根据水质评价的特点，针对上述BP网络结构，水质评价的训练样本为相应的水质分级标准，即网络输入为相应水质标准中各指标标准值，网络的希望输出为相应标准值组对应的水质等级。-According to the characteristics of water quality assessment for the BP network structure, the quality assessment of training samples to the corresponding water quality grading standards, namely the network input water quality standards for the corresponding standard value of each index, the network' s hope that the output value for the corresponding standard quality level corresponding to the group .