Afsaneh Abbassi; Hoshang Ghaemi
Volume 17, Issue 43 , October 2013, , Pages 145-168
Abstract
In this research five synoptic stations are selected including Mehrabad, Karaj, Gazvin, Ramsar and Noshahr. After analysis and processing of the parameters such as wind speed, dew point, pressure and storm coefficient data, PMP in continuation of 24 and 48 hours for related basin was estimated, in order ...
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In this research five synoptic stations are selected including Mehrabad, Karaj, Gazvin, Ramsar and Noshahr. After analysis and processing of the parameters such as wind speed, dew point, pressure and storm coefficient data, PMP in continuation of 24 and 48 hours for related basin was estimated, in order of 140/56 , 254/ 58mm. Considering resulted number and obtained flow in 1374/68 and 40% ronoff average daily flow we estimated 550 , which in comparison with the maximum daily flow in Siera (dam entrance) station with 20 years statistical period which is 154/54 for being acceptable. According to synoptic charts, three rainfall systems caused 24 hours Maximum precipitation turn in 48 hours.
Farnaz Pourasghar; Saeed Jahanbakhsh; Behrooz Sari saraf; Hooshang Ghaemi; Masomeh Tadayoni
Volume 17, Issue 44 , September 2013, , Pages 27-46
Abstract
This is a study of change in annual precipitation amounts and variability in southern part of Iran during 1974-2005. Southern part of Iran has been regionalized based on six factors in 183 stations using Principal Component Analysis (PCA) and Cluster Analysis (CA). The stations were grouped into four ...
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This is a study of change in annual precipitation amounts and variability in southern part of Iran during 1974-2005. Southern part of Iran has been regionalized based on six factors in 183 stations using Principal Component Analysis (PCA) and Cluster Analysis (CA). The stations were grouped into four individual clusters. Topography and latitude play an important role in determining boundaries between identified subdivisions and existence of spatial differences between them as well. Spatial variability and relationship between the precipitation series at 183 of stations were investigated by principal component analysis. A PCA of annual precipitation reveals five components that account for 68% of the total variance. The annual precipitation PCs are controlled by atmospheric circulation. Analysis of the results revealed that annual precipitation in south part of Iran is mainly related to Sudan and Mediterranean wave.
