拉浪水库降水量变化趋势分析

根据拉浪水库1969-2006年降水量资料，利用时间序列周期方差分析外推法，对水库38年降水序列进行了周期分析，结果表明：水库降水表现为4年的振荡周期；利用周期性叠加趋势模型，对年降水量进行了预测，结果显示：未来几年降水量将呈现丰枯交替的变化趋势。

Analysis of precipitation trend for Lalang reservoir

Based on the precipitation data of Lalang reservoir from 1969 to 2006, the author analyzed the precipitation series of 38 years with time series cycle variance analysis extrapolation.The results of analysis demonstrate that the significant period of precipitation at reservoir is 4 years.Annual precipitation is predicted by periodic overlapping tendency model,indicating the tendency of high and low precipitation occurring alternatively in the coming years.