净需水量 meaning in Chinese

net water requirement
water requirement， net

The paper deals with the calculation methods of river diluting and self - cleaning water demand . optimal model is mentioned for the first time considering self - cleaning , sewage treatment extent and water fee , and the ecological water requirement is to be forecasted base on the change of sewage drainage in the near future . lastly , calculating procedure for ecological water requirement in south china is presented
着重研究了河流稀释自净需水量的计算方法，初步构建了考虑水体自净与污水处理率及用水费用相结合的生态需水量优化模型，依据未来年份污水排放量的变化，预测生态需水量，并通过实例说明南方河流系统生态需水量的计算过程。