TY - JOUR ID - 78749 TI - Investigation Optimal Input using Gamma Test in Rainfall-Runoff Modeling of Northern Karun Watershed JO - Iranian journal of Ecohydrology JA - IJE LA - en SN - 2423-6098 AU - Roshun, Sayed Hussein AU - Habibnejad Roshan, Mahmoud AU - Shahedi, Kaka AU - Chormanski, Jaroslaw AD - Ph.D. Candidate, Watershed Management Engineering, Faculty of Natural Resources, Sari Agricultural Sciences and Natural Resources University. Sari, Iran AD - Professor, Watershed Management Engineering, Faculty of Natural Resources, Sari Agricultural Sciences and Natural Resources University, Sari, Iran AD - Associated Professor, Watershed Management Engineering, Faculty of Natural Resources, Sari Agricultural Sciences and Natural Resources University. Sari, Iran AD - Professor, Faculty of Civil and Environmental Engineering, Warsaw University of Life Sciences, Warsaw, Poland Y1 - 2020 PY - 2020 VL - 7 IS - 4 SP - 967 EP - 979 KW - Auto-correlation Coefficient KW - Gamma Statistic KW - North Karun Watershed KW - Rainfall-Runoff Process KW - WinGamma DO - 10.22059/ije.2020.306944.1359 N2 - Rainfall-Runoff (R-R) is one of the most complicated processes in hydrology. The aim of this study was to select the effective parameter and optimum combination for R-R modeling using Gamma test in the WinGamma software for Northern Karun watershed. For this purpose, daily precipitation and discharge data in 1997-2017 was used. Lake data was removed and homogeny of data done using Run-Test. Statistical corrections were corrected by correlation method and data homogeneity test was performed by Run-Test method. The coefficients of auto-correlation, partial auto-correlation and cross-correlation in the R Studio software environment were used to determine rainfall and discharge delays. Optimum inputs and combinations were also obtained using the Gamma test in WinGamma software environment. The results showed that 9 optimum input parameters include precipitation today (Pt), precipitation with a delay of one day (Pt-1), two days (Pt-2), three days (Pt-3) and four days (Pt- 4), As well as discharge the day before (Qt-1), discharge with a delay of two days (Qt-2), three days (Qt-3) and four days (Qt-4) had a significant level of confidence at the level of 5%, which for the creation of 130 suitable combinations was identified and based on the lowest Gamma (Γ) statistics, a suitable composition was determined for each sub-watershed. Finally, for the whole basin, the optimum inputs include the parameters Pt, Pt-1, Qt-1, Qt-2 and Qt-4, and the best combinations are Pt, Pt-1, Qt-1, Qt-2, Qt-3. In general, in all sub-watersheds and the whole watershed precipitation of the current day, the precipitation of one or two days ago as well as the discharge of the previous day and two days ago have a significant effect on the run-off entering the in river basin. UR - https://ije.ut.ac.ir/article_78749.html L1 - https://ije.ut.ac.ir/article_78749_0422b4a2b0f8c6c17847465ba3c24fa0.pdf ER -