International Science Community Association Research Journal of Recent Sciences 2277 - 2502 4 3 2015 March 2 Detection of Outlier in Flood Observations: A Case Study of Tamer Watershed 150 153 EN Zanganeh Mohsen 1 New Castle University School of Electrical, Electronic and Computer Engineering, Zanjan, IRAN Farshid Norouzi 2 Khuram Mushtaque 1 Federal Urdu University of Arts, Science and Technology, Karachi, PAKISTAN Kamran Ahsan 2 Mohammad Ali Jinnah University, Karachi, PAKISTAN Ahmer Umer 3 Tekei Abdolghader 1 Department of Public Administration, Science and Research branch, Islamic Azad University, Tehran, IRAN Memarzadeh Gholamreza. 2 Reza Najafbeigi 3 Mahdi Mortazavi 1 Department of Management, Institute of Management and Planning Studies, IRAN Elham Vahedi 2 Department of Executive Master of Business Administration, Alborz, Qazvin, IRAN Zarei Mohammadreza 3 Dept. of Master of Business Administration, Science and Culture University, IRAN Farzane Hemmatian 4 Dept. Entrepreneurship Management, Tehran University, IRAN Razavi Maryam 1 Department of industrial management, Science and Research Branch, Islamic Azad University, Tehran, IRAN AbbasToloie Eshlaghy 2 Gizem SAYGILI 1 Faculty of Education, Süleyman Demirel University, TURKEY Khadse Shaila 1 LIT, RTM Nagpur University, Nagpur, MH, INDIA Patil P.V. 2 Department of Chemistry, Dr. Ambedkar College, Deekshaboomi, Nagpur, INDIA Panhekar Deepa 3 Department of Chemistry, Institute of Science, Civil lines, Nagpur, INDIA Satpute Shridhar 4 Khodabakhshi Faranak 1 Islamic Azad University, Astara, IRAN Badri Abbasi 2 Srivastava Nitisha 1 Department of Botany, University of Allahabad, Allahabad-211002, U. P., INDIA Kumar Girjesh 2 MohammadSadegh Barkhordari 1 Bachelor of Civil Engineering, Isfahan University of technology, Isfahan, IRAN Gran Badshah 1 Faculty of Computer Systems and Software Engineering, Universiti Malaysia Pahang,TunRazak HighwayGambang, 26300 Kuantan, Pahang MALAYSIA Siau-Chuin Liew 2 JasniMohamad Zain 3 IzharHisham Syifak 4 Amatul Zehra 5 Tahereh Soleymaniahooie 1 Department of Chemistry, Islamic Azad University, North Tehran Branch, IRAN Shujah Maham 1 Department of Computer Science, COMSATS Institute of Information Technology, M.A., Jinnah Campus, Defence Road, Lahore, PAKISTAN Tabbasum Naz 2 Sadiq Ayesha 3 AmirmohseniAnbardan Ayoub 1 Islamic Azad University, Science and Research Branch, Tabriz, IRAN Farhad NaseriSarband 2 Islamic Azad University, Qazvin Branch, IRAN Satari Shiva 3 Islamic Azad University, Medical Science, Tehran, IRAN Umair Saeed 1 Department of Computer Science, Federal Urdu University of Arts, Sciences and Technology, Karachi, PAKISTAN Muhammad Sarim 2 Amna Usmani 3 Aniqa Mukhtar 4 BasitShaikh Abdul 5 SheikhKashif Raffat 6 Ashrafalsadat Zakeri 1 Master of Private law, Tehran University, Tehran, IRAN Hassani M. 1 Dept. of Civil Engineering, Shahid Beheshti University, Tehran, IRAN Safi M. 2 Hassani N. 3 AmirFarmahini Farahani 1 Department of Industrial Engineering, Payame Noor University, Tehran, IRAN Ehsan Ahadmotlaghi 2 Department of management, Payame Noor University, Tehran, IRAN FarmahiniFarahani Ahmad 3 Institute for International Energy Studies (IIES), Tehran, IRAN Aidin Valafar 4 Dept. of Business Management, Rasht Branch, Islamic Azad University, Rasht, IRAN Safar Fazli 1 Member of scientific board, Imam Khomeini Int. University, Qazvin, IRAN Saddaee Maryam 2 Department of Science, Imam Khomeini Int.University, Qazvin, IRAN Heidarpour B. 1 Department of Civil Engineering, Young Researcher Club ,Roudsar and Amlash Branch, Islamic Azad University, Roudsar, IRAN PanjalizadehMarseh B. 2 Department of Civil Engineering, Langroud Branch, Islamic Azad University, Langroud, IRAN Ekramirad A. 3 A. Hosseinnezhad 4 GhasemianLangroudi A. 5 > Case Study 2013 12 18 2015 March 2 In this research for determining outlier data by traditional methods, has used [Mean ± 3S], Box plot, Grubbs' Test and Grubbs and Beck Test. Based on the traditional methods and the box plot (boxplot), discharge of 783 m/s was determined in 2004-2005 water year. as the outlier data in the data series of Annual maximum instantaneous peak streamflow in Tamer hydrometric station. The station is located in the outlet of Tamer watershed in Iran in an area about 1,531 square kilometers southern Caspian Sea coastline. Moreover, the outlier data in Grubbs’ Test was achieved in two modes – observational data series and normalized data series. Based on this, discharge of 783 m/s in observational data series was determined as the outlier data. After normalizing the data using Box-Cox transformation, no outlier data were achieved using Grubbs’ Test. By using Grubbs-Beck relation, no outlier data were obtained in Tamer hydrometric station. Copyright@ International Science Community Association