在灰色系统理论下，运用几种方法弱化原始需水量数据，并进行对比分析。分析表明二阶弱化算子修正与累加生成相结合的方法精度较高，最终验证了该模型应用于重庆市北碚区需水量预测的可行性及有效性，预测2015年北碚区需水量为2.45亿m_³，2020年北碚区需水量为2.69亿m_³。

On the basis of the gray system theory, we weaken the original data of water demand by using several methods, then conduct comparative analysis on forecasting results. Analysis shows that the result obtained from the combination of second-order weakening operator with the AGO can get the highest accuracy. Finally, we validate the feasibility and effectiveness of the model which is applied to forecasting water demand in Beibei, Chongqing. The forecasted result is that: water demand of Beibei District is 245 million m_³ in 2015, and 269 million m_³ for the year of 2020.