基于水环境承载力的沁河流域系统优化调控

基于水环境承载力核算模型,提出流域系统优化调控方法,并应用于沁河流域。通过承载力核算模型计算出2015年和2020年流域水环境承载力,当系统动力学预测的2015年和2020年经济发展规模高于承载力时,通过约束条件中工业企业排放浓度、城镇生活污水收集率、水资源利用率、尾水回用率等4项调控指标进行敏感度分析,最终确定最优的经济发展。结果表明:沁河流域应该优先调控城镇生活污水收集率;2015年,执行工业污水排放二级标准,收集率须达到71.4%以上,优化后的经济规模阈值为475.6亿元;2020年,执行工业一级标准,城镇生活污水收集率须为78.4%以上,相应地经济规模阈值为816.0亿元。

Optimal regulation of Qinghe River watershed system based on water carrying capacity

Optimal watershed system regulation approach is proposed based on water carrying capacity model,and it is applied in the Qinhe River Watershed,one of tributaries of Yellow River.The proposed approach consists of three parts:(i)to calculate watershed-scale water carrying capacity for 2015 and 2020 subject to aquatic,water resources and the others constraints;(ii)to compare the computed water carrying capacity with the economic sizes of 2015 and 2020 predicted by system dynamics;(iii)to analyze the sensitivity of industrial emission standard,collection rate of municipal sewage wastewater,utilization efficiency of water resources,reuse rate of recycled water,leading to determine optimal economic development mode.The results indicate that:(i)it is essential to give priority to adjust collection rate of municipal sewage wastewater;(ii)for 2015,industrial emission standard and collection rate of municipal sewage wastewater would be set as the second level and more than 71.4%,respectively,the corresponding the threshold of economic size of Qinhe River Watershed is 47.6 billion;(iii)for 2020,industrial emission standard should be enhanced to the first level,while the collection rate of municipal sewage wastewater is also increased to 78.4%,leading to the threshold of economic size of 81.6 billion;(iv)For more specific suggestions,By 2015,daily capacity of urban domestic sewage treatment should reach 8.71 t for COD and 1.08t for NH₄⁺-N;By 2020,daily capacity of urban domestic sewage treatment should reach 11.13t for COD and 1.38 t for NH₄⁺-N.