We estimated the default in the river water normal detection data by KNN (kith nearest neighbor) in pattern recognition.Then we made a comparison with other methods.

• 采用模式识别中的KNN最近邻法，以监测数据样本行为预测参照，对河水水质常规监测数据中存在的缺损值进行预测，并与其余的方法比较，证明方法的可靠性。