Kalman filter estimation model in flood forecasting     

Tahir Husain 《Advances in water resources》1985,8(1):15-21

Elementary precipitation and runoff estimation problems associated with hydrologic data collection networks are formulated in conjunction with the Kalman Filter Estimation Model. Examples involve the estimation of runoff using data from a single precipitation station and also from a number of precipitation stations. The formulations demonstrate the role of state-space, measurement, and estimation equations of the Kalman Filter Model in flood forecasting. To facilitate the formulation, the unit hydrograph concept and antecedent precipitation index is adopted in the estimation model. The methodology is then applied to estimate various flood events in the Carnation Creek of British Columbia.  相似文献   

Temporal changes of soft-bottom zoobenthic communities in and around Alsancak Harbor (Izmir Bay, Aegean Sea), with special attention to the autecology of exotic species     

Melih Ertan Çinar  Tuncer Katagan  Bilal Öztürk  Özdemir Egemen  Zeki Ergen  Ahmet Kocatas  Mesut Önen  Fevzi Kirkim  Kerem Bakir  Güley Kurt  Ertan Dagli  Asli Kaymakçi  Sermin Açik  Alper Dogan  & Tahir Özcan 《Marine Ecology》2006,27(3):229-246

Temporal and spatial variation in soft‐bottom benthic communities following recovery from a pollution episode were studied between January and September 2004 in and around Alsancak Harbor, located in the polluted part of Izmir Bay (Aegean Sea, eastern Mediterranean). Samples were collected at seven stations by van Veen grab. Three additional stations were sampled by means of a beam trawl to take into account large mobile animals and for a better estimate of the local biodiversity. A total of 231 species belonging to 10 zoobenthic groups were found. Polychaetes contributed 90% of the total faunal populations and mollusks 87% of the total biomass in the area. Community parameters varied significantly among stations and sampling periods; number of species ranged from 2 to 79 per 0.1 m² grab sample; density from 20 to 81,720 ind·m^?2; biomass from 0.1 to 4190 g·m^?2; Shannon–Wiener diversity index (log₂ base) from 0.4 to 4.4; and Pielou's evenness index from 0.11 to 1.0. Collections indicate that a number of species, including those sensitive to pollution, have colonized the area where azoic conditions had been previously reported. A total of six exotic species, Streblospio gynobranchiata, Polydora cornuta, Hydroides dianthus, Hydroides elegans, Anadara demiri and Fulvia fragilis, probably transferred to the area via ballast water or hull fouling, dominated soft or hard substrata in and near Alsancak Harbor. The first two species accounted for more than 70% of the total population in the area, while A. demiri contributed the most to the biomass (93%, at station 7).  相似文献   

Determination of Free Nickel Ion Concentrations Using the Ion Exchange Technique: Application to Aqueous Mining and Municipal Effluents     

Yamini Gopalapillai  Ismail I. Fasfous  John D. Murimboh  Tahir Yapici  Parthasarathi Chakraborty  Chuni L. Chakrabarti 《Aquatic Geochemistry》2008,14(2):99-116

Free metal ion concentration is generally considered a useful indicator of a metal’s bioavailability and ecotoxicity to aquatic biota. This article reports the speciation of nickel in mining and municipal effluents from Sudbury (Ontario, Canada), and also in model solutions containing a fully characterized laurentian fulvic acid (LFA) at environmentally relevant concentrations. A column ion exchange technique (IET) using a cation exchange resin (Dowex 50W-X8) was applied to determine free nickel ion concentrations. In model solutions, reasonable correlation was found between the predictions of an equilibrium-based computer speciation code, Windermere Humic Aqueous Model (WHAM) VI, and the results obtained by IET at low nickel-to-fulvic acid ratios. However at higher mole ratios, the WHAM VI predicted higher free nickel ion concentrations than IET. Only three out of six effluent samples showed reasonable agreement between the IET and the WHAM VI results, indicating the need for further development of IET for application to effluent waters.  相似文献   

Comparative assessment of spatiotemporal snow cover changes and hydrological behavior of the Gilgit,Astore and Hunza River basins (Hindukush–Karakoram–Himalaya region,Pakistan)     

Adnan Ahmad Tahir  Jan Franklin Adamowski  Pierre Chevallier  Ayaz Ul Haq  Silvia Terzago 《Meteorology and Atmospheric Physics》2016,128(6):793-811

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Effect of magnesium chloride solution on the physico-chemical characteristics of tropical peat     

Nima Latifi  Ahmad Safuan A. Rashid  Aminaton Marto  Mahmood Md Tahir 《Environmental Earth Sciences》2016,75(3):220

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Discriminant analysis for the prediction of sand mass distribution in a holding pond using deposition thickness model of a single grain-sized particle     

Jeremy Andy Dominic  Ahmad Zaharin Aris  Wan Nor Azmin Sulaiman  Wan Zakaria Wan Md Tahir 《Environmental Earth Sciences》2016,75(9):812

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Assessment of toxicological health risk of trace metals in vegetables mostly consumed in Punjab,Pakistan     

Zafar Iqbal Khan  Kafeel Ahmad  Muhammad Ashraf  Nadia Shoaib  Rukhsana Parveen  Zahara Bibi  Irfan Mustafa  Ijaz Rasool Noorka  Hafiz Muhammad Tahir  Nudrat Aisha Akram  Muhammad Fahad Ullah  Rabia Yaqoob  Vincenzo Tufarelli  Mariano Fracchiolla  Eugenio Cazzato 《Environmental Earth Sciences》2016,75(5):433

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The 2014 seismic hazard model of the Middle East: overview and results     

Karin Şeşetyan  Laurentiu Danciu  Mine B. Demircioğlu Tümsa  Domenico Giardini  Mustafa Erdik  Sinan Akkar  Levent Gülen  Mehdi Zare  Shota Adamia  Anooshiravan Ansari  Avetis Arakelyan  Ayşegül Askan  Mher Avanesyan  Hektor Babayan  Tamaz Chelidze  Raffi Durgaryan  Ata Elias  Hossein Hamzehloo  Khaled Hessami  Doğan Kalafat  Özkan Kale  Arkady Karakhanyan  Muhammad Asif Khan  Tahir Mammadli  Mahmood Al-Qaryouti  Mohammad Sayab  Nino Tsereteli  Murat Utkucu  Otar Varazanashvili  Muhammad Waseem  Hilal Yalçın  Mustafa Tolga Yılmaz 《Bulletin of Earthquake Engineering》2018,16(8):3535-3566

The Earthquake Model of Middle East (EMME) Project aimed to develop regional scale seismic hazard and risk models uniformly throughout a region extending from the Eastern Mediterranean in the west to the Himalayas in the east and from the Gulf of Oman in the south to the Greater Caucasus in the North; a region which has been continuously devastated by large earthquakes throughout the history. The 2014 Seismic Hazard Model of Middle East (EMME-SHM14) was developed with the contribution of several institutions from ten countries. The present paper summarizes the efforts towards building a homogeneous seismic hazard model of the region and highlights some of the main results of this model. An important aim of the project was to transparently communicate the data and methods used and to obtain reproducible results. By doing so, the use of the model and results will be accessible by a wide community, further support the mitigation of seismic risks in the region and facilitate future improvements to the seismic hazard model. To this end all data, results and methods used are made available through the web-portal of the European Facilities for Earthquake Hazard and Risk (www.efehr.org).  相似文献   

Seismic based characterization of total organic content from the marine Sembar shale,Lower Indus Basin,Pakistan     

Omer Aziz  Tahir Hussain  Matee Ullah  Asher Samuel Bhatti  Aamir Ali 《Marine Geophysical Researches》2018,39(4):491-508

The exploration and production of unconventional resources has increased significantly over the past few years around the globe to fulfill growing energy demands. Hydrocarbon potential of these unconventional petroleum systems depends on the presence of significant organic matter; their thermal maturity and the quality of present hydrocarbons i.e. gas or oil shale. In this work, we present a workflow for estimating Total Organic Content (TOC) from seismic reflection data. To achieve the objective of this study, we have chosen a classic potential candidate for exploration of unconventional reserves, the shale of the Sembar Formation, Lower Indus Basin, Pakistan. Our method includes the estimation of TOC from the well data using the Passey’s ΔlogR and Schwarzkofp’s methods. From seismic data, maps of Relative Acoustic Impedance (RAI) are extracted at maximum and minimum TOC zones within the Sembar Formation. A geostatistical trend with good correlation coefficient (R²) for cross-plots between TOC and RAI at well locations is used for estimation of seismic based TOC at the reservoir scale. Our results suggest a good calibration of TOC values from seismic at well locations. The estimated TOC values range from 1 to 4% showing that the shale of the Sembar Formation lies in the range of good to excellent unconventional oil/gas play within the context of TOC. This methodology of source rock evaluation provides a spatial distribution of TOC at the reservoir scale as compared to the conventional distribution generated from samples collected over sparse wells. The approach presented in this work has wider applications for source rock evaluation in other similar petroliferous basins worldwide.  相似文献   

Laboratory planetary physics using intense heavy ion beams at the Facility for Antiprotons and Ion Research at Darmstadt: the HEDgeHOB collaboration     

N. A. Tahir  T. Stöhlker  A. Shutov  I. V. Lomonosov  V. E. Fortov  M. French  N. Nettelmann  R. Redmer  A. R. Piriz  C. Deutsch 《Astrophysics and Space Science》2011,336(1):61-65

Development of ultra-high power lasers has lead to the very interesting and important field of Laboratory Astrophysics. Recent progress and expected near future developments in the technology of strongly bunched intense particle beams has opened up the possibility of studying planetary interiors in the laboratory which hopefully will eventually converge in the new field of Laboratory Planetary Physics. GSI Helmholzzentrum für Schwerionenforschung, Darmstadt is a well known laboratory worldwide due to its unique particle accelerator facilities. Construction of the new huge accelerator complex, the Facility for Antiprotons and Ion Research (FAIR), will substantially improve the existing capabilities of the GSI. A dedicated program named, HEDgeHOB, that aims to study different problems in High Energy Density (HED) Physics at the FAIR facility, has been proposed. One of these proposed experiments LAPLAS (LAboratory PLAnetary Science), aim to study materials at extreme conditions as relevant for the interiors of giant planets. In this paper we present simulation results that show that various regions of the high-pressure phase diagram of water can be probed within the LAPLAS experiments. For instance, the plasma and the superionic phase are predicted to occur in the interior of water-rich planets such as Uranus and Neptune as well as in extrasolar planets such as GJ 436b.  相似文献