Vulnerability of Yazd Province in Drought Using Standardized Precipitation Index and Geostatistical Methods
Subject Areas : Article frome a thesis
1 - دانشجوی دکترای زمینشناسی- آبشناسی، دانشکده علوم، دانشگاه شیراز.
2 - استادیار بخش علوم زمین، دانشکده علوم، دانشگاه شیراز.
Keywords: ordinary Kriging, Monitoring drought, simple kriging, zoning intensity of drought, 12-month Standardized Precipitation Index,
Abstract :
Standardized Precipitation Index (SPI) has been widely used for evaluation of drought. Different time scales of SPI could be used e.g., 3, 6, 9, 12, 18, 24 and 48-months. SPI 12-month is used for evaluation of drought condition and vulnerability of drought in the study area. SPI 12-month was computed in 28 stations based on 30 years of data period in the study area. Spatial distribution of SPI 12-month was analyzed using different interpolation techniques of geostatistics. The precise interpolation technique was selected based on the cross-validation criteria. In order to access vulnerability of the study area in drought, two years were selected as end-members (1378-79 and 1377-78 for minimum and maximum precipitation, respectively) and 1376-77 was selected as average climatological condition due to annual precipitation values. The results show that in extreme year (1377-78), more than 99٪ of the study area leave from the drought condition. However in minimum condition of annual precipitation (1378-79), more than 98٪ of the study area belongs to drought. As a results, Yazd, Taft, Mehriz, Bafgh, Naibandan and Kharanagh show high vulnerability to drought in the Yazd Province.