柴河水库饮用水水源保护区划分合理性研究分析
Research on the Rationality of the Division of Drinking Water Source Protection Zone in Chaihe Reservoir in China
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摘要: 过去饮用水水源地保护区划分以类比经验法为主,无法准确考虑水源地水质的时空变化及达标状况。根据最新出台饮用水规范,开展柴河水库饮用水水源地保护区划分的研究工作,运用EFDC构建水源地二维水质模型,根据柴河水库水动力和水质状况模拟水龄与污染物迁移在水库中变化规律,对水源地富营养化风险与取水口主要水质指标达标状况进行分析,评价柴河水库饮用水水源保护区划分的合理性。研究表明,柴河水库在丰平枯3种典型年条件下,枯水期水龄最长,水力停留周期长,存在污染风险;在丰平枯3种水动力条件及入库污染物为Ш类水质标准条件下,模拟氨氮和总磷在水库中迁移衰减过程,结果表明取水口水质均达标;类比经验法划分的柴河水库一级保护区能保证取水口水质安全。Abstract: The protection areas were divided mainly by the analogical empirical method at the early stage,which could not accurately measure the water quality indicators and the situation of reaching the standard requirements. Based on the Technical Standard for Drinking Water Sources Reserve Division(HJ 338-2018),this paper carries out the research on the protection zone division of Chaihe Reservoir drinking water source,EFDC is used to construct a two-dimensional water quality model of Chaihe Reservoir. The changes of water age and pollutant migration in Chaihe Reservoir are simulated,and the eutrophication risk and main water quality in front of the dam are analyzed to evaluate the rationality of the division of water source protection zone. The results show that the water age of Chaihe Reservoir and the hydraulic retention period are the longest in the dry season under the three typical years of abundant,average and dry seasons. The migration and attenuation of contaminants in the reservoir are simulated,the results indicate that the water quality at the intake can reach the requirements,under the abundant,average and dry seasons,respectively. The division of the first-grade protection zone of Chaihe Reservoir can ensure the water quality of the intake,it is reasonable to use the analogy experience method to divide the protection zone.