Estimation of Krieger Regional Coefficient in Mountainous Areas

Subject Areas : hydrology

rohoullah mohtashamzadeh ¹ , sajad mashali ² , Bfhrooz Dahanzadeh ³

1 - Department of water science, Shoushtar branch,Islamic Azad Univercity,Shoushtar, Iran
2 - Azad aslami university -branch of shooshtar ,water science college.
3 - Department of Irrigation & Drainage, Shoushtar branch,Islamic Azad Univercity,Shoushtar, Iran

Received: 2018-03-21 Accepted : 2018-03-21 Published : 2017-11-22

Keywords: Lorestan, Craiger coefficient, Return period, Regional coefficient,

Abstract :

Iran has different climatic conditions due to its climatic characteristics. These climatic differences necessitate a suitable hydrological study in each region. Lorestan province, due to its mountainousness, is more humid than other parts. Therefore, this region is more favorable for flood occurrence and requires specific hydrological studies. The purpose of this study is to investigate the Krieger regional coefficient in mountainous areas. Therefore, based on the latest statistics published by the provincial water company, the statistics of the maximum instantaneous flow rates of 24 hydrometric stations were obtained in different parts of the province .The area of ​​the studied watersheds varied from 9550 km2 (Kashkan Poldokhtar) to 35 km2 (small plumber). The results of this study showed that the range of Chigger coefficients in Lorestan province catchment areas is much lower than the cultivars that have been recommended so far. Also, with the increase of the return period, the Krieger coefficient increases in mountainous regions with higher trend than arid regions. This issue should be considered in the planning and management of quantitative water resources.