ارزيابي ريسك خشكسالي استان اصفهان

چكيده انگليسي :

Drought Risk Assessment in Isfahan Province Saeedeh Ghasemi Nejad Email address S ghaseminejad@gmail com Date of Submission 24 12 2011 Department of Natural Resources Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisors Saeed Soltani Koupai ssoltani @cc iut ac irAlireza Soffianian soffianoan @ cc iut ac irAbstract Drought is a one of the most important natural disasters that has high socio economic and environmentalimpacts Drought is related to a deficiency of precipitation over an extended period of time This deficiencyresults in a water shortage for some activity group or environmental sector Drought is also related to thetiming of precipitation Other climatic factors such as high temperature high wind and low relative humidityare often associated with drought However drought is more than a physical phenomenon or natural event Itsimpact results from the relation between a natural event and demands on the water supply and it is oftenexacerbated by human activities The traditional approach to drought management has been reactive relying oncrisis management Due to the fallacy of crisis management employing proper risk management techniques hasbeen suggested In order to move from crisis management to risk management in this study risk of drought inIsfahan province was evaluated Drought hazard index and vulnerability index are components of the droughtrisk management Standardized Precipitation Index SPI was used as index of drought hazard For thecalculation of SPI the monthly rainfall data in 47 meteorological stations during the period of 1975 2007 werecollected The time series of rainfall data were prepared and for calculation of the standardized precipitationindex in 6 7 9 and 12 months timescales were imported to SPI program Percent of drought occurrence in eachseverity and time scale of drought was calculated and then the drought index map was obtained Vulnerabilityindex was calculated through socio economic indicators population density and percentage of people involvedin agriculture and physical indicators available water capacity of soil and land use Weighted LinearCombination WLC technique was applied for combination of vulnerability indicators To assign weights to thecriteria an Analytical Hierarchy Process AHP was used After providing the maps fuzzy membershipfunctions for every criterion were used for their standardization For the weighting of the criteria Questionnairewas prepared and criteria comparison was done using the participatory approach by a group of experts Finally the drought risk index was calculated by multiplying of drought hazard index and vulnerability index Theresults showed that risk of very severe drought are mainly concentrated in the central part of province TheNorth and North East of Isfahan province could experience condition of severe drought South West of Isfahanprovince is under moderate drought condition comparing the other parts of the province Due to rainfallfluctuations the eastern southeastern northeastern and central parts of Isfahan province are in high risk ofdrought Map of drought vulnerability index show that the most vulnerability is in the West South and North East of province Map of drought risk index showed that the Northern Province demonstrated high risk in alltimescales The results revealed that drought risk in Isfahan province is a function of climate andvulnerability To reduce the drought risk in Isfahan province improving monitoring mitigation and earlywarning building environmental awareness and promoting water resource management practices should beconsidered Keywords Drought Risk assessment Vulnerability Isfahan province

قاسمي نژاد، سعيده

ارزيابي ريسك خشكسالي استان اصفهان

آسيب پذيري استان اصفهان