Investigation of climatological droughts in Isfahan province | ||
| مهندسی و مدیریت آبخیز | ||
| Article 4, Volume 1, Issue 3, October 2009, Pages 167-178 PDF (707.6 K) | ||
| Document Type: Research Paper | ||
| Authors | ||
| Mohammad Reza Yazdani* 1; Sattar Chavoshi2; Morteza Khodagholi2; Bahram Saghafian3 | ||
| 1MSc, Agricultural and Natural Resources Research Center, Isfahan, Iran | ||
| 2Scientific Board, Agricultural and Natural Resources Research Center, Isfahan, Iran | ||
| 3Associate Professor, Soil Conservation and Watershed Management Research Institute, Iran | ||
| Abstract | ||
| Most parts of the Isfahan province are located in central arid land of Iran and are sensitive to drought occurrences. So it is required to study drought for prediction. There are many ways to define drought using different indicators. Climatology drought was evaluated using annual precipitation time series and different truncation levels including 30% 40, 50, 60, 70, 80, 90 and 95%. In this study 85 precipitation stations were selected in Isfahan province and around of it, in period of 1966-1998.Interpolation methods such as, kriging, Co-kriging, inverse distance weighted and TPSS were evaluated for interpolation of truncation levels and the error of each method was calculated. In the selected methods, Co-kriging method had minimum error and TPSS method had maximum error. Drought extension maps were drawn for each truncation levels using ILWIS software. Also water volume of probable precipitation is calculated for each truncation levels. Results showed about half of rainfall events occurred in 30 percent truncation level, whereas about 80 percent of the events are in 30 percent truncation level. Thus intense droughts occurred in the study area. Maximum frequency of drought occurrences in basis of truncation levels in study area are 30, 80, 60, 50, 40, 90, 70, 95%, respectively. Results indicated that truncation levels are suitable method for climatological drought evaluation in the studied area. | ||
| Keywords | ||
| Co-kriging; Drought index; Interpolation; Kriging; Truncation levels | ||
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