Frequency Analysis of Daily Droughts in Iran by Using Effective Drought Index
Iran's Potential for the occurrence of drought at various severities illuminates the need to examine this phenomenon with new indexes. The major deficiency of the current indexes is that they cannot monitor the droughts in daily scale. Effective Drought Index (EDI) overcomes this defect. The go...
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Kharazmi University
2015-03-01
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| Series: | تحقیقات کاربردی علوم جغرافیایی |
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| Online Access: | http://jgs.khu.ac.ir/article-1-2177-en.pdf |
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| author | firooz mojarad razieh kheiri Zahra Noorisameleh |
| author_facet | firooz mojarad razieh kheiri Zahra Noorisameleh |
| author_sort | firooz mojarad |
| collection | DOAJ |
| description | Iran's Potential for the occurrence of drought at various severities illuminates the need to examine this phenomenon with new indexes. The major deficiency of the current indexes is that they cannot monitor the droughts in daily scale. Effective Drought Index (EDI) overcomes this defect. The goal of this study is to analyze the frequency of daily droughts by EDI in 43 synoptic stations in a 30-year period. Accordingly, the frequency of daily droughts in the stations was calculated by EDI during the seasons and the year. Then the stations were divided into five groups using cluster analysis based on total frequency of mild to most severe droughts (categories 1 to 4), and frequency patterns in each group were examined. The results showed that the most severe droughts have not happened in the stations except for Gorgan, Zanjan and Torbat-Heydariyeh. In contrast, the frequencies of mild, moderate and severe droughts, all being equal, are much more than most severe droughts, and their frequencies are almost equal. In 56 percent of the days, a variety of droughts (mild to most severe) has occurred in the whole country. Based on the output maps, frequency distribution of droughts in the country does not follow a certain geographical pattern, so it could be cocluded that all types of droughts have happened in all regions of the country. However, maximum total frequency of daily droughts (mild to most severe) is observed in the east and center parts. The decrease in the EDI values over time shows the tendency of the most stations towards drought. |
| format | Article |
| id | doaj-art-e3833b4f25ff4b7abffb35ebeb583b99 |
| institution | Kabale University |
| issn | 2228-7736 2588-5138 |
| language | fas |
| publishDate | 2015-03-01 |
| publisher | Kharazmi University |
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| series | تحقیقات کاربردی علوم جغرافیایی |
| spelling | doaj-art-e3833b4f25ff4b7abffb35ebeb583b992025-01-31T17:22:10ZfasKharazmi Universityتحقیقات کاربردی علوم جغرافیایی2228-77362588-51382015-03-0114352948Frequency Analysis of Daily Droughts in Iran by Using Effective Drought Indexfirooz mojarad0razieh kheiri1Zahra Noorisameleh2 Associate Professor of Climatology, Department of Geography of Razi University of Kermanshah, Iran. Master of Climatology, Department of Geography of Razi University of Kermanshah, Iran. Master of Climatology, Department of Geography of Razi University of Kermanshah, Iran. Iran's Potential for the occurrence of drought at various severities illuminates the need to examine this phenomenon with new indexes. The major deficiency of the current indexes is that they cannot monitor the droughts in daily scale. Effective Drought Index (EDI) overcomes this defect. The goal of this study is to analyze the frequency of daily droughts by EDI in 43 synoptic stations in a 30-year period. Accordingly, the frequency of daily droughts in the stations was calculated by EDI during the seasons and the year. Then the stations were divided into five groups using cluster analysis based on total frequency of mild to most severe droughts (categories 1 to 4), and frequency patterns in each group were examined. The results showed that the most severe droughts have not happened in the stations except for Gorgan, Zanjan and Torbat-Heydariyeh. In contrast, the frequencies of mild, moderate and severe droughts, all being equal, are much more than most severe droughts, and their frequencies are almost equal. In 56 percent of the days, a variety of droughts (mild to most severe) has occurred in the whole country. Based on the output maps, frequency distribution of droughts in the country does not follow a certain geographical pattern, so it could be cocluded that all types of droughts have happened in all regions of the country. However, maximum total frequency of daily droughts (mild to most severe) is observed in the east and center parts. The decrease in the EDI values over time shows the tendency of the most stations towards drought.http://jgs.khu.ac.ir/article-1-2177-en.pdfdaily droughtfrequencyeffective drought index (edi)trendiran |
| spellingShingle | firooz mojarad razieh kheiri Zahra Noorisameleh Frequency Analysis of Daily Droughts in Iran by Using Effective Drought Index تحقیقات کاربردی علوم جغرافیایی daily drought frequency effective drought index (edi) trend iran |
| title | Frequency Analysis of Daily Droughts in Iran by Using Effective Drought Index |
| title_full | Frequency Analysis of Daily Droughts in Iran by Using Effective Drought Index |
| title_fullStr | Frequency Analysis of Daily Droughts in Iran by Using Effective Drought Index |
| title_full_unstemmed | Frequency Analysis of Daily Droughts in Iran by Using Effective Drought Index |
| title_short | Frequency Analysis of Daily Droughts in Iran by Using Effective Drought Index |
| title_sort | frequency analysis of daily droughts in iran by using effective drought index |
| topic | daily drought frequency effective drought index (edi) trend iran |
| url | http://jgs.khu.ac.ir/article-1-2177-en.pdf |
| work_keys_str_mv | AT firoozmojarad frequencyanalysisofdailydroughtsiniranbyusingeffectivedroughtindex AT raziehkheiri frequencyanalysisofdailydroughtsiniranbyusingeffectivedroughtindex AT zahranoorisameleh frequencyanalysisofdailydroughtsiniranbyusingeffectivedroughtindex |