基于河道断面自净需水要求的自净补水研究

Self-purification Supplement Research Based on Water Requirement of River Self-purification of Channel Cross-section

根据汾河干流污染较为严重的现状和污染物类型,以一维水质数学模型和水量平衡原理为基础,建立了河流自净需水量的计算模型,据此计算出满足地面水环境质量目标的自净需水量,并根据年径流量的大小,进一步确定河道断面的自净补水量。结果表明,选取COD和NH3-N作为控制因子,计算的二坝和义棠断面自净需水量分别为2.97×10~8、5.53×10~8m^3,义棠断面自净需水量较大;自净补水主要发生在平水年和枯水年,丰水年的自净需水量基本满足要求,自净补水主要发生在一年的非汛期中;所得结果为汾河干流生态恢复和汾河水库的生态调度研究提供一定的理论基础。

According to the seriously polluted situation and types of pollutants of Fenhe River,taking 1-D water quality mathematical model and water balance principle as the foundation,a calculation model of water requirement of river self-purification was established.And then water requirement of river self-purification which should meet the standards for surface water environmental quality was calculated.Furthermore,water supplement of river cross-section self-purification was determined according to the annual runoff.The results show that choosing COD and NH3-N as control factors,water requirement of river self-purification of Erba and Yitang were 2.97×10~8 m^3 and 5.53×10~8 m^3 respectively;water requirement of river self-purification of Yitang was bigger;water lack of self-purification water mainly occured in the median water year and dry year;water requirement of river self-purification of the wet year met the requirements;water lack of self-purification water mainly occured in the non-flood season in a year.The results can provide some theoretical foundation for ecological restoration of Fenhe River and ecological operation of Fenhe reservoir.