近50年宁夏沙坡头区降水变化特征分析

目的]对宁夏沙坡头区中心气象站1961～2010年降水资料进行分析,以期找到该区降水变化的历史演变规律,为中长期降水趋势预测提供依据。方法]采用五点滑动平均法、趋势系数法、Mann-Kendall趋势检验法和方差分析法,分析了沙坡头区1961～2010年的降水资料。结果]1961～2010年宁夏沙坡头区年降水序列有下降趋势,但变化趋势不显著;季降水序列中春季降水与年降水变化基本一致;夏季降水在1978年以前呈微弱下降趋势,1978年以后呈明显下降趋势;秋季降水变化趋势在1978年以前呈下降趋势,1978年以后呈上升趋势,但是变化趋势不显著;冬季降水变化趋势在1978年以前呈明显上升趋势,1978年以后呈上升趋势,但是变化趋势不显著。年降水和季降水序列均具有明显的周期变化规律。结论]该研究结果有助于了解宁夏沙坡头区年降水序列变化总体趋势及其季节分布特征和变化规律,为该地区未来水情预报提供可靠依据,为中长期降水变化趋势估报提供参考。

Analysis on Characteristics of Precipitation Variation in Shapotou District in Recent 50 Years

Objective] This study aimed to explore the historical evolution rules of precipitation variation in Shapotou District by analyzing the annual precipitation data during 1961 to 2010 from Shapotou District 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 Shapotou District.Result] Annual precipitation series in Shapotou District of Ningxia during 1961 to 2010 had shown 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 had shown a decreasing trend before 1978 and an insignificantly increasing trend after 1978,winter precipitation had shown 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] Results of this study was conducive to understand the overall trend of annual precipitation series variation in Shapotou District of Ningxia and its seasonal distribution characteristics and variation rules and had provided a reliable basis for the hydrological forecasting in this region and reference for the middle and long term estimation and forecast of the trend of precipitation variation.