ABSTRACT
ABSTRACT: Based on the monthly precipitation during 1980-2011 in Jarud County, the variation of precipitation were conducted the statistical analysis by means of linear trend estimation and mutation detection by using Mann-Kendall method. As was demonstrated in the results, the annual, spring, summer and autumn precipitation in Jarud showed a decreasing trend, whose linear tendency rate was −35.3 mm/10a, −10.23 mm/10a, −118.8 mm/10a and −13.99 mm/10a respectively, especially in summer. However, the winter precipitation increased slightly. Precipitation has a fluctuation in each month, which reduced the most is August, followed by July. There was obvious annual variation in annual, seasonal and monthly precipitation. The abrupt change point of annual and summer in Jarud appeared in 2000, the abrupt change point of spring and autumn precipitation appeared in 1993 and 1994 respectively, while winter precipitation under went mutation in 1984, and showed an obvious increasing trend after 1984.
