Trend Analysis for the precipitation time subseries in Fars Province

The information of the temporal variations of the beginning and end of a precipitation trend is important for estimating climate changes. In this study، the sequential Mann Kendall nonparametric test was used to determine changes in time of annual precipitation for synoptic stations in Fars province. This sequential test is useful to trend analysis of a time subseries. The results indicated that in Abadeh station، a downward trend of precipitation has been begun in 1980 and 2005 and this downward trend in 1985 and 1990 is statistically significant at 5% level. In 1955 and 2007 a downward precipitation trend was beginning in Shiraz Station. In this station، a significant downward trend has been occurred in precipitation of years 1962، 1963، 1964، 1966، 1971 and 1973 at 10% level. In Fasa station، a downward trend of precipitation was beginning in 1970 and 1997 such that the minimum value of the sequential Mann Kendall test statistics is happened in 2010 and therefore، the downward trend of precipitation is much strong in this year.