Investigation of drought characteristics in north-west of Iran using Deciles Index | ||
| مهندسی و مدیریت آبخیز | ||
| Article 6, Volume 10, Issue 4, January 2019, Pages 552-563 PDF (1015.11 K) | ||
| Document Type: Research Paper | ||
| DOI: 10.22092/ijwmse.2018.115672.1360 | ||
| Authors | ||
| Amin Salehpour Jam* 1; Mahmoudreza Tabatabaei1; Amir Sarreshtehdari2; Jamal Mosaffaie1 | ||
| 1Assistant Professor, Soil Conservation and Watershed Management Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran | ||
| 2Scientific Board, Soil Conservation and Watershed Management Research Institute, Agricultural Research, Education and Extension Organization (AREEO) Tehran, Iran | ||
| Abstract | ||
| Investigation of drought event has a great importance in the natural resources management and planning water resources management. In this research, the drought characteristics in the selected synoptic stations in northwest of Iran, including Ardebil, Khoy, Oroomieh, Tabriz, Zanjan, Sanandaj and Saghez were investigated using the Deciles Index. First, after rebuilding monthly missing data in the period of 1977-2014, time series of precipitation in each station normalized using Box-Cox Transformation. Then, the Deciles Index in different time scales of monthly, seasonal and yearly was calculated based on the normalized monthly precipitation of stations in the period of 1977-2014 by MATLAB and DIP softwares. Then, the drought characteristics, including intensity, duration and frequency were calculated in each synoptic station. In this research, to find the trend of precipitation in the 38 years, 1977-2014, First, trends of the selected stations were determined using Mann-Kendall trend test at the different time scales of the 19 year period, 1977-1995, then compared with trend of the 38 years and finally, determined the changes of the mean precipitation values in two subsequent periods, 1977-1995 and 1996-2014. Obtained results show that the mean annual precipitation at the all stations was decreased in the second period than base period. The results also show that the drought occurrence with different intensity, duration and frequency occurred in selected synoptic stations in northwest of Iran. The results also indicate that there is the decreasing trend of precipitation at the synoptic stations of Saghez and Sanandaj in yearly time scales. Although the stations of Saghez and Zanjan have no trend in the period of 1977-1995, they have decreasing and increasing trends in some time scales in the period of 1977-2014. | ||
| Keywords | ||
| Box-Cox transformation; Intensity; duration and frequency; Mann-Kendall; Normal distributed precipitation; Synoptic station | ||
| References | ||
|
| ||
|
Statistics Article View: 735 PDF Download: 487 |
||
Journal management system. designed by sinaweb