M. Akbarpour¹, A. Motamedi¹, R. Rostami², D. Baharlouee¹
1 Dams & HEPP Operation Division, Khuzestan Water & Power Authority (KWPA), Ahwaz, Iran.
2Miandoab Agricultural Education Center, Urmia, Iran.

Abstract: Droughts effects as destructive and unavoidable they seem in any climate can be controlled and mitigated by applying well-established management procedures. In the present paper percent of normal precipitation obtained from rain gages across Khuzestan province southwest Iran was used to study this phenomenon. Ward clustering method was used to identify the homogenous regions in the province by dividing it into three different areas. By using Hosking and Wallis non-homogeneity index was calculated for three areas and the regional frequently distribution parameters were assessed by using L-moment rates. To determine the best distribution frequency, a goodness-of-fit testing and L-moment diagram were used and a drought index with different return periods was calculated. 

Key words: drought, percent of normal precipitation (PN), L-moment, frequency analysis