and has a good performance to be used for the basins with Mediterranean climate. The obtained results for the simulation by the GR2M model over the studied period (1973–1986) showed that there no significant difference between the obtained value for the yearly average flow (197.70 hm³) and that measured at Missa hydrometric station (200.80 hm³), which allow us to estimate quantitatively the flow in Missa hydrometric station. While, for the period of 2000–2012, the results showed that the yearly average flow value (171.90 hm³), is significantly different (reduction of 15% for 12 years), in comparison with that measured at Missa hydrometric station (200.80 hm³). This can be due to the dryness which struck the region since 2000, and the local degradation of the forest ecosystem, which has considerably affected the runoff surface.  相似文献   

Bayesian inference of spatially varying Manning’s n coefficients in an idealized coastal ocean model using a generalized Karhunen-Loève expansion and polynomial chaos     

Siripatana  Adil  Le Maitre  Olivier  Knio  Omar  Dawson  Clint  Hoteit  Ibrahim 《Ocean Dynamics》2020,70(8):1103-1127

Ocean Dynamics - Bayesian inference with coordinate transformations and polynomial chaos for a Gaussian process with a parametrized prior covariance model was introduced in Sraj et al. (Comput...  相似文献   

Features of soil redistribution and major element migration in a karst hillslope of Southwest China     

Chang-shun Song  Hong-bing Ji  Howard Omar Beckford  Hua-shuo Chu  Kun Zhang  Shi-jie Wang 《山地科学学报》2018,15(9):1892-1908

In this study, we investigated the spatial characteristics of the rate of soil distribution and the mechanism of major element migration in a typical karst hillslope in Guangxi Province, Southwestern China. Soil redistribution was examined using ¹³⁷Cs technique under different hillslope components. With the combination of geochemical methods, the migration characteristics of major elements in soils of three hillslope components in both the horizontal and vertical directions were determined. Thirty-seven soil samples were collected and analyzed for ¹³⁷Cs and the major elements were determined. By using the profile distribution model the mean soil redistribution rates were found to be -17.01, 0.40 and -23.30 t ha^-1 yr^-1 in the summit (BYSD), shoulder (BYSY) and toeslope (BYSJ) components of the studied hillslope, respectively. In comparison to BYSD, the sesquioxides of Fe₂O₃ and TiO₂ tend to be enriched, whereas the alkalis (CaO, MgO, Na₂O and K₂O) tend to be depleted, both in the shoulder and toeslope components. Due to human and animal activities, the contents of CaO, MgO, K2O and Na₂O have somewhat increased within the topsoil. The results indicated that ¹³⁷Cs activities are significantly correlated with clay particles and organic matter, and are affected by the pedogenic process and vegatation. Overall, it maybe necessary to use techniques such as ¹³⁷Cs to investigate soil erosion with the combination of geochemical methods.  相似文献   

Nitrogenous Excretion of Penaeus monodon Postlarvae Fed with Different Diets     

F. Shishehchian  F. M. Yusoff  H. Omar  M. S. Kamarudin 《Marine pollution bulletin》1999,39(1-12):224-227

This study is designed to determine ammonia and nitrite excretion by Penaeus monodon 25–30 day old postlarvae fed with different diets (artificial and natural). Shrimps were fed with Chaetoceros calcitrans (phytoplankton), chironomid larvae (benthos), Brachionus sp. (rotifer) and artificial diet. In the control treatment, shrimps were not fed. The highest concentration of ammonia was excreted by shrimps fed with artificial diet and the lowest by that of control treatment. All treatments except where shrimps fed on C. calcitrans showed a sudden increase in ammonia-N excretion after 36 h. C. calcitrans contributed to high ammonia excretion only after 61 h. Shrimps fed with Brachionus sp. (rotifer) showed significantly higher nitrite excretion rate compared to other treatments. Shrimps fed on C. calcitrans depicted the lowest nitrite excretion. This experiment indicated that nitrogenous excretion was predominant in shrimps fed with artificial diets. Live food like algae and chironomids, despite a high protein content, contribute to low nitrogenous excretion and hence pose less adverse effects on water quality compared to artificial diets.  相似文献   

Mitigating Carbon Emissions while Advancing National DevelopmentPriorities: The Case of Mexico     

Claudia Sheinbaum  Omar Masera 《Climatic change》2000,47(3):259-282

We analyze and integrate energy andforestry carbon mitigation scenarios for Mexicobetween the year 1994 and 2010. The energy optionsrange from efficient end-use technologies to renewabletechnologies for electricity generation. Forestryoptions include avoiding deforestation through themanagement of native forests, and two afforestationoptions: restoration plantations and agroforestrysystems. The methodology utilized to evaluatedifferent energy and forestry scenarios is based on a`bottom up' model. In the year 2010, total carbonemissions will reach 879 Tg of CO₂, of which 83%comes from energy consumption. The total carbonmitigation potential reaches 348 Tg of CO₂ by2010, 62% of which comes from forestry options.Mitigation costs range from $–45.9/ton CO₂ to$106.4/ton CO₂. Several options, particularlyconcerning energy technologies, are cost effectivefrom a national perspective. In each sector, differentbarriers can hinder the implementation of mitigationalternatives.  相似文献   

Feeding ecology and ontogenic diet shifts of juvenile fish species in an inverse estuary: The Sine-Saloum,Senegal     

Ndombour Gning  Guy Vidy  Omar Thiom Thiaw 《Estuarine, Coastal and Shelf Science》2008

We examined the diet of juvenile fish of four species – Eucinostomus melanopterus (Gerreidae), Ethmalosa fimbriata (Clupeidae), Monodactylus sebae (Monodactylidae), and Sarotherodon melanotheron (Cichlidae) – between their appearance on the nursery ground and the end of the recruitment season, when they began to shift to deeper parts of the estuary. Fish were collected from the Sine-Saloum, an inverse estuary in Senegal, West Africa. Sampling was conducted at six sites located along the salinity gradient. The study was conducted in the context of an inverse estuary where increasing salinity leads to the disappearance of mangroves.  相似文献