【期刊名称】《农业科学与技术（英文版）》【年(卷,期】2011(012012 【摘要】[Objective] This study aimed to explore the historical evolution rules of precipitation variation in Zhongwei City by analyzing the annual precipitation data during 1961 to 2010 from Zhongwei Municipal Meteorological Bureau of Ningxia,to provide the basis for middle and long term precipitation trend forecast.[Method] Five-point moving average method,trend coefficient analysis method,Mann-Kendall trend test method and variance analysis method were used to analyze the annual precipitation data during 1961 to 2010 in Zhongwei City.[Result] Annual precipitation series in Zhongwei City of Ningxia during 1961 to 2010 showed an insignificantly decreasing trend;among the seasonal precipitation series,spring precipitation had shown a consistent variation with the annual precipitation,summer precipitation had shown a slightly decreasing trend before 1978 and a significantly decreasing trend after 1978,autumn precipitation showed a decreasing trend before 1978 and an insignificantly increasing trend after 1978,winter precipitation showed a significantly increasing trend before 1978 and an insignificantly increasing trend after 1978.Both the annual and seasonal precipitation series had significant periodic variation rules.[Conclusion]
